Experience of prolonged aortic cross-clamping of two hours or more in early infancy and method of its myocardial protection.

Hyperoxia causes oxygen free radical-mediated membrane injury and alters myocardial function and hemodynamics in the newborn

“…During the medical and/or surgical management of these patients, exposure to high levels of oxygen (hyperoxia) for varying durations can occur (1,2,35,41). For example, during ECMO or CPB, systemic oxygen levels can reach an arterial PO 2 (Pa O 2 ) of up to 500 mmHg, which can last several days during extracorporeal membrane oxygenation or for 2-5 h during a cardiac operation (1,35).…”

“…NEWBORN CHILDREN requiring critical care in such cases as extracorporeal membrane oxygenation (ECMO) or undergoing cardiopulmonary bypass (CPB) are often exposed to high oxygen levels (hyperoxia) during their medical and/or surgical management (1,2,35,41). Pediatric ECMO patients have one of the lowest survival rates partly as a result of secondary organ dysfunction after several days of conventional critical management (36).…”

Does hyperoxia affect glucose regulation and transport in the newborn?

“…6,[9][10][11] Infants and children suffering from congenital heart disease are often exposed to hyperoxia for varying duration during CPB or extracorporeal membrane oxygenation. [12][13][14][15] Under these conditions, systemic hyperoxia can reach an arterial partial pressure of oxygen (PaO 2 ) range of 250 to 500 mm Hg, which can last for 2 to 5 hours during a cardiac operation or several days during extracorporeal membrane oxygenation. 12,15 We examined a cohort of children undergoing routine CPB for primary repair for congenital defects at the Hospital for Sick Children (Toronto, Canada) and found that despite normal preoperative blood glucose levels, during surgery they demonstrated a significant and strong positive correlation between their absolute oxygen and blood glucose levels.…”

“…[12][13][14][15] Under these conditions, systemic hyperoxia can reach an arterial partial pressure of oxygen (PaO 2 ) range of 250 to 500 mm Hg, which can last for 2 to 5 hours during a cardiac operation or several days during extracorporeal membrane oxygenation. 12,15 We examined a cohort of children undergoing routine CPB for primary repair for congenital defects at the Hospital for Sick Children (Toronto, Canada) and found that despite normal preoperative blood glucose levels, during surgery they demonstrated a significant and strong positive correlation between their absolute oxygen and blood glucose levels. 3 This identified that hyperoxia is indeed an important contributor to the hyperglycemic response seen in children who are placed on CPB.…”