Comparison of full versus short induced-sleep polysomnography for the diagnosis of sleep apnea

Objectives/Hypothesis: Polysomnography (PSG) is the gold‐standard method for diagnosing obstructive sleep apnea (OSA). However, the gap between demand and capacity in performing PSG is a major health‐care problem. We sought to validate a short day‐time induced sleep for the diagnosis of OSA. Study Design: Prospective diagnostic method validation. Methods: We studied 25 consecutive patients referred to the sleep laboratory and 15 healthy volunteers. All subjects were evaluated by means of full overnight PSG (Full‐PSG) and short day‐time induced‐sleep PSG (Induced‐PSG). Sleep was monitored during both procedures (Embla, 16 channels). Sleep was induced by slow intravenous drip infusion of midazolam. Results: The population studied (N = 40) was 60% male (mean age, 42 ± 10 years; body mass index, 29 ± 6.5 kg/m2). Sleep was successfully induced in all subjects, and no complications were observed (midazolam doses, 6.2 ± 3.8 mg; time of induced sleep 41.5 ± 18.9 minutes). The apnea‐hypopnea index (AHI) and minimal oxygen saturation during Full‐PSG versus Induced‐PSG were similar: median AHI (with 25%–75% interquartile range) was 13 (3–35) events per hour versus 17 (4–36) events per hour, and median oxygen saturation was 84% (75–90) versus 85% (76–92); P =.89 and P =.53, respectively. The majority of the respiratory events during induced sleep were obstructive and similar to those observed during Full‐PSG. AHI and lowest oxygen saturation during Induced‐PSG correlated significantly with Full‐PSG (r = 0.67 and r = 0.77, respectively). Sensitivity and specificity for the diagnosis of OSA (AHI > 15 events per hour) by Induced‐PSG were 0.83 and 0.72, respectively. Conclusions: Induced‐PSG by midazolam during the day is safe and correlates with Full‐PSG; it therefore is a promising alternative method in the diagnosis of OSA.