Emergency abdominal surgery is a high-risk procedure often performed on high-risk patients. The incidence of Postoperative pulmonary complications (PPCs) in emergency abdominal surgery is not well established yet. Several factors, such as the ventilatory approach, may be associated with PPCs but data on patients undergoing emergency abdominal surgery is scarce. The primary aim of the study was to describe the incidence of PPCs during the first 7 postoperative days.

Prospective international cohort study including all consecutive patients > 18 y/o undergoing emergency abdominal surgery. From April to June 2023 each hospital selected a single 7-day period for the recruitment with a 7-day follow-up. The PPCs included the following international standard definitions for the primary outcome: acute respiratory failure; pneumothorax; weaning failure; acute respiratory distress syndrome; pulmonary infection; atelectasis; pleural effusion; bronchospasm; aspiration pneumonitis; pulmonary thromboembolism; and pulmonary edema.

45 hospitals from 5 geographical areas participated in the study with 507 patients included in the final analysis. A total of 114 (22.5%) patients developed PPCs and 38 (7.5%) developed severe PPCs. The multivariate analysis showed that the independent risk factors for PPCs were: high ARISCAT score (Odds Ratio: 2.67; 95%CI 1.06–6.86), laparotomy (OR: 2.29; 95%CI 1.06–5.01), and postoperative positive air-test (OR: 2.05; 95%CI 1.02–4.24). Conversely, neuromuscular block reversal was associated with a reduced risk of PPCs (OR: 0.36; 95%CI 0.16−0.82).

Incidence of PPCs in patients undergoing emergency abdominal surgery is significant. Among the modifiable risk factors, a lack of neuromuscular block reversal and postoperative positive air test were associated with the increased incidence of PPCs.