Drug-induced sedation endoscopy versus clinical exploration for the diagnosis of severe upper airway obstruction in OSAHS patients

Background Identifying the sites of obstruction of the upper airway in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) is paramount for surgical planning. The aim of this study is to compare wake physical exam findings to the ones obtained during drug-induced sedation endoscopy (DISE) in the diagnosis of severe collapse of the upper airway in OSAHS patients. A retrospective chart review of OSAHS patients who underwent DISE at our institution during the 2006-2010 period was conducted. All the patients had previously undergone a physical examination that included modified Mallampati index (MMI), the Muller maneuver (MM), and the Friedman staging system. Level and severity of airway collapse were evaluated. A severe collapse was attributed to obstructions equal or greater than 75 % of the airway. A total of 138 patients were included in the study. The incidence of severe airway collapse was compared between DISE and MM; at retropalatal level, no significant difference was found. At retrolingual level, 69 % of patients had severe collapse with DISE in comparison to a 28 % with the MM (p < 0.05). No relationship was found either with the MMI or with the Friedman staging system when compared to the incidence of severe retrolingual collapse diagnosed by DISE. Concordance was low between awake and DISE exploration in both retropalatal and retroglossal level. The Muller maneuver underestimates tongue base severe obstruction diagnosis when compared to that obtained after DISE in OSAHS patients. The wake patient exploration does not accurately correlate to DISE exploration.