Optimal Parameters for Return of Spontaneous Circulation in Resuscitating Out-of-hospital Cardiac Arrest Patients

Background: To study the parameters of out-of-hospital cardiac arrest (OHCA) patients to improve the return of spontaneous circulation (ROSC) rate during resuscitation. Methods: Records of 112 consecutive non-traumatic OHCA cases from January 1, 2007 to June 30, 2007 in a medical center in north Taiwan were retrospectively analyzed. We excluded 15 cases with missing laboratory data. Data of the 97 enrolled cases included age, clinical experience of the doctor (in years), arterial blood gas (ABG) pH, PaCO2 (mmHg), hemoglobin, glucose, creatinine and potassium, and were analyzed by the statistical software SPSS version 11.5.0. We calculated the odds ratio (OR) of ROSC and the Pearson's correlation coefficient to evaluate the optimal parameters for ROSC. Results: Multivariate analysis of ROSC in OHCA patients showed that an ABG pH >7.10 (OR, 1.33), age of 65 years and older (OR, 1.76), and glucose >110mg/dL (OR, 1.33) were associated with ROSC. PaCO2 > 45mmHg (OR, 0.76), potassium >5.3mEq/L (OR, 0.81), and creatinine >1.3mg/dL (OR, 0.86) were associated with non-achievement of ROSC. We used the regression method for curve estimation, and found that an ABG pH >7.178, serum glucose < 385.9mg/dL, and PaCO2 < 29.2mmHg were associated with achievement of ROSC. Conclusion: Less acidosis, less hypercarbia and less hyperkalemia predispose to achievement of ROSC. This study suggests values of the parameters (pH > 7.178, PaCO2 < 29.2mmHg, glucose < 385.9mg/dL) to aim for during resuscitation of OHCA patients