The Effect of Prone Position on Pulmonary Compliances by Anesthesia Duration

Cho, Sang Yoon; Noh, Gyu Jeong; Yeom, Jong Hoon; Shin, Woo Jong; Kim, Yong Chul; Kim, Kyoung Hun; Lee, Dong Ho

Abstract

BACKGROUND: We investigated the effects of the prone position on the compliance of the total respiratory system, the lung, and chest wall by measuring anesthesia duration in 10 anesthetized, and paralyzed tracheally intubated patients during mechanical ventilation undergoing a spine fusion operation.
METHODS
We used the esophageal balloon technique together with rapid airway occlusions during constant inspiratory flow to partition the mechanics of the respiratory system into its pulmonary and chest wall components. Measurements were taken in supine position and after 30, 60, and 90 min in the prone position maintaining the same respiratory pattern (tidal volume 10 mL/kg, respiratory rate 12 beats/min, FIO2 0.4).
RESULTS
We found that the prone position did not significantly affect the respiratory system (CRS) and the lung (CL), but there was a significantl changes from the value of Ccw, supine to the value of Ccw 60, 90 min (P < 0.05). Therefore, there was a significant change of CW in increased anesthesia duration (P < 0.05).
CONCLUSIONS
In conclusion, moving from supine to prone position during anesthesia did not significantly reduce compliance of the respiratory system and lung, but significantly reduced chest wall compliance. These changes should be considered in patients such as those with decreased chest wall compliance (obesity, kyphoscoliosis, ankylosing spondylitis) undergoing spinal surgery in prone position.