View Abstract

A5282 - Nasal High-Flow Oxygen Therapy for Sleep-Related Hypoventilation in Acute on Chronic Respiratory Failure
Author Block: V. K. Patel1, A. Madanieh1, C. Orabi1, R. J. Sartori2, S. M. Mina2, E. J. Geigel3; 1Graduate Medical Education, Internal Medicine Residency Program, University of Central Florida College of Medicine / HCA GME Consortium, Orlando, FL, United States, 2Department of Sleep Medicine, Orlando Veterans Affairs Medical Center, Orlando, FL, United States, 3Department of Pulmonary and Critical Care Medicine, Orlando Veterans Affairs Medical Center, Orlando, FL, United States.
Introduction
Obstructive sleep apnea is characterized by upper airway obstruction during sleep leading to intermittent episodes of hypoxia, sleep fragmentation, metabolic dysfunction and unfavorable cardiovascular outcome. Current first-line therapy is continuous positive airway pressure (CPAP), which implements constant pressure to maintain airway patency. Non-adherence to CPAP remains a major challenge, leading to suboptimal outcomes. However, some patients fail to demonstrate improvement despite optimal adherence to all attempted therapies. Despite lack of current clinical evidence, heated humidified high-flow nasal cannula oxygen therapy may be a promising alternative in patients who fail other obstructive sleep apnea treatment modalities.
Case
Sixty-year-old man with chronic obstructive pulmonary disease, obstructive sleep apnea and obesity hypoventilation syndrome was admitted to the hospital for inpatient evaluation and monitoring after presenting with asymptomatic acute on chronic hypercapnic respiratory failure with pH 7.26, pCO2 78 mmHg and serum bicarbonate 35 mEq/L. Vital signs and physical examination were unremarkable. He reported CPAP non-adherence related to claustrophobia since diagnosis several years prior. Sleep apnea was suspected as a predominant contributing factor based on his lack of symptoms while awake. Patient underwent inpatient polysomnography, which revealed moderate-severe sleep-disordered breathing, with initial apnea/hypopnea index (AHI) of 29.1 events per hour and SpO2 nadir of 77%. Hypoxic episodes quickly responded to supplemental oxygen and immediately resolved upon awakening. CPAP trial was ineffective due to recurrent hypoxic episodes. He showed mild improvement on Bi-level after pressures were titrated up to 15/10 cmH2O with 3 liters of supplemental oxygen, until he experienced recurrent desaturation down to 61% the following night. Repeat polysomnography with trial of heated humidified high-flow nasal cannula oxygen therapy was attempted, resulting in marked improvement of sleep-related hypoventilation with AHI of 0.3 events per hour, resolution of hypoxic episodes and normalization of sleep pattern. Repeat arterial blood gas showed pH 7.33 with pCO2 57.1 mmHg at time of follow up Pulmonary clinic visit.
Discussion
Heated humidified high-flow nasal cannula oxygen therapy improved our patient’s acute on chronic hypercapnic respiratory failure by eliminating sleep-related hypoventilation. Mechanistically, the high-flow is theorized to facilitate washout of anatomic dead space, increase lung volume and recruit collapsed alveoli, while creating enough end-expiratory pharyngeal airway pressure to maintain a patent airway. We present a case in which heated humidified high-flow nasal cannula oxygen therapy was found to be a viable therapeutic alternative in the management of obstructive sleep apnea in the setting of acute on chronic hypercapnic respiratory failure.