Management of Hypoglycemia

Definition and Classification

Clinical Features

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

• Headache, dizziness, difficulty concentrating, confusion, visual disturbances, drowsiness, bizarre behavior, seizures, loss of consciousness, coma

Note: Beta-blockers can mask adrenergic symptoms, leaving only neuroglycopenic clues. Hypoglycemia can also mimic acute ischemic stroke.

Acute/Urgent Management

Step 1 - Conscious patient (mild to moderate hypoglycemia)

• Give 15-20 g of glucose orally (glucose tablets preferred)
• Recheck blood glucose in 15 minutes
• Repeat if still hypoglycemic
• Once resolved, have patient eat a meal or snack to replete glycogen stores

• Glucose tablets (preferred)
• Sugar-containing beverages
• Candy, fruit, milk

Avoid pure protein (peanut butter, cheese) - negligible effect on blood glucose. Avoid pure fructose - does not cross the blood-brain barrier. In resource-limited settings, sublingual 40% dextrose gel or a teaspoon of sugar may suffice.

Step 2 - Unconscious or unable to take oral intake

• Give 25 g (50 mL of 50% dextrose, D50W) IV bolus immediately
• Follow with D5W or D10W infusion to maintain glucose > 100 mg/dL
• Prolonged IV dextrose infusion + close observation warranted for:
  • Sulfonylurea overdose
  • Elderly patients
  • Patients with defective counterregulation

• 1 mg IM or SC in adults
• Acts via glycogenolysis - onset 10-15 minutes
• Intranasal glucagon (3 mg) is also an approved alternative
• Limitations:
  • Ineffective in glycogen-depleted patients (e.g., alcohol-induced hypoglycemia, starvation, liver disease)
  • Stimulates insulin secretion - less useful in T2DM
  • Frequently causes nausea and vomiting (aspiration risk)
• Once patient is alert enough to swallow, give oral glucose immediately

Management by Cause

Iatrogenic (Insulin / Sulfonylurea-Induced) - Most common

• Correct hypoglycemia acutely as above
• Sulfonylurea-induced hypoglycemia can persist for hours to days - requires prolonged monitoring and dextrose infusion
• Octreotide (somatostatin analogue) can suppress insulin secretion in SFU-induced hypoglycemia and is considered superior to glucose and diazoxide in this setting
• Review and adjust insulin/SFU doses, meal timing, and physical activity
• Use CGM with alarms to reduce recurrence
• Education: teach patient and caregivers to recognize symptoms and use glucagon kits

Insulinoma

• Surgical resection is the treatment of choice (pancreatectomy)
• For unresectable/malignant insulinoma or surgical bridge:
  • Diazoxide (5-20 mg/kg/day PO TID) - suppresses insulin secretion
  • Octreotide (long- or short-acting)
  • Everolimus (mTOR inhibitor) - effective for malignant insulinoma or non-surgical candidates
• Localization: endoscopic ultrasound (test of choice, sensitivity 86-92%), or arterial stimulation with venous sampling for < 2 cm tumors

Congenital Hyperinsulinemic Hypoglycemia

• Diazoxide (5-20 mg/kg/day PO TID) - first-line; combine with hydrochlorothiazide 25-50 mg/day to counter fluid retention
• Second-line: short- or long-acting octreotide, or glucagon infusion (1-10 mcg/kg/hr SC/IV)
• Last resort: sirolimus (mTOR inhibitor, 0.5 mg/m²/day) or near-total pancreatectomy

Postprandial / Dumping Syndrome Hypoglycemia

• Frequent small, low-carbohydrate meals
• Acarbose (alpha-glucosidase inhibitor) - slows carbohydrate absorption
• Diazoxide, Octreotide
• Emerging: calcium channel blockers, SGLT1 inhibitors (e.g., canagliflozin)
• Severe cases may require pancreatectomy

Critical Illness-Associated Hypoglycemia

• Treat the underlying illness (sepsis, organ failure)
• Discontinue or adjust causative medications
• Glucose infusion to maintain normoglycemia

Adrenal Insufficiency / Hormone Deficiency

• Hydrocortisone 10-12 mg/m²/day (+ mineralocorticoid for adrenal insufficiency) - can be life-saving
• Recombinant growth hormone (0.02-0.03 mcg/kg/day) for GH deficiency
• Replacement therapy is definitive

Insulin Autoimmune Syndrome

• Glucocorticoids (e.g., prednisolone 0.5 mg/kg) are mainstay
• Some patients respond to diazoxide and octreotide
• Often self-limited

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

• Surgical resection of the primary tumor
• If unresectable: glucocorticoids or GH administration may reduce episodes

Drug/Toxin-Induced Hypoglycemia

• Remove or avoid the offending agent
• Supportive glucose replacement

Glycogen Storage Disorders / Fatty Acid Oxidation Defects

• Avoid prolonged fasting
• Raw uncooked cornstarch at bedtime (slow-release glucose source)
• For severe cases: overnight intragastric glucose infusion

Prevention of Recurrent Hypoglycemia

1. Identify and treat the underlying cause
2. Adjust diabetes medications - reduce insulin or SFU doses where appropriate
3. Educate patient on meal timing, carbohydrate distribution, and exercise
4. Increase monitoring frequency with SMBG; consider CGM with low-glucose alerts
5. Provide glucagon emergency kits to caregivers of T1DM patients
6. Strict avoidance of fasting in metabolic enzyme defects
7. Avoid excessive alcohol

Special Situations

Summary Algorithm

Hypoglycemia detected
        |
  Patient conscious?
  /           \
YES             NO
 |               |
Oral glucose     IV access?
15-20 g         /        \
Recheck 15 min  YES       NO
Repeat if       |          |
needed          D50W 25g IV  Glucagon 1mg IM/SC
                + D5W/D10W   (if not glycogen-depleted)
                infusion      |
                    |       Once alert → oral glucose
                    Monitor; identify/treat cause

• Harrison's Principles of Internal Medicine 22E, pp. 3279-3280
• Goldman-Cecil Medicine, pp. 2495-2497
• Tintinalli's Emergency Medicine, pp. 1463-1464
• Washington Manual of Medical Therapeutics, pp. 909-911