Measurement of end-tidal carbon dioxide concentration during cardiopulmonary resuscitation.
End-tidal carbon dioxide concentrations were measured prospectively in 12 cardiac arrest patients undergoing cardiopulmonary resuscitation (CPR) in an accident and emergency department. The end-tidal carbon dioxide (CO2) concentration decreased from a mean (+/- SD) of 4.55 +/- 0.88% 1 min after chest compression and ventilation was established, to values ranging from 2.29 +/- 0.84% at 2 min to 1.56 +/- 0.66% following 8 min of CPR. Spontaneous circulation was restored in five patients. This was accompanied by a rapid rise in end-tidal CO2 which peaked at 2 min (3.7 +/- 1.08%). Changes in end-tidal CO2 values were often the first indication of return of spontaneous cardiac output. There was a significant difference in the end-tidal CO2 in patients undergoing CPR before return of spontaneous circulation (2.63 +/- 0.32%) and patients who failed to develop spontaneous output (1.64 +/- 0.89%) (p < 0.001). We conclude that measurement of end-tidal CO2 concentration provides a simple and non-invasive method of measuring blood flow during CPR and can indicate return of spontaneous circulation.
Steedman
D J
DJ
Department of Emergency Medicine, Royal Infirmary, Edinburgh.
Robertson
C E
CE
D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000032:analysis*; D016887:Cardiopulmonary Resuscitation; D005260:Female; D006323:Heart Arrest / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013990:Tidal Volume
D002245:Carbon Dioxide