Hidetoshi Ikeda1, Takao Ayuse, Kumiko Oi. 1. Division of Clinical Physiology, Department of Translational Medical Sciences, College of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Japan.
Abstract
STUDY OBJECTIVE: To test the hypothesis that the change of body and head position affects upper airway patency during midazolam sedation. DESIGN: Clinical study using 30 healthy subjects. SETTING: Research unit for sleep study. INTERVENTIONS: We used a pressure-flow relationship to evaluate critical closing pressure (Pcrit) and upper airway resistance (Rua) in different condition of body and head position. A pressure-flow relationship was obtained in 3 body postures (supine, 15 degrees elevation, and 30 degrees elevation) and was obtained in 3 head positions (supine with the head in the neutral, supine with head extension, and supine position with head rotated). MEASUREMENTS: The pressure and inspiratory flow at subjects' nose mask were recorded. Polysomnographic parameters (electroencephalograms, electrooculograms, submental electromyograms, upper esophageal pressure, and plethysmogram) were also recorded. MAIN RESULTS: In experiment 1, 30 degrees elevation of the body significantly decreased Pcrit (P < 0.05) to -13.3 +/- 1.3 cm H(2)O compared with -8.2 +/- 1.4 cm H(2)O in supine condition without changing the slope (1/Rua). In experiment 2, head extension significantly decreased Pcrit (-12.5 +/- 1.3 cm H(2)O) (P < 0.05) compared with the value (-8.2 +/- 1.0 cm H(2)O) in supine condition without changing the slope (1/Rua). CONCLUSIONS: Our findings indicate that 30 degrees body elevation and head extension significantly decreased upper airway collapsibility during midazolam sedation and established the relative potency of maneuvers that maintain upper airway patency.
STUDY OBJECTIVE: To test the hypothesis that the change of body and head position affects upper airway patency during midazolam sedation. DESIGN: Clinical study using 30 healthy subjects. SETTING: Research unit for sleep study. INTERVENTIONS: We used a pressure-flow relationship to evaluate critical closing pressure (Pcrit) and upper airway resistance (Rua) in different condition of body and head position. A pressure-flow relationship was obtained in 3 body postures (supine, 15 degrees elevation, and 30 degrees elevation) and was obtained in 3 head positions (supine with the head in the neutral, supine with head extension, and supine position with head rotated). MEASUREMENTS: The pressure and inspiratory flow at subjects' nose mask were recorded. Polysomnographic parameters (electroencephalograms, electrooculograms, submental electromyograms, upper esophageal pressure, and plethysmogram) were also recorded. MAIN RESULTS: In experiment 1, 30 degrees elevation of the body significantly decreased Pcrit (P < 0.05) to -13.3 +/- 1.3 cm H(2)O compared with -8.2 +/- 1.4 cm H(2)O in supine condition without changing the slope (1/Rua). In experiment 2, head extension significantly decreased Pcrit (-12.5 +/- 1.3 cm H(2)O) (P < 0.05) compared with the value (-8.2 +/- 1.0 cm H(2)O) in supine condition without changing the slope (1/Rua). CONCLUSIONS: Our findings indicate that 30 degrees body elevation and head extension significantly decreased upper airway collapsibility during midazolam sedation and established the relative potency of maneuvers that maintain upper airway patency.
Authors: Suzanne B Karan; Elia D Rackovsky; William A Voter; Ashok N Shah; Denham S Ward Journal: J Clin Monit Comput Date: 2012-06-06 Impact factor: 2.502
Authors: Rafael S Arias; Branden Etienne; Vsevolod Y Polotsky; William Checkley; Alan R Schwartz; Luu V Pham Journal: Respir Physiol Neurobiol Date: 2019-05-24 Impact factor: 1.931
Authors: Takao Ayuse; Yuko Hoshino; Shinji Kurata; Terumi Ayuse; Hartmut Schneider; Jason P Kirkness; Susheel P Patil; Alan R Schwartz; Kumiko Oi Journal: Anesth Analg Date: 2009-10 Impact factor: 5.108