Postoperative pulmonary complications (PPCs) are common after cardiac surgery and are associated with significant morbidity and mortality. Lung-protective ventilation strategies have been proposed to reduce PPCs, but the optimal level of positive end-expiratory pressure (PEEP) and the use of alveolar recruitment manoeuvres (RMs) remain controversial.

In this investigator-initiated, multicentre, open, randomised, parallel-group, superiority clinical trial, elective cardiac surgery patients at risk of PPCs will be assigned to one of two intraoperative ventilation strategies: (1) an open-lung ventilation strategy with protective ventilation, moderate PEEP and RMs or (2) a standard protective ventilation with low PEEP and no RM. The primary outcome will be a composite of prolonged (>24 hour) postoperative mechanical ventilation, reintubation for any cause or hospital-acquired pneumonia within 7 days of surgery, or death within 28 days of surgery. Data will be analysed on an intention-to-treat basis.

The VACARM (impact of intraoperatiVe moderAte positive end-expiratory pressure with reCruitment mAnoeuvres versus low positive end-expiRatory pressure on major postoperative pulMonary complications and death after on-pump cardiac surgery in high-risk patients) trial has been approved by an independent ethics committee for all study centres. Recruitment began in July 2021. Results will be published in international peer-reviewed medical journals.

ClinicalTrials.gov NCT04408495.