Al-Sharif, Hussam

Abstract Introduction Central sleep apnea (CSA) may occur as an adverse effect of sodium oxybates, a medication commonly used to treat narcolepsy with cataplexy. Management is challenging, as sodium oxybates remain essential for symptom control in many patients, yet untreated CSA poses substantial respiratory risk. We present a rare case of sodium-oxybate–associated CSA successfully treated with adaptive servo ventilation (ASV), representing, to our knowledge, the first documented use of ASV for this indication. Methods A 49-year-old woman with longstanding narcolepsy with cataplexy presented with worsening daytime sleepiness despite stable use of sodium oxybate. She had been receiving a very high dose prescribed by an outside provider (6.75 g twice nightly), exceeding the recommended maximum of 4.5 g twice nightly, and her dose was subsequently adjusted to 4.5 g twice nightly. An in-lab polysomnogram revealed moderate central sleep apnea (AHI 21; RDI 23) with predominantly central events. Because the patient did not wish to wean or discontinue sodium oxybate—reporting that it remained the only therapy that consistently improved her sleep and cataplexy—adaptive servo ventilation (ASV) titration was pursued as the next step in management. She had previously failed multiple stimulants, wake-promoting agents, and SSRIs due to either limited efficacy or intolerable side effects. Her BMI was 18 kg/m2, she was not taking any CNS depressant medications, and her echocardiogram demonstrated a normal ejection fraction. Results The patient tolerated ASV well. Final settings included an EPAP of 5 cm H₂O with a pressure support range of 3–15 cm H₂O and minimal leak. Her adherence was excellent, with more than 93% of nights exceeding four hours of use. Residual AHI improved to 4.6 events per hour, accompanied by noticeable improvement in daytime alertness. She continued sodium oxybate without any respiratory complications. Conclusion ASV may be an effective and well-tolerated therapy for sodium-oxybate–induced CSA in patients who must continue the medication. Sodium oxybate can induce CSA by acting on GABA-B receptors in the Kölliker–Fuse and pre-Bötzinger complex, suppressing respiratory drive and depressing hypoglossal motor output. This case highlights the successful use of ASV in treating CSA secondary to oxybates when the medication cannot be weaned or discontinued. Support (if any)

Abstract Introduction Positive airway pressure (PAP) therapy is the standard treatment for obstructive sleep apnea (OSA); however, its use may be contraindicated in patients with recurrent pneumothorax, particularly in the presence of emphysematous lung disease and bleb formation. Hypoglossal nerve stimulation (HGNS) offers a non–positive-pressure alternative for appropriately selected patients. We describe what is, to our knowledge, the first reported case of successful HGNS therapy in an older adult with severe OSA and multiple recurrent pneumothoraces. Methods An 87-year-old man with severe OSA (baseline AHI 38, predominantly obstructive events) experienced multiple right-sided pneumothoraces beginning in December 2022, several of which were temporally associated with BiPAP use at 17/9 cm H₂O. His episodes required repeated interventions, including chest tubes, thoracoscopy with apical bleb resection and pleurodesis, and several pigtail catheter placements. Chest CT imaging demonstrated emphysema with multiple blebs, raising concern for the safety of continued PAP therapy. A mandibular advancement device was deemed inappropriate due to disease severity. The patient’s BMI was 27 kg/m2. HGNS was considered a suitable alternative. Results HGNS implantation was completed without complications. At activation, both the sensation and functional thresholds measured 0.8 V, with excellent tongue protrusion and waveform quality. The device was programmed to 0.8–1.8 V with a 30-minute start delay, 12-hour nightly duration, and 15-minute pause. On follow-up, the patient demonstrated excellent adherence (average 70 hours/week), progressed to level 8 (1.6 V), and reported significant clinical improvement with resolution of snoring and apneas. Functional threshold and waveform analysis at 1.6 V remained optimal. Importantly, the patient tolerated HGNS well without any further episodes of pneumothorax following implantation. Conclusion HGNS may represent a safe and effective alternative to PAP therapy in patients at risk for pneumothorax. While positive pressure ventilation can theoretically worsen pneumothorax by increasing pleural pressure, HGNS operates through an entirely different mechanism: it maintains upper airway patency without altering intrathoracic pressure dynamics, making it a potentially safer option for select high-risk OSA patients. Support (if any)