Diabetic Ketoacidosis (DKA)
Summary
Diabetic ketoacidosis (DKA) is a life-threatening metabolic emergency occurring primarily in Type 1 diabetes (and sometimes late-stage Type 2). It is characterised by the triad of hyperglycaemia, ketosis, and metabolic acidosis. DKA results from absolute or relative insulin deficiency, leading to uncontrolled lipolysis and ketone body production. Patients present with polyuria, polydipsia, vomiting, abdominal pain, Kussmaul respiration, and altered consciousness. Diagnosis requires blood glucose >11 mmol/L, ketones >3.0 mmol/L, and pH <7.3 or bicarbonate <15 mmol/L. Management follows the Joint British Diabetes Societies (JBDS) protocol: IV fluids, fixed-rate insulin infusion, potassium replacement, and treatment of the precipitant. Monitoring for hypokalaemia and cerebral oedema (especially in children) is essential.
Key Facts
- Definition triad: Hyperglycaemia + Ketosis + Acidosis
- Diagnostic criteria:
- Glucose >11 mmol/L (or known diabetes)
- Blood ketones >3.0 mmol/L (or urine ketones ++)
- pH <7.3 or Bicarbonate <15 mmol/L
- Precipitants: Infection (commonest); Missed insulin; New-onset diabetes; MI; Drugs
- Severity: Mild (pH 7.25-7.30); Moderate (pH 7.0-7.24); Severe (pH <7.0)
- Management mnemonic — FIG-PICK: Fluids, Insulin, Glucose, Potassium, Infection, Chart, Ketones
- Mortality: ~1% in adults; Higher if cerebral oedema (children)
Clinical Pearls
"Check Potassium Before Insulin": Insulin drives K+ into cells. If K+ is already low (<3.5), giving insulin causes life-threatening hypokalaemia. Replace K+ first.
"Continue Long-Acting Insulin": During DKA, STOP short-acting insulin but CONTINUE long-acting (basal) insulin. This prevents rebound DKA when IV insulin stops.
"Fix Rate, Not Blood Glucose": Use fixed-rate insulin infusion (FRII) at 0.1 units/kg/hr. Don't chase glucose levels with variable rates.
"Add Dextrose at BM <14": When glucose falls below 14 mmol/L, add 10% glucose to prevent hypoglycaemia while continuing insulin to clear ketones.
"Cerebral Oedema Kills Children": In paediatric DKA, rapid fluid correction causes cerebral oedema. Use slower fluid rates and avoid boluses unless shocked.
Why This Matters Clinically
DKA is common and preventable. Prompt recognition and protocol-driven management save lives. Failure to replace potassium, over-aggressive fluid resuscitation, and premature discontinuation of insulin are common errors that increase morbidity.[1,2]
Incidence & Prevalence
| Parameter | Data |
|---|---|
| DKA incidence | 4-8 per 1,000 people with diabetes/year |
| Mortality | ~1% overall; Higher with severe DKA, elderly |
| New-onset T1DM presenting with DKA | 15-30% |
| Recurrent DKA | Often due to insulin omission |
Precipitants (The 5 I's)
| Precipitant | Notes |
|---|---|
| Infection | Commonest trigger; UTI, pneumonia, skin |
| Infarction | MI, stroke |
| Insulin omission | Non-compliance; Pump failure |
| Intercurrent illness | Surgery, trauma |
| Intoxication | Alcohol, drugs |
Mechanism
Step 1: Insulin Deficiency
- Absolute (Type 1) or relative (severe illness, counter-regulatory hormones)
- Cannot utilise glucose for energy
Step 2: Counter-Regulatory Hormone Excess
- Glucagon, cortisol, catecholamines, GH all increased
- Promotes gluconeogenesis and glycogenolysis → Hyperglycaemia
Step 3: Lipolysis
