Can mainstream end-tidal carbon dioxide measurement accurately predict the arterial carbon dioxide level of patients with acute dyspnea in ED.
Am J Emerg Med. 2011 Jan 27;
Authors: Cinar O, Acar YA, Arziman I, Kilic E, Eyi YE, Ocal R
OBJECTIVE: This study was designed to determine whether the mainstream end-tidal carbon dioxide (ETCO(2)) measurement can accurately predict the partial arterial carbon dioxide (Paco(2)) level of patients presented to emergency department (ED) with acute dyspnea. METHODS: This prospective, observational study was conducted at a university hospital ED, which serves more than 110?000 patients annually. Nonintubated adult patients presented with acute dyspnea who required arterial blood gas analysis were recruited in the study for a 6-month period between January and July 2010. Patients were asked to breathe through an airway adapter attached to the mainstream capnometer. Arterial blood gas samples were obtained simultaneously. RESULTS: We included 162 patients during the study period. The mean ETCO(2) level was 39.47 ± 10.84 mm Hg (minimum, 19 mm Hg; maximum, 82 mm Hg), and mean Paco(2) level was 38.95 ± 12.27 mm Hg (minimum, 16 mm Hg; maximum, 94 mm Hg). There was a positive, strong, statistically significant correlation between ETCO(2) and Paco(2) (r = 0.911, P < .001). The Bland-Altman plot shows the mean bias ± SD between ETCO(2) and Paco(2) as 0.5 ± 5 mm Hg (95% confidence interval, -1.3165-0.2680) and the limits of agreement as -10.5 and +9.5 mm Hg. Eighty percent (n = 129) of the ETCO(2) measurements were between the range of ±5 mm Hg. CONCLUSION: Mainstream ETCO(2) measurement accurately predicts the arterial Paco(2) of patients presented to ED with acute dyspnea. Further studies comparing mainstream and sidestream methods in these patients are required.
PMID: 21277140 [PubMed - as supplied by publisher]