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The following is a summary of “Perioperative lung expansion and pulmonary outcomes after open abdominal surgery versus usual care in the USA (PRIME-AIR): a multicentre, randomised, controlled, phase 3 trial,” published in the May 2025 issue of Lancet Respiratory Medicine by Fernandez-Bustamante et al. 

Researchers conducted a retrospective study to assess whether a perioperative lung expansion bundle with individualized intraoperative management reduced postoperative pulmonary complication (PPC) severity in an open abdominal surgery compared with usual care.  

They enrolled adult patients aged 18 years or older scheduled for elective open abdominal surgery lasting at least 2 hours, with an Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score of 26 or higher and a BMI below 35 kg/m², across 17 academic hospitals in 10 U.S. states. Participants were randomly assigned (1:1) using permuted block randomization with block sizes of 2 and 4 in a 1:2 ratio, stratified by center, to either usual care or a lung expansion bundle, which included preoperative education on PPCs, individualized intraoperative protective ventilation with positive end-expiratory pressure optimization, weight- and neuromuscular transmission-monitored neuromuscular blockade and reversal, and postoperative supervised incentive spirometry with mobilization encouragement. Anesthesiologists were also randomized to intervention or usual care groups at each site. At least 1 masked and unmasked investigator was designated per participant, with assessors blinded to treatment assignment. The primary outcome was the highest grade (0–4) severity of a composite of PPCs by postoperative day 7, assessed in the modified intention-to-treat population, excluding those who withdrew consent or were ineligible post-randomization. The trial was registered under ClinicalTrials.gov, NCT04108130, and has been completed.  

The results showed that between January 24, 2020, and April 5, 2023, 1,462 patients were screened, and 794 were enrolled and randomized. The modified intention-to-treat population included 751 participants, with 379 (50%) in the intervention bundle group and 372 (50%) in the usual care group. The mean age was 61.8 years (SD 12.8), with 360 (48%) females and 391 (52%) males; 572 (76%) were White, 44 (6%) Black, 35 (5%) Asian, and 10 (1%) other or multiple races. Bundle adherence ranged from 72% to 98%. The intervention group received higher mean positive end-expiratory pressure (7.5 cmH₂ O [SD 2.5] vs 5.6 cmH₂ O [1.4]) and more consistent neuromuscular blockade dosing (334 [88%] vs 214 [58%]) and reversal (322 [86%] vs 250 [70%]) compared to usual care. By postoperative day 7, grade 2 PPCs were most frequent (211 [56%] vs 225 [60%]), with similar mean severity scores (1.60 [SD 0.94] vs 1.53 [0.93]; mean difference 0.07 [95% CI –0.03 to 0.18]; P=0.19). Serious adverse events (AEs) and mortality rates were comparable between groups at 7, 30, and 90 days postoperatively. The AEs occurred in 71 (19%) intervention and 54 (14%) usual care patients, while serious AEs were equal to 35 (9%) in each group.  

Investigators concluded that in patients with a BMI under 35 kg/m² at moderate-to-high risk for PPCs undergoing open abdominal surgery, a perioperative lung expansion bundle did not decrease the severity of complications compared with usual care. 

Source: thelancet.com/journals/lanres/article/PIIS2213-2600(25)00040-2/abstract