Anaesthetic management and measurements
snoring, ORI, upper lip bite, head and neck movement
SECONDARY, OBSTRUCTIVE SLEEP APNOEA
In the operating room, patients were placed in a supine position with a pillow behind their head. An electrocardiogram was obtained, and blood pressure, oxygen saturation, and brain function (SedLine®, Masimo Corp., Irvine, CA, USA) were monitored non-invasively. Each patient’s pulse oximetry was measured using the RD Rainbow SET®-2 Neo sensor (Massimo Corp.) attached to the patient’s finger and covered with a light-shielding black bag. The ORI was monitored using the Rainbow SET Radial-7 Pulse CO-Oximeter (software version 2.1.3.5; Masimo Corp.).Prior to initiating anaesthesia induction, an airway assessment was performed, including assessments for obstructive sleep apnoea, snoring while sleeping, interincisor distance, hyomental distance, and head and neck movement. The modified Mallampati and upper lip bite test scores were also determined.In the HFNO group, the Optiflow (Fisher & Paykel Healthcare, Auckland, New Zealand) nasal cannula was placed on the patient’s nares. Cannula size was adjusted with respect to the nasal opening. Preoxygenation was performed for 3 min at 40 L·minAfter preoxygenation, anaesthesia induction was accomplished intravenously using propofol (1–2 mg·kgIn the FMV group, the facemask was placed in contact with the patient’s nose and mouth, and oxygen was supplied at 10 L·minThe ORI was continuously monitored until the endotracheal intubation was completed. ORI and SpOPatient characteristics such as age, sex, height, weight, and the American Society of Anesthesiologists physical class were recorded. The number of intubation attempts, intubation time, and Cormack–Lehane grade were recorded. The primary outcome was the highest ORI value achieved by oxygenation. The secondary outcome was the time required to reach the highest ORI observed during the induction of anaesthesia.