Background Patients receiving intraoperative ventilation during general anesthesia often have low end-tidal CO2 (etCO(2)). We examined the association of intraoperative etCO(2) levels with the occurrence of postoperative pulmonary complications (PPCs) in a conveniently-sized international, prospective study named 'Local ASsessment of Ventilatory management during General Anesthesia for Surgery' (LAS VEGAS). Methods Patients at high risk of PPCs were categorized as 'low etCO(2)' or 'normal to high etCO(2)' patients, using a cut-off of 35 mmHg. The primary endpoint was a composite of previously defined PPCs; the individual PPCs served as secondary endpoints. The need for unplanned oxygen was defined as mild PPCs and severe PPCs included pneumonia, respiratory failure, acute respiratory distress syndrome, barotrauma, and new invasive ventilation. We performed propensity score matching and LOESS regression to evaluate the relationship between the lowest etCO(2) and PPCs. Results The analysis included 1843 (74 %) 'low etCO(2)' patients and 648 (26 %) 'normal to high etCO(2)' patients. There was no difference in the occurrence of PPCs between 'low etCO(2)' and 'normal to high etCO(2)' patients (20 % vs. 19 %; RR 1.00 [95 %-confidence interval 0.94 to 1.06]; P = 0.84). The proportion of severe PPCs among total occurring PPCs, were higher in 'low etCO(2)' patients compared to 'normal to high etCO(2)' patients (35 % vs. 18 %; RR 1.16 [1.08 to 1.25]; P < 0.001). Propensity score matching did not change these findings. LOESS plot showed an inverse relationship of intraoperative etCO(2) levels with the occurrence of PPCs. Conclusions In this cohort of patients at high risk of PPCs, the overall occurrence of PPCs was not different between 'low etCO(2)' patients and 'normal to high etCO(2)' patients, but severe PPCs occurred more often in 'low etCO(2)', with an inverse dose-dependent relationship between intraoperative etCO(2) levels and PPCs.
Associations of intraoperative end–tidal CO2 levels with postoperative outcome–secondary analysis of a worldwide observational study
Leva B.;Severgnini P.
2025-01-01
Abstract
Background Patients receiving intraoperative ventilation during general anesthesia often have low end-tidal CO2 (etCO(2)). We examined the association of intraoperative etCO(2) levels with the occurrence of postoperative pulmonary complications (PPCs) in a conveniently-sized international, prospective study named 'Local ASsessment of Ventilatory management during General Anesthesia for Surgery' (LAS VEGAS). Methods Patients at high risk of PPCs were categorized as 'low etCO(2)' or 'normal to high etCO(2)' patients, using a cut-off of 35 mmHg. The primary endpoint was a composite of previously defined PPCs; the individual PPCs served as secondary endpoints. The need for unplanned oxygen was defined as mild PPCs and severe PPCs included pneumonia, respiratory failure, acute respiratory distress syndrome, barotrauma, and new invasive ventilation. We performed propensity score matching and LOESS regression to evaluate the relationship between the lowest etCO(2) and PPCs. Results The analysis included 1843 (74 %) 'low etCO(2)' patients and 648 (26 %) 'normal to high etCO(2)' patients. There was no difference in the occurrence of PPCs between 'low etCO(2)' and 'normal to high etCO(2)' patients (20 % vs. 19 %; RR 1.00 [95 %-confidence interval 0.94 to 1.06]; P = 0.84). The proportion of severe PPCs among total occurring PPCs, were higher in 'low etCO(2)' patients compared to 'normal to high etCO(2)' patients (35 % vs. 18 %; RR 1.16 [1.08 to 1.25]; P < 0.001). Propensity score matching did not change these findings. LOESS plot showed an inverse relationship of intraoperative etCO(2) levels with the occurrence of PPCs. Conclusions In this cohort of patients at high risk of PPCs, the overall occurrence of PPCs was not different between 'low etCO(2)' patients and 'normal to high etCO(2)' patients, but severe PPCs occurred more often in 'low etCO(2)', with an inverse dose-dependent relationship between intraoperative etCO(2) levels and PPCs.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.



