DISE-PAP: a method for troubleshooting residual AHI elevation despite positive pressure therapy.

Despite excellent positive airway pressure (PAP) adherence, a subset of patients with obstructive sleep apnea experience residual elevation of the apnea-hypopnea index (AHI). Drug-induced sleep endoscopy during PAP application provides an opportunity to examine the anatomic effect of PAP therapy on the upper airway and to troubleshoot refractory residual AHI elevation. We present a patient who demonstrated persistent moderate-severe AHI elevation during titration polysomnogram and subsequent data download reports despite numerous mask refits, chin strap, positional modifications, and multiple pressure and mode adjustments in both the clinic and sleep laboratory settings. Drug-induced sleep endoscopy was performed with the flexible endoscope passed through the PAP circuit into the upper airway. Jaw laxity and associated mandibular retrusion at sleep onset was found to result in a complete fixed tongue base obstruction that PAP therapy, delivered via the patient's oronasal interface, was unable to overcome. Various strategies to overcome these obstacles are discussed.