Head Elevation During Pre-oxygenation Can Delay Desaturation Time

Preoxygenation 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 with head elevation 20°, 30° and 45° and conventional position to the time of desaturation before endotracheal intubation in patients undergoing general anesthesia. This was a randomized clinical trial of 56 patients, divided into four groups (conventional or 0° head elevation group, 20° head elevation group, 30° head elevation and 45° head elevation group). All subject was preoxygenated for 3 minutes with 100% oxygen. Induction of anesthesia was started with fentanyl, propofol, followed by rocuronium after the patient lost consciousness. Time was recorded from the start of induction until the oxygen saturation showed 93% or a time limit of 5 minutes. There was a significant difference in mean desaturation time among the four groups (p = 0.011). The most significant different was in 45o head elevation group (p < 0.05). . In patients undergoing general anesthesia, pre-oxygenation with head elevation 20°, 30° and 45° slows down the time for desaturation before endotracheal intubation compared to the conventional position. The 45° head elevation has the best result.

Inclusion criteria

• undergo endotracheal intubation with general anesthesia for elective surgery
• aged 18-60 years old
• ASA physical status 1-2 preoperatively

Exclusion criteria

• Patients with difficult airway, cardiopulmonary disease, anemia, grade II obesity, pregnant, history of hypersensitivity to induction agents
• Patients did not give consent to follow the study