Am. J. Respir. Crit. Care Med., Vol 155, No. 4, 04 1997, 1482-1485.
Continuous versus bilevel positive airway pressure in a patient with idiopathic central sleep apnea
F Hommura, M Nishimura, M Oguri, H Makita, K Hosokawa, H Saito, K Miyamoto and Y Kawakami
First Department of Medicine, Hokkaido University School of Medicine, Kita-ku, Sapporo, Japan.
A 57-yr-old man with idiopathic central apnea is reported. He presented at
our hospital complaining of excessive daytime sleepiness. Polysomnography,
including esophageal pressure monitoring, confirmed central sleep apnea
with an apnea index of 27/h. He had mild non- insulin-dependent diabetes
mellitus (NIDDM) but no signs of diabetic neuropathy or other background
diseases. The ventilatory responses to hypoxia and hypercapnia tested while
he was awake indicated increased respiratory chemosensitivity. We applied
nasal continuous positive airway pressure (CPAP) and bilevel positive
airway pressure (BPAP) in an attempt to compare the possible difference in
therapeutic efficacy. Although nasal CPAP completely reversed central
apnea, nasal BPAP adversely affected both apnea length and frequency in an
applied pressure-dependent manner. Arterial blood gas analyses while he was
being treated indicted alveolar hypoventilation with CPAP and
hyperventilation with BPAP. Additionally, administration of a mixed gas
containing 5% CO2 through a face mask had a significant effect on the
disappearance of central apnea in this patient. These findings support the
theory that the arterial PCO2 level is critical in generating idiopathic
central apnea and that nasal CPAP therapy may be effective in eliminating
central apnea by raising the PaCO2.
