High-Resolution Pulse Oximetry (HRPO): A Cost-Effective Tool in Screening for Obstructive Sleep Apnea (OSA) in Acute Stroke and Predicting Outcome.

INTRODUCTION

Obstructive sleep apnea (OSA) is a well-known risk factor for stroke. This is attributed to multiple mechanisms such as endothelial dysfunction, atrial fibrillation, hypertension, and comorbid obesity. STOP questionnaire alone is unreliable to diagnose OSA and in-hospital sleep study is costly and can be technically challenging. We used high-resolution pulse oximetry (HRPO) to test the feasibility of screening for OSA and predicting outcome.

METHODS

Data from 115 stroke patients who underwent HRPO was collected including Oxygen desaturation index (ODI) <4%, pulse rate, arterial oxygen saturation (SaO), and time spent at SaO saturation <88%. We also collected data on various confounders. The outcomes measured were NIHSS (National Institutes of Health Stroke Scale), mRS (modified Rankin Score) on discharge, and discharge disposition.

RESULTS

Overall 115 patients with valid HRPO data were included in the study. Mean age was 64±12years with 68% white, 22% black, and 10% Hispanic population. Of this cohort of 115 patients, 56% were males. Of the subjects enrolled 22 had atrial fibrillation, 27 had type 2 diabetes, 7 had resistant hypertension, and 7 had patient foramen ovale. Of the 115 patients, 75 patients were found to have ODI of >10 and the mean ODI was 29±30. The NIHSS on admission was 6.14±6.93 and on discharge was 4.46±4.59, mRS on discharge was 1.70±1.67 with 52% being discharged home, 43% to rehab, 2% nursing home, and 3% to long-term acute care facility. In this study, we show a strong association between atrial fibrillation and increasing ODI (P<.001, OR 1.01, CI 1.00-1.03). In addition, our study also shows an association between discharges outcome of rehab (more deficits leading to higher disability) versus discharge to home (lesser deficits) if ODI was ≤10 (P = 0.005, OR 3.76, CI 1.49-9.52).

CONCLUSIONS

Our study showed that there is a significant burden of OSA in acute stroke patients. ODI emerged as a predictor of atrial fibrillation and discharge disposition in our study. HRPO may be a cost-effective tool to screen and evaluate for OSA in acute stroke patients.