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  • 1.
    Abrahamsson, Pernilla
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åberg, Anna-Maja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Optimised sample handling in association with use of the CMA 600 analyser2008Ingår i: Journal of Pharmaceutical and Biomedical Analysis, ISSN 0731-7085, E-ISSN 1873-264X, Vol. 48, nr 5, s. 940-945Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A large degree of variability for batched analysis of serially collected microdialysis samples measured with the CMA 600 analyser has been described. This study was designed to identify sources of variability related to sample handling. Standard concentrations of four solutes were placed in microdialysis vials and then stored and analysed at intervals. Results were analysed for variability related to vial and cap type, duration and temperature of storage, centrifugation and re-analysis. The main results were that centrifugation of samples reduced variability. When a batch of 24 samples was analysed, the use of crimp caps reduced evaporation. Samples in glass vials with crimp caps could be stored in a refrigerator for up to 14 days without large variability in concentration compared to plastic vials which demonstrated variability already when stored for more than 1 day. We conclude that variability in microdialysis results can occur in relation to storage and analysis routines if routines are not optimised concerning evaporation. Centrifugation before analyses, glass vials with crimp caps even during frozen storage, and attention to minimal times for samples to be uncapped during analysis all contribute to minimise variability in the handling and analysis of microdialysis samples.

  • 2.
    Abrahamsson, Pernilla
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åberg, Anna-Maja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Waldenström, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Detection of myocardial ischaemia using surface microdialysis on the beating heart2011Ingår i: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 31, nr 3, s. 175-181Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microdialysis (MD) can be used to study metabolism of the beating heart. We investigated whether microdialysis results obtained from epicardial (surface) sampling reflect acute changes in the same way as myocardial sampling from within the substance of the ventricular wall. In anaesthetized open-thorax pigs a coronary snare was placed. One microdialysis probe was placed with the sampling membrane intramyocardially (myocardial), and a second probe was placed with the sampling membrane epicardially (surface), both in the area which was made ischaemic. Ten minutes collection intervals were used for microdialysis samples. Samples from 19 pigs were analysed for lactate, glucose, pyruvate and glycerol during equilibration, baseline, ischaemia and reperfusion periods. For both probes (surface and myocardial), a total of 475 paired simultaneous samples were analysed. Results from analyses showed no differences in relative changes for glucose, lactate and glycerol during baseline, ischaemia and reperfusion. Surface microdialysis sampling is a new application of the microdialysis technique that shows promise and should be further studied.

  • 3.
    Abrahamsson, Pernilla
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åberg, Anna-Maja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Blind, Per-Jonas
    Kirurgi, Skåne Universitets sjukhus, Lund.
    Comparison between outcome of  surface and intraparenchymatous sampling using microdialysis in an experimental liver ischemia modelManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Introduction. We recently have shown that samples from MD probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces.

    Material and methods.  In thirteen anesthetized pigs transient liver ischemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface, and two in parenchyma were perfused with a flow rate of 1 µL/min (n=13). An identical set up was used for probes with a flow rate of 2 µL/min (n=9). Samples were collected for every 15 minute period during 60 minutes of baseline, 45 minutes of ischemia and 60 minutes of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present paper.

    Results. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and parenchyma. No significant differences in relative changes of lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischemia or reperfusion with a flow rate of 1 µL/min.

    Conclusion. MD sampling applied on the liver surface is a new application area for the MD technique, and may be used to monitor liver metabolism both during physiological and pathophysiological conditions.

  • 4.
    Abrahamsson, Pernilla
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åberg, Anna-Maja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Blind, Per-Jonas
    Surface microdialysis sampling: a new approach described in a liver ischaemia model2012Ingår i: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 32, nr 2, s. 99-105Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We recently have shown that samples from microdialysis (MD) probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces. In 13 anesthetized pigs, transient liver ischaemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface and two in parenchyma were perfused with a flow rate of 1 mu l per min (n = 13). An identical set-up was used for probes with a flow rate of 2 mu l per min (n = 9). Samples were collected for every 15-min period during 60 min of baseline, 45 min of ischaemia and 60 min of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present study. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and those on parenchyma. No significant differences in relative changes in lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischaemia or reperfusion with a flow rate of 1 mu l per min. MD sampling applied on the liver surface is a new application area for the MD technique and may be used to monitor liver metabolism during both physiological and pathophysiological conditions.

  • 5.
    Ahlström, Katarina
    et al.
    Anesthesia and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Biber, Björn
    Anesthesia and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Åberg, Anna-Maja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Abrahamsson, Pernilla
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Ronquist, Gunnar
    Department of Medical Chemistry, Uppsala University, Uppsala, Sweden.
    Waldenström, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Haney, Michael F.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Exogenous carbon monoxide does not affect cell membrane energy availability assessed by sarcolemmal calcium fluxes during myocardial ischaemia-reperfusion in the pig2011Ingår i: European Journal of Anaesthesiology, ISSN 0265-0215, E-ISSN 1365-2346, Vol. 28, nr 5, s. 356-362Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carbon monoxide is thought to be cytoprotective and may hold therapeutic promise for mitigating ischaemic injury. The purpose of this study was to test low-dose carbon monoxide for protective effects in a porcine model of acute myocardial ischaemia and reperfusion.In acute open-thorax experiments in anaesthetised pigs, pretreatment with low-dose carbon monoxide (5% increase in carboxyhaemoglobin) was conducted for 120 min before localised ischaemia (45 min) and reperfusion (60 min) was performed using a coronary snare. Metabolic and injury markers were collected by microdialysis sampling in the ventricular wall. Recovery of radio-marked calcium delivered locally by microperfusate was measured to assess carbon monoxide treatment effects during ischaemia/reperfusion on the intracellular calcium pool.Coronary occlusion and ischaemia/reperfusion were analysed for 16 animals (eight in each group). Changes in glucose, lactate and pyruvate from the ischaemic area were observed during ischaemia and reperfusion interventions, though there was no difference between carbon monoxide-treated and control groups during ischaemia or reperfusion. Similar results were observed for glycerol and microdialysate Ca recovery.These findings show that a relatively low and clinically relevant dose of carbon monoxide did not seem to provide acute protection as indicated by metabolic, energy-related and injury markers in a porcine myocardial ischaemia/reperfusion experimental model. We conclude that protective effects of carbon monoxide related to ischaemia/reperfusion either require higher doses of carbon monoxide or occur later after reperfusion than the immediate time frame studied here. More study is needed to characterise the mechanism and time frame of carbon monoxide-related cytoprotection.

