Authors :
Christine Wheeler, Barrow Neurological Institute at Phoenix Children's Hospital; Lisa Vanatta, Barrow Neurological Institute at Phoenix Children's Hospital; Angus Wilfong, University of Arizona College of Medicine; and Randa Jarrar, Barrow Neurological In
Rationale: In the updated recommendations from the International Ketogenic Diet Study Group, 80% of surveyed centers initiate the classic ketogenic diet (KD) on an inpatient basis.
1 The European consensus infant guidelines recommends all infants < 12 months of age be hospitalized for initiation of KD, for close monitoring and treatment of known adverse effects.
2 At Phoenix Children’s Hospital, all non-emergent patients are initiated on KD in an outpatient setting, regardless of age and are closely monitored by our ketogenic diet team. This study is to evaluate our experience and report on the safety and efficacy of initiating KD in an outpatient setting in infants = 18 months of age. Methods: A retrospective chart review of infants initiated on a KD from 2014 to 2018 at Phoenix Children’s Hospital was performed. Initiation protocol utilized a non-fasting approach with advancement to goal diet within 3-4 days. Lab monitoring as recommended by the International Ketogenic Diet Study Group was completed pre-diet, 1 month following initiation and every 3 months while on diet therapy or sooner if clinically indicated. Efficacy of dietary treatment was defined as >50% reduction of seizures within 3 months of diet initiation. Adverse effects reviewed were metabolic acidosis (CO2 <19 or symptomatic), impaired growth (decrease in pre-established growth curve requiring dietary adjustment), and gastrointestinal complaints (vomiting, diarrhea and/or constipation). Inclusion criteria: patients initiated on KD in an outpatient clinic (non-emergent) = 18 months of age, maintained on diet for at least 3 months, and with complete records available to review. Results: A total of 9 patients were identified that met inclusion criteria. The most common adverse effect observed was metabolic acidosis with 6 patients requiring addition of bicarbonate and/or reduction of concomitant medications that are carbonic anhydrase inhibitors. Six patients developed acidosis. Five out of these 6 patients with acidosis were successfully managed outpatient. One patient, newly diagnosed with GLUT-1 deficiency syndrome, was admitted with fever, vomiting, and lethargy three days after initiation of a 4:1 KD. The patient was on topiramate at diet initiation, which was weaned in the hospital and acidosis resolved without addition of bicarbonate or dietary intervention. In this group, two-thirds of patients experienced a greater than 50% reduction in seizures. This is consistent with other efficacy studies in infants. (Table 1 for patient demographics) Conclusions: KD can be safely and effectively initiated in infants = 18 months of age in an outpatient clinic. Adverse effects observed in this group were similar to those in older patients and successfully managed outpatient in all but one case, which may have had other contributing factors. To mitigate metabolic acidosis risk, consideration should be given for infants on carbonic anhydrase inhibitors to receive prophylactic treatment or reduction in dosage prior to KD initiation.References[1] Kossoff E, et al. Optimal clinical management of children receiving dietary therapies for epilepsy: updated recommendations of the International Ketogenic Diet Study Group. Epilepsia Open. 2018:1-18. doi:10.1002/epi4.12225[2] Van der Louw E et al. Ketogenic diet guidelines for infants with refractory epilepsy, European Journal of Paediatric Neurology. 2016.
http://dx.doi.org/10.1016/j.ejpn.2016.07.009 Funding: None