- Fat breakdown for energy
- Free fatty acids released
Step 4: Ketogenesis
- Liver converts FFAs to ketone bodies (β-hydroxybutyrate, acetoacetate, acetone)
- Ketones accumulate → Metabolic acidosis (anion gap)
Step 5: Osmotic Diuresis
- Hyperglycaemia → Glycosuria → Osmotic diuresis
- Fluid and electrolyte losses (Na+, K+, Mg2+, Phosphate)
Step 6: Clinical Presentation
- Dehydration; Acidosis; Electrolyte disturbance; Altered consciousness
Biochemical Changes
| Parameter | Change | Reason |
|---|---|---|
| Glucose | ↑↑ | Gluconeogenesis, glycogenolysis |
| Ketones | ↑↑ | Lipolysis and ketogenesis |
| pH | ↓ | Accumulation of ketoacids |
| Bicarbonate | ↓ | Buffering acidosis |
| Potassium | Variable (often ↑ initially) | Shifts out of cells; But TOTAL body K+ is LOW |
| Sodium | Variable | Dilutional effect of hyperglycaemia |
| Anion gap | ↑ | Unmeasured ketoacid anions |
Symptoms
| Symptom | Notes |
|---|---|
| Polyuria | Osmotic diuresis |
| Polydipsia | Thirst from dehydration |
| Nausea/Vomiting | Ketones; Abdominal pain |
| Abdominal pain | Can mimic acute abdomen |
| Weakness | Dehydration; Electrolyte disturbance |
| Altered consciousness | Severe DKA; Cerebral oedema |
Signs
| Sign | Notes |
|---|---|
| Kussmaul respiration | Deep, sighing breaths to blow off CO2 |
| Acetone breath | "Pear drops" / "Nail varnish remover" |
| Dehydration | Dry mucous membranes; Reduced skin turgor |
| Tachycardia | Volume depletion |
| Hypotension | Severe dehydration |
| Reduced GCS | Severe DKA |
Red Flags
[!CAUTION] Red Flags — Life-Threatening:
- pH <7.0 (severe DKA)
- Bicarbonate <5 mmol/L
- K+ <3.5 mmol/L before insulin (do NOT give insulin until K+ replaced)
- GCS <12
- SpO2 <92%
- Systolic BP <90 mmHg
- Anuria
- Children: Headache, confusion, irritability → CEREBRAL OEDEMA
Structured Approach
General:
- Conscious level (GCS)
- Signs of dehydration
- Kussmaul breathing
- Acetone smell
Cardiovascular:
- Heart rate (tachycardia)
- Blood pressure (hypotension in severe)
- Capillary refill
Abdominal:
- Tenderness (DKA can mimic acute abdomen)
- Exclude surgical cause
Neurological:
- GCS
- Focal signs (rare; consider stroke if present)
Blood Tests
| Test | Finding |
|---|---|
| Capillary glucose | >11 mmol/L |
| Blood ketones | >3.0 mmol/L |
| Venous blood gas | pH <7.3; Bicarbonate <15 |
| U&E | K+ variable; Raised urea/creatinine (dehydration) |
| FBC | Raised WCC (even without infection) |
| CRP | If infection suspected |
| Lactate | May be elevated |
| Amylase | May be elevated (not necessarily pancreatitis) |
Urine
| Test | Notes |
|---|---|
| Ketones | ++ or +++ |
| MSU | If infection suspected |
Other
| Investigation | Purpose |
|---|---|
| ECG | Hypokalaemia changes; Exclude MI as trigger |
| CXR | If pneumonia suspected |
| Blood cultures | If sepsis suspected |
DKA Severity
| Severity | pH | Bicarbonate | Features |
|---|---|---|---|
| Mild | 7.25-7.30 | 15-18 | Alert |
| Moderate | 7.0-7.24 | 10-15 | Drowsy |
| Severe | <7.0 | <10 | Stupor/coma |
Management Algorithm (JBDS Protocol)
DKA MANAGEMENT (FIG-PICK)
↓
┌──────────────────────────────────────────────────────────────┐
│ IMMEDIATE ASSESSMENT (0-60 minutes) │
├──────────────────────────────────────────────────────────────┤
│ ➤ ABC assessment │
│ ➤ IV access (large bore x2) │
│ ➤ Bloods: VBG, glucose, ketones, U&E, FBC │
