Hyperosmolar hyperglycemic state

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Pathophysiology & Triggers - Sugar Tsunami

  • Relative insulin deficiency: Unlike DKA's absolute lack, some insulin is present-enough to suppress ketogenesis but not enough to prevent severe hyperglycemia (glucose > 600 mg/dL).
  • Osmotic Diuresis: Extreme hyperglycemia overwhelms the kidneys' ability to reabsorb glucose, causing massive water loss, profound dehydration, and hyperosmolarity (serum Osm > 320 mOsm/kg).
  • Common Triggers: Infections (e.g., pneumonia, UTI), acute illness (MI, stroke), or medication non-compliance.

Pathophysiology of Hyperosmolar Hyperglycemic State (HHS)

⭐ The hallmark of HHS is profound hyperglycemia and hyperosmolarity without significant ketoacidosis, a key distinction from Diabetic Ketoacidosis (DKA).

Clinical Presentation - Dried & Dazed

  • Profound Dehydration ("Dried"): The hallmark, driven by severe osmotic diuresis.

    • Signs: ↓ skin turgor, dry mucous membranes, tachycardia, hypotension.
    • Leads to significant hyperosmolality (serum Osm > 320 mOsm/kg).
  • Neurological Dysfunction ("Dazed"): Directly correlates with the degree of hyperosmolality.

    • Spectrum: Lethargy, confusion, delirium → focal neurologic deficits (hemiparesis, aphasia) → seizures, coma.
    • 📌 Onset is typically insidious over days to weeks.

⭐ Focal neurologic deficits can mimic a stroke; always check a fingerstick glucose in any patient with altered mental status!

Diagnosis & Labs - The Numbers Game

  • Severe Hyperglycemia: Blood glucose >600 mg/dL (often >1000).
  • Profound Hyperosmolality: Effective serum osmolality >320 mOsm/kg H₂O.
    • Calculated: $2 \times \text{Na} + \frac{\text{Glucose}}{18}$
  • Absence of Significant Acidosis:
    • Arterial pH >7.3
    • Serum bicarbonate >18 mEq/L
  • Minimal or No Ketosis:
    • Urine & serum ketones are negative or only mildly positive, distinguishing it from DKA.
  • Other Key Labs:
    • ↑ BUN/Cr ratio (prerenal azotemia from extreme dehydration).
    • Anion gap is typically normal (<12).
    • Sodium: May be low due to hyperglycemic-induced pseudohyponatremia.

⭐ The hallmark is severe dehydration, with an average total body water deficit of 8-12 liters, far exceeding that seen in DKA.

Management - First, Fluids!

  • Primary Goal: Aggressive IV hydration to restore perfusion and correct severe dehydration (total body water deficit is typically 8-12 L).
  • Initial Fluid: Start with 1-1.5 L of 0.9% Normal Saline (NS) over the first hour, regardless of sodium level.
  • Subsequent Fluids: After the initial bolus, calculate the corrected serum sodium to guide fluid choice.
    • $Corrected\ Na⁺ = Measured\ Na⁺ + [2.4 \times (Serum\ Glucose - 100)/100]$
    • Adjust infusion rate to 250-500 mL/hr.

⭐ The goal is to replace half of the free water deficit over the first 24 hours. Lowering serum osmolality by more than 3 mOsm/kg/h increases the risk of cerebral edema.

High‑Yield Points - ⚡ Biggest Takeaways

  • HHS features severe hyperglycemia (>600 mg/dL), profound dehydration, and serum osmolality >320 mOsm/kg.
  • Typically seen in Type 2 DM, often triggered by illness, leading to altered mental status.
  • No significant ketoacidosis is present due to small amounts of circulating insulin.
  • Primary treatment is aggressive IV fluid resuscitation with isotonic saline to correct dehydration.
  • IV insulin is administered after initial fluid replacement.
  • Always correct hypokalemia before initiating insulin therapy to prevent cardiac complications.

Practice Questions: Hyperosmolar hyperglycemic state

Test your understanding with these related questions

A 62-year-old man presents to the emergency department with confusion. The patient’s wife states that her husband has become more somnolent over the past several days and now is very confused. The patient has no complaints himself, but is answering questions inappropriately. The patient has a past medical history of diabetes and hypertension. His temperature is 98.3°F (36.8°C), blood pressure is 127/85 mmHg, pulse is 138/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is notable for a confused man with dry mucous membranes. Initial laboratory studies are ordered as seen below. Serum: Na+: 135 mEq/L Cl-: 100 mEq/L K+: 3.0 mEq/L HCO3-: 23 mEq/L BUN: 30 mg/dL Glucose: 1,299 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.2 mg/dL Which of the following is the most appropriate initial treatment for this patient?

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Flashcards: Hyperosmolar hyperglycemic state

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The osmotic diuresis in diabetic ketoacidosis may lead to fatal arrhythmias by causing _____ depletion

TAP TO REVEAL ANSWER

The osmotic diuresis in diabetic ketoacidosis may lead to fatal arrhythmias by causing _____ depletion

total body K+

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