Analysis of the association of serum potassium and lactic acid with neurologic outcome in out-of hospital post-cardiac arrest adult patients

Objective:
This study aimed to identify the effects of serum potassium and lactate on neurologic outcomes in out-of-hospital post-cardiac arrest adult patients.
Method:
This study was a single center, retrospective observational study. We recruited out-of-hospital post-cardiac arrest adult patients admitted to an intensive care unit from 2011 to 2017. Primary outcome was good neurologic outcome at discharge. To evaluate the prognostic impact of serum potassium and lactate, univariate and multivariate logistic regression analyses were performed.
Results:
A total of 57 patients were included in this study. The number of patients with good neurologic outcome was 19 (33.3%). In the univariate analysis, good neurologic outcome patients showed a higher smoking rate, shorter pre-hospital transportation time, higher rate of percutaneous coronary intervention, and lower severity score (all P<0.05). The good neurologic outcome patients also presented higher pH, lower partial pressure of carbon dioxide, and lower potassium regarding laboratory findings on the first hospital day (all P<0.05). In the multivariate analysis, the independent factors favoring good neurologic outcome were pre-hospital transportation time (adjusted odds ratio [aOR], 0.82; 95% confidence interval [CI], 0.69-0.97; P=0.019) and lower partial pressure of carbon dioxide on the first hospital day (aOR, 0.95; 95% CI, 0.91-0.99; P=0.034).
Conclusion:
Serum potassium and lactate were not significantly associated with good neurologic outcome in out-of-hospital post-cardiac arrest adult patients. The prognostic factors for good neurologic outcome were pre-hospital transportation time and initial partial pressure of carbon dioxide.

Key words: Cardiopulmonary resuscitation; Heart arrest; Prognosis