  • 6.
    Ahlström, Katarina
    et al.
    Anestesi, Sahlgrenska akademin, Göteborgs universitet.
    Biber, Björn
    Anestesi, Sahlgrenska akademin, Göteborgs universitet.
    Åberg, Annamaja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Waldenström, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Ronquist, Gunnar
    Abrahamsson, Pernilla
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Strandén, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Metabolic responses in ischemic myocardium after inhalation of carbon monoxide2009Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 53, nr 8, s. 1036-1042Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: To clarify the mechanisms of carbon monoxide (CO) tissue-protective effects, we studied energy metabolism in an animal model of acute coronary occlusion and pre-treatment with CO. METHODS: In anesthetized pigs, a coronary snare and microdialysis probes were placed. CO (carboxyhemoglobin 5%) was inhaled for 200 min in test animals, followed by 40 min of coronary occlusion. Microdialysate was analyzed for lactate and glucose, and myocardial tissue samples were analyzed for adenosine tri-phosphate, adenosine di-phosphate, and adenosine mono-phosphate. RESULTS: Lactate during coronary occlusion was approximately half as high in CO pre-treated animals and glucose levels decreased to a much lesser degree during ischemia. Energy charge was no different between groups. CONCLUSIONS: CO in the low-doses tested in this model results in a more favorable energy metabolic condition in that glycolysis is decreased in spite of maintained energy charge. Further work is warranted to clarify the possible mechanistic role of energy metabolism for CO protection.

  • 7.
    A'Roch, Roman
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Gustafsson, Ulf
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Poelaert, Jan
    Anesthesiology, University of Brussels, Belgium.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model2012Ingår i: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 10, nr 22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function. Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility, though their load-sensitivity has been studied in different settings, but still remains a matter of controversy. We sought to characterize the effects of acute load change (both preload and afterload) and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility.

    METHODS: Thirteen anesthetized juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and transthoracic echocardiography. Transient inflation of a vena cava balloon catheter produced controlled load alterations. At least eight consecutive beats in the sequence were analyzed with tissue velocity echocardiography during the load alteration and analyzed for change in peak systolic velocities and strain during same contractile status with a controlled load alteration. Two pharmacological inotropic interventions were also included to generate several myocardial contractile conditions in each animal.

    RESULTS: Peak systolic velocities reflected the drug-induced changes in contractility in both radial and longitudinal axis. During the acute load change, the peak systolic velocities remain stable when derived from signal in the longitudinal axis and from the radial axis. The peak systolic velocity parameter demonstrated no strong relation to either load or inotropic intervention, that is, it remained unchanged when load was systematically and progressively varied (peak systolic velocity, longitudinal axis, control group beat 1- 5.72 +/- 1.36 with beat 8- 6.49 +/- 1.28 cm/sec, 95% confidence interval), with the single exception of the negative inotropic intervention group where peak systolic velocity decreased a small amount during load reduction (beat 1- 3.98 +/- 0.92 with beat 8- 2.72 +/- 0.89 cm/sec). Systolic strain, however, showed a clear degree of load-dependence.

    CONCLUSIONS: Peak systolic velocity appears to be load-independent as tested by beat-to-beat load reduction, while peak systolic strain appears to be load-dependent in this model. Peak systolic velocity, in a controlled experimental model where successive beats during load alteration are assessed, has a strong relation to contractility. Peak systolic velocity, but not peak strain rate, is largely independent of load, in this model. More study is needed to confirm this finding in the clinical setting.

  • 8.
    A'roch, Roman
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Gustafsson, Ulf
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Poelaert, Jan
    Dept of Anesthesiology and Perioperative Medicine, University hospital of Brussels. Belgium.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Strain and peak systolic velocities: relation to load in a porcine modelManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background:  Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function.  Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility.  Their load-sensitivity has been studied in different settings, but still remains a matter of controversy.  We sought to characterize the effects of acute load change and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility, and particularly to determine if these parameters were load-dependent.

    Methods: Thirteen anesthetised juvenile pigs were studied, using direct measurement of left ventricular (LV) pressure and volume and transthoracic echocardiography. Transient inflation of a vena cava balloon catheter produced controlled preload alterations.  At least eight consecutive beats in the preload alteration sequence were analysed with tissue velocity echocardiography (TVE) during the preload alteration and analysed for change in peak systolic velocities (PSV) and strain (e) during same contractile status with a controlled preload alteration.  Two pharmacological inotropic interventions were also included to generate several myocardial contractile conditions in each animal.

    Results: PSV reflected the drug-induced changes in contractility in both radial and longitudinal axis.  During the acute load change, the PSV remain stable when derived from signal in the longitudinal axis and from the radial axis.  The peak systolic velocity parameter demonstrated no strong relation to either load or inotropic intervention, that is, it remained unchanged when load was systematically and progressively varied.  Peak systolic strain, however, showed a clear degree of load-dependence.

    Conclusion:  Peak systolic velocity appears to be load-independent as tested by beat to beat load reduction, while peak systolic strain appears to be load-dependent in this model.  Peak systolic velocity has a strong relation to contractility, independent of load, in serial measures, in this model.  More study is needed to confirm this in the clinical setting.

  • 9.
    A'roch, Roman
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Gustafsson, Ulf
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Poelaert, Jan
    Dept of Anesthesiology and Perioperative Medicine, University hospital of Brussels. Belgium.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Left ventricular twist is load-dependentManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of LV contractility.

    Methods: Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular (LV) pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon catheter (IVCBO) produced controlled load reduction.  First and last beats in the sequence of eight were analysed with speckle tracking (STE) during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status.  Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal.

    Results: The IVCBO load change compared for first to last beat resulted in LV twist increase (11.67° ±2.65° vs. 16.17° ±3.56° respectively, p < 0.004) during the load alteration and under adrenaline stimulation LV twist increase 12.56° ±5.1° vs. 16.57° ±4.6° (p < 0.013), and though increased, didn’t reach significance in nega­tive inotropic condition.  Untwisting rate increased significantly at baseline from    -41.7°/sec ±41.6°/sec vs. -122.6°/sec ±55.8°/sec (P < 0.039) and under adrenaline stimulation untwisting rate increased  (-55.3°/sec ±3.8°/sec vs.  -111.4°/sec ±24.0°/sec (p<0.05), but did not systematically changed in negative inotropic condition.

    Conclusions: Peak systolic LV twist and peak early diastolic untwisting rate are load dependent.  Changes in LV load should be considered when interpreting  LV rotation/ twist.

  • 10.
    A'Roch, Roman
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Gustafsson, Ulf
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Poelaert, Jan
    Anesthesiology, University of Brussels, Belgium.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load2012Ingår i: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 10, nr 26Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of left ventricular (LV) contractility.

    METHODS: Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon (IVCB) catheter produced controlled load reduction. First and last beats in the sequence of eight were analysed with speckle tracking (STE) during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status. Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal. Paired comparisons were made for different load states using the Wilcoxon's Signed Rank test.