│ ➤ ECG │
│ ➤ Fluid resuscitation started │
│ ➤ Catheterise if severely unwell or not passing urine │
│ ➤ Start monitoring chart │
└──────────────────────────────────────────────────────────────┘
↓
┌──────────────────────────────────────────────────────────────┐
│ F = FLUIDS │
├──────────────────────────────────────────────────────────────┤
│ ➤ 0.9% Saline: │
│ • 1L stat over 1 hour (if SBP <90: Give 500mL bolus) │
│ • 1L over next 2 hours │
│ • 1L over next 2 hours │
│ • 1L over next 4 hours │
│ • 1L over next 4 hours │
│ • 1L over next 6 hours │
│ ⚠️ SLOWER RATE IN YOUNG PEOPLE / ELDERLY / CARDIAC DISEASE │
│ │
│ ➤ When glucose <14 mmol/L: │
│ • ADD 10% Glucose 125 mL/hr alongside 0.9% saline │
│ • Prevents hypoglycaemia while continuing insulin │
└──────────────────────────────────────────────────────────────┘
↓
┌──────────────────────────────────────────────────────────────┐
│ I = INSULIN (Fixed Rate IV Infusion) │
├──────────────────────────────────────────────────────────────┤
│ ➤ 50 units Actrapid in 50 mL 0.9% saline │
│ ➤ Infuse at 0.1 units/kg/hour │
│ │
│ STOP patient's short-acting insulin │
│ CONTINUE patient's long-acting insulin (prevents rebound) │
│ │
│ ⚠️ DO NOT START INSULIN IF K+ <3.5 — REPLACE K+ FIRST │
│ │
│ TARGETS: │
│ ➤ Ketones should fall by ≥0.5 mmol/L/hour │
│ ➤ Glucose should fall by ≥3 mmol/L/hour │
│ ➤ If not achieving targets: Increase rate to 0.15 U/kg/hr │
└──────────────────────────────────────────────────────────────┘
↓
┌──────────────────────────────────────────────────────────────┐
│ P = POTASSIUM │
├──────────────────────────────────────────────────────────────┤
│ ⚠️ CRITICAL — Insulin drives K+ into cells │
│ │
│ K+ Level Replace with │
│ ───────────────────────────────────────── │
│ <3.5 mmol/L DO NOT start insulin until K+ replaced │
│ Give 40 mmol KCl in 1L saline │
│ 3.5-5.5 mmol/L Add 40 mmol KCl to each litre of saline │
│ >5.5 mmol/L No potassium initially │
│ │
│ ➤ Recheck K+ every 1-2 hours │
│ ➤ Cardiac monitoring if K+ abnormal │
└──────────────────────────────────────────────────────────────┘
↓
┌──────────────────────────────────────────────────────────────┐
│ I = INFECTION / PRECIPITANT │
├──────────────────────────────────────────────────────────────┤
│ ➤ Identify and treat precipitating cause │
│ ➤ Infection: Antibiotics │
│ ➤ MI: Cardiology input │
│ ➤ New-onset diabetes: Long-term management plan │
└──────────────────────────────────────────────────────────────┘
↓
┌──────────────────────────────────────────────────────────────┐
│ C = CHART (Monitoring) │
├──────────────────────────────────────────────────────────────┤
│ ➤ Hourly: Capillary glucose │
│ ➤ Hourly: Blood ketones (until <0.6) │
│ ➤ 1-2 hourly: K+, VBG │
│ ➤ Continuous: ECG if K+ abnormal │
│ ➤ Fluid balance chart │
│ ➤ Observations (BP, HR, RR, SpO2) │
│ ➤ GCS (especially children) │
└──────────────────────────────────────────────────────────────┘
↓
┌──────────────────────────────────────────────────────────────┐
│ K = KETONES (Resolution Criteria) │
├──────────────────────────────────────────────────────────────┤
│ DKA RESOLVED WHEN: │
│ ➤ Ketones <0.6 mmol/L AND │
│ ➤ pH >7.3 AND │
│ ➤ Bicarbonate >15 mmol/L AND │
│ ➤ Patient eating and drinking │
│ │
│ THEN: │
│ ➤ Give SC rapid-acting insulin with meal │
│ ➤ Stop IV insulin 30-60 mins AFTER SC insulin given │
