Monitored anesthesia care (MAC) has been described as a specific anesthesia service for diagnostic or therapeutic procedures performed under local anesthesia along with sedation and analgesia, titrated to a level preserving spontaneous breathing and airway reflexes. Radio-frequency ablation (RFA) is a kind of methods to remove benign thyroid nodules (BTNs) by inducing the irreversible injuries with the use of an ultrasound-guided RF electrode placed inside the nodules. A 37 years old, 157 cm, 81 kg woman underwent RFA of BTNs under MAC. We present with a case report where laryngospasm under MAC was resolved by the use of positive pressure ventilation without any complications.

Acute upper airway obstruction can cause negative pressure pulmonary edema (NPPE). It is a well-known perianesthetic complication, but is uncommon for intubated patients. Radiation injury of lung can easily lead to pulmonary hemorrhage or NPPE caused by changes of transthoracic or transpulmonary pressure. It is due to injury of alveolar-capillary membrane by radiation. We report the case of a 71-year-old man with a history of radiation therapy for lung cancer after surgical resection who developed the abrupt onset of pulmonary hemorrhage and NPPE during general anesthesia for hydrocele and inguinal hernia operation.

Upper airway obstruction is a common problem in pediatric patients. There were a few reports that airway obstruction caused by redundant arytenoid mucosa. The etiology of redundant arytenoid remains unknown. Redundant arytenoid mucosa is diagnosed endoscopically when one or both arytenoids anteriorly displace into the glottic inlet upon inspiration. The common symptoms are hoarseness, stridor, snoring or dyspnea on exertion. These symptoms are similar to croup and they can be easily misdiagnosed as croup. We experienced rare case of upper airway obstruction caused by redundancy of arytenoid mucosa and report it with review of literatures.