Ventilatory efficiency as a prognostic factor for postoperative complications in patients undergoing elective major surgery: a systematic review

Thomas Vetsch; Sabrina Eggmann; François Jardot; Marc von Gernler; Dominique Engel; Christian M Beilstein; Patrick Y Wuethrich; Prisca Eser; Matthias Wilhelm

doi:10.1016/j.bja.2024.03.013

Ventilatory efficiency as a prognostic factor for postoperative complications in patients undergoing elective major surgery: a systematic review

Br J Anaesth. 2024 Apr 20:S0007-0912(24)00144-2. doi: 10.1016/j.bja.2024.03.013. Online ahead of print.

Authors

Thomas Vetsch¹, Sabrina Eggmann², François Jardot³, Marc von Gernler⁴, Dominique Engel³, Christian M Beilstein³, Patrick Y Wuethrich³, Prisca Eser⁵, Matthias Wilhelm⁵

Affiliations

¹ Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Centre for Rehabilitation & Sports Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Graduate School for Health Sciences, University of Bern, Bern, Switzerland. Electronic address: thomas.vetsch@insel.ch.
² Department of Physiotherapy, Inselspital, Bern University Hospital, Bern, Switzerland.
³ Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
⁴ Medical Library, University Library of Bern, University of Bern, Bern, Switzerland.
⁵ Centre for Rehabilitation & Sports Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

PMID: 38644158
DOI: 10.1016/j.bja.2024.03.013

Abstract

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/VCO₂). The aim of this systematic review was to summarise evidence regarding VE/VCO₂ 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/VCO₂ was reported as a prognostic factor for short-term complications after thoracic and abdominal surgery. VE/VCO₂ 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/VCO₂ from the final multivariable regression owing to data-driven model-building approaches.

Conclusions: This systematic review identifies VE/VCO₂ 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.

Systematic review protocol: PROSPERO (CRD42022369944).

Keywords: VE/VCO(2); exercise testing; major surgery; postoperative complications; postoperative mortality; prediction models; preoperative assessment; ventilatory efficiency.

Publication types

Review