A 44-year-old woman (body mass index 32) with myotonic dystrophy was admitted for bilateral para- thyroidectomy. Her risk of post-operative respiratory complications was high due to respiratory muscle weakness (%VC 52.8%) and high sputum volume. Difficulties in surgery were anticipated under local anesthesia due to obesity and bilateral tumors. There- fore, general anesthetic management without muscle relaxant was selected and early extubation conducted to prevent respiratory complications. She was extubated 1 hour after surgery in the intensive care unit (ICU) and F10₂ 0.6, 10 l · min⁻¹ oxygen mask was administrated. Paco₂ gradually increased (54 mmHg 15 minutes later, 61 mmHg 2 hours later after extubation). A high flow nasal can- nula was administered to facilitate CO₂ elimination, and Paco₂ decreased to 46 mmHg after 4 hours. An intra- pulmonary percussive ventilator was administered for the purpose of sputum discharge which facilitated effi- cient expectoration of sputum. She was discharged from the ICU on postoperative day (POD) 1 and from hospital on POD 6 without complications.