Last Modified: 9:13pm 08/04/2021

Diagnosis and Assessment of Severity


The Hyperglycaemic Hyperosmolar State (HHS) is a medical emergency. In the UK it is less common than diabetic ketoacidosis (DKA), though in areas with a high proportion of patients of African origin this may not be the case. HHS is associated with a significant morbidity and higher mortality than DKA and must be diagnosed promptly and managed intensively. The diabetes specialist team should be involved as soon as possible after admission.

For young people under the age of 16 years contact your paediatric diabetes service and refer to
published paediatric guidelines for the management of HHS such as those by Zeitler (2011) Hyperglycemic Hyperosmolar Syndrome in Children. Pathophysiological


The characteristic features of a person with HHS are:
• Hypovolaemia
• Marked hyperglycaemia (30 mmol/L or more) without significant hyperketonaemia (less than 3
mmol/L), ketonuria (2+ or less) or acidosis (pH greater than 7.3, bicarbonate greater than 15 mmol/L)
• Osmolality usually 320 mosmol/kg or more

N.B.  A mixed picture of HHS and DKA may occur

Assessment of severity

Patients with HHS are complex and often have multiple co-morbidities so require intensive monitoring.
Consider the need for admission to a high-dependency unit / level 2 environment, when one or more of
the following are present:
• osmolality greater than 350 mosmol/kg
• sodium above 160 mmol/L
• venous ⁄ arterial pH below 7.1
• hypokalaemia (less than 3.5 mmol/L) or hyperkalaemia (greater than 6 mmol/L) on admission
• Glasgow Coma Scale (GCS) less than 12 or abnormal
• AVPU (Alert, Voice, Pain, Unresponsive) scale
• oxygen saturation below 92% on air (assuming normal baseline respiratory function)
• systolic blood pressure below 90 mmHg
• pulse over 100 or below 60 bpm
• urine output less than 0.5 ml/kg/hr
• serum creatinine >200 µmol/L
• hypothermia
• macrovascular event such as myocardial infarction or stroke
• other serious co-morbidity.

JBDS Guidelines