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.