[Pulmonary edema due to acute airway obstruction immediately after tracheal extubation]

A 33-year-old male was scheduled for tonsillectomy and pharyngoplasty due to sleep apnea syndrome. The intubation was uneventful following induction with thiamylal and vecuronium. Anesthesia was maintained with O2-N2O-sevoflurane. No complications were observed during the 90 min operation. After the termination of the anesthesia, a hyperadrenergic state was observed: arterial pressure and heart rate rose to 230/135 mmHg and 135 bpm, respectively. Immediately after extubation, he developed dyspnea with tracheal tag and stridor, and became cyanotic despite the use of a simple oxygen mask and assisted ventilation. Laryngospasm was suspected. The patient was reintubated and suctioned; pink, frothy sputum was not obtained. Arterial blood gases 5 minutes after reintubation revealed a pH of 7.24, Pao2 86 mmHg (FIo2 1.0), and Paco2 54 mmHg. Chest X-ray 30 minutes after reintubation revealed bilateral diffuse alveolar infiltration. The diagnosis was interstitial pulmonary edema. The patient was ventilated mechanically by applying a positive end-expiratory pressure of 5cm H2O, and furosemide and dopamine were administered intravenously. The patient was extubated the next day, and discharged from hospital ten days later. We considered that the lung edema was induced by the severe negative pressure generated by inspirating against a closed upper airway, as well as by the hyperadrenergic state and severe hypoxemia observed during and after extubation.