Ventilator Y-Piece Pressure Compared with Intratracheal Airway Pressure in Healthy Intubated Children |
| |
| Authors: | Omer Nasiroglu MD FAAP Bruce Craig Weldon MD Lawrence S. Berman MD Ikram Ul Haque MD FAAP |
| |
| Affiliation: | (1) Department of Anesthesiology, University of Florida, Gainesville, USA;(2) Department of Pediatrics, University of Florida, Gainesville, USA;(3) Department of Anesthesiology, University of Duke, Durham, USA;(4) Department of Pediatrics/Division of Critical Care Medicine, University of Florida College of Medicine, PO Box 100296 UFHSC, 1600 SW, Archer Road, Gainesville, FL, 32610-0296, usa |
| |
| Abstract: | Objective. Compare airway pressure measurements at the ventilator Y-piece of the breathing circuit (P Y ) to intratracheal pressure measured at the distal end (P T ) of the endotracheal tube (ETT) during mechanical ventilation and spontaneous breathing of intubated children. Methods. Thirty children (age range 29 days to 5 years) receiving general anesthesia were intubated with an ETT incorporating a lumen embedded in its sidewall that opened at the distal end to measure P T . Peak inflation pressure (PIP) was measured at P Y and P T during positive pressure ventilation. Just before extubation, all measurements were repeated and imposed resistive work of breathing (WOBi) was calculated at both sites while breathing spontaneously. Results. Average PIP was approximately 25% greater at P Y (19.7 ± 3.4 cm H2O) vs. P T (15.0 ± 2.9 cm H2O), p < 0.01. During spontaneous inhalation P T was 59% lower ({bond}8.5 ± 4.0 cm H2O) vs. P Y ({bond}3.5 ± 2.0 cm H2O), p < 0.01. WOBi measured at P Y (0.10 ± 0.02 Joule/L) was 86% less than WOBi measured at P T (0.70 ± 0.40 Joule/L), p < 0.01. Conclusions. In healthy children P Y significantly overestimates PIP in the trachea during positive pressure ventilation and underestimates the intratracheal airway pressure during spontaneous inhalation. During positive pressure ventilation P T better assesses the pressure generated in the airways and lungs compared to P Y because P T also includes the difference in airway pressure across the ETT tube due to resistance. During spontaneous inhalation, P T reflects the series resistance of the ETT and ventilator circuit, while P Y reflects only the resistance of the ventilator circuit, accounting for the smaller decreases in pressure. Additionally, P Y underestimates the total WOBi load on the respiratory muscles. Thus, P T is a more accurate reflection of pulmonary airway pressures than P Y and suggests that it should be incorporated into ventilator systems to more accurately trigger the ventilator and to reduce work of breathing. |
| |
| Keywords: | respiration artificial infant child intermittent positive-pressure ventilation intubation intratracheal work of breathing |
| 本文献已被 PubMed SpringerLink 等数据库收录！ |
|
