Diabetic Coma 

Description

Diabetic coma is a life-threatening complication of diabetes mellitus resulting in altered consciousness or coma. It can arise from:

1. Diabetic Ketoacidosis (DKA) – usually in type 1 diabetes

2. Hyperglycaemic Hyperosmolar State (HHS / Non-Ketotic Hyperosmolar State) – usually in type 2 diabetes

3. Severe hypoglycaemia – due to insulin or oral hypoglycaemic agents

All forms cause electrolyte imbalance, dehydration, and metabolic derangements leading to altered mental status, seizures, or coma.

Pathophysiology

• DKA: Insulin deficiency → hyperglycaemia → lipolysis → ketone body formation → metabolic acidosis.

• HHS: Extreme hyperglycaemia → osmotic diuresis → severe dehydration → hyperosmolarity → altered mental status.

• Hypoglycaemic coma: Glucose < 2.8 mmol/L → inadequate cerebral glucose → CNS dysfunction, seizures, coma.

Risk Factors

• Poor diabetes control or missed insulin

• Infection, trauma, surgery, myocardial infarction

• Medications: steroids, diuretics

• Alcohol, dehydration

• Elderly patients for HHS

Signs and Symptoms

• General symptoms: Polydipsia, polyuria, weight loss, fatigue, lethargy, nausea, vomiting, abdominal pain

• DKA-specific: Kussmaul’s respiration (deep, rapid breathing), fruity/acetone breath odor

• HHS-specific: Severe dehydration, hypotension, neurologic deficits (confusion, seizure, coma)

• Hypoglycemia-specific: Sweating, tremor, palpitations, intense hunger, confusion, possible convulsions

• Other findings: Low GCS, hypotension, tachycardia, poor perfusion

Investigations

• Blood glucose: Random plasma glucose

• Urinalysis: Ketones, glucose, protein

• FBC: Evaluate infection, Hb, WBC

• U&E, Cr: Electrolytes and renal function

• LFTs: Rule out hepatic involvement

• ABG: Metabolic acidosis (DKA)

• Serum osmolality: Important for HHS

• Glycosylated Hb (HbA1C): Diabetes control

• CXR / ECG: Rule out infection, cardiac complications

• Blood cultures / Urine MCS: If infection suspected

• Electrocardiogram: Detect hypokalemia/hyperkalemia effects

Management

1. ABC Approach

• Airway: Assess and protect; intubate if GCS < 8

• Breathing: Oxygen supplementation as needed

• Circulation: Establish 2 large-bore IV lines; monitor vitals and perfusion

2. Fluid Resuscitation

• DKA: 0.9% NaCl 15–20 mL/kg in first hour; then 0.45% NaCl if corrected sodium high

• HHS: Aggressive isotonic saline (0.9% NaCl) to restore perfusion, followed by 5% dextrose when glucose < 14 mmol/L

3. Insulin Therapy

• DKA: IV insulin infusion: 0.1 U/kg bolus followed by 0.1 U/kg/hr; continue until acidosis resolves

• HHS: Insulin started after adequate fluid replacement; lower doses 0.05–0.1 U/kg/hr

4. Electrolyte Management

• Potassium: Start supplementation if K+ < 5.0 mmol/L; monitor serum K+ every 2–4 hours

• Other electrolytes: Phosphate, magnesium as needed

5. Treat Underlying Cause

• Infection (antibiotics)

• Myocardial infarction

• Trauma or other precipitating factors

6. Monitoring

• Hourly glucose, vitals, neurological status

• Urine output via catheter

• ABG and electrolytes frequently

7. Hypoglycemia Management

• Mild: Oral glucose

• Severe or comatose: 50% dextrose 25–50 mL IV or glucagon 1 mg IM/SC

Complications

• Cerebral edema (more common in children)

• Hypokalemia-induced arrhythmias

• Thrombosis and DVT

• Acute kidney injury

• Sepsis

• Multi-organ failure

Key Points

• Differentiate DKA vs HHS vs hypoglycemia by history, labs, and clinical features

• Fluid resuscitation is the cornerstone of DKA/HHS management

• Monitor electrolytes closely to prevent cardiac complications

• ICU or high dependency admission recommended for severe cases

• Address precipitating factors to prevent recurrence