Effect of ventilator-induced lung injury on the development of reperfusion injury in a rat lung transplant model.
OBJECTIVE
Although mechanical ventilation can potentially worsen preexisting lung injury, its importance in the setting of lung transplantation has not been explored. This study was undertaken to examine the effect of 2 ventilatory strategies on the development of ischemia-reperfusion injury after lung transplantation.


METHODS
In a rat lung transplant model animals were randomized into 2 groups defined by the ventilatory strategy during the early reperfusion period. In conventional mechanical ventilation the transplanted lung was ventilated with a tidal volume equal to 50% of the inspiratory capacity of the left lung and a low positive end-expiratory pressure. In minimal mechanical stress ventilation the transplanted lung was ventilated with a tidal volume equal to 20% of the inspiratory capacity of the left lung, and positive end-expiratory pressure was adjusted according to the shape of the pressure-time curve to minimize pulmonary stress.


RESULTS
After 3 hours of reperfusion, oxygenation from the transplanted lung was significantly higher with minimal mechanical stress ventilation than with conventional ventilation. In addition, elastance, cytokine levels, and morphologic signs of injury were significantly lower in the group with minimal mechanical stress ventilation.


CONCLUSIONS
This study demonstrates that the mode of mechanical ventilation used in the early phase of reperfusion of the transplanted lung can influence ischemia-reperfusion injury, and a protective ventilatory strategy on the basis of minimizing pulmonary mechanical stress can lead to improved lung function after lung transplantation.
de Perrot
Marc
M
Thoracic Surgery Research Laboratory, Toronto General Hospital, Toronto, Ontario, Canada.
Imai
Yumiko
Y
Volgyesi
George A
GA
Waddell
Thomas K
TK
Liu
Mingyao
M
Mullen
J Brendan
JB
McRae
Karen
K
Zhang
Haibo
H
Slutsky
Arthur S
AS
Ranieri
V Marco
VM
Keshavjee
Shaf
S
D000818:Animals; D016040:Lung Transplantation; D008297:Male; D011659:Pulmonary Gas Exchange; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000209:etiology*; D012121:Respiration, Artificial / Q000379:methods; D015656:Respiratory Mechanics; D013314:Stress, Mechanical; D012122:Ventilators, Mechanical / Q000009:adverse effects*