Abstract 18379: Association Between Partial Pressure of Arterial Carbon Dioxide and Neurological Outcome After Cardiac Arrest Treated With Therapeutic Hypothermia
Introduction: Current guidelines for the management after cardiac arrest (CA) recommend to maintain partial pressure of arterial CO2 (PaCO2) at 35 to 45mmHg. However, it is still unclear if exposure to hypocapnia or hypercapnia during the early phase of post-cardiac arrest syndrome is associated with neurologic outcome.
Hypothesis: Hypocapnia and/or hypercapnia were associated with poor neurologic outcome at 6months after CA.
Methods: We analyzed a prospectively collected cardiac arrest registry at a single academic center. All adult CA with return of spontaneous circulation (ROSC) and treated with therapeutic hypothermia (TH) between January, 2009 and December, 2014 were included. We analyzed arterial blood gas data during 0 to 24 hours after ROSC. We calculated the cumulative exposure of hypocapnia or hypercapnia with the area under the curve (AUC) for four different time intervals (0-6hrs, 0-12hrs, 0-18hr, 0-24hrs). The primary outcome was poor neurologic outcome at 6 months after CA, defined as Cerebral Performance Category (CPC) ≥ 3. We used multivariate logistic regression, adjusted for age, cause of arrest, initial rhythm and witness status.
Results: Of 161 subjects, mean age was 53 (SD 17) years and 111 (69%) were male. Ventricular fibrillation or tachycardia (VF/VT) was the initial rhythm for 65 (40%). Sixty-one (38%) had a good neurologic outcome at 6 months after CA. In multivariate analysis, hypocapnia was not associated with poor neurologic outcome. However, hypercapnia was significantly associated with poor neurologic outcome at 6 months after CA, odds ratio 1.018 (95% confidence interval, 1.001-1.023) for 0-6 hrs, 1.015 (95% confidence interval, 1.003-1.026) for 0-12hrs, 1.013 (95% confidence interval, 1.003 - 1.023) for 0-18hrs and 1.013 (95% confidence interval, 1.004 - 1.022) for 0-24hrs, respectively.
Conclusions: Cumulative PaCO2 analysis showed that hypercapnia within 24hrs after ROSC was significantly associated with poor neurologic outcome at 6 months after CA. We could not find any harm from hypocapnia exposure.
Author Disclosures: C. Youn: None. S. Kim: None. K. Park: None.
- © 2016 by American Heart Association, Inc.