Umeå University's logo

umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Delirium after cardiac surgery: incidence and risk factors
Umeå University, Faculty of Medicine, Department of Nursing. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery. Cardiothoracic Division, Department of Surgery and Perioperative Science, Umeå University.
Umeå University, Faculty of Medicine, Department of Nursing. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences. Cardiothoracic Division, Department of Surgery and Perioperative Science, Umeå University.
Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Geriatric Medicine.
Umeå University, Faculty of Medicine, Department of Nursing. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.ORCID iD: 0000-0002-3754-5026
Show others and affiliations
2013 (English)In: Interactive Cardiovascular and Thoracic Surgery, ISSN 1569-9293, E-ISSN 1569-9285, Vol. 17, no 5, p. 790-796Article in journal (Refereed) Published
Abstract [en]

OBJECTIVES: Delirium after cardiac surgery is a problem with consequences for patients and healthcare. Preventive strategies from known risk factors may reduce the incidence and severity of delirium. The present aim was to explore risk factors behind delirium in older patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS: Patients (≥70 years) scheduled for routine cardiac surgery were included (n = 142). The patients were assessed and monitored pre-/postoperatively, and delirium was diagnosed from repeated assessments with the Mini-Mental State Examination and the Organic Brain Syndrome Scale, using the DSM-IV-TR criteria. Variables were analysed by uni-/multivariable logistic regression, including both preoperative variables (predisposing) and those extracted during surgery and in the early postoperative period (precipitating).

RESULTS: Delirium was diagnosed in 78 patients (54.9%). Delirium was independently associated with both predisposing and precipitating factors (P-value, odds ratio, upper/lower confidence interval): age (0.036, 1.1, 1.0/1.2), diabetes (0.032, 3.5, 1.1/11.0), gastritis/ulcer problems (0.050, 4.0, 1.0/16.1), volume load during operation (0.001, 2.8, 1.5/5.1), ventilator time in ICU (0.042, 1.2, 1.0/1.4), highest temperature recorded in ICU (0.044, 2.2, 1.0/4.8) and sodium concentration in ICU (0.038, 1.2, 1.0/1.4).

CONCLUSIONS: Delirium was common among older patients undergoing cardiac surgery. Both predisposing and precipitating factors contributed to delirium. When combined, the predictive strength of the model improved. Preventive strategies may be considered, in particular among the precipitating factors. Of interest, delirium was strongly associated with an increased volume load during surgery.

Place, publisher, year, edition, pages
Oxford University Press, 2013. Vol. 17, no 5, p. 790-796
Keywords [en]
cardiac surgery, delayed, early, hemispheric, stroke survival
National Category
Surgery Cardiac and Cardiovascular Systems Nursing
Identifiers
URN: urn:nbn:se:umu:diva-86091DOI: 10.1093/icvts/ivt323ISI: 000326725300011PubMedID: 23887126Scopus ID: 2-s2.0-84902394707OAI: oai:DiVA.org:umu-86091DiVA, id: diva2:697028
Available from: 2014-02-17 Created: 2014-02-17 Last updated: 2023-03-24Bibliographically approved
In thesis
1. Delirium in older people after cardiac surgery: risk factors, dementia, patients’ experiences and assessments
Open this publication in new window or tab >>Delirium in older people after cardiac surgery: risk factors, dementia, patients’ experiences and assessments
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Akut förvirringstillstånd (delirium) hos äldre personer som genomgått hjärtkirurgi : riskfaktorer, demens, patienternas erfarenheter och skattningsinstrument.
Abstract [en]

Background:

Delirium is common in older people undergoing cardiac surgery. Delirium is an acute or subacute neuro-psychiatric syndrome, characterized by a change in cognition, disturbances in consciousness; it fluctuates, develops over a short period of time and always has an underlying cause. It is associated with a disturbance in psychomotor activity, and is classified according to different clinical profiles such as hypoactive, hyperactive and mixed delirium. Delirium after cardiac surgery is not harmless, it increases the risk of complications such as prolonged stay in hospital, falls, reduced quality of life, reduced cognitive function and increased mortality.

