Combination hypoglossal nerve stimulation and low-pressure continuous positive airway pressure for obstructive sleep apnea and obesity hypoventilation syndrome: a case report

Obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS) frequently coexist, with obesity serving as a major risk factor for both conditions. Continuous positive airway pressure (CPAP) is considered first-line therapy; however, adherence is often limited by discomfort, mask leak, and intolerance to high pressures. Hypoglossal nerve stimulation has emerged as an alternative treatment for patients with CPAP intolerance, though its efficacy in patients with concomitant OHS remains unclear. We present the case of a 73-year-old male with severe OSA and chronic hypercapnia who experienced persistent hypoxemia despite prior uvulopalatopharyngoplasty and HNS implantation. The patient was unable to tolerate high-pressure bilevel positive airway pressure therapy due to mask intolerance and nasal bridge injury. Home sleep testing while using Inspire® alone demonstrated persistent severe sleep-disordered breathing with respiratory events. Thoracic plication for right hemidiaphragm elevation improved pulmonary mechanics but failed to fully resolve nocturnal hypoventilation. Subsequent combination therapy with Inspire®, mandibular advancement device, and low-pressure CPAP resulted in marked clinical improvement. Follow-up demonstrated 100% CPAP compliance, residual AHI of 0.3 events/hour, improved serum bicarbonate levels, reduction in nocturnal hypoxemia, and resolution of morning headaches with improved sleep quality. This case highlights the potential utility of combined HNS and CPAP therapy in patients with overlapping OSA and OHS who are intolerant of high-pressure PAP therapy alone. HNS may improve upper airway obstruction while adjunctive low-pressure CPAP improves ventilation and gas exchange, allowing enhanced tolerability and adherence. Further studies are needed to evaluate the broader applicability of this combined therapeutic approach in complex OSA/OHS overlap syndromes.