• M A Wayne, R L Levine, and C C Miller.
• Division of Emergency Medical Services, Whatcom Medic One, Bellingham, Washington, USA.
• Ann Emerg Med. 1995 Jun 1;25(6):762-7.

Study ObjectiveEnd-tidal CO2 (ETCO2) measurement can be used to predict death in prehospital cardiac arrest patients with pulseless electrical activity (PEA).DesignA prospective, observational study.SettingAn urban and rural emergency medical services system in northwestern Washington state.ParticipantsNinety consecutive victims of prehospital cardiac arrest with PEA.InterventionsPatients were intubated in the field and treated using standard advanced cardiac life support protocols with online medical control. In addition, all patients were evaluated using mainstream ETCO2 monitoring. In this study, a hypothetical decision was made to cease resuscitative efforts based on an ETCO2 level of 10 mm Hg or less after 20 minutes of advanced cardiac life support.ResultsThe study included 90 patients (61 were men) with a mean age of 67.6 +/- 13.6 years (range, 27 to 95 years). The initial ETCO2 averaged 11.7 +/- 6.6 mm Hg in nonsurvivors (range, 5 to 50 mm Hg) and 10.9 +/- 4.9 mm Hg in survivors (range, 5 to 24 mm Hg) (P > .672 [NS]). After 20 minutes of advanced cardiac life support, ETCO2 averaged 3.9 +/- 2.8 mm Hg (range, 0 to 12 mm Hg) in patients in whom the theoretical decision was made to cease field resuscitation. In contrast, survivors' ETCO2, just before restoration of circulation, averaged 31 +/- 5.3 mm Hg (range, 16 to 35 mm Hg) (P < .0001). Using an ETCO2 of 10 mm Hg or less as a theoretical threshold to predict death in the field successfully discriminated between the 16 survivors to hospital admission (those that achieved return of spontaneous circulation) and 75 prehospital deaths. Of the 16 survivors to hospital admission, 9 died in the hospital, and 7 were discharged from the hospital alive. In 13 of the 16 survivors, the first evidence of return of spontaneous circulation, before a palpable pulse or blood pressure, was a rising ETCO2. The logistic-regression parameters for the model are 4.4391 + ETCO2*-0.3624 (P < .0001). Sensitivity was 97.3%; specificity 100%; positive predictive value 100%; and negative predictive value 88.9%.ConclusionThis study suggests that a low ETCO2 (10 mm Hg or less) can be used to predict irreversible death in patients with pulseless electrical activity undergoing prehospital advanced cardiac life support. If future studies validate this model, use of ETCO2 may allow for triage decisions in the field.

24 keywords...

hide…