Post-cardiac arrest intensive care in Sweden: A survey of current clinical practice.

BACKGROUND: European guidelines recommend targeted temperature management (TTM) in post-cardiac arrest care. A large multicentre clinical trial, however, showed no difference in mortality and neurological outcome when comparing hypothermia to normothermia with early treatment of fever. The study results were valid given a strict protocol for the assessment of prognosis using defined neurological examinations. With the current range of recommended TTM temperatures, and applicable neurological examinations, procedures may differ between hospitals and the variation of clinical practice in Sweden is not known. AIM: The aim of this study was to investigate current practice in post-resuscitation care after cardiac arrest as to temperature targets and assessment of neurological prognosis in Swedish intensive care units (ICUs). METHODS: A structured survey was conducted by telephone or e-mail in all Levels 2 and 3 (= 53) Swedish ICUs during the spring of 2022 with a secondary survey in April 2023. RESULTS: Five units were not providing post-cardiac arrest care and were excluded. The response rate was 43/48 (90%) of the eligible units. Among the responding ICUs, normothermia (36-37.7°C) was applied in all centres (2023). There was a detailed routine for the assessment of neurological prognosis in 38/43 (88%) ICUs. Neurological assessment was applied 72-96 h after return of spontaneous circulation in 32/38 (84%) units. Electroencephalogram and computed tomography and/or magnetic resonance imaging were the most common technical methods available. CONCLUSION: Swedish ICUs use normothermia including early treatment of fever in post-resuscitation care after cardiac arrest and almost all apply a detailed routine for the assessment of neurological prognosis. However, available methods for prognostic evaluation varies between hospitals.

Early predictors of poor outcome after out-of-hospital cardiac arrest.

BACKGROUND: Early identification of predictors for a poor long-term outcome in patients who survive the initial phase of out-of-hospital cardiac arrest (OHCA) may facilitate future clinical research, the process of care and information provided to relatives. The aim of this study was to determine the association between variables available from the patient's history and status at intensive care admission with outcome in unconscious survivors of OHCA. METHODS: Using the cohort of the Target Temperature Management trial, we performed a post hoc analysis of 933 unconscious patients with OHCA of presumed cardiac cause who had a complete 6-month follow-up. Outcomes were survival and neurological function as defined by the Cerebral Performance Category (CPC) scale at 6 months after OHCA. After multiple imputations to compensate for missing data, backward stepwise multivariable logistic regression was applied to identify factors independently predictive of a poor outcome (CPC 3-5). On the basis of these factors, a risk score for poor outcome was constructed. RESULTS: We identified ten independent predictors of a poor outcome: older age, cardiac arrest occurring at home, initial rhythm other than ventricular fibrillation/tachycardia, longer duration of no flow, longer duration of low flow, administration of adrenaline, bilateral absence of corneal and pupillary reflexes, Glasgow Coma Scale motor response 1, lower pH and a partial pressure of carbon dioxide in arterial blood value lower than 4.5 kPa at hospital admission. A risk score based on the impact of each of these variables in the model yielded a median (range) AUC of 0.842 (0.840-0.845) and good calibration. Internal validation of the score using bootstrapping yielded a median (range) AUC corrected for optimism of 0.818 (0.816-0.821). CONCLUSIONS: Among variables available at admission to intensive care, we identified ten independent predictors of a poor outcome at 6 months for initial survivors of OHCA. They reflected pre-hospital circumstances (six variables) and patient status on hospital admission (four variables). By using a simple and easy-to-use risk scoring system based on these variables, patients at high risk for a poor outcome after OHCA may be identified early.

Mild induced hypothermia and survival after out-of-hospital cardiac arrest.

