Effects of Ultrasound-Guided Recruitment Manoeuvres on Postoperative Pulmonary Complications in Obese Patients

Objectives and Design

This prospective, randomised, two-arm clinical trial aims to test the hypothesis that recruitment manoeuvres (RMs) guided by lung ultrasound (LUS) reduce the incidence of postoperative pulmonary complications (PPCs) in obese patients scheduled for laparoscopic bariatric surgeries, compared to conventional RMs. The trial involves 476 patients from the Third People’s Hospital of Chengdu, randomly assigned to two intraoperative RMs strategies. The study adheres to the WMA Declaration of Helsinki and CIOMS Principles, with ethical approval from the Third People’s Hospital of Chengdu and registration in the Chinese Clinical Trial Registry.

Study Population

Obese patients scheduled for laparoscopic metabolic and bariatric surgery are screened and recruited. Inclusion criteria include age over 18 years, ASA physical status I–III, meeting criteria for surgical indications, and informed consent. Exclusion criteria include participation in another trial, severe COPD, severe or uncontrolled bronchial asthma, cardiac dysfunction, ongoing renal replacement therapy, intracranial injury or tumour, neuromuscular disease, and expected prolonged postoperative mechanical ventilation.

Intervention

RMs are performed post-endotracheal intubation and at surgery's end. The intervention group undergoes LUS-guided RMs, while the control group undergoes conventional manual RMs. Perioperative lung ultrasound examinations are conducted by trained anaesthesia care providers, with LUS scores calculated based on lung aeration loss.

Blinding and Randomisation

This is a patient- and evaluator-blinded trial, with participants randomly allocated to either group. The randomised sequence is generated by SPSS, with anaesthesia care providers performing RMs according to group assignment.

Perioperative Management

Routine monitoring and care pathways are followed, with specific interventions for nausea and vomiting prevention, anaesthesia maintenance, and postoperative pain relief. Mechanical ventilation settings are standardised, with patients extubated with positive airway pressure and transferred to the PACU.

Study Outcomes

The primary outcome is the incidence of PPCs within the first 5 postoperative days. Secondary outcomes include LUS score at 30 minutes post-extubation, severity of PPCs, safety-related events, emergency time, length of hospital stay, ICU admission, and quality of postoperative recovery.

Sample Size and Statistical Analysis

The sample size is calculated based on the primary outcome, with data analysis performed using SPSS and GraphPad Prism, following intention-to-treat analysis principles.

Data Collection and Monitoring

Preoperative, intraoperative, and postoperative data are collected, with a focus on education and patient advocacy to improve trial adherence. Data monitoring includes regular backups and recording of all changes and analysis steps.