│ ➤ Resume usual diabetes regimen │
└──────────────────────────────────────────────────────────────┘
| Complication | Notes |
|---|---|
| Hypokalaemia | Most dangerous; Arrhythmias; Monitor closely |
| Hypoglycaemia | From insulin without glucose replacement |
| Cerebral oedema | Mainly children; Rapid fluid correction; Treat with Mannitol/hypertonic saline |
| Aspiration | If reduced GCS |
| DVT/PE | Dehydration → Hypercoagulability |
| AKI | Dehydration |
| ARDS | Rare |
Cerebral Oedema (Children)
[!WARNING]
- Headache, confusion, irritability, bradycardia
- More common if rapid fluid/glucose correction
- Treatment: Mannitol 0.5-1 g/kg IV or 3% saline 3-5 mL/kg
| Factor | Outcome |
|---|---|
| Mortality overall | ~1% |
| Severe DKA (pH <7.0) | Higher mortality |
| Cerebral oedema | High mortality (20-40%) and morbidity |
| Recurrent DKA | Often indicates psychosocial issues / non-adherence |
Key Guidelines
| Guideline | Organisation | Year | Key Points |
|---|---|---|---|
| Management of DKA in Adults | JBDS-IP | 2023 | UK standard; FRII protocol |
What is DKA?
Diabetic ketoacidosis (DKA) is a serious condition that happens when the body doesn't have enough insulin. Without insulin, the body can't use sugar for energy, so it breaks down fat instead. This produces harmful acids called ketones that build up in the blood.
What are the symptoms?
- Feeling very thirsty and urinating a lot
- Feeling sick or vomiting
- Tummy pain
- Sweet-smelling breath (like pear drops)
- Fast, deep breathing
- Feeling confused or drowsy
What causes it?
- Forgetting to take insulin
- Infections (most common trigger)
- Starting diabetes for the first time
- Being very unwell
How is it treated?
- In hospital with a drip (fluids into a vein)
- Insulin through a drip
- Replacing salts that the body has lost
- Treating any infection
How can I prevent it?
- Never stop taking your insulin
- Test your blood glucose and ketones when unwell
- Follow sick-day rules: increase monitoring, drink fluids, seek help early
- Joint British Diabetes Societies Inpatient Care Group. The Management of Diabetic Ketoacidosis in Adults. 2023. JBDS Guidelines
High-Yield Exam Topics
| Topic | Key Points |
|---|---|
| Diagnostic criteria | Glucose >11, Ketones >3, pH <7.3 or Bicarb <15 |
| FIG-PICK | Fluids, Insulin, Glucose, Potassium, Infection, Chart, Ketones |
| Fixed-rate insulin | 0.1 units/kg/hr |
| Potassium | Replace before insulin if <3.5; Monitor closely |
| Add glucose | When BM <14 mmol/L |
| Resolution criteria | Ketones <0.6, pH >7.3, Bicarb >15, Eating |
| Cerebral oedema | Children; Rapid correction; Mannitol |
Sample Viva Question
Q: How do you manage potassium in DKA?
Model Answer: Potassium management is critical because insulin drives K+ into cells, risking life-threatening hypokalaemia. Approach:
- K+ <3.5: Do NOT start insulin. Give 40 mmol KCl in 1L saline and recheck before insulin.
- K+ 3.5-5.5: Add 40 mmol KCl to each litre of IV fluid.
- K+ >5.5: No potassium initially.
- Monitoring: Recheck K+ every 1-2 hours. Continuous cardiac monitoring if K+ abnormal. Despite high initial serum K+ (due to acidosis shifting K+ out of cells), total body K+ is LOW due to osmotic diuresis. Treatment always requires K+ replacement.
Last Reviewed: 2025-12-24 | MedVellum Editorial Team