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

Abstract

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±55.0mlmin−1vs. 72.0±11.2mlmin−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±25.0pgml−1vs. 131.4±27.0pgml−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±19.1UL−1vs. 29.1±8.0UL−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.