Stark E; Department of Anaesthesiology and Intensive Care, Centre for Clinical Research, Sörmland, Nyköping Hospital, Nyköping, Sweden.
Gerring E; Hylander J; Björnsson B;Sandström P; Hedman K; Kristenson K
Acta anaesthesiologica Scandinavica [Acta Anaesthesiol Scand] 2025 Jan; Vol. 69 (1), pp. e14562.
Background: Ventilation as a function of elimination of CO 2 during incremental exercise (VE/VCO 2 slope) has been shown to be a valuable predictor of complications and death after major non-cardiac surgery. VE/VCO 2 slope and partial pressure of end-tidal carbon dioxide (PetCO 2 ) are both affected by ventilation/perfusion mismatch, but research on the utility of PetCO 2 for risk stratification in major abdominal surgery is limited.
Aim: We aimed to determine the correlation between VE/VCO 2 slope and PetCO 2 measured during preoperative cardiopulmonary exercise testing (CPET) and its association with major cardiopulmonary complications (MCPCs) or death following oesophageal and other major abdominal cancer surgeries.
Method: In a retrospective cohort of 116 patients undergoing preoperative CPET 2008-2023, VE/VCO 2 slope and PetCO 2 (kPa) were recorded. The main outcome was MCPC during hospitalisation or death ≤90 days of surgery. We determined threshold values for each measure, corresponding to 90% specificity, using receiver operating characteristics analysis.
Results: A strong negative correlation was found between PetCO 2 after a 5-minute warm-up and VE/VCO 2 slope (Pearson r = -.88). In oesophagus cancer, VE/VCO 2 slope >38 and PetCO 2 < 4.1 kPa (30.8 mmHg) were both significant thresholds for the main outcome. For other major abdominal surgery patients, threshold analyses were non-significant. The area under the curve to predict outcome was similar using VE/VCO 2 slope (0.70, 95% confidence interval 0.51-0.89) as compared to PetCO 2 (0.71, 0.53-0-90).
Conclusion: Both preoperative VE/VCO 2 slope and PetCO 2 could identify subjects with a very high risk of complications following oesophageal resection, with similar prognostic utility. PetCO 2 can be measured with simpler equipment and could therefore be useful when CPET is not available.