Singer AJ et al. – This study compared the accuracy of end tidal CO2 (ETCO2) and cerebral oxygen saturations (rSO2) at predicting return of spontaneous circulation (ROSC) in emergency department patients with out–of–hospital cardiac arrest (OHCA). Both parameters had poor correlation but had similar diagnostic characteristics at predicting ROSC in OHCA with ETCO2 being more sensitive and rSO2 being more specific.

Methods

• A prospective, observational study of adult patients presenting to the emergency department with a cardiac arrest.

Results

• Of 225 patients with cardiac arrest, 100 recorded both ETCO2 and rSO2 measurements.
• In all, 33% had sustained ROSC and only 2 survived.
• At the optimal cutoffs for rSO2 (50%) and ETCO2 (20 mm Hg), rSO2 had greater specificity and ETCO2 had greater sensitivity.