Abstract
Objectives. Cerebral hypoxia may promote cerebral damage in patients with obstructive sleep apnoea (OSA). We investigated whether OSA patients experience nocturnal cerebral hypoxia that is prevented by continuous positive airway pressure (CPAP).
Methods. OSA patients using CPAP underwent sleep studies including pulse oximetry (SpO2) and near-infrared spectroscopy to monitor cerebral tissue oxygenation (CTO) at baseline and after 2 weeks on either subtherapeutic or therapeutic CPAP according to randomised allocation. Changes in oxygenation at end of the 2-week intervention were compared between groups.
Results. Among 21 patients (mean apnoea/hypopnoea-index 50.3/h), OSA recurred in all 9 using subtherapeutic and in 0 using therapeutic CPAP: mean (95%CI) between-group differences in changes of oxygen-desaturation-index baseline to 2 weeks +40.7/h(+31.1;+50.4) for SpO2 and +37.0/h(+25.3;+48.7) for CTO (both p<0.001). Mean nocturnal SpO2 and CTO decreased more in patients using subtherapeutic vs. therapeutic CPAP: −2.4%(−3.4;−1.1) and −3.8%(−7.4;−0.1), respectively, both p<0.03. Severe CTO-drops ≥13% associated with cerebral dysfunction in previous studies occurred in 4/9 patients using subtherapeutic but in 0/12 using therapeutic CPAP (p=0.01).
Conclusions. In patients with OSA, CPAP-withdrawal resulted in nocturnal cerebral deoxygenation suggesting a role of cerebral hypoxia in predisposing untreated OSA patients to cerebral damage.
Clinical trials registration number: NCT01797653.
Abstract
Untreated OSA predisposes to severe cerebral hypoxia during sleep
Footnotes
This manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.
Conflict of interest: Dr. Schwarz has nothing to disclose.
Conflict of interest: Dr. Furian has nothing to disclose.
Conflict of interest: Dr. Schlatzer has nothing to disclose.
Conflict of interest: Dr. Stradling reports personal fees from ResMed Uk, outside the submitted work.
Conflict of interest: Dr. Kohler has nothing to disclose.
Conflict of interest: Dr. Bloch has nothing to disclose.
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