Occurs most commonly in older people with type 2 diabetes. Contributes to less than 1% of all diabetes-related admissions. However, mortality is high (5% to 15%).
Presents with polyuria, polydipsia, weakness, weight loss, tachycardia, dry mucous membranes, poor skin turgor, hypotension, and, in severe cases, shock.
Acute cognitive impairment (lethargy, disorientation, stupor) is common and correlates best with effective serum osmolality. Coma is rare and, if seen, is usually associated with a serum osmolality >340 mOsm/kg (>340 mmol/kg)
Treatment includes correction of fluid deficit and electrolyte abnormalities, and intravenous insulin.
Hyperosmolar hyperglycaemic state (HHS), also known as non-ketotic hyperglycaemic hyperosmolar syndrome (NKHS), is characterised by profound hyperglycaemia (glucose >30 mmol/L [>540 mg/dL]), hyperosmolality (effective serum osmolality >320 mOsm/kg [>320 mmol/kg]), and volume depletion in the absence of significant ketoacidosis (pH >7.3 and bicarbonate >15 mmol/L [>15 mEq/L]), and is a serious complication of diabetes. HHS may be the first presentation of type 2 diabetes. Although both HHS and diabetic ketoacidosis (DKA) are often discussed as distinct entities, they represent two points on the spectrum of metabolic derangements in diabetes. Both HHS and DKA are characterised by relative or absolute insulin deficiency combined with increased counter-regulatory hormones. Approximately 33% of patients with hyperglycaemic crises present with a mixed picture of DKA and HHS.
History and exam
Gerry Rayman, MD, FRCP
Consultant Physician and Head of Service
Diabetes and Endocrine Centre and the Diabetes Research Unit
Ipswich Hospitals NHS Trust
GR is Lead and Innovator of the National Inpatient Diabetes Audit; and Joint Clinical Lead of the Diabetes, Getting It Right First Time programme.
GR has been paid for advisory board meetings with the following companies: Sanofi Aventis, Abbott Diabetes UK, Lilly Diabetes, and Bayer. GR has received lecture fees from Sanofi Aventis, Abbott Diabetes UK, Lilly Diabetes, Novo Nordisk, and Napp Pharmaceuticals Ltd.
BMJ Best Practice would like to gratefully acknowledge the previous expert contributors, whose work has been retained in parts of the content:
Natasha Khazai, MD
Joslin Diabetes Clinic
Guillermo Umpierrez, MD
Professor of Medicine
Emory University School of Medicine
NK declares that she has no competing interests. GU is supported by research grants from the American Diabetes Association and the National Institutes of Health, and has received research funds from Sanofi-Aventis, Novo Nordisk, Takeda, and GlaxoSmithKline.
Edward Jude, MBBS, DNB, MRCP
Honorary Professor of Medicine
University of Manchester
Tameside and Glossop Integrated Care NHS Foundation Trust
EJ declares that he has no competing interests.
Section Editor, BMJ Best Practice
AS declares that she has no competing interests.
Lead Section Editor, BMJ Best Practice
RW declares that she has no competing interests.
Comorbidities Editor, BMJ Best Practice
JC declares that she has no competing interests.
Drug Editor, BMJ Best Practice
AM declares that he has no competing interests.
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