Protection of the endothelium and endothelial glycocalyx by hydrogen against ischemia-reperfusion injury in a porcine model of cardiac arrest

Hydrogen is a potent antioxidant agent that can easily be administered by inhalation. The aim of the study was to evaluate whether hydrogen protects the glycocalyx layer after successful cardiopulmonary resuscitation (CPR). Fourteen anesthetized piglets underwent CPR after induced ventricular fibrillation. During CPR and return of spontaneous circulation, 2% hydrogen gas was administered to seven pigs (hydrogen group) and seven constituted a control group. Biochemistry and sublingual microcirculation were assessed at baseline, during CPR, at the 15th, 30th, 60th, and 120th minute. All seven subjects from the hydrogen group and six subjects in the control group were resuscitated after 6–10 minutes. At baseline, there were no statistically significant differences in examined variables. After the CPR, blood pH, base excess, and lactate showed significantly smaller derangement in the hydrogen group than in the control group. By contrast, plasma syndecan-1 and the variables in sublingual microcirculation did not change after the CPR; here, the measured values were virtually identical between the groups. In pigs, hydrogen gas inhalation during CPR and post-resuscitation care was associated with less pronounced metabolic acidosis than in controls. However, we could not find evidence of injury to the endothelium or glycocalyx in any studied groups.

氢气是一种强效抗氧化剂，可通过吸入途径便捷给药。本研究旨在评估成功实施心肺复苏（cardiopulmonary resuscitation, CPR）后，氢气是否对糖萼层（glycocalyx layer）具有保护作用。14只麻醉仔猪在诱发心室颤动后接受心肺复苏操作，其中7只在心肺复苏及自主循环恢复阶段吸入2%氢气（氢气组），剩余7只作为对照组。分别于基线状态、心肺复苏期间，以及自主循环恢复后第15、30、60、120分钟，检测血液生化指标并观察舌下微循环情况。氢气组全部7只仔猪与对照组6只仔猪均在6~10分钟内成功复苏。基线状态下，各观测变量均无统计学显著性差异。心肺复苏后，氢气组的血液pH值、碱剩余及乳酸水平的异常程度显著低于对照组。与之相反，血浆多配体蛋白聚糖-1（syndecan-1）水平与舌下微循环相关指标在心肺复苏后均未发生明显变化，两组间实测值几乎一致。在仔猪实验模型中，心肺复苏期间及复苏后护理阶段吸入氢气，可较对照组显著减轻代谢性酸中毒程度。但本研究未在任何受试组中发现内皮细胞或糖萼层损伤的相关证据。