Aim:

The overall aim of this thesis was to investigate postoperative delirium in older people undergoing cardiac surgery with Cardiopulmonary Bypass (CPB), focusing on risk factors, dementia and patients’ experiences; and to evaluate an assessment for screening delirium.

Methods:

This thesis compromises four studies. All participants (n=142) were scheduled for cardiac surgery with use of CPB at the Cardiothoracic Surgery Department, Heart Centre, Umeå University Hospital, Sweden, between February and October 2009. Six structured interviews were conducted preoperatively, day one and day four postoperatively, and in home visits, one, three and five years after surgery (2010, 2012 and 2014). The assessment scales used in Studies I, II and IV were: the Mini-Mental State Examination (MMSE) for cognition, the Organic Brain Syndrome Scale (OBS) for delirium, Geriatric Depression Scale 15 (GDS-15) for depression, Katz staircase with Activities of Daily Living (ADL) for participants’ functional status and the Numerical Rating Scale (NRS) for pain. During the hospital stay, nursing staff used the Swedish version of the Nursing Delirium Screening Scale (Nu-DESC) to assess delirium. Semi-structured interviews were also carried out (III) in the one-year follow up. Delirium, dementia and depression were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV TR).

Results:

Out of 142 participants 54.9% (78/142) developed delirium after cardiac surgery (I). Independent risk factors, predisposing and precipitating, associated with delirium were: age, diabetes, gastritis/peptic ulcer, volume load during operation, longer time on ventilator in intensive care, increased temperature and plasma sodium concentration in the intensive care unit. Out of 114 participants thirty (26.3%) developed dementia within the five years of follow-up. It was shown that a lower preoperative MMSE score and postoperative delirium were factors independently associated with development of dementia (II). One year after cardiac surgery, participants diagnosed with postoperative delirium described in detail feelings of extreme vulnerability and frailty. Despite this, the participants were grateful for the care they had received (III). Hypoactive was the most common symptom profile for delirium. The Swedish version of Nu-DESC showed high sensitivity in detecting hyperactive delirium, but low sensitivity in detecting hypoactive delirium (IV).

Conclusion:

Delirium was common among older patients undergoing cardiac surgery. Both predisposing and precipitating factors contributed to postoperative delirium. Preventive strategies should be considered in future randomized studies. It might also be suggested that cognitive function should be screened for preoperatively and patients who develop delirium should be followed up to enable early detection of symptoms of dementia. Whether prevention of postoperative delirium can reduce the risk of future dementia remains to be studied. To minimise unnecessary suffering, patients and next of kin should be informed about and prepared for the risk of delirium developing during hospitalization. The Swedish version of Nu-DESC should be combined with cognitive testing to improve detection of hypoactive delirium, but further research is needed. Healthcare professionals need knowledge concerning postoperative delirium in order to prevent, detect and treat delirium so as to avoid and relieve the suffering it might cause.

Abstract [sv]

Akut förvirringstillstånd (delirium) hos äldre personer som genomgått hjärtkirurgi –riskfaktorer, demens, patienternas erfarenheter och skattningsinstrument.

Bakgrund:

Delirium är vanligt hos äldre personer som genomgår hjärtkirurgi. Delirium är ett akut eller subakut neuropsykiatriskt syndrom, som kännetecknas av förändrad kognitiv förmåga samt en förändad medvetande nivå. Delirium utvecklas under en kort tidsperiod, tenderar att fluktuera och har alltid en bakomliggande orsak. Delirium kan klassificeras som hypoaktivt, hyperaktivt eller en blandform av båda dessa. Delirium efter hjärtkirurgi kan öka risken för andra komplikationer som tillexempel; förlängd vårdtid, fall, försämrad livskvalité, nedsatt kognitiv förmåga samt mortalitet.

