Intraoperative end-tidal carbon dioxide levels and derived calculations correlated with outcome in trauma patients

• Published in: The journal of trauma Vol. 41; no. 4; p. 606
• Main Authors: Wilson, R F, Tyburski, J G, Kubinec, S M, Warsow, K M, Larky, H C, Wilson, S R, Schermerhorn, T
• Format: Journal Article
• Language: English
• Published: United States 01.10.1996
• Subjects: Adult; Carbon Dioxide - analysis; Carbon Dioxide - blood; Female; Humans; Male; Middle Aged; Monitoring, Intraoperative; Prognosis; Respiratory Dead Space; Respiratory Transport; Retrospective Studies; Survival Rate; Wounds and Injuries - blood; Wounds and Injuries - mortality; Wounds and Injuries - physiopathology; Wounds and Injuries - surgery
• ISSN: 0022-5282
• DOI: 10.1097/00005373-199610000-00003

To determine the relationship between the prognosis of seriously injured patients requiring emergency surgery and intraoperative end-tidal CO2 variables and "excess Pco2." Retrospective chart review of 100 seriously injured patients admitted to Detroit Receiving Hospital and requiring major surgery (mortality rate of 40%). Standard intraoperative monitoring, including continuous capnography, plus arterial blood analyses every 15 to 30 minutes during surgery. After resuscitation for 45 to 90 minutes, 11 patients had a systolic blood pressure < 100 mm Hg and, of these patients, 10 (91%) died. Of the remaining 89 patients, mortality rates were 53% (16/30), with an end-tidal CO2 of 22 mm Hg or less, versus 24% (14/59) with an end-tidal CO2 of 23 mm Hg or more (p = 0.011). An arterial to end-tidal Pco2 difference of 13 mm Hg or more after resuscitation was associated with an increased mortality rate (50% (20/34 vs. 18% (20/55)) (p < 0.005). The mortality rate was particularly high, with a final arterial to end-tidal Pco2 difference of 12 mm Hg or more (73% (30/41) versus 17% (10/59) (p < 0.001). A final Paco2 excess (i.e., the amount by which the Paco2 was higher than expected from the bicarbonate) > 1.0 mm Hg was also associated with an increased mortality rate ((62% (33/53) vs. 15% (7/47)) (p < 0.001). Values derived from the end-tidal CO2 and the excess Pco2 should be monitored intraoperatively in critically injured patients. Efforts should be made to improve cardiac output and adjust ventilation to maintain an end-tidal Pco2 of 25 mm Hg or more, an arterial to end-tidal CO2 difference of 12 mm Hg or less, and an excess Paco2 of 1.0 mm Hg or less.