Adoption of Lung Protective ventilation IN patients undergoing Emergency laparotomy: the ALPINE study. A prospective multicentre observational study

Background Emergency abdominal surgery is associated with a high risk of postoperative pulmonary complications (PPCs). The primary aim of this study was to determine whether patients undergoing emergency laparotomy surgery are ventilated using a lung-protective ventilation strategy comprising of tidal volume ≤8 ml kg −1 ideal body weight −1 , PEEP >5 cm H 2 O, and recruitment manoeuvres. The secondary aim was to investigate the association between ventilation factors (lung-protective ventilation strategy, intraoperative FiO 2 , and peak inspiratory pressure) and the occurrence of PPCs. Methods Data were collected prospectively in 28 hospitals across London as part of routine National Emergency Laparotomy Audit. Patients were followed up for 7 days. Complications were defined according to the European Perioperative Clinical Outcome definition. Results Data were collected from 568 patients. The median [inter-quartile range (IQR)] tidal volume observed was 500 ml (450–540 ml), corresponding to a median tidal volume of 8 ml kg −1 ideal body weight −1 (IQR: 7.2–9.1 ml). An lung-protective ventilation strategy was employed in 4.9% (28/568) of patients and was not protective against the occurrence of PPCs in the multivariable analysis (hazard ratio=1.06; P =0.69). A peak inspiratory pressure of 2 O was protective against the development of PPC (hazard ratio=0.46; confidence interval: 0.30–0.72; P =0.001). The median FiO 2 was 0.5 (IQR: 0.44–0.53) and an increase in FiO 2 by 5% increased the risk of developing a PPC by 8% (2.6–14.1%; P =0.008). Conclusions Both intraoperative peak inspiratory pressure and FiO 2 are independent factors significantly associated with the development of a postoperative pulmonary complication in emergency laparotomy patients. Further studies are required to identify their causality effect and to demonstrate if their manipulation could lead to better clinical outcomes.