Comparison of four clinical risk scores in comatose patients after out-of-hospital cardiac arrest.

BACKGROUND AND AIMS: Several different scoring systems for early risk stratification after out-of-hospital cardiac arrest have been developed, but few have been validated in large datasets. The aim of the present study was to compare the well-validated Out-of-hospital Cardiac Arrest (OHCA) and Cardiac Arrest Hospital Prognosis (CAHP)-scores to the less complex MIRACLE2- and Target Temperature Management (TTM)-scores. METHODS: This was a post-hoc analysis of the Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial. Missing data were handled by multiple imputation. The primary outcome was discriminatory performance assessed as the area under the receiver operating characteristics-curve (AUROC), with the outcome of interest being poor functional outcome or death (modified Rankin Scale 4-6) at 6 months after OHCA. RESULTS: Data on functional outcome at 6 months were available for 1829 cases, which constituted the study population. The pooled AUROC for the MIRACLE2-score was 0.810 (95% CI 0.790-0.828), 0.835 (95% CI 0.816-0.852) for the TTM-score, 0.820 (95% CI 0.800-0.839) for the CAHP-score and 0.770 (95% CI 0.748-0.791) for the OHCA-score. At the cut-offs needed to achieve specificities >95%, sensitivities were <40% for all four scoring systems. CONCLUSIONS: The TTM-, MIRACLE2- and CAHP-scores are all capable of providing objective risk estimates accurate enough to be used as part of a holistic patient assessment after OHCA of a suspected cardiac origin. Due to its simplicity, the MIRACLE2-score could be a practical solution for both clinical application and risk stratification within trials.

Hypothermia versus Normothermia after Out-of-Hospital Cardiac Arrest.

BACKGROUND: Targeted temperature management is recommended for patients after cardiac arrest, but the supporting evidence is of low certainty. METHODS: In an open-label trial with blinded assessment of outcomes, we randomly assigned 1900 adults with coma who had had an out-of-hospital cardiac arrest of presumed cardiac or unknown cause to undergo targeted hypothermia at 33°C, followed by controlled rewarming, or targeted normothermia with early treatment of fever (body temperature, ≥37.8°C). The primary outcome was death from any cause at 6 months. Secondary outcomes included functional outcome at 6 months as assessed with the modified Rankin scale. Prespecified subgroups were defined according to sex, age, initial cardiac rhythm, time to return of spontaneous circulation, and presence or absence of shock on admission. Prespecified adverse events were pneumonia, sepsis, bleeding, arrhythmia resulting in hemodynamic compromise, and skin complications related to the temperature management device. RESULTS: A total of 1850 patients were evaluated for the primary outcome. At 6 months, 465 of 925 patients (50%) in the hypothermia group had died, as compared with 446 of 925 (48%) in the normothermia group (relative risk with hypothermia, 1.04; 95% confidence interval [CI], 0.94 to 1.14; P = 0.37). Of the 1747 patients in whom the functional outcome was assessed, 488 of 881 (55%) in the hypothermia group had moderately severe disability or worse (modified Rankin scale score ≥4), as compared with 479 of 866 (55%) in the normothermia group (relative risk with hypothermia, 1.00; 95% CI, 0.92 to 1.09). Outcomes were consistent in the prespecified subgroups. Arrhythmia resulting in hemodynamic compromise was more common in the hypothermia group than in the normothermia group (24% vs. 17%, P<0.001). The incidence of other adverse events did not differ significantly between the two groups. CONCLUSIONS: In patients with coma after out-of-hospital cardiac arrest, targeted hypothermia did not lead to a lower incidence of death by 6 months than targeted normothermia. (Funded by the Swedish Research Council and others; TTM2 ClinicalTrials.gov number, NCT02908308.).

Skeletal and soft tissue injuries after manual and mechanical chest compressions.

AIMS: To determine the rate of injuries related to cardiopulmonary resuscitation (CPR) in cardiac arrest non-survivors, comparing manual CPR with CPR performed using the Lund University Cardiac Assist System (LUCAS). METHODS AND RESULTS: We prospectively evaluated 414 deceased adult patients using focused, standardized post-mortem investigation in years 2005 through 2013. Skeletal and soft tissue injuries were noted, and soft tissue injuries were evaluated with respect to degree of severity. We found sternal fracture in 38%, rib fracture in 77%, and severe soft tissue injury in 1.9% of cases treated with CPR with manual chest compressions (n = 52). Treatment with LUCAS CPR (n = 362) was associated with significantly higher rates of sternal fracture (80% of cases), rib fracture (96%), and severe soft tissue injury (10%), including several cases of potentially life-threatening injuries. CONCLUSION: LUCAS CPR causes significantly more CPR-related injuries than manual CPR, while providing no proven survival benefit on a population basis. We suggest judicious use of the LUCAS device for cardiac arrest.

