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Drug-Induced Sleep Endoscopy (DISE) with Target Controlled Infusion (TCI) and Bispectral Analysis in Obstructive Sleep Apnea
Published on: December 6, 2016
Developing quantitative physiological phenotypes of sleep apnea for epidemiological studies
J P Kirkness1, B M McGinley, F P Sgambati
1Johns Hopkins Sleep Disorders Center, Division of Pulmonary Medicine, Johns Hopkins University, Baltimore, MD, USA.
Summary
Estimating critical collapsing pressure (P(CRIT)) for obstructive sleep apnea using airflow at atmospheric pressure (V(atm)) offers a scalable alternative to labor-intensive methods. This approach accurately assesses upper airway patency in large patient cohorts.
Area of Science:
- Respiratory Physiology
- Sleep Medicine
- Biomedical Engineering
Background:
- Existing physiological databases lack sufficient detail for obstructive sleep apnea (OSA) pathophysiology.
- Critical collapsing pressure (P(CRIT)) is key for upper airway patency but is labor-intensive, limiting large-scale studies.
- Upstream resistance (R(US)) is known to be relatively consistent across individuals.
Purpose of the Study:
- To develop and validate a method for estimating P(CRIT) from airflow at atmospheric pressure (V(atm)).
- To determine the minimum sample size required for reliable estimation of R(US) variance.
- To assess the agreement between estimated P(CRIT) (ЄP(CRIT)) and measured P(CRIT).
Main Methods:
- Utilized a dataset of 126 subjects with measured P(CRIT) and R(US).
- Employed bootstrap procedures to determine the minimum sample size for estimating R(US) mean and variance (~40 subjects).
- Developed a linear regression model using V(atm) and estimated R(US) to calculate ЄP(CRIT) in 75 individuals.
- Performed Bland-Altman analysis to compare measured P(CRIT) and ЄP(CRIT).
Main Results:
- The mean R(US) was 23 ± 1 cmH(2)O/L/s, with ~40 subjects needed to estimate population variance.
- The developed model yielded ЄP(CRIT) values ranging from 0 to -9.6 cmH(2)O.
- Bland-Altman analysis showed no significant mean difference between measured P(CRIT) and ЄP(CRIT) (-0.01 cmH(2)O), with limits of agreement at ± 2.3 cmH(2)O.
Conclusions:
- Estimating P(CRIT) from V(atm) using a fixed R(US) is a valid method for assessing upper airway properties.
- This approach enables large-scale studies on upper airway patency in OSA patients.
- Quantitative airflow measurements during polysomnography can effectively characterize upper airway function.
