Therapeutic hypothermia for cardiac arrest: Real-world utilization trends and hospital mortality

BACKGROUND: Therapeutic hypothermia (TH) improves outcomes following cardiac arrest in small clinical trials. OBJECTIVE: To study real-world utilization and outcomes in US hospitals. DESIGN: Retrospective cohort study. SETTING: California hospitals. PATIENTS: Patients eligible for therapeutic hypothermia after cardiac arrest. INTERVENTIONS: We analyzed all discharges from California (1999-2008) to identify patients eligible for TH after cardiac arrest. Patients were considered eligible for TH if both cardiac arrest and anoxic brain injury were among the administrative diagnoses (n = 46,833). Patients undergoing TH (n = 204) were identified through billing codes. MEASUREMENTS: TH utilization and in-hospital mortality. RESULTS: Use of TH increased over the study period with 87.3% (178/204) of TH occurring between 2006 and 2008. Few hospitals appeared to perform TH over the study period (47/419, 11.2%). Utilization of TH was concentrated in a few centers, with the top 3 of 419 centers accounting for 31.4% (64/204) of cases. Patients undergoing TH were younger, less likely to be male, more likely to be treated at teaching centers, and had similar comorbidities compared to eligible individuals who did not undergo TH. The adjusted odds ratio for hospital mortality among patients undergoing TH was 0.80 (95% confidence interval [CI] 0.60-1.06, P = 0.11). CONCLUSIONS: TH utilization appears low, but implementation is increasing. Case selection and referral biases limit the analysis of the relationship between center TH volume and in-hospital mortality.