Pulseless electrical activity is associated with improved survival in out-of-hospital cardiac arrest with initial non-shockable rhythm.

OBJECTIVE: To describe the prevalence, baseline characteristics and factors associated with survival in out-of-hospital cardiac arrest (OHCA) with initial non-shockable rhythm sub-grouped into pulseless electrical activity (PEA) and asystole as presenting rhythm. METHODS: The Swedish Registry of Cardiopulmonary Resuscitation is a prospectively recorded nationwide registry of modified Utstein parameters, including all patients with attempted resuscitation after OHCA. Data between 1990-2016 were analyzed. RESULTS: After exclusions, the study population consisted of 48,707 patients presenting with either PEA or asystole. The proportion of PEA increased from 12% to 22% during the study period with a fivefold increase in 30-day survival reaching 4.9%. Survival in asystole showed a modest increase from 0.6% to 1.3%. In the multivariable analysis, PEA was independently associated with survival at 30 days (OR 1.54, 95% CI 1.26-1.88). CONCLUSION: Between 1990 and 2016, the proportion of PEA as the first recorded rhythm doubled with a five-fold increase in 30-day survival, while survival among patients with asystole remained at low levels. PEA and asystole should be considered separate entities in clinical decision-making and be reported separately in observational studies and clinical trials.

Use of automated chest compression devices after out-of-hospital cardiac arrest in Sweden.

OBJECTIVE: To evaluate the implementation of automated chest compression cardiopulmonary resuscitation (ACC-CPR) after out-of-hospital cardiac arrest (OHCA) in Sweden during the years 2011 through 2015. The association between ACC-CPR and 30-day survival was studied as a secondary objective. METHODS: The Swedish cardiopulmonary resuscitation registry is a prospectively recorded nationwide registry of modified Utstein parameters including all patients with attempted resuscitation after OHCA. Propensity score matching (PSM) was used to adjust for known confounders in the secondary analysis. RESULTS: Of the 24,316 patients included in the study population, 32.4% received ACC-CPR, with substantial regional variation ranging from 0.8% to 78.8%. Male gender and an initial shockable rhythm were associated with ACC-CPR, whereas crew witnessed status was associated with manual CPR. Potential markers of prolonged resuscitation attempts (drug administration and endotracheal intubation) were more prevalent in the ACC-CPR group. The unadjusted 30-day survival rate was 6.3% for ACC-CPR patients. The adjusted odds ratio for 30-day survival regarding use of an ACC device was 0.72 (95% CI 0.62-0.84, p<0.001, n=13922). CONCLUSION: The use of ACC devices varied significantly between Swedish regions and overall survival to 30days was low among patients receiving ACC-CPR. Although measured and unmeasured confounding might explain our finding of lower survival rates for patients exposed to ACC-CPR, specific guidelines recommending when and how ACC-CPR should be used are warranted as there might be circumstances where these devices do more harm than good.

Safety, feasibility, and outcomes of induced hypothermia therapy following in-hospital cardiac arrest-evaluation of a large prospective registry*.

OBJECTIVES: Despite a lack of randomized trials, practice guidelines recommend that mild induced hypothermia be considered for comatose survivors of in-hospital cardiac arrest. This study describes the safety, feasibility, and outcomes of mild induced hypothermia treatment following in-hospital cardiac arrest. DESIGN: Prospective, observational, registry-based study. SETTING: Forty-six critical care facilities in eight countries in Europe and the United States reporting in the Hypothermia Network Registry and the International Cardiac Arrest Registry. PATIENTS: A total of 663 patients with in-hospital cardiac arrest and treated with mild induced hypothermia were included between January 2004 and February 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A cerebral performance category of 1 or 2 was considered a good outcome. At hospital discharge 41% of patients had a good outcome. At median 6-month follow-up, 34% had a good outcome. Among in-hospital deaths, 52% were of cardiac causes and 44% of cerebral cause. A higher initial body temperature was associated with reduced odds of a good outcome (odds ratio, 0.79; 95% CI, 0.68-0.92). Adverse events were common; bleeding requiring transfusion (odds ratio, 0.56; 95% CI, 0.31-1.00) and sepsis (odds ratio, 0.52; 95% CI, 0.30-0.91) were associated with reduced odds for a good outcome. CONCLUSIONS: In this registry study of an in-hospital cardiac arrest population treated with mild induced hypothermia, we found a 41% good outcome at hospital discharge and 34% at follow-up. Infectious complications occurred in 43% of cases, and 11% of patients required a transfusion for bleeding. The majority of deaths were of cardiac origin.