Background

The Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score predicts the risk of post-operative pulmonary complications (PPC) when undergoing surgery. Breathing reserve (BR) is a measure of pulmonary limitation calculated during cardiopulmonary exercise testing (CPET).  BR could be used as an adjunct to ARISCAT in predicting the risk of PPC.

Objective

To investigate whether BR is predictive of PPC.

Methods

Records of consecutive patients who completed CPET before major elective non-cardiac surgery were reviewed retrospectively. Criteria for a PPC were identical to those in the ARISCAT study. Multiple logistic regression was used to determine if BR and ARISCAT were predictive of PPC.

Results

Two hundred and three patients underwent CPET between June 2019 and March 2021. Many had their surgery delayed due to the COVID-19 pandemic, so only 76 were included in the final analysis. PPC were not significantly associated with either BR (OR 1.01; 95% CI 0.98, 1.05) or ARISCAT (OR 1.03; 95% CI 0.97, 1.09) in this cohort. FEV₁ was weakly correlated with BR (OR 0.38; 95% CI 0.16, 0.56).

Conclusion

Neither BR nor ARISCAT were predictive of PPC. The weak correlation between FEV₁ and BR may suggest a submaximal breathing effort during CPET in a proportion of patients. The small number of patients in this cohort is a limitation and it would be interesting to see in future if BR at anaerobic threshold can be a predictor of PPC.