Pulse oximetry screening for sleep-disordered breathing in stroke

Background: The prevalence of sleep-disordered breathing, particularly obstructive sleep apnea, among stroke patients is high. Routine screening with the current diagnostic gold standard of polysomnography is not feasible. Pulse oximetry could be a simple screening test.

Methods: The signal of pulse oximetry, recorded during full polysomnography in 184 stroke patients during neurological rehabilitation, was analyzed automatically by software for desaturations >/= 4 %. The polysomnographic apnoea-hypopnoea-index (AHI) was used as the diagnostic gold standard and compared with the oxygen desaturation index (ODI).

Results: Correlation between AHI of PSG and ODI of oximetry was r = 0.84 (p < 0.001). Dependent on the definition of SDB (AHI 10, 15, 20 or 30/h) and the cut-off-point for the ODI (e. g. 15/h) sensitivity was 32 - 83 % and specificity 99 - 96 %. The diagnostic accuracy as determined by the area under the ROC-curve was 96 %.

Conclusions: Automated analysis of pulse oximetry gives reasonable results for screening for SDB in stroke patients and could be used in populations with high pre-test probability.