Hypoglycaemia: A Guide for Junior Doctors

Hypoglycaemia is a common medical emergency that can present in various ways, from mild symptoms like sweating and shakiness to severe neurological impairment such as seizures or loss of consciousness. Understanding the rapid assessment and management of hypoglycaemia is crucial for junior doctors working in emergency settings. This blog will guide you through the essential aspects of history-taking, clinical examination, investigations, and management.

·     History Taking: Essential Questions

When assessing a patient with suspected hypoglycaemia, a structured history is key. Begin by exploring the presenting complaint and associated symptoms. Tailor your questions to uncover the underlying cause.

·       Key Questions to Ask:

·       Symptoms at onset: "What symptoms did you notice before or during this episode?" Common early signs include sweating, trembling, palpitations, confusion, or behavioral changes.

·       Onset and duration: "How quickly did these symptoms come on?" Hypoglycaemia can have a rapid onset, and knowing this helps differentiate from other causes of altered consciousness.

·       Medications: "Are you on insulin, oral hypoglycaemic agents, or steroids?" Diabetics on insulin or sulfonylureas are at higher risk of hypoglycaemia.

·       Food intake: "When did you last eat?" and "Have you changed your diet recently?" Missed meals or reduced carbohydrate intake may precipitate hypoglycaemia, especially in those on glucose-lowering therapies.

·       Alcohol use: "Have you consumed alcohol recently?" Alcohol can suppress gluconeogenesis, especially after prolonged fasting.

·       Physical exertion: "Did you engage in any strenuous activity?" Exercise can deplete glycogen stores, especially in patients on insulin.

·       Comorbid conditions: "Do you have any liver disease, renal failure, or malignancies?" These conditions can affect glucose metabolism and insulin clearance.

·       Past episodes: "Have you had similar episodes before?" Recurrent hypoglycaemia may point to medication dosing issues or insulinomas.

·       Examination Findings: What to Look For

A thorough examination should focus on both the immediate identification of hypoglycaemia and the search for an underlying cause.

·       Key Examination Findings:

• General appearance: Look for sweating, pallor, or agitation—classic signs of sympathetic activation.

• Neurological signs: Assess for confusion, drowsiness, seizures, or coma. Focal neurological deficits, while rare, can occur and mimic stroke in severe hypoglycaemia.

• Cardiovascular: Tachycardia and hypertension are often seen as compensatory mechanisms.

• Hypothermia: Check for low body temperature, as hypoglycaemia can impair thermoregulation.

• Signs of chronic liver disease: Spider nevi, jaundice, or ascites may indicate an underlying hepatic cause of hypoglycaemia.

• Injection sites: Examine for insulin injection marks or bruises, especially in diabetics or those at risk of misuse.

  
  

·       Investigations: Confirming Hypoglycaemia and Identifying the Cause

In the emergency department, confirming hypoglycaemia and identifying any precipitating factors is vital.

Immediate Tests:

·       Capillary blood glucose: This is the cornerstone test for diagnosing hypoglycaemia. A reading <3.0 mmol/L is generally diagnostic, though patients may have symptoms at higher levels if they have poor hypoglycaemia awareness.

·       Plasma glucose: If available, measure plasma glucose for a more accurate reflection, especially in severe cases or diagnostic dilemmas.

Additional Investigations:

·       Urea and electrolytes: To assess for renal failure, a common risk factor in diabetic patients on insulin or oral hypoglycaemics.

·       Liver function tests: Hypoglycaemia can be caused by hepatic dysfunction, particularly in patients with liver disease or alcohol abuse.

·       Cortisol levels: Consider in cases of recurrent hypoglycaemia to rule out adrenal insufficiency.

·       C-peptide and insulin levels: These are crucial in identifying endogenous causes of hypoglycaemia, such as insulinomas or factitious insulin use.

·       Drug screen: If there’s suspicion of substance abuse or overdose (especially insulin or sulfonylureas), a drug screen may be useful.

·       ECG: Hypoglycaemia can precipitate arrhythmias, particularly in patients with underlying cardiovascular disease.

·       Management Plan: Immediate and Ongoing Care

The management of hypoglycaemia involves rapid glucose replacement and addressing the underlying cause.

Immediate Treatment:

Mild to moderate hypoglycaemia (Conscious, able to swallow):

• Oral glucose: Administer 15-20g of fast-acting carbohydrate, such as glucose tablets, sugary drinks, or snacks.

• Recheck blood glucose after 15 minutes, and repeat if necessary.

• Once stable, provide a longer-acting carbohydrate (e.g., a sandwich or biscuits) to maintain glucose levels.

• Severe hypoglycaemia (Altered consciousness or unable to swallow):

• Intravenous glucose: Give 50ml of 10-20% glucose over 5-10 minutes.

• If IV access is not available, consider intramuscular glucagon (1 mg in adults).

• Recheck blood glucose every 10-15 minutes until stable.

Preventing Recurrence:

Once stabilized, identify and address the cause to prevent future episodes.

·       Adjust diabetic medications: Consider reducing insulin or oral hypoglycaemics, especially in elderly patients or those with impaired renal function.

·       Patient education: Advise patients on the importance of regular meals, carbohydrate intake, and the risks of alcohol use.

·       Referral to specialist: If hypoglycaemia is recurrent or unexplained, refer the patient for endocrine or diabetic specialist follow-up.