Point-of-Care Ultrasound of Upper Airway Changes During Cardiopulmonary Bypass in Coronary Artery Bypass Grafting: A Randomized Controlled Trial

Background and Objectives: Elevated endotracheal tube (ETT) cuff pressure impairs tracheal mucosal perfusion and may contribute to upper airway soft-tissue changes. During cardiopulmonary bypass (CPB), the cuff usually remains inflated although ventilation is suspended, yet the relevance of cuff pressure management during CPB is unclear. We compared two ETT cuff pressure strategies during CPB (0 vs. 20–30 cmH2O) on point-of-care ultrasound (POCUS) measurements of upper airway soft tissue in patients undergoing coronary artery bypass grafting (CABG). Materials and Methods: In this single-center, prospective, randomized, observer-blinded trial, 76 patients (ASA III–IV, aged 18–80 years) undergoing elective CABG were randomized 1:1 to a 0 cmH2O or 20–30 cmH2O ETT cuff pressure strategy throughout CPB (n = 38 per group). Transesophageal echocardiography (TEE) was not used in any patient. POCUS measurements of lateral pharyngeal wall (LPW) thickness, tongue thickness, parapharyngeal distance, midsagittal tongue area, and tongue width were obtained at four time points (T0–T3). The primary analysis was the omnibus group × time interaction for LPW thickness in a generalized estimating equations (GEE) model; the between-group difference in change from T0 to T2 was a planned supporting contrast.