A 42-year-old male with hypertension and asthma was evaluated for excessive daytime sleepiness and loud snoring. On exam it was found that BMI was 35 kg/m2, neck circumference was 41 cm, upper airway was crowded, and there was no audible wheezing on lung auscultation. A nocturnal polysomnogram revealed moderate obstructive sleep-disordered breathing. On continuous positive airway pressure (CPAP) of 9 cm H2O using full face mask, the patient exhibited the breathing pattern shown in Figure 1.
Figure 1.
The combination of snoring and flow limitation during expiration (as seen in Figure 1) indicates expiratory pharyngeal narrowing that requires higher distending pressure with CPAP. Increasing CPAP to 15 cm H2O during the same stage of sleep and body position eliminated expiratory snoring and flow limitation, as shown in Figure 2.
Figure 2.
Supported by the Department of Veterans Affairs, the National Heart, Lung, and Blood Institute, and the Medical Staff Trust Fund–Harper University Hospital.
Author Disclosure: A.G.S-T. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript; M.S.W. received $5,001-$10,000 from Inspire Medical in industry-sponsored grants for a clinical trial (VA based, no funds to PI), $10,001-$50,000 from Ventus Medical in institutional grants for a randomized clinical trial, and more than $100,001 from the NIH for peer-reviewed grants.