Mild hypothermia attenuate kidney injury in canines with oleic acid-induced acute respiratory distress syndrome

BackgroundHypothermia may attenuate ventilator induced-lung injury in acute respiratory distress syndrome (ARDS). However, the impact of hypothermia on extra-pulmonary organ injury in ARDS remains unclear. The purpose of this study was to investigate whether hypothermia affects extra-pulmonary organ injury in a canine ARDS model induced by oleic acid.ObjectivesTwelve anesthetized canines with oleic acid-induced ARDS were randomly divided (n = 6 per group) into a hypothermia group (core temperature of 33 ± 1 °C, HT group) and a normothermia group (core temperature of 38 ± 1 °C, NT group) and treated for four hours. The liver, small intestine and kidney were assessed by evaluating biochemical parameters, plasma and tissue cytokine levels, and tissue histopathological injury scores.ResultsThe HT group showed a lower plateau pressure, lung elastance and pulmonary vascular resistance. Hypothermia was associated with lower oxygen consumption (138.4 ± 55.0 ml min−1vs. 72.0 ± 11.2 ml min−1, P < 0.05) and higher oxygen saturation of mixed venous blood (62.8% ± 8.0% vs. 77.5% ± 10.1%, P < 0.05). Both groups had similar levels of tumour necrosis factor-α in the plasma and extra-pulmonary organ, however, plasma interleukin-10 (97.1 ± 25.0 pg ml−1vs. 131.4 ± 27.0 pg ml−1, P < 0.05) was higher in the HT group. Further, the animals in the HT group had a lower levels of plasma creatinine (54.6 ± 19.1 U L−1vs. 29.1 ± 8.0 U L−1, P < 0.05), and lower renal histopathological injury scores [4.0(3.5;7.0) vs. 1.5(0.8;3.0), P < 0.05]. Hypothermia did not affect the histopathological injury of the liver and small intestine.ConclusionsShort-term mild hypothermia can reduce lung elastance and pulmonary vascular resistance, increase the systemic anti-inflammatory response and attenuate kidney histopathological injury in a canine ARDS model induced by oleic acid.