    RESULTS: The inferior vena cava balloon occlusion (IVCBO) load change compared for first to last beat resulted in LV twist increase (11.67degrees +/-2.65degrees vs. 16.17degrees +/-3.56degrees respectively, p < 0.004) during the load alteration and under adrenaline stimulation LV twist increase 12.56degrees +/-5.1degrees vs. 16.57degrees +/-4.6degrees (p < 0.013), and though increased, didn't reach significance in negative inotropic condition. Untwisting rate increased significantly at baseline from 41.7degrees/s +/-41.6degrees/s vs.122.6degrees/s +/-55.8degrees/s (P < 0.039) and under adrenaline stimulation untwisting rate increased (55.3degrees/s +/-3.8degrees/s vs.111.4degrees/s +/-24.0degrees/s (p < 0.05), but did not systematically changed in negative inotropic condition.

    CONCLUSIONS: Peak systolic LV twist and peak early diastolic untwisting rate are load dependent. Differences in LV load should be included in the interpretation when serial measures of twist are compared.

  • 11.
    A'Roch, Roman
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Steendijk, Paul
    Oldner, Anders
    Weitzberg, Eddie
    Konrad, David
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Left ventricular mechanical dyssynchrony is load independent at rest and during endotoxaemia in a porcine model2009Ingår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 196, nr 4, s. 375-383Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    AIM: In diseased or injured states, the left ventricle displays higher degrees of mechanical dyssynchrony. We aimed at assessing mechanical dyssynchrony ranges in health related to variation in load as well as during acute endotoxin-induced ventricular injury.

    METHODS: In 16 juvenile anaesthetized pigs, a five-segment conductance catheter was placed in the left ventricle as well as a balloon-tipped catheter in the inferior vena cava. Mechanical dyssynchrony during systole, including dyssynchrony time in per cent during systole and internal flow fraction during systole, were measured at rest and during controlled pre-load reduction sequences, as well as during 3 h of endotoxin infusion (0.25 microg kg(-)1 h(-1)).

    RESULTS: Systolic dyssynchrony and internal flow fraction did not change during the course of acute beat-to-beat pre-load alteration. Endotoxin-produced acute pulmonary hypertension by left ventricular dyssynchrony measures was not changed during the early peak of pulmonary hypertension. Endotoxin ventricular injury led to progressive increases in systolic mechanical segmental dyssynchrony (7.9 +/- 1.2-13.0 +/- 1.3%) and ventricular systolic internal flow fraction (7.1 +/- 2.4-16.6 +/- 2.8%), respectively for baseline and then at hour 3. There was no localization of dyssynchrony changes to segment or region in the ventricular long axis during endotoxin infusion.

    CONCLUSION: These results suggest that systolic mechanical dyssynchrony measures may be load independent in health and during acute global ventricular injury by endotoxin. More study is needed to validate ranges in health and disease for parameters of mechanical dyssynchrony.

  • 12.
    Axelsson, Birger
    et al.
    Örebro University, Örebro, Sweden .
    Häggmark, Sören
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Svenmarker, Staffan
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Gupta, Anil
    Örebro University, Örebro, Sweden .
    Tyden, Hans
    Örebro University, Örebro, Sweden .
    Wouters, Patrick
    Ghent, Belgium.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Effects of Combined Milrinone and Levosimendan Treatment on Systolic and Diastolic Function During Postischemic Myocardial Dysfunction in a Porcine Model2016Ingår i: Journal of Cardiovascular Pharmacology and Therapeutics, ISSN 1074-2484, E-ISSN 1940-4034, Vol. 21, nr 5, s. 495-503Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is not known whether there are positive or negative interactions on ventricular function when a calcium-sensitizing inotrope is added to a phosphodiesterase inhibitor in the clinical setting of acute left ventricular (LV) dysfunction. We hypothesized that when levosimendan is added to milrinone treatment, there will be synergetic inotropic and lusitropic effects. This was tested in an anesthetized porcine postischemic global LV injury model, where ventricular pressures and volumes (conductance volumetry) were measured. A global ischemic injury was induced by repetitive left main stem coronary artery occlusions. Load-independent indices of LV function were assessed before and after ventricular injury, after milrinone treatment, and finally after addition of levosimendan to the milrinone treatment. Nonparametric, within-group comparisons were made. The protocol was completed in 12 pigs, 7 of which received the inotrope treatment and 5 of which served as controls. Milrinone led to positive lusitropic effects seen by improvement in tau after myocardial stunning. The addition of levosimendan to milrinone further increased lusitropic state. The latter effect could however not be attributed solely to levosimendan, since lusitropic state also improved spontaneously in time-matched controls at the same rate during the corresponding period. When levosimendan was added to milrinone infusion, there was no increase in systolic function (preload recruitable stroke work) compared to milrinone treatment alone. We conclude that in this model of postischemic LV dysfunction, there appears to be no clear improvement in systolic or diastolic function after addition of levosimendan to established milrinone treatment but also no negative effects of levosimendan in this context.

  • 13.
    Axelsson, Birger
    et al.
    Dept of Cardiovascular and Thoracic Surgery and Anesthesiology and Intensive Care, Örebro University Hospital.
    Häggmark, Sören
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Svenmarker, Staffan
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Gupta, Anil
    Dept of Clinical Medicine, School of Health and Medical Sciences, Örebro University.
    Tydén, Hans
    Dept of Clinical Medicine, School of Health and Medical Sciences, Örebro University.
    Wouters, Patrick
    Dept of Anesthesiology, University Hospital Ghent, Ghent, Belgium.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Systolic and diastolic effects of milrinone and levosimendan in porcine post-ischemic myocardial dysfunctionManuskript (preprint) (Övrigt vetenskapligt)
  • 14.
    Axelsson, Birger
    et al.
    Dept of Cardiovascular and Thoracic Surgery, Örebro University hospital.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Abrahamsson, Pernilla
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Gupta, Anil
    Dept of Anesthesiology and Intensive Care, Örebro University hospital.
    Tydén, Hans
    Dept of Cardiovascular and Thoracic Surgery, Örebro University hospital.
    Wouters, Patrick
    Dept of Anesthesiology, University hospital Ghent, Belgium.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Milrinone and levosimendan during porcine myocardial ischemia: no effects on calcium overload and metabolism2013Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 57, nr 6, s. 719-728Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Although inotropic stimulation is considered harmful in the presence of myocardial ischaemia, both calcium sensitisers and phosphodiesterase inhibitors may offer cardioprotection. We hypothesise that these cardioprotective effects are related to an acute alteration of myocardial metabolism. We studied in vivo effects of milrinone and levosimendan on calcium overload and ischaemic markers using left ventricular microdialysis in pigs with acute myocardial ischaemia.

