Diurnal sleep study for sleep related breathing disorders--the utility of nasendoscopic diurnal polysomnography using diazepam

Abstract

Twenty two patients with obstructive sleep apnea syndrome were examined by nocturnal polysomnography (n-PSG), and the obstructive sites in the upper airway were observed by nasendoscopic diurnal polysomnography using diazepam (n-d-PSGD). The types of apnea were divided into three groups according to the obstructive sites in the upper airway: soft palate apnea, tongue base apnea, and combined type apnea. Among the 22 patients, there were 17 soft palate apneas, 3 tongue base apneas and 2 combined type apneas. All patients underwent uvulopalatopharyngoplasty (UPPP). Preoperative values of AI, AR, DI and mean sleep SaO2 were 37.2, 24.5%, 31.4 and 92.5%, and the postoperative values were 10.4, 7.3%, 6.8 and 94.8%, respectively. Criteria were established to define UPPP responders, as follows: 50% or more reduction in AI and postoperative AI less than 20. The overall improvement rate was 81.0%. The improvement rates for soft palate apnea, combined type apnea and tongue base apnea were 93.8%, 50.0%, and 0%, respectively. In 15 of the 22 patients, measurements of mesopharyngeal and esophageal pressures were performed simultaneously with n-d-PSGD. In these 15 patients, 12 soft palate apneas, 2 combined type apneas and 3 tongue base apneas were observed with n-d-PSGD, while 7 soft palate apneas, 3 combined type apneas and 5 tongue base apneas were detected by measuring the pressures. The results of these two methods concurred in only nine of fifteen patients. It was suspected that the obstructive sites in the upper airway were identified by tissues with n-d-PSGD, but by region with the pressure measuring method. It was suggested that UPPP is the most suitable treatment for patients with soft palate type apnea, without pathologic obesity. n-d-PSGD is a useful method of evaluating respiratory status during sleep, can be performed in a few hours, and can simultaneously identify the obstructive site in the upper airway, so as to allow treatment planning.