Nasal high-flow oxygen therapy system for improving sleep-related hypoventilation in chronic obstructive pulmonary disease: a case report

Sleep-related hypoventilation should be considered in patients with chronic obstructive pulmonary disease, because appropriate respiratory management during sleep is important for preventing elevation of PaCO₂ levels. A nasal high-flow oxygen therapy system using a special nasal cannula can deliver suitably heated and humidified oxygen at up to 60 L/min. Since the oxygen concentration remains a constant independent of minute ventilation, this system is particularly useful in patients with chronic obstructive pulmonary disease who have hypercapnia. This is the first report of sleep-related hypoventilation with chronic obstructive pulmonary disease improving using a nasal high-flow oxygen therapy system.

We report the case of a 73-year-old Japanese female who started noninvasive positive-pressure ventilation for acute exacerbation of chronic obstructive pulmonary disease and CO₂ narcosis due to respiratory infection. Since she became agitated as her level of consciousness improved, she was switched to a nasal high-flow oxygen therapy system. When a repeat polysomnography was performed while using the nasal high-flow oxygen therapy system, the Apnea Hypopnea Index was 3.7 times/h, her mean SpO₂ had increased from 89 to 93%, percentage time with SpO₂ ≤ 90% had decreased dramatically from 30.8 to 2.5%, and sleep stage 4 was now detected for 38.5 minutes. As these findings indicated marked improvements in sleep-related hypoventilation, nasal high-flow oxygen therapy was continued at home. She has since experienced no recurrences of CO₂ narcosis and has been able to continue home treatment.

Use of a nasal high-flow oxygen therapy system proved effective in delivering a prescribed concentration of oxygen from the time of acute exacerbation until returning home in a patient with chronic obstructive pulmonary disease, dementia and sleep-related hypoventilation. The nasal high-flow oxygen therapy system is currently used as a device to administer high concentrations of oxygen in many patients with type I respiratory failure, but may also be useful instead of a Venturi mask in patients like ours with type II respiratory failure, additionally providing some positive end-expiratory pressure.