Perioperative management of pediatric patients with inborn errors of metabolism during liver transplantation

Inborn errors of metabolism (IEM) are rare disorders, most are liver-based with liver transplantation (LT) emerging as an effective cure in the pediatric population. LT has been shown to offer a cure or deter disease progression and provide symptomatic improvement in patients with IEM. Each metabolic disorder is unique, with the missing enzyme or transporter protein causing substrate deficiency or toxic byproduct production. Knowledge about the distribution of deficient enzymes, the percentage of enzymes replaced by LT, and the extent of extrahepatic involvement helps anticipate and manage complications in the perioperative period. Most patients have multisystem involvement and can be on complex dietary regimens. Metabolic decompensation can be triggered due to the stress response to surgery, fasting and other unanticipated complications perioperatively. Thus, a multidisciplinary team's input including those from metabolic specialists is essential to develop disease and patient-specific strategies for the perioperative management of these patients during LT. In this review, we outline the classification of IEM, indications for LT along with potential benefits, basic metabolic defects and their implications, details of extrahepatic involvement and perioperative management strategies for LT in children with some of the commonly presenting IEM, to assist anesthesiologists handling this cohort of patients.