Hyperosmolar hyperglycaemic state

Hyperosmolar hyperglycaemic state (HHS) 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 20%).

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.

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 usually ≥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.​​[1]Kitabchi AE, Umpierrez GE, Miles JM, et al. Hyperglycemic crises in adult patients with diabetes. Diabetes Care. 2009 Jul;32(7):1335-43. http://care.diabetesjournals.org/content/32/7/1335.long http://www.ncbi.nlm.nih.gov/pubmed/19564476?tool=bestpractice.com ​​[2]Joint British Diabetes Societies for Inpatient Care Group. Diabetes at the front door: a guideline for dealing with glucose related emergencies at the time of acute hospital admission. May 2023 [internet publication]. https://abcd.care/resource/jbds-16-diabetes-front-door ​​​ HHS and diabetic ketoacidosis (DKA) are often discussed as distinct entities, but they represent opposite ends of the spectrum of metabolic derangements in diabetes, and the conditions can overlap.[3]Stoner GD. Hyperosmolar hyperglycemic state. Am Fam Physician. 2017 Dec 1;96(11):729-36. http://www.ncbi.nlm.nih.gov/pubmed/29431405?tool=bestpractice.com ​ Both HHS and DKA are characterised by relative or absolute insulin deficiency combined with increased counter-regulatory hormones.​[1]Kitabchi AE, Umpierrez GE, Miles JM, et al. Hyperglycemic crises in adult patients with diabetes. Diabetes Care. 2009 Jul;32(7):1335-43. http://care.diabetesjournals.org/content/32/7/1335.long http://www.ncbi.nlm.nih.gov/pubmed/19564476?tool=bestpractice.com [4]Glaser N, Fritsch M, Priyambada L, et al. ISPAD clinical practice consensus guidelines 2022: diabetic ketoacidosis and hyperglycemic hyperosmolar state. Pediatr Diabetes. 2022 Nov;23(7):835-56. http://www.ncbi.nlm.nih.gov/pubmed/36250645?tool=bestpractice.com ​​​ Approximately 27% of patients with hyperglycaemic crises present with a mixed picture of DKA and HHS.[5]Pasquel FJ, Tsegka K, Wang H, et al. Clinical outcomes in patients with isolated or combined diabetic ketoacidosis and hyperosmolar hyperglycemic state: a retrospective, hospital-based cohort study. Diabetes Care. 2020 Feb;43(2):349-57. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6971788 http://www.ncbi.nlm.nih.gov/pubmed/31704689?tool=bestpractice.com ​​

This topic covers HHS in adults. Bear in mind that people aged 16 to 18 may be managed by either a paediatric team or an adult medical team according to local arrangements. The Joint British Diabetes Societies (JBDS) recommend following paediatric guidelines if the patient is being managed by a paediatric team, and following adult guidance if they are being managed by an adult team.[6]Joint British Diabetes Societies for Inpatient Care Group. The management of the hyperosmolar hyperglycaemic state (HHS) in adults with diabetes. Feb 2022 [internet publication]. https://abcd.care/resource/jbds-06-management-hyperosmolar-hyperglycaemic-state-hhs-adults-diabetes

In the UK, the Association of Children’s Diabetes Clinicians and the British Society of Paediatric Endocrinology and Diabetes (BSPED) publish joint guidance for the management of HHS in children.[7]Association of Children’s Diabetes Clinicians; British Society of Paediatric Endocrinology and Diabetes. Practical management of hyperglycaemic hyperosmolar state (HHS) in children. Apr 2021 [internet publication]. https://www.a-c-d-c.org/wp-content/uploads/2012/08/Practical-Management-of-Hyperglycaemic-Hyperosmolar-State-HHS-in-children-8.pdf