    METHODS: Anaesthetised juvenile pigs, average weight 36 kg, were randomised to one of three intravenous treatment groups: milrinone 50 μg/kg bolus plus infusion 0.5 μg/kg/min (n = 7), levosimendan 24 μg/kg plus infusion 0.2 μg/kg/min (n = 7), or placebo (n = 6) for 60 min prior to and during a 45 min acute regional coronary occlusion. Systemic and myocardial haemodynamics were assessed, and microdialysis was performed with catheters positioned in the left ventricular wall. (45) Ca(2+) was included in the microperfusate in order to assess local calcium uptake into myocardial cells. The microdialysate was analysed for glucose, lactate, pyruvate, glycerol, and for (45) Ca(2+) recovery.

    RESULTS: During ischaemia, there were no differences in microdialysate-measured parameters between control animals and milrinone- or levosimendan-treated groups. In the pre-ischaemic period, arterial blood pressure decreased in all groups while myocardial oxygen consumption remained stable.

    CONCLUSIONS: These findings reject the hypothesis of an immediate energy-conserving effect of milrinone and levosimendan during acute myocardial ischaemia. On the other hand, the data show that inotropic support with milrinone and levosimendan does not worsen the metabolic parameters that were measured in the ischaemic myocardium.

  • 15.
    Bjornestad, Elin Eb
    et al.
    Kirurgisk serviceklinikk, Klinikkoverlege, Helse Bergen HF, Norway.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    An obstetric anaesthetist: A key to successful conversion of epidural analgesia to surgical anaesthesia for caesarean delivery?2019Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576Artikel i tidskrift (Refereegranskat)
  • 16.
    Broomé, Michael
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åneman, Anders
    Biber, Björn
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Acute effects of angiotensin II on myocardial performance2001Ingår i: Acta Anaesthesiol Scand, Vol. 45, nr 9, s. 1147-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Specific angiotensin II (Ang II) receptors exist in many organs including peripheral blood vessels, cardiac myocytes and the central nervous system. This suggests multiple sites of actions for Ang II throughout the cardiovascular system. Cardiac effects of Ang II are not completely understood, though its prominent vasoconstrictor actions are well described. This study was designed to assess left ventricular function during administration of Ang II using relatively load-independent methods in a whole-animal model. METHODS: Ang II was infused in incremental doses (0-200 microg x h(-1)) in anaesthetised instrumented pigs (n=10). Cardiac systolic and diastolic function were evaluated by analysis of the left ventricular pressure-volume relationship. RESULTS: Heart rate (HR), mean arterial pressure (MAP) and systemic vascular resistance (SVR) increased dose-dependently with Ang II, while cardiac output (CO) remained unchanged. Systolic function indices, end-systolic elastance (Ees) and preload recruitable stroke work (PRSW), demonstrated dose-dependent increases. The diastolic function parameter tau (tau) did not change with increasing Ang II dose. CONCLUSION: Ang II infusion caused increases in contractility indices in anaesthetised pigs in the doses used in this study. The mechanisms for these systolic function effects may be a direct myocardial effect or modulated through changes in autonomic nervous system activity.

  • 17.
    Broomé, Michael
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åneman, Anders
    Biber, Björn
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Pressure-independent cardiac effects of angiotensin II in pigs.2004Ingår i: Acta Physiologica Scandinavica, ISSN 0001-6772, Vol. 182, nr 2, s. 111-9Artikel i tidskrift (Refereegranskat)
  • 18.
    Broomé, Michael
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Österlund, Barbro
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Biber, Björn
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    The cardiac effects of intracoronary angiotensin II infusion2002Ingår i: Anesth Analg, Vol. 94, nr 4, s. 787-93, table of contentsArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    Angiotensin II (Ang II) is a potent vasoconstrictor, which recently has been shown to also have significant inotropic effects. Previous results regarding the mechanisms of the acute inotropic effects of Ang II are not conclusive. We designed this study to investigate the local cardiac effects of intracoronary Ang II infusion in doses not affecting systemic circulation. Ang II (2.5-40 microg/h) was infused in the left coronary artery of Yorkshire pigs (n = 9) reaching calculated intracoronary Ang II concentrations of 842 +/- 310, 3342 +/- 1238, and 12448 +/- 4393 pg/mL, respectively. Cardiac systolic and diastolic function was evaluated by analysis of the left ventricular pressure-volume relationship. Coronary flow was measured by using a coronary sinus catheter and the retrograde thermodilution technique. No significant changes were seen in the systolic and diastolic function variables of heart rate, end-systolic elastance, preload recruitable stroke work, the time constant for isovolumetric relaxation, or in coronary vascular resistance and flow. The positive inotropic and chronotropic effects of Ang II seen in previous studies seem thus to be mediated via extracardiac actions of Ang II. Coronary vascular tone is not affected by local Ang II infusion in anesthetized pigs. IMPLICATIONS: The positive inotropic and chronotropic effects of angiotension II (Ang II) seen in previous studies seem to be mediated via extracardiac actions of Ang II. Coronary vascular tone is not affected by local Ang II infusion in anesthetized pigs.

  • 19.
    Broomé, Michael
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åneman, Anders
    Haney, Michael
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Biber, Björn
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Angiotensin II mesenteric and renal vasoregulation: dissimilar modulatory effects with nitroprusside2000Ingår i: Acta Anaesthesiol Scand, Vol. 44, nr 10, s. 1238-45Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: The role of systemic arterial pressure for the vascular effects of angiotensin II (Ang II) and the interactions between Ang II and perfusion pressure-dependent local vascular control mechanisms are not well understood. This study addresses these aspects of exogenous Ang II in the mesenteric and renal regional circulations. METHODS: Ang II was infused in incremental doses (0-200 microg/h) in anesthetized instrumented pigs (n=10). Renal and portal blood flows were measured by perivascular ultrasound. In the second part of the study, sodium nitroprusside (SNP) was infused at doses titrated to keep mean arterial pressure constant, in spite of concurrent Ang II administration. RESULTS: Powerful dose-dependent vasoconstrictions by Ang II were found in renal and mesenteric vascular beds (at highest Ang II doses vascular resistances increased by 109% and 88% respectively). Ang II-induced vasoconstriction was fully inhibited in the mesenteric, but not in the renal circulation, during conditions of constant mean arterial pressures achieved by SNP infusion. CONCLUSIONS: Mesenteric, but not renal, vasoconstriction by Ang II was inhibited by pharmacological maintenance of perfusion pressure. This could reflect differences between these vascular beds as regards the importance of co-acting myogenic pressure-dependent vasoconstriction. Alternatively, as the drug chosen for pressure control, sodium nitroprusside, serves as a nitric oxide donor, the relative balance between nitric oxide-mediated vasodilation and Ang II-induced vasoconstriction could have regional differences.

