Hypoglycemia

Pathophysiology

• Hypoglycemia is generally defined as a blood glucose level < 50 mg/dl in adults/children, and < 30 mg/dl in neonates.
• Glucose homeostasis involves a tightly regulated balance between insulin and its counter regulatory hormones (glucagon, epinephrine, cortisol, growth hormone). An excess of insulin or deficiency of counter regulatory hormones will tip the balance toward hypoglycemia.
• Hypoglycemia is most often seen as a complication of diabetes therapy but is also seen in no diabetics, usually as a complication of other disease processes.
• In pediatric patients, hypoglycemia may be seen in the acutely ill or septic child due to lack of oral intake, hyper metabolic state, or secondary to accidental ingestions (alcohol, salicylates, oral hypoglycemic).

Diagnosis and Evaluation

Signs and Symptoms

• The exact level of glucose at which patients demonstrate the signs and symptoms of hypoglycemia varies among individuals based on age, weight, sex, activity level, and coexisting disease. Most adults will be symptomatic with levels < 50 mg/dl, but the rate of fall also contributes to symptoms.
• It is conceptually useful to divide the signs and symptoms of hypoglycemic into two categories: neuroglycopenic and adrenergic.
• Neuroglycopenic symptoms represent the direct CNS affects of hypoglycemia. Signs and symptoms include dizziness, fatigue, inability to concentrate, confusion, psychosis, headache and focal neurologic findings.
• Adrenergic symptoms are produced by the counter regulatory surge (i.e., epinephrine) in response to hypoglycemia. Signs and symptoms include tremor, anxiety, diaphoresis, tachycardia, nausea, and hunger.
• A subset of patients with diabetes has “hypoglycemic unawareness” due to an impaired adrenergic response secondary to autonomic neuropathy.
• The neonate and the young infant may be asymptomatic or demonstrate only subtle, nonspecific signs (lethargy, tachycardia, seizures, or apnea). Laboratories/Studies
• All patients with altered mental status require immediate finger stick glucose (accucheck, D-stick).
• Further laboratory tests (metabolic panel, CBC, cultures, CXR, EKG, or head CT) should be tailored to the patient’s history and physical condition when ruling out precipitant or underlying illness.

ED Management

• For symptomatic hypoglycemia, intravenous dextrose should be given as 50 ml of D50W (1 amp) and may be repeated as necessary.

  Etiologies of hypoglycemia

  Increased insulin levels	Overdose of insulin or oral hypoglycemic Insulinoma Post-gastrectomy/gastrojejunostomy (due to rapid gastric emptying and exaggerated insulin response).
  Underproduction of glucose Liver disease	Alcohol Sepsis Malnutrition Adrenal insufficiency Pituitary insufficiency Hypothyroidism Growth hormone deficiency Glucagon deficiency Chronic renal failure Medications (salicylates, â-blockers) Akee fruit Fasting

  Normal adults can maintain blood glucose levels up to 72 h of fasting.

• Oral glucose can be given if the patient is awake and there is no risk of aspiration (milk, juice, fruit).
• Some patients may need continuous infusion of glucose for persistent hypoglycemia, particularly in oral hypoglycemic overdoses.
• Consider glucagon 1 mg IM/SC/intranasal if IV access is delayed. Glucagon has a more important role in the prehospital setting. The effect will be seen in 10-20 min after stimulation of hepatic glucose release and will not work in the setting of hepatic insufficiency. Patients at risk for hypoglycemia should have glucagon available at home and a family member instructed in proper use.
• When chronic alcohol, alcoholic ketoacidosis abuse is suspected, thiamine should be given concurrently with glucose, as there is a theoretical risk of precipitating Wernicke’s encephalopathy.
• Pediatric hypoglycemia is treated with lower concentrations of dextrose to avoid hyperosmolarity, nonketotic hyperosmolar syndrome. Young children and infants: Give 25% dextrose, 2-4 ml/kg. Neonates: Give 10% dextrose 1-2 ml/kg.

Admission Criteria

• Patients need a monitored setting in the presence of unresolved neurological injury, severe hypoglycemia, recurrent hypoglycemia in the emergency department despite treatment, long-acting oral hypoglycemic overdoses, hypoglycemia at the extremes of age or with severe underlying illness.
• Patients may be discharged home if all of the following conditions are met: mild hypoglycemia only, complete resolution of symptoms, close primary physician follow-up, and the ability to administer insulin or oral hypoglycemic correctly.