Nocturnal hypoxemic episodes after thoracic surgery

In this study, the incidence, timing, and risk factors of postoperative nocturnal hypoxemic episodic A (SpO2 below 90% for at least 10 seconds) were evaluated by arterial hemoglobin oxygen saturation monitoring using pulse oximetry in 56 patients who underwent thoracic surgery. The mean oxgen saturation was significantly better on postoperative nights than on preoperative nights, due to oxygen administration. Despite the improved better oxygenation, hypoxemic episodic A occurred in 35 patients. No risk factors were identified. Hypoxemic episode A occurred most frequently on the third postoperative night. No patient developed severe complications, but 3 aged patients who had severe hypoxemia developed delirium. A relationship between hypoxemic episode A and delirium was suspected. Furthemore, an apnea recorder in 7 patients evaluated sleep apnea, which can cause hypoxemia. Obstructive sleep apneas were more frequent and developed into more severe hypoxemia than other types. These findings suggest the patients who have undergone thoracic surgery may need treatment in order to avoid unpredictable hypoxemia.