Hypocapnia measured by end-tidal carbon dioxide tension during anesthesia is associated with increased 30-day mortality rate.
OBJECTIVE
To evaluate the relationship between intraoperative end-tidal carbon dioxide (etco2) values and clinical outcomes with special attention on 30-day postoperative mortality and secondarily on hospital length of stay (LOS).


METHODS
Retrospective, observational study.


METHODS
Surgical theaters of the University Hospital Center of Charleroi.


METHODS
Five thousand three hundred seventeen patients ASA I-IV undergoing various surgical procedures (except pediatric and cardiac surgery) under general anesthesia.


METHODS
No intervention on the patients.


METHODS
The mean etco2level measured during anesthesia was secondarily extracted from an electronic information management system. Patients were divided into 2 separate groups based on etco2values less than or greater than or equal to 35 mm Hg. The primary end point was the in- and outhospital mortality in the 30-day period after surgery. The second was the LOS more than 6 days.


RESULTS
Hypocapnia occurred in 66% of the patients. Mortality rate at 30-day was 84 of 3554 (2.4%) in the low etco2group vs 15 of 1763 (0.9%) in the other (odds ratio, 2.99 [1.69-5.28]; P<.001). In multivariate analysis, age and ASA scores had significant independent associations with mortality rate. Adjusting for these factors had an effect on the relative odds ratio of etco2on mortality of 1.99 ([1.11-3.56]; P<.001). Patients with low etco2experienced higher LOS (14.1±9.4 vs 13.1±8.9 days; P<.001). Thirty five percent of the patients in the low etco2group were still hospitalized more than 6 days compared with 30% in the other (P<.001).


CONCLUSIONS
Low etco2level during anesthesia is associated with an increase in postoperative mortality rate and LOS. These results emphasize the importance of preventing hypocapnia during anesthesia to improve surgical outcomes.
Department of Anesthesiology, University Hospital Center of Charleroi, Belgium.
Philippe
P
Dony
School of Public Health, Research Center for Epidemiology, Free University of Brussels, 1070 Brussels, Belgium.
Michele
M
Dramaix
Department of Anesthesiology, University Hospital Center of Charleroi, Belgium. Electronic address: jean.boogaerts@chu-charleroi.be.
Jean G
JG
Boogaerts
D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000009:adverse effects*; D002245:Carbon Dioxide / Q000032:analysis*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016857:Hypocapnia / Q000209:etiology* / Q000401:mortality*; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D011183:Postoperative Complications / Q000401:mortality*; D012189:Retrospective Studies; D013514:Surgical Procedures, Operative / Q000401:mortality; D013990:Tidal Volume
D002245:Carbon Dioxide
Anesthesia; Carbon dioxide; Hypocania; Length of stay; Mortality; Outcomes