  • 20.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Eriksson, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Rättsmedicin.
    Giesbrecht, Gordon
    University of Manitoba, Winnipeg, Canada. Dep of Anesthesia.
    Ängquist, Karl-Axel
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Kirurgi.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Fatal hypothermia: an analysis from a sub-arctic region2012Ingår i: International Journal of Circumpolar Health, ISSN 1239-9736, E-ISSN 2242-3982, Vol. 71, nr 0, s. 1-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives. To determine the incidence as well as contributing factors to fatal hypothermia.

    Study design. Retrospective, registry-based analysis.

    Methods. Cases of fatal hypothermia were identified in the database of the National Board of Forensic Medicine for the 4 northernmost counties of Sweden and for the study period 1992-2008. Police reports, medical records and autopsy protocols were studied.

    Results. A total of 207 cases of fatal hypothermia were noted during the study period, giving an annual incidence of 1.35 per 100,000 inhabitants. Seventy-two percent occurred in rural areas, and 93% outdoors. Many (40%) were found within approximately 100 meters of a building. The majority (75%) occurred during the colder season (October to March). Some degree of paradoxical undressing was documented in 30%. Ethanol was detected in femoral vein blood in 43% of the victims. Contributing co-morbidity was common and included heart disease, earlier stroke, dementia, psychiatric disease, alcoholism, and recent trauma.

    Conclusions. With the identification of groups at high risk for fatal hypothermia, it should be possible to reduce risk through thoughtful interventions, particularly related to the highest risk subjects (rural, living alone, alcohol-imbibing, and psychiatric diagnosis-carrying) citizens.

  • 21.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Giesbrecht, Gordon
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Ängquist, Karl-Axel
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Kirurgi.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Accidental cold-related injury leading to hospitalization in northern Sweden (2000-2007)Manuskript (preprint) (Övrigt vetenskapligt)
  • 22.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Giesbrecht, Gordon G.
    Kinesiology and Recreation Management, and Anesthesia, University of Manitoba, Winnipeg, Canada.
    Ängquist, Karl-Axel
    Emergency and Disaster Medical Center, Umeå University Hospital, Sweden.
    Haney, Michael F.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Accidental cold-related injury leading to hospitalization in northern Sweden: an eight-year retrospective analysis2014Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 22, s. 6-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Cold injuries are rare but important causes of hospitalization. We aimed to identify the magnitude of cold injury hospitalization, and assess causes, associated factors and treatment routines in a subarctic region. Methods: In this retrospective analysis of hospital records from the 4 northernmost counties in Sweden, cases from 2000-2007 were identified from the hospital registry by diagnosis codes for accidental hypothermia, frostbite, and cold-water drowning.Results were analyzed for pre-hospital site events, clinical events in-hospital, and complications observed with mild (temperature 34.9 - 32 degrees C), moderate (31.9 - 28 degrees C) and severe (<28 degrees C), hypothermia as well as for frostbite and cold-water drowning. Results: From the 362 cases, average annual incidences for hypothermia, frostbite, and cold-water drowning were estimated to be 3.4/100 000, 1.5/100 000, and 0.8/100 000 inhabitants, respectively. Annual frequencies for hypothermia hospitalizations increased by approximately 3 cases/year during the study period. Twenty percent of the hypothermia cases were mild, 40% moderate, and 24% severe. For 12%, the lowest documented core temperature was 35 degrees C or higher, for 4% there was no temperature documented. Body core temperature was seldom measured in pre-hospital locations. Of 362 cold injury admissions, 17 (5%) died in hospital related to their injuries. Associated co-factors and co-morbidities included ethanol consumption, dementia, and psychiatric diagnosis. Conclusions: The incidence of accidental hypothermia seems to be increasing in this studied sub-arctic region. Likely associated factors are recognized (ethanol intake, dementia, and psychiatric diagnosis).

  • 23.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Sundelin, Anna
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Hoseason, Daniela
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Sundström, Nina
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Birgander, Richard
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Koskinen, Lars-Owe
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation2017Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 25, artikel-id 50Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures. METHODS: A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations. RESULTS: Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during 'flight' would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop 'inflight' related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile. DISCUSSION: These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport. CONCLUSIONS: Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

  • 24.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Wiklund, Urban
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Karlsson, Marcus
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ängquist, Karl-Axel
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Kirurgi.
    Grip, Helena
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Autonomic nerve system responses for normal and slow rewarmers after hand cold provocation: effects of long-term cold climate training2013Ingår i: International Archives of Occupational and Environmental Health, ISSN 0340-0131, E-ISSN 1432-1246, Vol. 86, nr 3, s. 357-365Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: Differences among individuals concerning susceptibility to local cold injury following acute cold exposure may be related to function of the autonomic nervous system. We hypothesized that there are differences in heart rate variability (HRV) between individuals with normal or more pronounced vasoconstriction following cold exposure and that there is an adaptation related to prolonged cold exposure in autonomic nervous system response to cold stimuli.

    METHODS: Seventy-seven young men performed a cold provocation test, where HRV was recorded during cold hand immersion and recovery. Forty-three subjects were re-examined 15 months later, with many months of cold weather training between the tests. Subjects were analyzed as 'slow' and 'normal' rewarmers according to their thermographic rewarming pattern.

    RESULTS: For the 'pre-training' test, before cold climate exposure, normal rewarmers had higher power for low-frequency (P(LF)) and high-frequency (P(HF)) HRV components during the cold provocation test (ANOVA for groups: p = 0.04 and p = 0.005, respectively). There was an approximately 25 % higher P(HF) at the start in normal rewarmers, in the logarithmic scale. Low frequency-to-high frequency ratio (P(LF)/P(HF)) showed lower levels for normal rewarmers (ANOVA for groups: p = 0.04). During the 'post-training' cold provocation test, both groups lacked the marked increase in heart rate that occurred during cold exposure at the 'pre-training' setting. After cold acclimatization (post-training), normal rewarmers showed lower resting power values for the low-frequency and high-frequency HRV components. After winter training, the slow rewarmers showed reduced low-frequency power for some of the cold provocation measurements but not all (average total P(LF), ANOVA p = 0.05), which was not present before winter training.

    CONCLUSIONS: These HRV results support the conclusion that cold adaptation occurred in both groups. We conclude that further prospective study is needed to determine whether cold adaptation provides protection to subjects at higher risk for cold injury, that is, slow rewarmers.

  • 25.
    Brändström, Helge
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Lindholm, Lars
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Epidemiologi och global hälsa.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Regional intensive care transports: a prospective analysis of distance, time and cost for road, helicopter and fixed-wing ambulances2014Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 22, s. 36-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: There are three different types of ambulance systems, all of which can manage the same secondary intensive care patient transport mission: road ambulance, rotor-wing ambulance, and fixed-wing ambulance. We hypothesized that costs for specific transport distances would differ between systems. We aimed to analyze distances and observed times for ambulance intensive care secondary transport missions together with system costs to assess this. Methods: We prospectively collected data for consecutive urgent intensive care transports into the regional tertiary care hospital in the northern region of Sweden. Distances and transport times were gathered, and a cost model was generated based on these together with fixed and operating costs from the three different ambulance systems. Distance-cost and time-cost estimations were then generated for each transport system. Results: Road ambulance cost relatively less for shorter distances (within 250 kilometers/155 miles) but were relatively time ineffective. The rotor-wing systems were most expensive regardless of distance; but were most time-effective up to 400-500 km (248-310 miles). Fixed-wing systems were more cost-effective for longer distance (300 km/186 miles), and time effective for transports over 500 km (310 miles). Conclusions: In summary, based on an economic model developed from observed regional ICU patient transports, and cost estimations, different ambulance system cost-distances could be compared. Distance-cost and time results show that helicopters can be effective up to moderate ICU transport distances (400-500), though are expensive to operate. For longer ICU patient transports, fixed-wing transport systems are both cost and time effective compared to helicopter-based systems.

  • 26.
    Cholley, B.
    et al.
    Univ Sorbonne Paris Cite, Dept Anesthesiol & Intens Care, Hop Europeen Georges Pompidou, Paris, France.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Ultrasound diagnostics during acute circulatory disturbance in the perioperative or intensive care setting2012Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 56, nr 7, s. 805-806Artikel i tidskrift (Övrigt vetenskapligt)
  • 27. Cholley, BP
    et al.
    Mayo, PH
    Poelaert, J
    Vieillard-Baron, A
    Vignon, P
    Alhamid, S
    Balik, M
    Beaulieu, Y
    Breitkreutz, R
    Canivet, J-L
    Doelken, P
    Flaatten, H
    Frankel, H
    Haney M, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Hilton, A
    Maury, E
    McDermid, RC
    McLean, AS
    Mendes, C
    Pinsky, MR
    Price, S
    Schmidlin, D
    Slama, M
    Talmor, D
    Teles, JM
    Via, G
    Voga, G
    Wouters, P
    Yamamoto, T
    International expert statement on training standards for critical care ultrasonography2011Ingår i: Intensive Care Medicine, ISSN 0342-4642, E-ISSN 1432-1238, Vol. 37, nr 7, s. 1077-1083Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Training in ultrasound techniques for intensive care medicine physicians should aim at achieving competencies in three main areas: (1) general critical care ultrasound (GCCUS), (2) "basic" critical care echocardiography (CCE), and (3) advanced CCE. A group of 29 experts representing the European Society of Intensive Care Medicine (ESICM) and 11 other critical care societies worldwide worked on a potential framework for organizing training adapted to each area of competence. This framework is mainly aimed at defining minimal requirements but is by no means rigid or restrictive: each training organization can be adapted according to resources available. There was 100% agreement among the participants that general critical care ultrasound and "basic" critical care echocardiography should be mandatory in the curriculum of intensive care unit (ICU) physicians. It is the role of each critical care society to support the implementation of training in GCCUS and basic CCE in its own country.

  • 28. Dalla, Keti
    et al.
    Hallman, Caroline
    Bech-Hanssen, Odd
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Ricksten, Sven-Erik
    Strain echocardiography identifies impaired longitudinal systolic function in patients with septic shock and preserved ejection fraction2015Ingår i: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 13, artikel-id 30Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Myocardial dysfunction is recognized in sepsis. We hypothesized that mechanical left (LV) and right (RV) ventricular function analysed using 2-dimensional speckle-tracking echocardiography in a cohort of early severe sepsis or septic shock patients, would be different to that of a group of critically ill, non-septic patients.

    Methods: Critically ill adult patients with early, severe sepsis/septic shock (n = 48) and major trauma patients with no sepsis (n = 24) were included retrospectively, as well as healthy controls (n = 16). Standard echocardiographic examinations, including right (RV) left (LV) volumes and mitral, aortic and pulmonary vein Doppler flow profiles, were retrospectively identified and the studies were then reanalysed for assessment of myocardial strain using speckle-tracking echocardiography. Endocardial tracing of the LV was performed in apical four-chamber (4-Ch), two-chamber (2-Ch), apical long-axis (3-Ch) and apical views of RV determining the longitudinal LV and RV free wall strain in each subject.

    Results: In septic patients, heart rate was significantly higher (p = 0.009) and systolic (p < 0.001) and mean arterial pressures (p < 0.001), as well as systemic vascular resistance (p < 0.001) were significantly lower when compared to the non-septic trauma group. Ninety-three per cent of the septic patients and 50 % of the trauma patients were treated with norepinephrine (p < 0.001). LV ejection fraction (LVEF) was lower in the septic patients (p = 0.019). In septic patients with preserved LVEF (>50 %, n = 34), seventeen patients (50 %) had a depressed LV global longitudinal function, defined as a LV global strain > -15 %, compared to two patients (8.7 %) in the non-septic group (p = 0.0014). In septic patients with preserved LVEF, LV global and RV free wall strain were 14 % (p = 0.014) and 17 % lower (p = 0.008), respectively, compared to the non-septic group with preserved LVEF. There were no significant differences between groups with respect to LV end-diastolic or end-systolic volumes, stroke volume, or cardiac output. There were no signs of diastolic dysfunction from the mitral or pulmonary vein Doppler profiles in the septic patients.

    Conclusions: LV and RV systolic function is impaired in critically ill patients with early septic shock and preserved LVEF, as detected by Speckle-tracking 2D echocardiography. Strain imaging may be useful in the early detection of myocardial dysfunction in sepsis.

  • 29. Fagley, R. Eliot
    et al.
    Haney, Michael F.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Beraud, Anne-Sophie
    Comfere, Thomas
    Kohl, Benjamin Adam
    Merkel, Matthias Johannes
    Pustavoitau, Aliaksei
    von Homeyer, Peter
    Wagner, Chad Edward
    Wall, Michael H.
    Critical Care Basic Ultrasound Learning Goals for American Anesthesiology Critical Care Trainees: Recommendations from an Expert Group2015Ingår i: Anesthesia and Analgesia, ISSN 0003-2999, E-ISSN 1526-7598, Vol. 120, nr 5, s. 1041-1053Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: In this review, we define learning goals and recommend competencies concerning focused basic critical care ultrasound (CCUS) for critical care specialists in training. DESIGN: The narrative review is, and the recommendations contained herein are, sponsored by the Society of Critical Care Anesthesiologists. Our recommendations are based on a structured -literature review by an expert panel of anesthesiology intensivists and cardiologists with formal training in ultrasound. Published descriptions of learning and training routines from anesthesia-critical care and other specialties were identified and considered. Sections were written by groups with special expertise, with dissent included in the text. RESULTS: Learning goals and objectives were identified for achieving competence in the use of CCUS at a specialist level (critical care fellowship training) for diagnosis and monitoring of vital organ dysfunction in the critical care environment. The ultrasound examination was divided into vascular, abdominal, thoracic, and cardiac components. For each component, learning goals and specific skills were presented. Suggestions for teaching and training methods were described. DISCUSSION: Immediate bedside availability of ultrasound resources can dramatically improve the ability of critical care physicians to care for critically ill patients. Anesthesia-critical care medicine training should have definitive expectations and performance standards for basic CCUS interpretation by anesthesiology-critical care specialists. The learning goals in this review reflect current trends in the multispecialty critical care environment where ultrasound-based diagnostic strategies are already frequently applied. These competencies should be formally taught as part of an established anesthesiology-critical care medicine graduate medical education programs.

  • 30. Flaatten, H
    et al.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Wernerman, J
    The Scandinavian critical care trials group: producing important new findings in challenging times2013Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 57, nr 2, s. 138-140Artikel i tidskrift (Refereegranskat)
  • 31. Flaatten, H.
    et al.
    Rasmussen, L. S.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Publication footprints and pitfalls of bibliometry2016Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 60, nr 1, s. 3-5Artikel i tidskrift (Övrigt vetenskapligt)
  • 32.
    Flaatten, Hans
    et al.
    Dep. of Anaesthesia and Intensive Care, Haukeland University Hospital, Bergen, Norway.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Improving reporting of ICU outcome data2019Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Clinical studies reporting outcomes after intensive care admissions are often published, including in this journal 1 . This is a field with much research activity, and with widespread clinical interest. For observational cohort studies, it is strongly recommended that authors form their reports using guidelines presented by the STROBE (Strengthening the reporting of observational studies in epidemiology) group 2 , and these recommendations are designed to strengthen the report based on their observations.

  • 33.
    Gustafsson, Ulf
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Larsson, M
    School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.
    Bjällmark, A
    School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.
    Lindqvist, Per
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Aroch, Roman
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Waldenström, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    The effect of acute myocardial ischemia on the rotation axis of the left ventricleManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Introduction: We have developed a method to assess the axis around which the left ventricle (LV) rotates. The aim was to assess the effect of acute regional ischemia on the otation axis.

    Method: Mid‐LAD occlusion was induced in six anesthetised pigs and echocardiographic images were recorded at baseline and after LAD occlusion. The rotation axis was calculated at three different levels of the LV throughout the cardiac cycle. Results: The direction of the rotation axis was significantly changed (p<0.01) after LAD occlusion, being directed towards the ischemic area. AV‐plane displacement was significantly reduced (p<0.05) during ischemia. No significant difference in twist or otation amplitudes was found.

    Conclusion: This new method of assessing rotational function seems as sensitive as AV‐plane displacement and superior to traditional rotation and twist parameters in detecting dysfunction in acute ischemic myocardium. The rotation axis method has the advantage of potentially identifying areas with dysfunction.

  • 34.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Coronary physiology2012Ingår i: Core Topics in Cardiac Anesthesi: 2nd Edition / [ed] Jonathan H. Mackay and Joseph E. Arrowsmith, CAMBRIDGE: Cambridge University Press, 2012, 2, s. 22-27Kapitel i bok, del av antologi (Refereegranskat)
  • 35.
    Haney, Michael
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    A'Roch, Roman
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Poelaert, Jan
    Biber, Björn
    Beat-to-beat change in myocardial performance index related to load2007Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 51, nr 5, s. 545-552Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: This study was designed to assess the relationship of the "myocardial performance index" (MPI) to the beat-by-beat change in pre-load with static or unchanged contractile status.

    METHODS: Eight anesthetized juvenile pigs were studied using direct measurement of the left ventricular pressure and volume. Transient inflation of a vena cava balloon catheter produced controlled pre-load alterations. Consecutive beats were analyzed, grouped for first, second, third, etc. during the pre-load alteration, and evaluated for the change in MPI during the same contractile status with a controlled pre-load alteration. Two pharmacologic inotropic interventions were also included to generate several myocardial conditions in each animal.

    RESULTS: MPI demonstrated a strong linear relationship to the pre-load and after-load. MPI increased progressively during decreasing end-diastolic volume, mostly related to changes in ejection time. MPI was observed at the same level for three different myocardial function conditions (all eight animals), with a different relationship between MPI and pre-load noted for each observation.

    CONCLUSIONS: MPI is strongly load dependent, and can vary widely in value for the same contractile status if the load is varied. The use of this index in critically ill patients should be limited in this respect. Further work is needed to establish the relationship of MPI to load and contractile status.

  • 36.
    Haney, Michael F
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Näslund, Ulf
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin. Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    ST changes and temporal relation to the J point during heart rate increase and myocardial ischemia.2009Ingår i: Journal of electrocardiology, ISSN 1532-8430, Vol. 42, nr 1, s. 6-11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is no concensus concerning where in the ST segment to measure. We studied the relation between different J point intervals to ST results during tachycardia and ischemia. Symptomatic (anesthetized) patients with coronary artery disease were paced at ascending incremental levels until they became ischemic. ST vector magnitude and ST vector change from baseline (STC-VM) as well as the sum of ST changes from all 12 electrocardiogram (ECG) leads (ECG ST sum) were measured at J point 0 millisecond, J + 20, J + 60, and J + 80 milliseconds for 34 patients. ST segments increased in similar fashion during pacing and ischemia. There was no difference in ST results when measurement was performed at different time intervals for both STC-VM and ECG ST sum. We conclude that ST assessment by ST change from baseline is not affected by different J point intervals during increased heart rate and ischemia in this clinical model of pacing-induced ischemia and vectorcardiographic ST analysis.

  • 37.
    Haney, Michael F
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Biber, Björn
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Myocardial systolic function increases during positive pressure lung inflation.2005Ingår i: Anesthesia and Analgesia, ISSN 0003-2999, Vol. 101, nr 5, s. 1269-74Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lung inflation with positive airway pressure may have rapid and dynamic effects on myocardial contractile function. We designed this study to assess the magnitude and time to onset of myocardial function changes during the initiation of single positive pressure lung inflation at clinically relevant inflation pressures. In 8 anesthetized 40-kg pigs, left ventricular pressures and volumes were measured directly (conductance volumetry). A 15 cm H2O airway pressure plateau with lung inflation (PPLI-15) was performed, and 2 single beats from that sequence, one from resting apnea at zero airway pressure and the second from the point when the lungs were first maximally inflated, were selected for analysis. Systolic function variables for zero airway pressure and PPLI-15 were analyzed. Systolic elastance, derived from bilinear time-varying elastance curves, increased approximately 15% during PPLI-15 from zero airway pressure. This agreed with other systolic function variables that identified an increase in left ventricular contractile function for the lung inflation beat. Serial measurements of myocardial function should be conducted with constant airway pressure and lung inflation conditions.

  • 38.
    Haney, Michael F
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Steendijk, Paul
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Biber, Björn
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    The effect of lung inflation on absolute ventricular volume measurement by conductance.2006Ingår i: Clin Physiol Funct Imaging, ISSN 1475-0961, Vol. 26, nr 4, s. 220-3Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Conductance catheter in vivo ventricular volume measurements during lung ventilation may provide important information on left ventricular (LV) function. Breathing potentially may alter parallel conductance (V(c)), complicating interpretation of the conductance-derived volume signals. The effects of controlled positive pressure lung inflation (PPLI) on measured parallel conductance with dual-field conductance volumetry were investigated. METHODS: Eight anaesthetized pigs were instrumented with an LV dual-field conductance volumetry catheter. V(c) was measured repeatedly, using the hypertonic saline injection method, at three different levels of lung insufflation: continuous positive airway pressure (PPLI) 0, 5, and 10 cm H(2)O. RESULTS: V(c)s measured at PPLI 0, 5 and 10 cm H(2)O were 70.9 +/- 4.8, 70.7 +/- 5.5 and 70.5 +/- 5.9 ml, respectively. The corresponding uncalibrated end-diastolic volumes (EDV(u)) were 115.5 +/- 7.1, 117.0 +/- 7.5 and 117.5 +/- 7.7 ml, respectively. Mean coefficients of variance for V(c) and EDV(u) at all three PPLI levels were 3.8% and 1.25%, respectively. DISCUSSION: Several levels of PPLI demonstrated no systematic change in parallel conductance for LV dual-field conductance volume signal. We concluded that lung inflation at these levels does not generate changes in V(c).

  • 39.
    Haney, Michael
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Biber, Björn
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Analysis of left ventricular systolic function during elevated external cardiac pressures: an examination of measured transmural left ventricular pressure during pressure-volume analysis2001Ingår i: Acta Anaesthesiol Scand, Vol. 45, nr 7, s. 868-74Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Variations or disturbances in intrathoracic and extracardiac pressures (ECP) occur in critically ill and anaesthetised patients. There are uncertainties concerning the analysis of left ventricular pressure-volume relationship (LVPVR) and the calculation of systolic function parameters when conducted without reference to transmural left ventricular pressure (LVPtm) in the setting of elevated ECP. METHODS: In 7 anaesthetised adult pigs, we measured LVPVR using conductance volumetry and tip manometry along with measurement of pericardial and other intrathoracic pressures. Experimental pericardial infusion and pleural insufflation were performed. Transient controlled preload reductions were accomplished using balloon occlusion of the inferior vena cava. Preload recruitable stroke work (PRSW) was calculated using both intracavitary left ventricular pressure (LVPic) and LVPtm, and differences were tested for using a paired t-test. RESULTS: The pericardial and pleural interventions produced significant elevations in ECP. No difference in PRSW calculated using LVPic and LVPtm was detected. CONCLUSION: These results suggest that LVPtm need not be measured and included in LVPVR analysis of systolic function when there is significant external cardiac pressure. To be able to employ LVPVR analysis of systolic function without reference to LVPtm is important for simplified application in the clinical setting, particularly when elevated extracardiac pressures are suspected, or have been therapeutically induced, as with continuous positive pressure ventilation.

  • 40.
    Haney, Michael
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Biber, Björn
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Heart-lung interactions during positive pressure ventilation: left ventricular pressure-volume momentary response to airway pressure elevation2001Ingår i: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 45, nr 6, s. 702-709Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Left ventricular (LV) pressure and volume changes are known to occur in response to positive airway pressure (PAP). We aimed to further describe the immediate LV response to increased PAP as demonstrated in successive heart cycles with LV pressure and volume alterations. We postulated that these acute systematic LV events during institution of PAP can follow a distinct pattern that would allow calculation of parameters of systolic function, including end-systolic elastance (Ees) and preload recruitable stroke work (PRSW). We also aimed to examine the relationship of PAP-derived Ees and PRSW to the same parameters derived from vascular occlusion. METHODS: Eight anesthetized adult pigs were studied with invasive circulatory measurements including LV pressure and volume (conductance). The PAP intervention was an airway pressure plateau of 15 cm H2O for 6 s (APP). Venous occlusion was performed by transient balloon inflation in the inferior vena cava (IVCO). Ees and PRSW were derived for each APP and IVCO intervention. RESULTS: Central circulatory variables during APP and IVCO are reported. LV systolic function parameters could be derived from each of the heart-lung interactions during APP sequences. Ees and PRSW derived from APP showed a significant positive bias in relation to those derived from the IVCO sequence. CONCLUSIONS: We conclude that the heart-lung interactions during APP of the magnitude and duration shown here can allow derivation of Ees and PRSW. These parameters are not interchangeable with Ees and PRSW derived from IVCO.

  • 41.
    Haney, Michael
    et al.
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Häggmark, Sören
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Biber, Björn
    Umeå universitet, Medicinsk fakultet, Kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Method of preload reduction during LVPVR analysis of systolic function: airway pressure elevation and vena cava occlusion2002Ingår i: Anesthesiology, Vol. 97, nr 2, s. 436-46Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: A graded preload reduction during analysis of the left ventricular pressure-volume relationship (LVPVR) is required for derivation of end-systolic elastance (Ees) and preload recruitable stroke work (PRSW). The authors aimed to measure serial changes in these systolic function parameters before and during planned circulatory interventions using two different methods of preload alteration: a positive airway pressure plateau (APP) and inferior vena cava occlusion (IVCO). METHODS: In eight animals, measurements were made at 38 degrees, 30 degrees, 32 degrees, 34 degrees, and posthypothermia 38 degrees C. In an additional eight animals, isoflurane, adrenaline, and aorta occlusion (balloon catheter occluder) were administered in series, each with a preintervention control measurement. Left ventricular volume was measured by conductance. Paired measurements of the systolic function parameters Ees and PRSW, each derived with two preload methods, were analyzed for bias. RESULTS: Circulatory alterations were achieved with the temperature, isoflurane, adrenaline, and aorta occlusion interventions. Measured changes in Ees and PRSW from control to intervention showed a strong correlation and no significant bias for APP in relation to IVCO. The APP-derived absolute values for Ees and PRSW demonstrated a consistent positive bias compared with IVCO. CONCLUSION: The APP method for preload reduction during LVPVR analysis detected changes in Ees and PRSW during the circulatory interventions in this model that were not different than those detected using another preload r