Endocrine Abstracts

Introduction: Adrenal function testing in neonates is undertaken for multiple indications however permanent neonatal adrenal insufficiency (AI) is rare. Accurate assessment of neonatal adrenal status is challenging due to changes in the adrenal gland perinatally, non-specific clinical signs, and a paucity of normative data.

Objective: Describe current UK practice regarding investigation and management of neonates considered at risk of AI.

Methods: A 46-question survey evaluating approach to: unstimulated and stimulated (SST) cortisol testing, result interpretation and management was sent to paediatric residents and consultants practising endocrinology at tertiary and secondary care centres throughout the UK.

Results: Responses were received from 35 centres, 18/22 tertiary and 17 secondary care centres. 88% of respondents were consultants (31/35). There was consensus on indications for neonatal cortisol testing with the majority having guidelines recommending testing in hypoglycaemia (33/35), ambiguous genitalia (27/35) & conjugated hyperbilirubinaemia (20/35). Only 9/35 of centres currently have a specific guideline relating to neonatal adrenal assessment, results interpretation or management. Most centres (31/35) do not use neonatal specific laboratory cut-offs for cortisol. Moreover, the laboratory cut-offs for cortisol sufficiency were significantly higher (median = 295nmol/l, range 100-500) than the level clinicians consider highly suspicious of AI (median = 100nmol/l range 50-420). Despite this discrepancy in biochemical and clinical thresholds the majority advised proceeding to an SST (26/35) following a laboratory reported abnormal cortisol. The SST testing method reported was generally uniform - standard dose and no recommended specific time of day (28/35). Approach to interpretation and management of abnormal SSTs varied. 14/35 employ a borderline category for peak cortisol cut off e.g. sick day steroids then retest prior to discharge. For failed SSTs the management and retesting also varied: individualised patient approach (11/35), start replacement hydrocortisone (14/35). Reported retesting timeframes ranged from 4 weeks to 6 months, at term or on discharge.

Conclusion: There is wide variation across the UK in approach to neonates at risk of AI, likely reflecting lack of a robust evidence-base to support safe but pragmatic testing, result interpretation and management of cortisol levels in neonates.