BACKGROUND: Mild induced hypothermia (MIH) was introduced for post cardiac arrest care in Sweden in 2003, based on two clinical trials. This retrospective study evaluated its association with 30-day survival after out-of-hospital cardiac arrest (OHCA) in a Swedish community from 2003 to 2015. METHODS: Out of 3680 patients with OHCA, 1100 were hospitalized after return of spontaneous circulation and 871 patients who remained unconscious were included in the analysis. Prehospital data were extracted from the Swedish Registry of Cardiopulmonary Resuscitation and in-hospital data were extracted from clinical records. Propensity score analysis on complete data sets and multivariable logistic regression with multiple imputations to compensate for missing data were performed. RESULTS: Unadjusted 30-day survival was 23.5%; 37% in 386/871 (44%) MIH treated and 13% in 485/871 (56%) non-MIH treated patients. Unadjusted odds ratio (OR) for 30-day survival in patients treated with MIH compared to non-MIH treated patients was 3.79 (95% CI 2.71-5.29; p<0.0001). Using stratified propensity score analysis and in addition adjusting for in-hospital factors, 30-day survival was not significantly different in patients treated with MIH compared to non-MIH treated patients; OR 1.33 (95% CI 0.83-2.15; p=0.24). Using multiple imputations to handle missing data yielded a similar adjusted OR of 1.40 (95% CI 0.88-2.22; p=0.15). Good neurologic outcome at hospital discharge was seen in 82% of patients discharged alive. CONCLUSION: Treatment with MIH was not significantly associated with increased 30-day survival in patients remaining unconscious after OHCA when adjusting for potential confounders.

Target Temperature Management after out-of-hospital cardiac arrest--a randomized, parallel-group, assessor-blinded clinical trial--rationale and design.

BACKGROUND: Experimental animal studies and previous randomized trials suggest an improvement in mortality and neurologic function with induced hypothermia after cardiac arrest. International guidelines advocate the use of a target temperature management of 32°C to 34°C for 12 to 24 hours after resuscitation from out-of-hospital cardiac arrest. A systematic review indicates that the evidence for recommending this intervention is inconclusive, and the GRADE level of evidence is low. Previous trials were small, with high risk of bias, evaluated select populations, and did not treat hyperthermia in the control groups. The optimal target temperature management strategy is not known. METHODS: The TTM trial is an investigator-initiated, international, randomized, parallel-group, and assessor-blinded clinical trial designed to enroll at least 850 adult, unconscious patients resuscitated after out-of-hospital cardiac arrest of a presumed cardiac cause. The patients will be randomized to a target temperature management of either 33°C or 36°C after return of spontaneous circulation. In both groups, the intervention will last 36 hours. The primary outcome is all-cause mortality at maximal follow-up. The main secondary outcomes are the composite outcome of all-cause mortality and poor neurologic function (cerebral performance categories 3 and 4) at hospital discharge and at 180 days, cognitive status and quality of life at 180 days, assessment of safety and harm. DISCUSSION: The TTM trial will investigate potential benefit and harm of 2 target temperature strategies, both avoiding hyperthermia in a large proportion of the out-of-hospital cardiac arrest population.

Survival in out-of-hospital cardiac arrest before and after use of advanced postresuscitation care: a survey focusing on incidence, patient characteristics, survival, and estimated cerebral function after postresuscitation care.

BACKGROUND: Knowledge of the epidemiology of postresuscitation care is insufficient. We describe the epidemiology of postresuscitation care in a community from a 26-year perspective, focusing on incidence, patient characteristics, survival, and estimated cerebral function in relation to intensified postresuscitation care and initial arrhythmia. METHODS: The study included patients with out-of-hospital cardiac arrest (OHCA) who were brought alive to a hospital ward in Göteborg, Sweden, between 1980 and 2006. Two periods (1980-2002 and 2003-2006) were compared. RESULTS: In all, 1603 patients were included. For age, sex, and history, no significant differences between the 2 periods were seen. There was a significant multiple increase in bystander cardiopulmonary resuscitation, the use of coronary angiography, coronary revascularization, and therapeutic hypothermia. The number of patients found in ventricular fibrillation (VF) decreased (P = .011). For all patients, 1-year survival did not change significantly (27% vs 32%; P = .14). Among patients found in VF, an increase in 1-year survival was found (37% vs 57%; P < .0001), whereas no significant change was seen in nonshockable rhythm (10% vs 7%; P = .38). Survivors to discharge displaying low cerebral function (ie, cerebral performance categories score >or=3) decreased from 28% to 6% (P = .0006) among all patients. CONCLUSION: After the introduction of a more intensified postresuscitation care, there was no overall improvement in survival but signs of an improved cerebral function among survivors. There was a marked increase in survival among patients found in a shockable rhythm but not among those found in a nonshockable rhythm.