Estimating Apnea Phenotypes From Polysomnography: Oxygen

NCT ID: NCT01751971

Last Updated: 2018-03-20

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 47 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-11-30
• Study Completion Date: 2016-07-31

Brief Summary

This study seeks to employ advanced methods to estimate the individual factors contributing to sleep apnea from standard recordings made during routine clinical sleep studies. This study focuses on breathing control or "loop gain" as one of the factors contributing to sleep apnea. Increased levels of oxygen in the air is known to make breathing more stable by lowering "loop gain". Here, our goal is to use a new method capable of detecting a reduction in loop gain with oxygen. The investigators also aim to test whether a high loop gain measured at baseline/placebo predicts a greater improvement in sleep apnea with oxygen therapy.

Detailed Description

In a single-blinded randomized crossover study, inspired oxygen/air (40%/21%) is delivered on two separate nights. Loop gain is measured from routine polysomnography using a novel mathematical method. A value of loop gain >1 reflects unstable breathing, and a value less than but approaching 1 denotes a system more prone to oscillate. Loop gain is measured as the changes in ventilatory drive/effort that arises subsequent to changes in ventilation (e.g. due to obstructive apnea). A simple chemoreflex model (gain, time constant, delay) is fit to surrogate ventilation data (derived from airflow) during sleep. The best model is one that best matches the elevated ventilatory drive (measured as ventilation in the absence of airflow obstruction) based on the prior apneic/hypopneic fall in ventilation. Loop gain is calculated from this model. We aim to use loop gain measured on and off oxygen to determine whether a strong response (reduction in apnea severity) can be predicted by a higher loop gain (in the sham arm) using our method. We also assessed whether assessing upper airway anatomy/collapsibility, dilator muscle responsiveness, and the arousal threshold helped to predict responses to treatment.

Conditions

Sleep Apnea

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Inspired Oxygen First

Participants breathe air with additional inspired oxygen (40%) for 1 night during an overnight sleep study (15 L/min via venturi mask). 1 week later participants will crossover to Sham (sham comparator).

Group Type: ACTIVE_COMPARATOR

Inspired oxygen (40%)

Intervention Type: DRUG

Supplemental oxygen at 40% inspired via venturi mask (15 L/min). Equivalent to 5 L/min via nasal cannula.

Sham

Intervention Type: OTHER

Medical air with 21% oxygen via venturi mask (15 L/min).

Sham First

Participants breathe air without additional inspired oxygen for 1 night during sleep (15 L/min via Venturi mask). 1 week later participants will crossover to Inspire Oxygen (active intervention).

Group Type: SHAM_COMPARATOR

Inspired oxygen (40%)

Intervention Type: DRUG

Supplemental oxygen at 40% inspired via venturi mask (15 L/min). Equivalent to 5 L/min via nasal cannula.

Sham

Intervention Type: OTHER

Medical air with 21% oxygen via venturi mask (15 L/min).

Interventions

Inspired oxygen (40%)

Supplemental oxygen at 40% inspired via venturi mask (15 L/min). Equivalent to 5 L/min via nasal cannula.

Intervention Type: DRUG

Sham

Medical air with 21% oxygen via venturi mask (15 L/min).

Intervention Type: OTHER

Other Intervention Names

Supplemental oxygen; Medical air

Eligibility Criteria

Inclusion Criteria

• Apnea/hypopnea index >20 events per hour
• Age 20-79 years

Exclusion Criteria

• COPD with desaturation (resting SpO2<96%)
• Use of respiratory stimulants or depressants
• Pregnancy

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 79 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role: collaborator

American Heart Association

OTHER

Sponsor Role: collaborator

Brigham and Women's Hospital

OTHER

Sponsor Role: lead

Responsible Party

Scott Aaron Sands

Instructor in Medicine

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

SCOTT A Sands, PhD

Role: PRINCIPAL_INVESTIGATOR

Brigham and Women's Hospital

Locations

Brigham and Women's Hospital

Boston, Massachusetts, United States

Countries

United States

References

Sands SA, Edwards BA, Terrill PI, Butler JP, Owens RL, Taranto-Montemurro L, Azarbarzin A, Marques M, Hess LB, Smales ET, de Melo CM, White DP, Malhotra A, Wellman A. Identifying obstructive sleep apnoea patients responsive to supplemental oxygen therapy. Eur Respir J. 2018 Sep 27;52(3):1800674. doi: 10.1183/13993003.00674-2018. Print 2018 Sep.

Reference Type: DERIVED

PMID: 30139771 (View on PubMed)

Other Identifiers

R01HL090897

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2005P001296-O2PSG

Identifier Type: -

Identifier Source: org_study_id