Reliability of the Muller maneuver and its association with sleep-disordered breathing

Objectives/Hypothesis: Use of the Muller maneuver (MM) in the evaluation of patients with obstructive sleep apnea is controversial. One criticism of t his test is that it is somewhat subjective. Our objective is to explore the reliability of this technique and its association with sleep-disordered br eathing. Study Design: Prospective study performed in an academic tertiary care center. Methods: An analysis of MM scores from 180 consecutive patient s obtained independently by two examiners was completed. These scores were compared with each other and with the apnea-hypopnea index (AHI) obtained f rom polysomnographic studies. Results: Collapse of the soft palate (PAL), l ateral pharyngeal wall (LPW), and base of the tongue (BOT) was rated on a f ive-point scale (0-4), The mean scores determined by the faculty examiner w ere 2,47, 2,06, and 1,58, respectively; the mean scores determined by the r esident examiner were 2,34, 2,25, and 1,48, respectively. The scores of the two examiners correlated to within +/-1 unit 83.9% of the time at the PAL, 91.1% at the LPW, and 85.0% at the BOT, The degree of correlation was not influenced by year of training of the resident. When the AHI was converted to a four-point scale based on severity, the score correlated within +/-1 o f the average MM score 72.1% of the time. Conclusions: Despite the subjecti ve nature of the MM, the five-point scale can be used by independent examin ers to achieve an evaluation of the upper airway that is reproducible. The preoperative severity of sleep disordered breathing based on the AHI is mod erately correlated with the MM score.