Diabetes mellitus and hypoglycaemia - ED revision
A concise, ED‑focused guide to classification, diagnostic thresholds, recognition and immediate management of hypoglycaemia, diabetic ketoacidosis (DKA) and hyperosmolar hyperglycaemic state (HHS).
Includes practical investigation priorities, common pitfalls and operational safety points (time‑critical medicines, point‑of‑care glucose, driving rules). Follow local trust/JBDS protocols for exact infusion preparations and replacement regimens; cited national guidance where relevant (NICE, Resuscitation Council UK, RCEM, GOV.UK).
Overview and classification
Diabetes mellitus (DM) denotes disorders producing persistent hyperglycaemia due to defective insulin secretion, insulin action (resistance), or both. In the ED the priority is recognising acute complications rather than establishing chronic diagnoses.
Major types
- Type 1: autoimmune β‑cell destruction → absolute insulin deficiency; requires lifelong insulin; predisposed to ketosis/DKA (NICE NG17).
- Type 2: insulin resistance with relative insulin deficiency; associated with age, obesity and family history (NICE NG28).
- Gestational: hyperglycaemia first detected in pregnancy; usually resolves postpartum.
- Other: monogenic forms, pancreatic disease, endocrinopathies, drug‑induced (e.g. corticosteroids), haemochromatosis.
Diagnostic thresholds used in adults (NICE)
> 11.1 mmol/L |
These thresholds are for diagnosis in ambulatory settings. In acute presentations use bedside glucose and targeted tests to identify complications (hypoglycaemia, DKA, HHS).