BACKGROUND
Preoxygenation prior to induction of general anesthesia is recommended to prolong the safe apnea time and avoid hypoxia during airway management, but conventional preoxygenation using a tight-fitting face mask can cause discomfort and be poorly tolerated by some patients, especially those experiencing claustrophobia or anxiety. Alternative techniques, such as high-flow nasal oxygen, require additional equipment and do not allow reliable monitoring of end-tidal oxygen levels. This case report seeks to offer an equipment-free alternative preoxygenation method for a patient in this subgroup.
CASE REPORT
A 44-year-old woman was scheduled for elective unilateral parotidectomy. In the operating room, she presented with significant anxiety and claustrophobia related to face mask ventilation. Her airway assessment was unremarkable, and she had no comorbidities. After unsuccessful attempts to improve tolerance to mask preoxygenation, she underwent successful preoxygenation using an alternative method. The patient breathed through the tip of an endotracheal tube connected to the anesthesia circuit, holding the tube herself while guided to inhale and exhale. An expiratory oxygen fraction of 80% was achieved within 2 minutes, allowing induction of anesthesia. No desaturation occurred during induction or airway management. The same tube was subsequently used for tracheal intubation. Postoperatively, the patient reported feeling more comfortable and in control compared with previous experiences.
CONCLUSIONS
Using tube-tip-in-mouth preoxygenation we found a very simple, equipment-free method that offered a feasible alternative for this patient who was intolerant to conventional mask preoxygenation. End tidal oxygen levels could still be measured before induction of general anesthesia. We believe that this technique could be considered an option for future patients.

Keywords: Anesthesia, Endotracheal; Claustrophobia; Communication; Humans; Intubation; Resource-Limited Settings