BSPED2018 Oral Communications Oral Communications 5 (9 abstracts)
1Department of Paediatric Endocrinology, Royal Hospital for Children, Glasgow, UK; 2Department of Paediatric Endocrinology, Great Ormond Street Hospital, London, UK; 3Department of Paediatric Endocrinology, Alder Hey Childrens Hospital, Liverpool, UK; 4Department of Paediatric Endocrinology, Royal Manchester Childrens Hospital, Manchester, UK; 5Department of Paediatric Endocrinology, Royal Hospital for Sick Children, Edinburgh, UK; 6Department of Paediatric Cardiology, Royal Hospital for Children, Glasgow, UK; 7Department of Paediatric Cardiology, Great Ormond Street Hospital, London, UK.
Objectives: Diazoxide is first line treatment for hypoglycaemia due to hyperinsulinaemic hypoglycaemia (HH). Although sporadic cases of pulmonary hypertension (PH) have been reported, no HH cohort has been systematically characterised to understand severity and risk factors for diazoxide-induced PH.
Methods: To investigate the onset, progress and associated factors in PH, patients with HH who developed diazoxide-induced PH in 4 regional centres were retrospectively reviewed. PH diagnosis was based on clinical and/or echocardiography evidence. Child and treatment-related risk factors were analysed for association. The time intervals from diazoxide initiation to onset and resolution of PH were also recorded.
Results: Twelve cases were identified (5M:7F). HH was diagnosed at median (range) 12 (1,180) days, with diazoxide started 3 (1,76) days from diagnosis, reaching highest dose of 8.0 (2.5,20) mg/kg/day. Only 3 (25%) patients had mutations in ABCC8/KCNJ11 establishing genetic causation. Total fluid intake was 170 (100,180) ml/kg/day prior to treatment. The majority developed PH within 2 weeks of diazoxide [12 (2,90) days], with 3 patients requiring intensive care ventilation (2 requiring high frequency oscillation). Two-thirds of (8/12) patients had baseline echocardiography before initiation of diazoxide. Diazoxide dose reduction did not ameliorate PH but complete withdrawal led to PH resolution at a variable time of 32.5 (3,985) days. In 3 patients, PH has yet to resolve after 6 months. Risk factors for the development of PH included low birthweight in 6 (50%) and fluid intake exceeding 130 ml/kg/day in 10 (83%) patients. Eight (67%) patients also had congenital heart disease (CHD). The presence or absence of CHD did not influence the time to develop PH (P=0.37) or time for PH resolution (P=0.99) respectively.
Conclusion: PH is a serious complication of diazoxide therapy in HH occurring at an unpredictable time from initiation of treatment. We recommend vigilance for PH in low birthweight infants with fluid intake exceeding 130 ml/kg/day. PH-specific echocardiography should be performed before diazoxide treatment to identify underlying CHD, followed by weekly monitoring for at least the first 2 weeks. If PH is identified, diazoxide should be discontinued to facilitate PH resolution.