The value of initial blood gas analysis in predicting the outcome of cardiopulmonary resuscitation among in-of-hospital cardiac arrest patients

Abstract

Abstract Objectives The aim of this study was to determine the value of blood gas parameters in predicting return of spontaneous circulation (ROSC) in patients with in-hospital cardiopulmonary arrest (CPA). Methods Adult patients with in-hospital cardiac arrest, and with blood gas analysis obtained on the first 10 min of CPR were included in the study. Patients were divided into two groups based on CPR outcomes, ROSC and non-ROSC. The ability of blood gas parameters to differentiate these two groups was subjected to statistical analysis. Results Sixty-seven patients, ROSC was achieved in 14 and could not achieved in 53, were accepted to study. The ability of PH, HCO3, PaCO2, PaO2, lactate, base deficit and potassium to differentiate the two groups was calculated, and only bicarbonate to found to exhibit a statistically significant difference between the two [ p:0.040; Area under ROC: 0.672; 64.2% sensitivity (95% CI; 35.1% - 87.2%), 58.4% specificity (95% CI; 44.1% - 71.8%)]. PaCO2 values of ROSC patients concentrated in the 57-108 mmHg range. Sensitivity of 75.4% (41.9-91.6%) and a positive predictive value of 88.9% (79.5-94.2%) in predicting ROSC were calculated for this range. Conclusion No statistical value was determined for any blood gas parameter, apart from bicarbonate, in predicting ROSC and non-ROSC. The value of bicarbonate was also limited. However, there may be a secondary relation between PaCO2 values and CPR outcomes. Moderate-high (57-108 mmHg) PaCO2 values may be useful in the establishment of ROSC. This hypothesis now needs to be confirmed with more extensive studies.