Effects of body temperature on ventilator-induced lung injury.
OBJECTIVE
To evaluate the effects of body temperature on ventilator-induced lung injury.


METHODS
Thirty-four male Sprague-Dawley rats were randomized into 6 groups based on their body temperature (normothermia, 37 +/- 1 degrees C; hypothermia, 31 +/- 1 degrees C; hyperthermia, 41 +/- 1 degrees C). Ventilator-induced lung injury was achieved by ventilating for 1 hour with pressure-controlled ventilation mode set at peak inspiratory pressure (PIP) of 30 cmH2O (high pressure, or HP) and positive end-expiratory pressure (PEEP) of 0 cmH2O. In control subjects, PIP was set at 14 cmH2O (low pressure, or LP) and PEEP set at 0 cmH2O. Systemic chemokine and cytokine (tumor necrosis factor alpha , interleukin 1 beta , interleukin 6, and monocyte chemoattractant protein 1) levels were measured. The lungs were assessed for histological changes.


RESULTS
Serum chemokines and cytokines were significantly elevated in the hyperthermia HP group compared with all 3 groups, LP (control), normothermia HP, and hypothermia HP. Oxygenation was better but not statistically significant in hypothermia HP compared with other HP groups. Cumulative mean histology scores were higher in hyperthermia HP and normothermia HP groups compared with control and normothermia HP groups.


CONCLUSIONS
Concomitant hyperthermia increased systemic inflammatory response during HP ventilation. Although hypothermia decreased local inflammation in the lung, it did not completely attenuate systemic inflammatory response associated with HP ventilation.
Akinci
Ozkan I
OI
Department of Anesthesiology and Intensive Care, Istanbul Medical Faculty, Capa, Turkey. iozkana@yahoo.com
Celik
Mehmet
M
Mutlu
Gökhan M
GM
Martino
Janice M
JM
Tugrul
Simru
S
Ozcan
Perihan E
PE
Yilmazbayhan
Dilek
D
Yeldandi
Anjana V
AV
Turkoz
Kemal H
KH
Kiran
Bayram
B
Telci
Lütfi
L
Cakar
Nahit
N
D000818:Animals; D016207:Cytokines / Q000097:blood; D004195:Disease Models, Animal; D006979:Hyperthermia, Induced; D007036:Hypothermia, Induced; D007249:Inflammation / Q000209:etiology / Q000628:therapy; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012128:Respiratory Distress Syndrome / Q000209:etiology* / Q000473:pathology / Q000628:therapy*; D012122:Ventilators, Mechanical / Q000009:adverse effects*
D016207:Cytokines