Postoperative Pulmonary Complications After Use of Supraglottic Airway Devices and Neuromuscular Blockade

SupAIR is an international, multicenter, randomized, controlled, parallel-group clinical trial evaluating the effects of airway management and neuromuscular blockade (NMB) on postoperative pulmonary complications after general anesthesia.

A total of 6,800 adults undergoing elective non-cardiac surgery will be randomized to one of five treatment arms:

• Tracheal tube with moderate NMB
• Tracheal tube with deep NMB
• Supraglottic airway device with moderate NMB
• Supraglottic airway device with deep NMB
• Supraglottic airway device without NMB

The five treatment arms result from an initial allocation to tracheal tube with NMB, supraglottic airway device with NMB, or supraglottic airway device without NMB. Participants assigned to NMB are additionally randomized to moderate or deep neuromuscular blockade.

The study addresses two primary hypotheses. First, among participants receiving NMB, use of a supraglottic airway device is hypothesized to reduce postoperative pulmonary complications compared with tracheal intubation. Second, among participants managed with a supraglottic airway device, the use of NMB is hypothesized not to increase postoperative pulmonary complications compared with no NMB. Finally, among participants receiving NMB depth of neuromuscular blockade will be used as secondary exposure.

The randomized intervention determines airway management and the use and depth of neuromuscular blockade. Quantitative neuromuscular monitoring is used in participants receiving NMB, and recovery from neuromuscular blockade is managed according to applicable clinical guidelines. All other aspects of perioperative anesthetic management are performed according to local clinical practice.

The primary outcome is the occurrence of at least one postoperative pulmonary complication from postoperative day 1 until hospital discharge or postoperative day 28, whichever occurs first. The composite includes respiratory failure, suspected pulmonary infection, pulmonary infiltrates, atelectasis, aspiration pneumonitis, bronchospasm, and pulmonary oedema.

Postoperative outcomes are assessed by blinded study personnel during the hospital stay. Secondary outcomes include intraoperative and postoperative complications, respiratory events in the post-anesthesia care unit, surgical conditions, quality of recovery, functional health, length of stay, intensive care treatment, and mortality. Participants are additionally followed by telephone approximately six months after surgery.

An interim analysis is planned after approximately 1,000 participants to assess assumptions relevant to sample-size planning. Interim results will be reviewed by the independent Data and Safety Monitoring Board, and the total sample size may be adjusted in accordance with the prespecified analysis plan.

Inclusion criteria

Adult patients (≥ 18 years) with an ASA physical status ≤ 3 scheduled for elective non-cardiac surgery under general anaesthesia whose airway can be secured via tracheal tube or SGA.

Exclusion criteria

Contraindications for using supraglottic devices, tracheal tube, or neuromuscular blocking agents (and reversal drugs); surgery in prone positioning; surgical procedures scheduled outside the operating room; ambulatory surgery; pregnancy; patients planned for consecutive anaesthetic/surgical procedures in the following 14 days or within the past 14 days.