Diabetic Ketoacidosis (DKA)
Lesson Objectives
By the end of this lesson, learners should be able to:
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Define Diabetic Ketoacidosis and describe its pathophysiology.
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Identify clinical features of DKA in children.
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Outline the investigations required for diagnosis and monitoring.
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Describe the stepwise management of DKA following the Zambian Paediatric Protocol.
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Calculate fluid and potassium requirements accurately.
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Recognize and manage complications such as cerebral oedema and hypokalaemia.
Description
Diabetic Ketoacidosis (DKA) is a life-threatening metabolic emergency characterized by uncontrolled catabolism due to insulin deficiency, resulting in hyperglycaemia (RBS > 11 mmol/L), ketonaemia (>3 mmol/L), and acidaemia (pH < 7.3).
It involves osmotic diuresis, dehydration, ketonuria (≥2+), and accumulation of fatty acids from increased fat metabolism.
DKA is the most common endocrine emergency in paediatric patients and can occur in both newly diagnosed and known diabetics.
The major causes of mortality are hypokalaemia and cerebral oedema (which is unpredictable, more common in younger or newly diagnosed children, and has a mortality of ~80%).
These guidelines are intended for the management of children who are ≥5% dehydrated, vomiting, drowsy, or clinically acidotic.
Clinical Features
| Category | Signs and Symptoms |
|---|---|
| General | Dehydration, weakness, drowsiness |
| Gastrointestinal | Abdominal pain, nausea, vomiting |
| Respiratory | Acidotic (Kussmaul) breathing, ketone (fruity) smell |
| Neurological | Drowsiness, irritability, unexplained coma |
| Metabolic | Acidosis, hyperglycaemia, ketonuria |
Investigations
| Test Type | Examples / Purpose |
|---|---|
| Blood glucose | Random blood sugar (RBS) |
| Renal and metabolic panel | Urea, electrolytes, creatinine, liver function tests |
| Haematology | Full blood count |
| Infectious screen | Malaria parasites, urine M/C/S |
| Urine | Urinalysis for ketones and glucose |
| Acid–base balance | Arterial blood gases (ABG) |
Initial Management — ABCDE Approach
| Step | Action |
|---|---|
| A – Airway | Ensure patency; insert airway if comatose. If vomiting, insert nasogastric tube (NGT), aspirate, and leave on open drainage. |
| B – Breathing | Give 100% oxygen where indicated. Provide bag-mask ventilation if apnoeic. |
| C – Circulation | Insert two large-bore IV cannulae and take blood samples. If in shock, give 20 mL/kg of 0.9% normal saline rapidly, repeat as needed (maximum 60 mL/kg). |
| D – Disability | Assess GCS/BCS. Watch for cerebral oedema: irritability, bradycardia, or hypertension. Perform fundal exam. |
| E – Evaluate | Search for precipitating infection and treat appropriately. |
🏥 Admit all DKA patients to ICU for close monitoring — fluid balance, hourly glucose checks, daily weight, GCS/BCS, and continuous cardiac monitoring.
Fluids
Formula:
Total Requirement = Maintenance + Deficit
| Component | Formula | Notes |
|---|---|---|
| Deficit | % dehydration × body weight (kg) | Typically assume 10% in moderate–severe cases |
| Maintenance | – 100 mL/kg for first 10 kg – 50 mL/kg for next 10 kg – 20 mL/kg for each kg thereafter | |
| Duration | Give total over 36–48 hours |
Example Calculation:
For a 25 kg child with 10% dehydration:
Deficit = 10% × 25 = 2.5 L (2500 mL) over 48 hrs → 1250 mL per 24 hrs
Maintenance = 1000 + 500 + 100 = 1600 mL per 24 hrs
Total = 2850 mL per 24 hrs
Give in divided doses (e.g., 950 mL every 8 hours).
Fluid Type:
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Start with 0.9% Normal Saline.
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Change to Dextrose Normal Saline (DNS) when RBS < 12 mmol/L.
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Use Half Normal Saline if hypernatraemia is present (consult senior).
Potassium Replacement
| Guideline | Details |
|---|---|
| Start potassium immediately | Unless serum K⁺ >7 mmol/L, anuria, or ECG shows peaked T waves. |
| Dosage | Add 10–20 mmol KCl per 500 mL IV fluid during first 24 hrs while on insulin. |
| Monitoring | Continuous cardiac monitoring and regular serum K⁺ checks. |
Insulin Therapy
| Drug | Dose | Administration | Notes |
|---|---|---|---|
| Soluble insulin | 0.1 IU/kg/hour | Continuous IV infusion | If glucose falls >5 mmol/L per hour, reduce rate to 0.05 IU/kg/hour to prevent cerebral oedema. |
Key Monitoring Parameters
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Hourly RBS and urine output
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Fluid balance chart
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Neurological status (GCS or BCS)
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Signs of cerebral oedema (headache, altered consciousness, bradycardia, hypertension)
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Electrolytes and acid–base status
Summary
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DKA results from insulin deficiency leading to hyperglycaemia, acidosis, and ketosis.
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Follow ABCDE for initial stabilization.
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Use Normal Saline for rehydration and calculate fluids accurately.
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Potassium replacement is essential once urine output is adequate.
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Start insulin infusion at 0.1 IU/kg/hour; adjust rate if glucose drops too quickly.
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Monitor closely to prevent hypokalaemia and cerebral oedema.
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All children with DKA should be managed in ICU settings.