Management of Hypoglycemia

Definition and Classification

Clinical Features

• Sweating, tremor, tachycardia, palpitations, anxiety, hunger, nausea

• Confusion, bizarre behavior, blurred vision, focal neurologic deficits, seizures, coma

Blood glucose is typically <40-50 mg/dL when symptomatic hypoglycemia occurs in adults. Hypoglycemia unawareness is a dangerous state where the autonomic prodrome is absent due to prior exposure to repeated hypoglycemic episodes, intensive insulin therapy, autonomic neuropathy, or long duration of type 1 DM. - ROSEN's Emergency Medicine

Acute / Emergency Management

Step 1: Conscious patient able to swallow - "15-15 Rule"

• Give 15-20 g of oral glucose - dextrose tablets, glucose gel, juice, candy, or any sugar-containing food/drink
• Recheck blood glucose in 15 minutes; repeat if still low
• Once glucose normalizes, the patient should eat a snack or meal to replenish glycogen stores

Step 2: Impaired consciousness or unable to swallow

• Adults: 25 g IV (50 mL of 50% dextrose) as a bolus over 2-3 minutes
• Follow with a continuous glucose infusion guided by serial glucose measurements
• Response is generally rapid

• 1 mg IM or SC in adults; effective within 15 minutes of restoring consciousness
• Intranasal glucagon 3 mg is an FDA-approved alternative (adults)
• For confused/semi-conscious patients at home: 2 tubes of 40% dextrose gel squeezed between gum and cheek for buccal absorption

Glucagon acts by stimulating glycogenolysis - it is ineffective in glycogen-depleted individuals (e.g., alcohol intoxication, marathon runners, prolonged starvation). Glucagon also stimulates insulin secretion, making it less useful in type 2 DM. - Harrison's Principles of Internal Medicine 22E

Glucagon is NOT recommended for sulfonylurea-induced hypoglycemia because it may paradoxically stimulate further insulin secretion. - Tintinalli's Emergency Medicine

Management by Specific Cause

Drug-Induced (Insulin or Sulfonylurea)

• Sulfonylurea-induced hypoglycemia can persist for hours to days - these patients must be admitted for observation
• Octreotide (somatostatin analogue) suppresses insulin secretion and is the preferred adjunct for refractory sulfonylurea-induced hypoglycemia:
  • 50-100 mcg SC after initial glucose correction; can repeat every 6-8 hours or as continuous IV infusion (125 mcg/hr) after a second episode
• Diazoxide (inhibits beta-cell insulin secretion): 300 mg IV over 30 min every 4 hours, for refractory sulfonylurea cases; monitor for hypotension
• For Somogyi phenomenon: reduce or retime insulin dose (not increase it), as nocturnal hypoglycemia causes rebound morning hyperglycemia

Critical Illness-Associated Hypoglycemia

• Treat the underlying cause: sepsis, organ failure (especially liver), or offending medications
• Focus on treating hepatic failure if present - the liver's glycogenolytic response is impaired

Congenital Hyperinsulinemic Hypoglycemia

• First-line: Diazoxide 5-20 mg/kg/day orally in 3 divided doses
  • Combine with hydrochlorothiazide 25-50 mg/day to counter fluid retention side effect
• Second-line: Octreotide (short-acting: 5-35 mcg/kg/day SC 3-4x daily, or long-acting formulation) or glucagon infusion (1-10 mcg/kg/hr SC or IV)
• Last resort: Sirolimus (mTOR inhibitor, 0.5 mg/m²/day) for diffuse hyperinsulinism refractory to medical therapy, or near-total pancreatectomy

Insulinoma

• Treatment of choice: Pancreatectomy
• Bridge therapy: Diazoxide and/or octreotide (including long-acting formulations)
• Malignant/unresectable insulinoma: Everolimus (mTOR inhibitor) has been reported effective

Post-Gastric Bypass / Dumping Syndrome

• Dietary modification (small frequent meals, low simple carbohydrates)
• Pharmacologic: Acarbose, diazoxide, octreotide
• Newer options: Calcium channel blockers, canagliflozin (SGLT1 inhibitor) have shown some success

Hormone Deficiency (Adrenal Insufficiency, GH Deficiency)

• Replace cortisol and/or growth hormone if deficient

Non-Islet Cell Tumor Hypoglycemia (IGF-2-omas)

• Surgical resection of the primary tumor is the treatment of choice

Prevention of Recurrent Hypoglycemia

• Patient education: recognition of early symptoms, carrying rapid-acting glucose at all times, wearing a medical alert bracelet
• Medication adjustment: discontinue or reduce dose of offending agents; avoid sulfonylureas in elderly patients
• Dietary measures: regular meals; bedtime long-acting carbohydrate snack (e.g., uncooked cornstarch) to prevent nocturnal hypoglycemia
• Glucose monitoring: check bedtime glucose; use continuous glucose monitoring (CGM) where available
• Insulin formulation: switch to ultra-long-acting analogues (glargine U-300, degludec) which carry lower hypoglycemia risk
• Hypoglycemia unawareness: restore awareness by strictly avoiding all hypoglycemic episodes for several weeks; adjust glycemic targets upward

Disposition

• Mild hypoglycemia (rapid glucose correction, identifiable reversible cause, no sulfonylurea or long-acting insulin): can be discharged with education and follow-up
• Admit if: sulfonylurea/long-acting insulin-induced, elderly, multiple episodes, unknown cause, persistent altered mental status, or inability to maintain oral intake

Key Points Summary