Nocturnal minimum oxygen saturation as a predictor of functional independence measure improvement in patients recovering from acute stroke: A prospective cohort study.

PURPOSE: Sleep-disordered breathing (SDB) has received limited attention in stroke rehabilitation, and screening for SDB is inadequate. This study aimed to examine the association between nocturnal hypoxia and functional independence improvement in stroke patients during recovery, with a focus on the potential relevance of SDB in rehabilitation outcomes.

METHODS

This prospective cohort study included 89 patients admitted for stroke rehabilitation in Chiba, Japan, between August 2021 and March 2024. SDB was assessed using WatchPAT, focusing on nocturnal oxygen saturation parameters, including the minimum SpO2 (MinSpO2) and the oxygen desaturation index at 3% (ODI3%). The functional independence measure (FIM) improvement per day of hospitalization (FIM change rate) was the primary outcome. The covariates included age, sex, body mass index, stroke severity, comorbidities, and levels of consciousness.

RESULTS

Multivariate regression analyses showed that MinSpO2 was significantly associated with the total FIM change rate (B [95% CI] = 0.008 [0.003-0.012], P = 0.001) and had a standardized coefficient of 0.337, whereas ODI3% showed no significant association. MinSpO2 was associated with both motor and cognitive FIM change rates.

CONCLUSIONS

Nocturnal hypoxia is associated with functional recovery in patients with stroke, highlighting the importance of sleep monitoring in rehabilitation. As a detectable and modifiable factor, it may present opportunities for dental professionals to contribute to patient care through airway assessment and collaborative intervention.