DETERMINING THE SITE OF AIRWAY COLLAPSE IN OBSTRUCTIVE SLEEP-APNEA WITH AIRWAY PRESSURE MONITORING

Twenty patients with obstructive sleep apnea (OSA) underwent complete polysomnography and simultaneous upper airway pressure monitoring with a custom-made, soft silicone-covered catheter measuring 2.3 mm in dia meter. The catheter had four solid-state microtip pressure sensors pos itioned in the posterior nasopharynx, immediately caudal to the tip of the uvula, at the level of the hyoid bone, and in the midesophagus. T he level(s) of airway collapse was determined by changes in the pressu re patterns between transducers. In 14 of the 20 patients, airway coll apse was confined or initiated at the oropharyngeal region. The obstru ction extended to the base of tongue in 7 and to the entire collapsibl e upper airway in 2 patients. Four patients had collapse at the base o f the tongue and 2 had collapse at the hypopharynx. The site of airway collapse remained fairly constant through various sleep stages and po sitions. Uvulopalatopharyngoplasty (UPPP) and postoperative polysomnog raphy were performed in 4 patients (2 with hypopharyngeal, 1 with base of tongue, and 1 with oropharyngeal airway collapse). Two patients ha d a favorable response to UPPP.