Dong L, Takeda C, Yamazaki H, Kamitani T, Kimachi M, Hamada M, Fukuhara S, Mizota T, Yamamoto Y. Intraoperative end-tidal carbon dioxide and postoperative mortality in major abdominal surgery: a historical cohort study.
Can J Anaesth 2021;
68:1601-1610. [PMID:
34357567 DOI:
10.1007/s12630-021-02086-z]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 06/23/2021] [Accepted: 06/23/2021] [Indexed: 11/26/2022] Open
Abstract
PURPOSE
There is a paucity of data on the effect of intraoperative end-tidal carbon dioxide (EtCO2) levels on postoperative mortality. The purpose of this study was to investigate the relationship between intraoperative EtCO2 and 90-day mortality in patients undergoing major abdominal surgery under general anesthesia.
METHODS
We conducted a historical cohort study of patients undergoing major abdominal surgery under general anesthesia at Kyoto University Hospital. We measured the intraoperative EtCO2, and patients with a mean EtCO2 value < 35 mm Hg were classified as low EtCO2. The time effect was determined based on minutes below an EtCO2 of 35 mm Hg, and cumulative effects were evaluated by measuring the area under the threshold of 35 mm Hg for each patient.
RESULTS
Of 4,710 patients, 1,374 (29%) had low EtCO2 and 55 (1.2%) died within 90 days of surgery. Multivariable Cox regression analysis-adjusted for age, American Society of Anesthesiologists Physical Status classification, sex, laparoscopic surgery, emergency surgery, blood loss, mean arterial pressure, duration of surgery, type of surgery, and chronic obstructive pulmonary disease-revealed an association between low EtCO2 and 90-day mortality (adjusted hazard ratio, 2.2; 95% confidence interval [CI], 1.2 to 3.8; P = 0.006). In addition, severity of low EtCO2 was associated with an increased 90-day mortality (area under the threshold; adjusted hazard ratio; 2.9, 95% CI, 1.2 to 7.4; P =0.02); for long-term exposure to an EtCO2 < 35 mm Hg (≥ 226 min), the adjusted hazard ratio for increased 90-day mortality was 2.3 (95% CI, 0.9 to 6.0; P = 0.08).
CONCLUSION
A mean intraoperative EtCO2 < 35 mm Hg was associated with increased postoperative 90-day mortality.
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