Vetsch T; Department of Anaesthesiology and Pain Medicine, Bern University Hospital, University of Bern, Bern, Switzerland;
Jardot F; von Gernler M; Engel D; Beilstein CM; Wuethrich PY; Eser P; Wilhelm M;
British journal of anaesthesia [Br J Anaesth] 2024 Apr 20.
Date of Electronic Publication: 2024 Apr 20.
Background: Major surgery is associated with high complication rates. Several risk scores exist to assess individual patient risk before surgery but have limited precision. Novel prognostic factors can be included as additional building blocks in existing prediction models. A candidate prognostic factor, measured by cardiopulmonary exercise testing, is ventilatory efficiency (VE/VCO 2 ). The aim of this systematic review was to summarise evidence regarding VE/VCO 2 as a prognostic factor for postoperative complications in patients undergoing major surgery.
Methods: A medical library specialist developed the search strategy. No database-provided limits, considering study types, languages, publication years, or any other formal criteria were applied to any of the sources. Two reviewers assessed eligibility of each record and rated risk of bias in included studies.
Results: From 10,082 screened records, 65 studies were identified as eligible. We extracted adjusted associations from 32 studies and unadjusted from 33 studies. Risk of bias was a concern in the domains ‘study confounding’ and ‘statistical analysis’. VE/VCO 2 was reported as a prognostic factor for short-term complications after thoracic and abdominal surgery. VE/VCO 2 was also reported as a prognostic factor for mid- to long-term mortality. Data-driven covariable selection was applied in 31 studies. Eighteen studies excluded VE/VCO 2 from the final multivariable regression owing to data-driven model-building approaches.
Conclusions: This systematic review identifies VE/VCO 2 as a predictor for short-term complications after thoracic and abdominal surgery. However, the available data do not allow conclusions about clinical decision-making. Future studies should select covariables for adjustment a priori based on external knowledge.