ABSTRACT
OBJECTIVES: Tailoring hypothermia duration to ischemia duration may improve outcome from out-of-hospital cardiac arrest. We investigated the association between the hypothermia/ischemia ratio and functional outcome in a secondary analysis of data from the Resuscitation Outcomes Consortium Amiodarone, Lidocaine, or Placebo Study trial. DESIGN: Cohort study of out-of-hospital cardiac arrest patients screened for Resuscitation Outcomes Consortium-Amiodarone, Lidocaine, or Placebo Study. SETTING: Multicenter study across North America. PATIENTS: Adult, nontraumatic, out-of-hospital cardiac arrest patients screened for Resuscitation Outcomes Consortium-Amiodarone, Lidocaine, or Placebo Study who survived to hospital admission and received targeted temperature management between May 2012 and October 2015. INTERVENTIONS: Targeted temperature management in comatose survivors of out-of-hospital cardiac arrest. We defined hypothermia/ischemia ratio as total targeted temperature management time (initiation through rewarming) divided by calculated total ischemia time (approximate time of arrest [9-1-1 call or emergency medical services-witnessed] to return of spontaneous circulation). MEASUREMENTS AND MAIN RESULTS: The primary outcome was hospital survival with good functional status (modified Rankin Score, 0-3) at hospital discharge. We fitted logistic regression models to estimate the association between hypothermia/ischemia ratio and the primary outcome, adjusting for demographics, arrest characteristics, and Resuscitation Outcomes Consortium enrolling site. A total of 3,429 patients were eligible for inclusion, of whom 36.2% were discharged with good functional outcome. Patients had a mean age of 62.0 years (SD, 15.8), with 69.7% male, and 58.0% receiving lay-rescuer cardiopulmonary resuscitation. Median time to return of spontaneous circulation was 21.1 minutes (interquartile range, 16.1-26.9), and median duration of targeted temperature management was 32.9 hours (interquartile range, 23.7-37.8). A total of 2,579 had complete data and were included in adjusted regression analyses. After adjustment for patient characteristics and Resuscitation Outcomes Consortium site, a greater hypothermia/ischemia ratio was associated with increased survival with good functional outcome (odds ratio, 2.01; 95% CI, 1.82-2.23). This relationship, however, appears to be primarily driven by time to return of spontaneous circulation in this patient cohort. CONCLUSIONS: Although a larger hypothermia/ischemia ratio was associated with good functional outcome after out-of-hospital cardiac arrest in this cohort, this association is primarily driven by duration of time to return of spontaneous circulation. Tailoring duration of targeted temperature management based on duration of time to return of spontaneous circulation or patient characteristics requires prospective study.
Subject(s)
Coma/etiology , Coma/therapy , Hypothermia, Induced/methods , Myocardial Ischemia/physiopathology , Out-of-Hospital Cardiac Arrest/complications , Adult , Age Factors , Aged , Aged, 80 and over , Body Temperature , Coma/mortality , Emergency Medical Services , Female , Hospital Mortality/trends , Humans , Hypothermia, Induced/mortality , Male , Middle Aged , Myocardial Ischemia/etiology , North America , Out-of-Hospital Cardiac Arrest/mortality , Out-of-Hospital Cardiac Arrest/therapy , Outcome and Process Assessment, Health Care , Patient Discharge , Prospective Studies , Retrospective Studies , Socioeconomic Factors , Time Factors , Trauma Centers/statistics & numerical dataABSTRACT
BACKGROUND: Bystander cardiopulmonary resuscitation (CPR) is associated with increased survival from cardiac arrest, yet bystander CPR rates are low in many communities. The overall prevalence of CPR training in the United States and associated individual-level disparities are unknown. We sought to measure the national prevalence of CPR training and hypothesized that older age and lower socioeconomic status would be independently associated with a lower likelihood of CPR training. METHODS AND RESULTS: We administered a cross-sectional telephone survey to a nationally representative adult sample. We assessed the demographics of individuals trained in CPR within 2 years (currently trained) and those who had been trained in CPR at some point in time (ever trained). The association of CPR training and demographic variables were tested using survey weighted logistic regression. Between September 2015 and November 2015, 9022 individuals completed the survey; 18% reported being currently trained in CPR, and 65% reported training at some point previously. For each year of increased age, the likelihood of being currently CPR trained or ever trained decreased (currently trained: odds ratio, 0.98; 95% CI, 0.97-0.99; P<0.01; ever trained: OR, 0.99; 95% CI, 0.98-0.99; P=0.04). Furthermore, there was a greater then 4-fold difference in odds of being currently CPR trained from the 30-39 to 70-79 year old age groups (95% CI, 0.10-0.23). Factors associated with a lower likelihood of CPR training were lesser educational attainment and lower household income (P<0.01 for each of these variables). CONCLUSIONS: A minority of respondents reported current training in CPR. Older age, lesser education, and lower income were associated with reduced likelihood of CPR training. These findings illustrate important gaps in US CPR education and suggest the need to develop tailored CPR training efforts to address this variability.