Syfte:

Det övergripande syftet med denna avhandling var att undersöka postoperativt delirium bland äldre personer som genomgått hjärtkirurgi med hjärt-lungmaskin med fokus på riskfaktorer, demens, patienters erfarenheter samt utvärdering av skattningsinstrument för delirium

Metod:

Denna avhandling består av fyra studier. Alla deltagare (n = 142) genomgick rutinmässig hjärtkirurgi med hjärt-lungmaskin vid Thoraxkirurgiska kliniken, Hjärtcentrum, Umeå Universitetssjukhus, mellan februari till oktober 2009. Sex intervjuer genomfördes; preoperativt, dag ett och dag fyra postoperativt, samt vid hembesök ett, tre och fem år efter operationen (2010, 2012 och 2015). Skattningsinstrument som användes i studie I, II och IV var; The Mini-Mental Test (MMSE) för kognition, The Organic Brain Syndrome Scale (OBS) för delirium, Geriatric Depression Scale (GDS-15) för depression, Katz ADL trappa-Katz-index aktiviteter för dagliga livet och Numerisk Rating Scale (NRS) för smärta. Under vårdtiden använde vårdpersonalen Nursing Delirium Screening Scale (Nu-DESC) tre gånger dagligen för att skatta delirium. Nu-DESC jämfördes med en sammanvägning av MMSE och OBS-skalan. Vid uppföljningen år 2010 genomfördes dessutom semistrukturerade intervjuer. Delirium, demens och depression diagnostiserades enligt Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR).

Resultat:

Studie I visade att 54.9% (78/142) av patienterna utvecklade delirium efter hjärtkirurgi. Oberoende riskfaktorer (bakomliggande och utlösande) för delirium var; ålder, diabetes, gastrit/magsår, volymbelastning under operation samt respiratortid, förhöjd kroppstemperatur och förhöjd natriumkoncentration i plasma på intensivvårds avdelning. Studie II visade att 26.3% (30/114) av deltagarna utvecklade demens under en femårs uppföljning. En nedsatt preoperativ kognitiv förmåga (indikerad av lägre MMSE-poäng) och förekomsten av postoperativ delirium var faktorer som ökade risken för att utveckla demens. Ett år efter operation kunde deltagarna som diagnostiserats med postoperativt delirium i detalj beskriva sin sårbarhet och skörhet under vårdtiden. Deltagarna beskrev också sin tacksamhet över den vård de fått (Studie III). Den vanligaste formen var hypoaktivt delirium. Den svenska versionen av Nu-DESC kunde upptäcka hyperaktivt men inte hypoaktivt delirium (Studie IV).

Slutsats:

Delirium var vanligt bland äldre patienter som genomgått hjärtkirurgi. Både bakomliggande och utlösande faktorer utgjorde ökad risk för att utveckla postoperativt delirium. Förebyggande strategier bör övervägas i framtida randomiserade studier. Kognitiv funktion bör skattas preoperativt och patienter bör skattas för delirium under vårdtiden och följas upp efter hemgång för att upptäcka tidiga demenssymtom. Huruvida förebyggandet av postoperativt delirium kan minska risken för demens senare återstår att studeras. För att minska onödigt lidande bör patienter och anhöriga bli informerade och förberedda på risken att utveckla delirium under vårdtiden. Den svenska versionen av Nu-DESC behöver förmodligen kombineras med ett kognitiv test för att upptäcka hypoaktivt delirium. För att lindra det lidande som syndromet kan orsaka behöver vårdpersonal fördjupad kunskap i syfte att förebygga, upptäcka och behandla postoperativt delirium.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2016. p. 79
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1783
Keywords
Cardiac surgery, Cardiovascular disease, Delirium, Dementia, Nursing, Older people, Patients’ experiences, Perioperative period
National Category
Nursing
Research subject
Caring Sciences
Identifiers
urn:nbn:se:umu:diva-118347 (URN)978-91-7601-423-3 (ISBN)
Public defence
2016-04-15, Vårdvetarhuset, Aula, Umeå universitet, Umeå, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2016-03-24 Created: 2016-03-16 Last updated: 2018-08-10Bibliographically approved
2. Delirium after cardiac surgery: risk factors, assessment methods and costs
Open this publication in new window or tab >>Delirium after cardiac surgery: risk factors, assessment methods and costs
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Background: Cardiac surgery is considered safe, but postoperative delirium (POD) remains frequently reported. Delirium is characterised by fluctuations in consciousness and cognition, and can be subdivided into disturbed psychomotoric activity (hyperactive and hypoactive) and psychiatric symptom profiles (psychotic and emotional). Delirium has an underlying cause that can be prevented and treated, provided the condition is detected. Undetected delirium could lead to serious consequences for the patient.

