Stroke and CPAP Outcome Study 2 (SCOUTS2)

Maximizing Use of Continuous Positive Airway Pressure in Stroke Rehabilitation Patients With Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is associated with impaired stroke recovery. Treatment with continuous positive airway pressure (CPAP) may prevent this but is limited by poor adherence. In this study, the investigators enrolled eligible stroke patients undergoing inpatient rehabilitation (IPR) into an intensive CPAP adherence protocol (iCAP) with an aim to increase tolerance and adherence to auto-titrating CPAP (APAP).

The SCOUTS (Stroke and CPAP Outcome Study 2) was a single-arm, open-label study performed at 2 IPR units of the University of Washington. Eligible stroke patients undergoing IPR were provided an intensive CPAP adherence protocol (iCAP) to increase tolerance and adherence to auto-titrating CPAP (APAP). The iCAP included patient education and encouragement, device adjustments, close monitoring of adherence and a 3-night run-in period of APAP to identify those patients who 1. have OSA and 2. have APAP tolerance-- defined as participant willingness to continue APAP during IPR and over the 3-month treatment period. If both criteria were met, APAP treatment with iCAP continued during the rehabilitation stay and over a 3-month period. The goal of the intervention was to achieve 50% of subjects meeting APAP adherence (an average ≥ 4 hours per night) over the 3-month treatment period. The investigators evaluated if demographic, co-morbid or stroke-specific factors predicted APAP adherence and assessed the relationship between APAP adherence and neurological recovery from stroke.

Participants will receive 3 nights of auto-CPAP in order to identify those with OSA using flow resistance detected by the device. After 3 nights, those without apparent OSA or with central apnea, and those who simply do not tolerate CPAP will be excluded from the study. An intensive CPAP adherence protocol (iCAP) will be initiated, including collaborative care with rehabilitation nurses, the study's sleep technologist and overnight respiratory therapists. After the run-in period, the sleep technologist will meet at least twice weekly with CPAP-tolerant participants during their rehabilitation stay for further OSA education and encouragement with a target adherence of 4 hours per night. Participants diagnosed with OSA by the device and tolerant will continue CPAP therapy during rehabilitation and at home for a treatment period of 3 months. Adherence will be downloaded remotely from participant's machines to encourage adherence to treatment and troubleshoot any problems with the device.

Auto-titrating Continuous Positive Airway Pressure (APAP) among patients admitted to a rehabilitation unit after ischemic or hemorrhagic stroke for 3 month treatment period.

Number of participants who continue CPAP after the run-in period who have acceptable adherence at 3 months, defined as using CPAP for an average of at least 4 hours a night on at least 70% of nights.

Number of eligible participants (those who continue CPAP after the run-in period) who are willing to continue CPAP treatment upon discharge from the rehabilitation unit.

Change in the cognitive subscale of the Functional Independence Measure (FIM) over 3 months. The FIM, a disability scale measuring the burden of care associated with aspects of motor and cognitive function, includes a motor and cognitive component. The cognitive subscale includes 5 cognitive items: comprehension, expression, social interaction, problem solving and memory. Each of the 5 cognitive items are scored from 1 (complete dependence) to 7 (complete independence). The total scores from these 5 items for the cognitive subscale range from 5 to 35 with lower scores indicating greater functional disability. The 5 items from the cognitive subscale are combined with 13 items from the motor subscale yielding the 18 items of the total FIM with a minimum score of 18 and a maximum score of 126 with lower scores indicating greater functional disability.

Change in the motor subscale of the Functional Independence Measure (FIM) over 3 months. The FIM, a disability scale measuring the burden of care associated with aspects of motor and cognitive function, includes a motor and cognitive component. The motor subscale includes 13 motor items: eating, grooming, bathing, upper body dressing, lower body dressing, toileting, bladder management, bowel management, bed/chair transfer, toilet transfer, tub/shower transfer, walk/wheelchair locomotion and stair locomotion. Each of the 13 motor items are scored from 1 (complete dependence) to 7 (complete independence). The total scores from these 13 items for the motor subscale range from 13 to 91 with lower scores indicating greater functional disability. The 13 items from the motor subscale are combined with 5 items from the cognitive subscale yielding the 18 items of the total FIM with a minimum total score of 18 and a maximum score of 126 with lower scores indicating greater functional

The National Institutes of Health Stroke scale (NIHSS) is a 15-item scale used to rank the severity of ischemic stroke. The NIHSS includes measurements for levels of consciousness, language, neglect, visual-field loss, extraocular movement, motor strength, ataxia, dysarthria, and sensory loss. The scores range from 0 to 42 with higher scores indicating greater neurologic impairment.

Inclusion Criteria: Adult patients admitted after acute ischemic or hemorrhagic stroke to one of two inpatient rehabilitation units Exclusion Criteria: The investigators will exclude participants if: their stroke was a subarachnoid hemorrhage or due to a secondary cause (vascular malformation, vasculitis, brain tumor, head trauma, or predisposition to bleeding); they have active CPAP use, advanced chronic lung disease requiring supplemental oxygen, heart failure (NYHA class III or IV); or they needed a nasogastric feeding tube.

Khot S, Barnett H, Davis A, Siv J, Crane D, Kunze A, Li Lue D, Bunnell A, McCann B, Bombardier C, Longstreth WT Jr, Watson N, Billings M. Intensive Continuous Positive Airway Pressure Adherence Program During Stroke Rehabilitation. Stroke. 2019 Jul;50(7):1895-1897. doi: 10.1161/STROKEAHA.119.024795. Epub 2019 May 20.

Khot SP, Barnett HM, Davis AP, Byun E, McCann BS, Bombardier CH, Rappisi K, Longstreth WT Jr, Billings ME, Brown DL, Garrison MM. Novel and modifiable factors associated with adherence to continuous positive airway pressure therapy initiated during stroke rehabilitation: An exploratory analysis of a prospective cohort study. Sleep Med. 2022 Sep;97:43-46. doi: 10.1016/j.sleep.2022.05.013. Epub 2022 May 26.