Continuous monitoring of ventilatory mechanics during one-lung ventilation.
OBJECTIVE
The Ultima SV respiratory monitor can be used to monitor the intraoperative effects of the lateral decubitus position and one-lung ventilation on ventilatory mechanics.


METHODS
Eight patients with esophageal cancer who required one-lung ventilation for esophagectomy and reconstruction were enrolled in the study. We monitored pressure-volume or flow-rate-volume loops continuously throughout the operation. Respiratory parameters were evaluated closely during five conditions of ventilation: two-lung ventilation in the supine position, two-lung ventilation in the lateral decubitus position, dependent one-lung ventilation in the lateral decubitus position, nondependent one-lung ventilation in the lateral decubitus position, and dependent one-lung ventilation in the lateral decubitus position with the chest opened. Respiratory rate was controlled at 10 breaths/min, and tidal volume was kept constant (10 ml/kg) during surgery.


RESULTS
Peak inspiratory pressure increased to 29.0 +/- 9.0 (mean +/- SD) cm H2O in the dependent one-lung in the lateral decubitus position with the chest opened (p < 0.01). Dynamic compliance decreased to 29.4 +/- 4.9 ml/cm H2O in the dependent one-lung in the lateral decubitus position with the chest opened (p < 0.01). The changing configuration of the loops also offered additional and instantaneous information during one-lung ventilation.


CONCLUSIONS
One-lung ventilation caused several changes in the whole respiratory system (lung, thorax, and endotracheal tube). Continuous monitoring of flow-rate-volume or pressure-volume loops with in-line spirometry provided comprehensive information regarding parameters in one-lung ventilation.
Iwasaka
H
H
Department of Anesthesiology, Oita Medical University, Japan.
Itoh
K
K
Miyakawa
H
H
Kitano
T
T
Taniguchi
K
K
Honda
N
N
D000368:Aged; D004938:Esophageal Neoplasms / Q000601:surgery; D006801:Humans; D008170:Lung Compliance; D016343:Monitoring, Intraoperative / Q000379:methods*; D011187:Posture; D012123:Pulmonary Ventilation; D012121:Respiration, Artificial; D013147:Spirometry / Q000379:methods