Abstract 296: Hypothermic to Ischemic Ratio as a Predictor for Good Neurologic Outcome From Out-of-Hospital Cardiac Arrest Presenting With a Shockable Rhythm
Objectives: The Hypothermic to Ischemic Ratio (HI Ratio = total hypothermic time / total ischemic time) has been externally validated as a predictor for survival from out of hospital cardiac arrest (OHCA). We sought to examine its relationship to “good” neurological outcome.
Methods: Adult, non-traumatic, OHCA patients presenting with a shockable rhythm and surviving to hospital admission between January 2008 and December 2011 were considered for inclusion. Structured data were collected, including all Utstein criteria and relevant time intervals between initiation of therapeutic hypothermia and rewarming. The outcome of interest was “good” or “poor” neurologic status at discharge, defined as cerebral performance category 1-2 and 3-5, respectively. Logistic regression models were used to evaluate the effect of predictor variables on our primary outcome. Odds ratios (OR) with 95% confidence intervals (CI) are reported.
Results: A total of 128 patients were included. Of those who survived to discharge (n=94), 68.1% had good neurologic outcome. Patients had a mean age of 58.3 years (SD 12.95, 95% CI 56.06, 60.59) and 50.8% were black. The majority of patients were male (71.9%) and had witnessed arrest (89.1%), with 61.7% receiving bystander CPR. In multivariable modeling, younger age (OR 0.92, 95% CI 0.88, 0.96), male gender (OR 3.64, 95% CI 1.30, 11.23), bystander CPR (OR 3.12, 95% CI 1.22, 8.52), and a larger HI Ratio were associated with better neurologic outcome. HI Ratio was the most significant predictor (OR 9.88, 95% CI 4.01, 29.85).
Conclusions: HI Ratio seems to be a significant predictor for good neurologic outcome after OHCA for patients presenting with a shockable rhythm. Prospective studies should consider HI Ratio as a potential predictor for investigation.
- © 2013 by American Heart Association, Inc.