What is Hyperosmolar Hyperglycemic State (HHS)?

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From the Guidelines

HHS is a life-threatening condition that requires immediate medical attention, and treatment should involve aggressive IV fluid replacement, insulin therapy, and electrolyte replacement, as outlined in the most recent guidelines 1.

Key Considerations

  • HHS typically occurs in type 2 diabetes and is characterized by extremely high blood glucose levels (often >600 mg/dL), severe dehydration, and altered mental status without significant ketoacidosis.
  • The mortality rate for HHS is high (10-20%), making prompt treatment crucial 1.
  • Treatment involves:
    • Aggressive IV fluid replacement (typically 0.9% normal saline at 15-20 mL/kg/hr initially, then adjusted based on response)
    • Insulin therapy (usually IV insulin at 0.1 units/kg/hr)
    • Electrolyte replacement (particularly potassium, phosphate, and magnesium as needed)
    • Addressing the underlying trigger

Management Goals

  • Restoration of circulatory volume and tissue perfusion
  • Resolution of ketoacidosis
  • Correction of electrolyte imbalance and acidosis
  • Treatment of any correctable underlying cause of HHS, such as sepsis, myocardial infarction, or stroke 1

Recent Guidelines

  • The use of bicarbonate in people with HHS is generally not recommended, as it has been shown to make no difference in the resolution of acidosis or time to discharge 1.
  • Recent studies have reported that the administration of a low dose of basal insulin analog in addition to intravenous insulin infusion may prevent rebound hyperglycemia without increased risk of hypoglycemia 1.
  • Successful transition from intravenous to subcutaneous insulin requires administration of basal insulin 2–4 h before the intravenous insulin is stopped to prevent recurrence of ketoacidosis and rebound hyperglycemia 1.

From the Research

Definition and Characteristics of HHS

  • Hyperosmolar hyperglycemic state (HHS) is a life-threatening emergency characterized by marked elevation of blood glucose, hyperosmolarity, and little or no ketosis 2, 3, 4, 5, 6
  • It is often associated with profound dehydration and various neurologic symptoms such as coma 2, 3
  • The condition is more common in patients with type 2 diabetes and can be triggered by underlying infections, certain medications, non-compliance, undiagnosed diabetes, substance abuse, and coexisting disease 2, 3, 5, 6

Treatment and Management of HHS

  • The first step of treatment involves careful monitoring of the patient and laboratory values 2, 3
  • Vigorous correction of dehydration with the use of normal saline is critical, requiring an average of 9 L in 48 hours 2, 3, 4
  • Potassium replacement should begin after urine output has been established 2, 3, 4
  • Insulin should be given as an initial bolus, followed by a continuous infusion until the blood glucose level falls to a target range 2, 3, 4
  • Identification and treatment of the underlying and precipitating causes are necessary 2, 3, 4, 5, 6

Complications and Prevention of HHS

  • Complications of HHS include vascular occlusions, myocardial infarction, low-flow syndrome, disseminated intravascular coagulopathy, and rhabdomyolysis 2
  • Preventing future episodes using patient education and instruction in self-monitoring is important 2
  • The patient with HHS should always be admitted to the intensive care unit 5
  • Research focuses on establishing safe and effective therapeutic strategies to reduce the high mortality of patients with HHS 5, 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Hyperosmolar hyperglycemic state.

American family physician, 2005

Research

Hyperosmolar Hyperglycemic State.

American family physician, 2017

Research

[Hyperosmolar hyperglycemic state].

Vnitrni lekarstvi, 2015

Research

Hyperosmolar Hyperglycemic State.

Emergency medicine clinics of North America, 2023

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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