Blood gas analyses could not improve the termination of resuscitation criteria to predict subsequent recovery of spontaneous circulation in patients with out-of-hospital cardiac arrest: A diagnostic accuracy studyBackground
The prehospital termination of resuscitation (TOR) rule including unwitnessed, no shock administered, no prehospital return of spontaneous circulation (ROSC) was widely accepted as a prediction model for survival to hospital discharge in patients with out-of-hospital cardiac arrest (OHCA). We hypothesized that blood gas analysis findings that can be achieved within minutes during resuscitation at emergency department (ED) in combination with conventional TOR criteria can improve prediction of ROSC in the ED.Methods
A retrospective diagnostic accuracy study of OHCA patients was conducted at the study hospital located in a rural area in Japan between January 2010 and December 2017. We enrolled consecutive OHCA patients who received chest compression on hospital arrival. The study index tests were defined as TOR criteria alone and 4 kinds of linear combinations in logistic regression of the TOR criteria with the blood gas analysis predictors: potassium level, partial pressure of oxygen (pO2), pH, and all these 3 predictors. The study reference standard was ROSC in the ED. Receiver operating characteristics analysis was used to assess the area under the curve, and specificity at the given sensitivity of 0.95.Results
Out of a total of 352 patients with OHCA, 283 had blood gas analysis data. ROSC was achieved in 67 patients (23.7%). Area under the curve for ROSC was 0.64, 0.69, 0.67, 0.64, and 0.71 with TOR criteria alone, the combination with potassium level, pO2, pH, and all the 3 predictors, respectively. Specificities at the given sensitivity of 0.95 were 0.10, 0.22, 0.17, 0.03, and 0.22 with TOR criteria alone, the combination with potassium level, pO2, pH, and the 3 predictors, respectively.Conclusion
Blood gas analyses in combination with TOR criteria did not sufficiently improve prediction of subsequent ROSC in OHCA patients, as compared to TOR criteria alone.