Right lung atelectasis during general anesthesia with laryngeal mask airway

Right upper lobe atelectasis after tracheal extubation in a morbidly obese patient

Background:

Acute lobar collapse caused by a reflex bronchoconstriction was previously reported to occur during the induction of anesthesia, however there are no reports on its occurrence during the emergence period.

Case Report:

A 56-year-old morbidly obese woman was scheduled for surgery due to a gastric ulcer perforation. Anesthesia was induced with thiopental 500 mg, fentanyl and rocuronium, and maintained with sevoflurane in a N₂O/O₂ mixture. The operative procedure and anesthesia were uneventful; however, the patient developed a sudden decrease in SaO₂ and blurring of consciousness after extubation. She was re-intubated and ventilated with 100% O₂. Arterial blood gas analysis at that time showed respiratory acidosis and hypoxemia. Further work-up revealed a bronchospasm-induced right upper lobe atelectasis, which occurred immediately after tracheal extubation. The patient was successfully treated using mechanical ventilation and bronchodilators.

Conclusions:

Bronchospasm may cause acute lobar atelectasis immediately after tracheal extubation. Morbid obesity and the use of 100% oxygen may facilitate atelectasis formation during emergence from anesthesia.