Effects of hydrocortisone on activation of inflammation via interleukin-33 in ventilator-induced lung injury.

Despite mechanical ventilation being a very important life-saving intervention, ventilator-induced lung injury (VILI) is related with inflammatory effects and causes high mortality. Our previous study demonstrated that the interleukin-33 (IL-33) cytokine pathway is a biomarker of VILI. The purpose of this study was to further explore the effects of hydrocortisone sodium succinate (HC) on pro-inflammatory IL-33 activation by VILI. The rats were intubated and received ventilation at 20 cmH₂O of inspiratory pressure (PC20) by a G5 ventilator for 4 h as a control group, and an intervention group received the same inspiratory pressure as well as treated with HC at 1 mg/kg at the third hour of ventilation (PC20+HC). The hemodynamic and respiratory data showed similar changes in the two groups that were exposed to VILI. The pathophysiological results showed that the HC treatment attenuated the VILI severity. Treatment of HC increased IL-33 expression in the bronchoalveolar lavage fluid (BALF). These results demonstrated that IL-33 is involved in VILI processing and HC treatment attenuated IL-33 involvement in inflammatory activation in VILI. In conclusion, IL-33 may play an important role in VILI.