Head elevation during preoxygenation can delay desaturation time: A randomized-controlled trial

Background: Preoxygenation before anesthesia induction is an important part of airway management to reduce the risk of hypoxemia when the patient is apneic. The effectivity of preoxygenation is influenced by several things such as patient's head position. This study aimed to compare preoxygenation between various degrees of head elevation (20°, 30°, and 45°) and 0° or no elevation position towards desaturation time before tracheal intubation in patients undergoing general anesthesia. Method: This was a single-blinded randomized clinical trial of 48 patients, assigned into four groups (0°, 20°, 30°, and 45° head elevation group). All subjects were preoxygenated for 3 min with 100% oxygen. Induction of anesthesia was started with fentanyl and propofol, followed by rocuronium after the patient lost consciousness. Time was recorded from the beginning of induction until the oxygen saturation decreased to 93% or a time limit of 5 min was reached. Result: The desaturation time in 45° head elevation group was significantly the longest, followed by 30°, 20°, and 0° group (224,0 ± 49,4; 196,4 ± 41,7; 187,2 ± 29,8; and 166,1 ± 51,3 s, respectively; P < 0.05). Conclusions: Patients with 45° head elevation had significant longer mean desaturation time compared to 0° and 20° head elevation group. In patients undergoing general anesthesia, preoxygenation with head elevation slowed down the time for desaturation before tracheal intubation compared to the conventional position. Clinical trial registration: NCT05688722.