Association between hydrogen gas inhalation and cardiac output in an asphyxiated piglet model.

About 80% of neonates with hypoxic-ischaemic encephalopathy (HIE) have cardiovascular dysfunction and are vulnerable to late-onset injury due to disrupted cerebral blood flow and metabolism. We previously reported the neuroprotective effect of hydrogen (H2) gas. This study investigated the effects of H2 gas inhalation on cardiac function in piglets after hypoxia-ischaemia (HI). Seventeen piglets ≤ 24 h old were subjected to HI insult for approximately 40 min and, after 10 min of resuscitation, were divided into an HI group (n = 10) and an HI-H2 gas inhalation group (2.2%–2.7% H2 gas for 6 h; n = 7). We examined biventricular single stroke volume (SV) and cardiac output (CO) within 6 h after HI insult using transthoracic echocardiography. The HI group (n = 10) showed a transient increase in SV and CO followed by a decline. In contrast, the HI-H2 group (n = 7) experienced a increase in right ventricular SV and CO, with a mild decrease in left ventricular parameters. Notably, right CO were significantly higher at 5 h after insult in the HI-H2 group (p = 0.023). Hydrogen gas inhalation may help preserve right ventricular performance after asphyxia.