Abstract 13214: Prognostic Value of Venous Blood pH Levels in Patients Treated with Extracorporeal Cardiopulmonary Resuscitation after Cardiac Arrest Due to Cardiac Etiology
Background: Our previous study (Circ J 2012; 76) demonstrated that venous blood levels of ammonia and pH on emergency room (ER) arrival provided valuable information regarding neurological outcome in patients with cardiac arrest. Few data of venous blood gas analysis is available for patients who were treated with extracorporeal cardiopulmonary resuscitation (ECPR) after cardiac arrest.
Methods: Since 1996, we have performed ECPR, inclusive of therapeutic hypothermia and percutaneous coronary intervention, for patients who arrived at the ER in cardiac arrest and failed to response to conventional CPR. From 2008 to 2011, we did a prospective study of 83 adult patients treated with ECPR whose venous blood gas levels were measured on ER arrival. The primary endpoint was 30-day favorable neurological outcome after cardiac arrest.
Results: Of the 83 patients, 14 (16.9%) had a favorable neurological outcome. Significant differences were seen between the favorable neurological outcome group and the unfavorable neurological outcome group in the time interval from collapse to initiation of ECPR (median; 31.5 vs. 52.0 minutes, p=0.032) and in the venous blood gas levels (median of pH; 7.159 vs. 6.784, p<0.0001, median of PvCO2; 51.7 vs. 94.2 mmHg, p=0.0001, median of HCO3-; 18.4 vs. 14.1 mEq/l, p=0.002, median of BE; -10.5 vs. -21 mEq/l, p=0.0002). However, PvO2 did not differ between the two groups (median; 45.4 vs. 42.1 mmHg, p=0.905). The area under the receiver-operating-characteristic curve was 0.919 in the pH, 0.824 in the HCO3-, 0.821 in the BE, and 0.778 in the PvCO2. The venous blood PH cutoff value of 6.881 for the identification of favorable neurological outcome had the highest combined sensitivity and specificity, and lower PH levels were associated with more accurate negative predictive values (for pH level of 6.881, negative predictive value was 100%).
Conclusion: Venous blood PH on ER arrival was useful predictive marker in patients who were treated with ECPR after cardiac arrest.
- © 2012 by American Heart Association, Inc.