A60-20 Sham Bilevel Positive Airway Pressure (BPAP) for a Prospective, Randomized, Double Blind, Controlled Trial Evaluating the Role of BPAP in Pediatric Acute Asthma Exacerbations

Rationale Blinding in a randomized control trial (RCT) is critical for minimizing bias and ensuring valid results. To successfully conduct a double-blind, RCT measuring the impact of bilevel positive airway pressure (BPAP) on acute moderate-to-severe pediatric asthma, a sham BPAP setup is required. The goal of sham BPAP is to mimic active BPAP without delivering therapeutic pressure, provide adequate flow for continuous albuterol delivery, prevent carbon dioxide re-breathing and ensure participants and providers remain blinded. We hypothesized that providers and participants would not be able to distinguish between those receiving active BPAP versus sham BPAP. Methods Patients 5 to 17-years-old being treated in the emergency department for moderate-to-severe asthma exacerbations were randomized to receive continuous inhaled albuterol through active or sham BPAP (NCT 05848115). The sham BPAP is composed of a single-limb BPAP circuit connected to a Respironics Trilogy 202 ventilator, a vented full-face mask, and a 6.0-millimeter endotracheal tube covered in corrugated tubing to act as resistor to attenuate the delivered pressures. Both arms were initiated on inspiratory positive airway pressure of 10 cm water and an expiratory positive airway pressure of 5 cm water. Continuous inhaled albuterol was administered into the BPAP set-up using an Aerogen mesh nebulizer. At the end of the four-hour study intervention period the clinical provider and patient were asked if they had received active versus sham BPAP. Adverse events were monitored prospectively by the research team. Results 67 participants were consented and randomized in the RCT. Of the 67 enrollments, 38 (57%) providers and 39 (58%) participants responded to the question of which of the two interventions they thought had been administered. Clinical providers accurately identified active and sham BPAP in 7/19 (37%) and 11/19 (58%) participants, respectively. Patients accurately identified receiving active or sham BPAP in 10/21 (48%) and 10/18 (56%) instances, respectively. Eight patients receiving sham BPAP reported anxiety, discomfort, or fear versus four in active BPAP. No serious adverse events (death, intubation, air leak syndrome, aspiration pneumonia) were reported in either arm. Conclusions The described sham BPAP set-up successfully mimics active BPAP while attenuating pressure without any serious adverse events. The preliminary data supports successful blinding in both arms with no concern for serious adverse events, but with a trend towards less tolerance of the sham BPAP set-up. With close monitoring, other clinical trials using non-invasive positive airway pressure in pediatric asthma could consider using the proposed sham set-up. This abstract is funded by: R33HL158814, R61HL158814, Children’s Hospital Colorado Research Scholar Award