Aim: This thesis aims to understand the underlying risk factors of delirium, to compare different assessment methods and documentation, and to understand its effects on hospitalisation costs after cardiac surgery.

Methods: Two cohorts of patients undergoing cardiac surgery at the Heart Centre, Umeå University Hospital, Sweden were analysed. Cohort-A (Studies I-IV) enrolled 142 patients, ≥70 years of age, scheduled in 2009 for surgery with cardiopulmonary bypass (CPB). POD was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders 4th ed, text rev (DSM-IV-TR), based on repetitive assessments with the Mini-Mental State Examination (MMSE) and the Organic Brain Syndrome (OBS) scale. This method was considered as reference. Predisposing and precipitating risk factors were explored (Study I), and a separate analysis was conducted with focus on CPB parameters (Study II). Patients were also assessed for POD with the Confusion Assessment Method (CAM), which was validated versus the reference method (Study III). Additionally in Study IV, data about how nurses assessed patients for POD symptoms using the Nursing Delirium Screening Scale (Nu-DESC) were analysed together with information extracted from the clinical database. Moreover, discharge summaries from both nurses and physicians were retrospectively reviewed for key words and expression associated with delirium. Cohort-B (Study V) included 1879 routine cardiac surgery patients (2014-2017) retrospectively extracted from the clinical database with concomitant Nu-DESC scoring. The association between the Nu-DESC and postoperative hospitalization costs was analysed.

Results: In cohort-A, 54.9% (78/142) patients developed POD. Both predisposing and precipitating risk factors were significantly associated with POD, of which the ‘volume load during operation’ had the strongest predictive influence (Study I). Among CPB variables the ‘duration of mixed-venous oxygen saturation <75%’ predicted POD (Study II). Hypoactive was more common than hyperactive delirium. Those with hypoactive delirium were less likely to be detected by the CAM method (Study III), an observation also demonstrated from information found in the clinical database and in discharge summaries. Nu-DESC did not detect all patients with POD, but significantly increased the detection rate (Study IV). The major hospitalisation costs associated with Nu-DESC ≥2 occurred in the ICU and independently of the surgical procedure performed. There were no significant differences in costs among patients with Nu-DESC ≥2, between age groups (70-year cut-off) or genders (Study V).

Conclusions: Both predisposing and precipitating risk factors contributed to POD and should be considered in future guidelines to prevent delirium after cardiac surgery. Hypoactive delirium was most common, but was the most difficult to detect without screening scales. Systematic assessment with Nu-DESC improved the detection rate of POD. Delirium after cardiac surgery has consequences on healthcare and is associated with increased costs.

Abstract [sv]

Bakgrund: Hjärtkirurgi anses idag vara en säker metod men det förkommer frekventa rapporter om postoperativt delirium (POD). Delirium kännetecknas av fluktuationer i medvetandet och kognition och kan delas in i störd psykomotorisk aktivitet (hyperaktiva och hypoaktiva) och psykiatriska symtomprofiler (psykotiska och emotionella). Delirium har underliggande orsaker som kan förebyggas och behandlas, förutsatt att tillståndet upptäcks. Ett oupptäckt delirium kan leda till allvarliga konsekvenser för patienten.

Syfte: Denna avhandling syftar till att förstå de underliggande riskfaktorerna för delirium, jämföra olika bedömningsmetoder och dokumentation samt förstå effekterna på vårdkostnaderna efter hjärtkirurgi.

