Stroke and CPAP Outcome Study: A Sham-controlled Trial of CPAP Among Stroke Rehabilitation Patients (SCOUTS)

University of Washington

Status and phase: Completed; Phase 2; Phase 1

Conditions: Stroke; Sleep Apnea, Obstructive

Treatments: Device: Sham-CPAP; Device: Auto-titrating CPAP

Study type: Interventional

Funder types: Other

Identifiers

NCT02551757

43428

Details and patient eligibility

About

The purpose of this study is to assess the effect of continuous positive airway pressure (CPAP) on functional outcome in patients with acute stroke, the investigators conducted a sham-controlled, double-blind pilot trial during inpatient rehabilitation.

Patients with acute stroke were recruited and randomly assigned to auto-titrating or sham-CPAP during their rehabilitation stay.

Full description

All acute stroke patients admitted to the inpatient rehabilitation service at the University of Washington were invited to participate in the study. Given the high prevalence of obstructive sleep apnea (OSA) in this population, no screen for OSA was performed. Enrolled patients were assigned randomly to active-CPAP with auto-titrating pressures or to sham-CPAP with an otherwise identical device but with pressures ≤ 1 cm water. Subjects used active or sham-CPAP for the duration of inpatient rehabilitation, but no longer than 28 days. CPAP compliance was assessed by memory card that recorded mask-on time. Other information on download, such as apnea-hypopnea index, was only available on active-CPAP and not assessed by investigators in real time. In this study, the investigators defined tolerance as any continued use of CPAP at night and adherence as mean hours of CPAP use per night in those who were CPAP tolerant.

Enrollment: 40 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• greater than 18 years of age
• admitted to an inpatient rehabilitation unit at the University of Washington
• head CT or brain MRI demonstrating an ischemic or hemorrhagic stroke
• enrolled in another research study

Exclusion criteria

• stroke was a subarachnoid hemorrhage or due to a secondary cause (vascular malformation, vasculitis, brain tumor, head trauma, or predisposition to bleeding)
• history of CPAP use, advanced chronic lung disease requiring supplemental oxygen, heart failure (NYHA class III or IV)
• require a nasogastric feeding tube.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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40 participants in 2 patient groups

Active-CPAP

Experimental group

Description:

Patients assigned to active-CPAP were treated with auto-titrating CPAP, where an auto-titrator adjusted the delivered pressure between 4 to 20 cm of water to eliminate obstructive events for a goal apnea-hypopnea index less than or equal to 5.

Treatment:

Device: Auto-titrating CPAP

Sham-CPAP

Sham Comparator group

Description:

The sham-CPAP device in our study was designed to entail no risks beyond those with standard CPAP and provide a high level of blinding. The sham-CPAP device is an auto-titrating CPAP with an internal flow restrictor and a modified elbow attached to the nasal mask. The elbow modification creates a larger than standard air leak that serves to prevent any chances of carbon dioxide rebreathing and delivers a pressure at the mask in¬terface of roughly 0.75 to 1 cm water. The elbow modification is not noticeable when the device is fully assembled to avoid the possibility of unblinding patients, providers, or study personnel. The elbow modification could only be used on standard nasal masks; consequently full facemasks and nasal pillows were excluded for patients in both active and sham-CPAP.

Treatment:

Device: Sham-CPAP