One-lung versus two-lung ventilation in the closed-chest anesthetized dog: a comparison of cardiopulmonary parameters.
OBJECTIVE
To evaluate cardiopulmonary effects of one-lung ventilation (OLV) versus two-lung ventilation (TLV) in closed-chest anesthetized dogs.


METHODS
Controlled, randomized experiment.


METHODS
Fourteen, 2- to 7-year-old adult dogs, weighing 23 +/- 6 kg.


METHODS
The dogs were anesthetized with acepromazine, morphine, thiopental, and halothane in oxygen, ventilated, and paralyzed with vecuronium. Tidal volume was 10 mL/kg. Respiratory rate was set to maintain end-tidal CO2 (ETCO2) at 40 +/- 2 mm Hg before instrumentation then not changed. The left bronchus of 7 dogs was obstructed with a Univent bronchial blocker (Fuji Systems Corp, Tokyo, Japan). Blood gas analysis and hemodynamic measurements were taken at predetermined intervals for 1 hour in the TLV group and at baseline and following bronchial obstruction in the OLV group.


RESULTS
Shunt fraction was not significantly different between groups, but in OLV shunt increased from baseline at 5 minutes. Arterial oxygen (PaO2) decreased after baseline in OLV compared with TLV. Arterial carbon dioxide (PaCO2) increased with OLV and decreased with TLV. In OLV, systemic vascular resistance was variable and decreased compared with TLV. Cardiac index increased over time in both groups but was not affected by treatment. Heart rate, mean arterial pressure, and diastolic arterial pressure increased with OLV compared with TLV but did not change over time.


CONCLUSIONS
This study shows that OLV statistically decreases oxygen tension and transiently increases shunt fraction, but with 100% O2 it appears to be a feasible procedure with minimal cardiopulmonary side effects in healthy dogs.


CONCLUSIONS
OLV is a feasible procedure in anesthetized dogs to better facilitate thoracic procedures such as bronchopleural fistula repair and thoracoscopy.
Department of Veterinary Anesthesia, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
S L
SL
Cantwell
T
T
Duke
P J
PJ
Walsh
A M
AM
Remedios
D
D
Walker
J G
JG
Ferguson
D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D004285:Dogs / Q000502:physiology* / Q000601:surgery*; D005260:Female; D007442:Intubation, Intratracheal / Q000662:veterinary; D008297:Male; D012121:Respiration, Artificial / Q000662:veterinary*; D019616:Thoracic Surgical Procedures / Q000662:veterinary*