Volume 122, Issue 2, Pages 473-478 (August 2002) Effect of Continuous Positive Airway Pressure on the Measurement of Thoracoabdominal Asynchrony and Minute Ventilation in Children Anesthetized With Sevoflurane and Nitrous Oxide Adrian Reber, MD, PhD, Jeremy M. Geiduschek, MD, Sandro A. Bobbià, MD, Heinz R. Bruppacher, MD, Franz J. Frei, MD CHEST Volume 122, Issue 2, Pages 473-478 (August 2002) DOI: 10.1378/chest.122.2.473 Copyright © 2002 The American College of Chest Physicians Terms and Conditions
Figure 1 Rib cage (RC) and abdominal wall (AB) motions are plotted against each other in a Lissajous figure. The ratio of m/s is an index of TAA. PA is calculated as the sine PA = m/s (see text). The counterclockwise direction indicates that abdominal wall expansion precedes rib cage expansion during inspiration. CHEST 2002 122, 473-478DOI: (10.1378/chest.122.2.473) Copyright © 2002 The American College of Chest Physicians Terms and Conditions
Figure 2 The effect of CPAP on measurements of TAA with an inspiratory component (PA, top; PhRIB, middle; and Ti/Ttot,bottom). Results from the study subjects scheduled for adenoidectomy and all other procedures (“others”) are presented. Data were skewed, and all data are therefore presented uniformly as median and 25 to 75% interquartile range. • = no CPAP; ○ = median value at CPAP of 5 cm H2O; □ = median value at CPAP of 10 cm H2O; * = Significantly different from no CPAP (p < 0.05). CHEST 2002 122, 473-478DOI: (10.1378/chest.122.2.473) Copyright © 2002 The American College of Chest Physicians Terms and Conditions
Figure 3 The effect of CPAP on measurements of Vt (top) and respiratory rate (f) [bottom]. Results from the study subjects scheduled for adenoidectomy and all other procedures (Others) are presented. Data were skewed, and all data are therefore presented uniformly as median and 25 to 75% interquartile range. • = no CPAP; ○ = median value at CPAP of 5 cm H2O; □ = median value at CPAP of 10 cm H2O; *Significantly different from no CPAP (p < 0.05). †Significantly different from CPAP of 5 cm H2O. CHEST 2002 122, 473-478DOI: (10.1378/chest.122.2.473) Copyright © 2002 The American College of Chest Physicians Terms and Conditions