Follow‐up to ‘Glycaemic management in a child with ornithine transcarbamylase deficiency undergoing cardiac surgery with hypothermic cardiopulmonary bypass’

We previously reported the case of a 2‐year‐old girl with ornithine transcarbamylase deficiency (OTCD) who developed uncontrollable hyperglycaemia during a Glenn procedure with hypothermic cardiopulmonary bypass (CBP), despite the use of a high‐dose insulin infusion [1]. This was attributed to steroid administration, surgical stress and dextrose overload. Eleven months after the Glenn procedure, the patient underwent a Fontan procedure with hypothermic CPB, but without using intraoperative steroids. The glucose level was stably controlled without insulin infusions.

Glucose administration is recommended in the peri‐operative management of patients with OTCD to prevent hyperammonaemia and avoid cerebral oedema. Glucose levels should be carefully monitored because hyperglycaemia can cause cerebral oedema. Corticosteroids are protective against cerebral oedema, but accelerate protein catabolism and induce insulin resistance, which may result in hyperammonaemia and hyperglycaemia respectively [2]. Furthermore, steroids suppress urea cycle‐related gene expression in OTCD and may weaken the effect of arginine, which is a treatment used for hyperammonaemia [3].

In our previous report, we described the occurrence of uncontrollable intra‐operative hyperglycaemia (maximum 25.4 mmol.l⁻¹), despite high‐dose insulin treatment (maximum 0.4 units.kg ⁻¹.h ⁻¹) [1]. In view of the possibility that steroid administration had contributed to hyperglycaemia and hyperammonaemia, during the subsequent Fontan procedure we decided not to administer steroids. Acceptable glycaemic control was achieved (maximum 10 mmol.l⁻¹) without the need for insulin during the operation, despite high‐dose dextrose administration (0.35 g.kg⁻¹.h⁻¹). The ammonia level was stable throughout and peaked at 51 μg.dl⁻¹. Considering this experience we advise caution regarding the administration of corticosteroids for prevention of cerebral oedema resulting from hyperammonaemia and uncontrollable hyperglycaemia in patients with OTCD.