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Abstract
Background: A Do-Not-Attempt-Cardiopulmonary-Resuscitation (DNACPR) order can beplaced when CPR is not in accordance with the patient’s will, when CPR is considered not tobenefit the patient, or when CPR is very unlikely to be successful because the patient is dyingfrom an irreversible condition. The decision to withhold CPR involves assessment of thepredictors for favourable outcome, in compound with the patient’s values and goals of care tomake a decision that is of benefit to the patient. Throughout this process there are ethicaldirectives and legislations to relate to. Previous studies have shown that it is difficult formedical personnel to accurately predict outcome after cardiac arrest, but there is nosupportive prediction model established in clinical practice. There are indications of shortagesin adherence to legislation regarding DNACPR orders in our setting, but clinical practice hasnot been evaluated on a larger scale. Further, there is scarce knowledge about the grounds forDNACPR decisions based on the clinical practice, about the use of DNACPR orders, and thecharacteristics of those receiving them.
Aims: The overall aim of this thesis was to facilitate and investigate the decision process forDNACPR order placement in the hospital setting and fill knowledge gaps in theepidemiology of DNACPR orders. More specifically, the aim was external validation of thepre-arrest prediction model the Good Outcome Following Attempted Resuscitation (GOFAR)score (study I), model update of the GO-FAR score with development of a predictionmodel for the Swedish setting (study II), evaluation of adherence to the Swedish legislationregarding documentation of DNACPR order placement, exploration of the decision processin clinical practice (study III), and assessment of the use of DNACPR orders, characteristicsand outcome for the patients (study IV).
Methods: Study I and II included adult in-hospital cardiac arrests (IHCA) in the SwedishRegistry for Cardiopulmonary Resuscitation (SRCR) from 2013 to 2104 in the Stockholmregion. Outcome in study I was neurologically intact survival defined as CerebralPerformance Category score (CPC) 1 and in study II outcome was favourable neurologicalsurvival defined as CPC 1–2. Outcome and patient characteristics were retrieved from SRCR,predictor variables from manual review of electronic patient records and from the Nationalpatient registry (NPR). External validation of the GO-FAR score was based on assessment ofthe discrimination with area under the receiver operating characteristics (AUROC) curve,calibration and risk group categorisation. Model update was based on the results in study Iand included change of outcome and addition of the predictor chronic comorbidity. The studypopulation and variables in III and IV was obtained from Karolinska University Hospital’slocal administrative database and NPR and included adult admissions through the EmergencyDepartment (ED) from 1 January to 31 October 2015. Study III included only patients withDNACPR orders issued during hospitalisation. In study III the DNACPR form in theelectronic patient record was used to evaluate adherence to legislation regardingdocumentation of DNACPR orders and to explore aspects of the decision process in clinicalpractice through qualitative content analysis.
Results: Study I and II included 717 IHCA. In study I the GO-FAR score showed gooddiscrimination with AUROC of 0.82 (95% CI 0.78–0.86), but risk group categorisation andcalibration showed an underestimation of the probability of neurologically intact survival.Study II provided the updated prediction model the Prediction of outcome for In-HospitalCardiac Arrest (PIHCA) score. The AUROC for the PIHCA score was 0.81 (95% CI 0.807–0.810). With a cut-off of 3% likelihood of favourable neurological survival the PIHCA scorecould classify patients with favourable neurological outcome correctly (99% sensitivity), butfor patients with poor outcome (death or CPC >2) the PIHCA score’s correct classificationwas limited (8% specificity).