Metod: Två kohorter av patienter som genomgått hjärtkirurgi vid Hjärtcentrum, Umeå Universitetssjukhus, Sverige analyserades. I kohort-A (Studie I-IV) inkluderades 142 patienter, ≥70 år planerade för operation med hjärt-lungmaskin under 2009. POD diagnostiserades enligt Diagnostic and Statistical Manual of Mental Disorders 4th ed, text rev (DSM-IV-TR), baserat på upprepade skattningar med Mini Mental State Examination (MMSE) och Organic Brain Syndrom(OBS) scale. Denna metod betraktas som referens. Predisponerande och utlösande riskfaktorer analyserades (Studie I), och en separat analys genomfördes med fokus på hjärt-lungmaskinens parametrar (Studie II). Patienterna bedömdes också för POD med Confusion Assessment Method (CAM), vilken validerades mot referensmetoden (Studie III). Vidare analyserades uppgifter om hur sjuksköterskor skattade patienterna för POD symtom med Nursing Delirium Screening Scale (Nu-DESC) tillsammans med information hämtad från den kliniska databasen. Dessutom granskades både sjuksköterskornas och läkarnas epikriser retrospektivt för nyckelord och uttryck associerade med delirium. Kohort-B (Studie V) inkluderade 1879 rutinmässiga hjärtkirurgiska patienter (2014-2017) som extraherades retrospektivt från den kliniska databasen med samtidiga Nu-DESC-poäng. Sambandet mellan Nu-DESC och de postoperativa vårdkostnaderna analyserades.

Resultat: I kohort-A, utvecklade 54,9% (78/142) av patienterna POD. Både predisponerande och utlösande riskfaktorer var signifikant associerade med POD, varav ’volymbelastningen under operation’ hade det starkaste prediktiva inflytandet (Studie I). Bland hjärt-lungmaskinens variabler bidrog ’duration av blandad venös syremättnad <75%’ till POD (Studie II). Hypoaktivt delirium var vanligare än hyperaktivt. Patienter med hypoaktiv delirium upptäcktes i mindre utsträckning med CAM (Studie III), en observation som också visade sig i information från den kliniska databasen och i epikriserna. Nu-DESC upptäckte inte alla patienter med POD men ökade detekteringsgraden signifikant (Studie IV). De största vårdkostnaderna i samband med Nu-DESC-poäng ≥2 inträffade på intensivvårdsavdelningen oberoende av kirurgiskt ingrepp som utförts. Det fanns inga signifikanta skillnader i kostnaderna mellan åldersgrupper (70-års brytpunkt) eller mellan män och kvinnor med Nu-DESC ≥2 (Studie V).

Slutsatser: Både predisponerande och utlösande riskfaktorer bidrar till POD och bör övervägas i framtida riktlinjer för att förhindra delirium efter hjärtkirurgi. Hypoaktivt delirium var vanligast men också svåraste att upptäcka utan bedömningsskalor. Systematisk bedömning med Nu-DESC förbättrade upptäckten av POD. Delirium efter hjärtkirurgi har konsekvenser för vården och är förknippad med ökade kostnader.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2018. p. 55
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1967
Keywords
Cardiac surgery, Cardiopulmonary bypass, Consequences, Delirium, Detection, Documentation, Economical aspect, Hospitalisation, Risk factors, Screening scales
National Category
Surgery Nursing
Research subject
Thoracic and Cardivascular Suregery; Caring Sciences
Identifiers
urn:nbn:se:umu:diva-151414 (URN)978-91-7601-909-2 (ISBN)
Public defence
2018-09-28, Aulan, Vårdvetarhuset, Umeå, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2018-09-07 Created: 2018-09-03 Last updated: 2023-04-26Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMedScopus

Authority records

Smulter, NinaClaesson Lingehall, HelenaGustafson, YngveOlofsson, BirgittaEngström, Karl Gunnar

Search in DiVA

By author/editor
Smulter, NinaClaesson Lingehall, HelenaGustafson, YngveOlofsson, BirgittaEngström, Karl Gunnar
By organisation
Department of NursingSurgeryDepartment of Surgical and Perioperative SciencesGeriatric MedicineOrthopaedics
In the same journal
Interactive Cardiovascular and Thoracic Surgery
SurgeryCardiac and Cardiovascular SystemsNursing

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 1248 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf