A 52 year old intellectually disabled woman with myotonic dystrophy type 1 and a history of malignant melanoma underwent an elective thoracoscopic neoplasm resection. Pre-operatively she had very poor pulmonary function tests with a vital capacity of 1.99 L. The operation was conducted under total i.v. anesthesia with a single dose of 20 mg rocuronium and one lung ventilation was achieved with left double lumen tube. At the end of the surgery the patient regain conciseness and was extubated. Following extubation the patient quickly deteriorated into type 2 respiratory failure with significant hypoxemia. She was alternately ventilated with face mask and breathing spontaneously for about 2 h until fully recovered.