Management of Diabetic Ketoacidosis
Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous intravenous regular insulin at 0.1 units/kg/hour without an initial bolus, while closely monitoring and replacing potassium to prevent life-threatening hypokalemia. 1, 2
Initial Assessment and Diagnosis
Obtain the following laboratory studies immediately upon presentation 1:
- Plasma glucose, serum ketones (preferably β-hydroxybutyrate), arterial blood gases
- Electrolytes with calculated anion gap, osmolality
- Blood urea nitrogen/creatinine
- Complete blood count, urinalysis with urine ketones
- Electrocardiogram
Diagnostic criteria for DKA: plasma glucose >250 mg/dL, arterial pH <7.30, serum bicarbonate <18 mEq/L, and positive serum/urine ketones 1. Note that euglycemic DKA can occur (particularly with SGLT2 inhibitor use) with normal or only mildly elevated glucose but meeting other acidosis criteria 3.
Fluid Resuscitation
Start with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour to restore intravascular volume and renal perfusion 1, 2. This aggressive initial resuscitation is critical for tissue perfusion and begins correcting the severe volume depletion 4.
Continue fluid replacement to correct estimated deficits within 24 hours, targeting 1.5 to 2 times the 24-hour maintenance requirements 1. Recent evidence suggests balanced crystalloid solutions may achieve faster DKA resolution than normal saline alone 5.
Common pitfall: Inadequate initial fluid resuscitation delays metabolic correction and increases complication risk 2.
Insulin Therapy
Initiate continuous intravenous regular insulin infusion at 0.1 units/kg/hour WITHOUT an initial bolus after starting fluid resuscitation 1, 2. The goal is reducing plasma glucose by 50-75 mg/dL per hour 1.
If glucose does not fall by 50 mg/dL in the first hour, double the insulin infusion rate hourly until steady glucose decline occurs 1.
Critical principle: Never stop insulin infusion until ketoacidosis resolves, regardless of glucose levels 2, 3. When glucose falls below 200-250 mg/dL, add dextrose-containing fluids (5% dextrose with 0.45-0.75% NaCl) to maintain glucose between 150-200 mg/dL while continuing insulin to clear ketosis 3. This is especially important in euglycemic DKA where dextrose must be added earlier 3.
Common pitfall: Prematurely stopping insulin when glucose normalizes before ketoacidosis resolves leads to rebound ketosis 3.
Electrolyte Management
Potassium Replacement
Monitor potassium closely as insulin therapy and acidosis correction cause rapid intracellular potassium shifts, creating life-threatening hypokalemia 1, 2.
Once renal function is confirmed (urine output present) and serum potassium is <5.3 mEq/L, add 20-30 mEq/L potassium to IV fluids (2/3 KCl and 1/3 KPO₄) 1, 3. Maintain serum potassium between 4-5 mmol/L throughout treatment 3.
Critical warning: Do not start insulin if potassium is <3.3 mEq/L until potassium is repleted, as insulin will further lower potassium and precipitate cardiac arrhythmias 1.
Bicarbonate
Bicarbonate administration is NOT recommended for pH >6.9, as it provides no benefit in resolution of acidosis or time to discharge and may worsen hypokalemia and increase cerebral edema risk 4, 3, 5. Consider bicarbonate only if pH <6.9 or in peri-intubation period when pH <7.2 to prevent hemodynamic collapse 5.
Phosphate and Magnesium
Monitor and replace as needed, though routine phosphate replacement is not required unless levels are critically low 3, 5.
Monitoring During Treatment
Check blood glucose every 1-2 hours 1, 3.
Draw blood every 2-4 hours to measure serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 3. Venous pH is adequate for monitoring and avoids repeated arterial punctures 3.
Follow venous pH and anion gap to track acidosis resolution, targeting venous pH >7.3 and anion gap ≤12 mEq/L 1, 3.
Resolution Criteria and Transition to Subcutaneous Insulin
DKA is resolved when ALL of the following are met: 1, 2, 3
- Glucose <200 mg/dL
- Serum bicarbonate ≥18 mEq/L
- Venous pH >7.3
- Anion gap ≤12 mEq/L
When transitioning to subcutaneous insulin, administer basal insulin (NPH or long-acting analog) 2-4 hours BEFORE stopping IV insulin to prevent rebound ketoacidosis and hyperglycemia 4, 1, 3. This overlap period is essential 4.
British guidelines suggest adding subcutaneous glargine alongside IV insulin during treatment may achieve faster resolution and shorter hospital stays 5.
Identification and Treatment of Precipitating Causes
Aggressively search for and treat underlying triggers 4, 6:
- Infections (most common precipitant)
- Myocardial infarction or acute coronary syndrome
- Stroke
- Medication non-adherence
- New-onset diabetes
SGLT2 inhibitor consideration: Discontinue SGLT2 inhibitors 3-4 days before surgery and maintain high suspicion for euglycemic DKA in patients on these medications 1, 3.
Special Considerations
Nutrition
Allow patients to eat when able rather than keeping NPO as standard practice 2. Early oral nutrition reduces ICU and hospital length of stay 5. Provide appropriate insulin coverage when eating resumes 2.
Thromboprophylaxis
DKA creates a hypercoagulable state; initiate standard hospital thromboprophylaxis protocols (such as enoxaparin) after initial fluid resuscitation, monitoring renal function as it improves 2.
Airway Management in Critically Ill Patients
For impending respiratory failure, avoid BiPAP due to aspiration risk 5. Proceed directly to intubation and mechanical ventilation with careful acid-base and fluid management 5. Consider bicarbonate administration peri-intubation if pH <7.2 to prevent hemodynamic collapse during apnea 5.
High-Risk Populations
Patients with renal disease, heart failure, pregnancy, or older age require modified fluid and electrolyte strategies, though specific protocols vary 7.
Prevention of Cerebral Edema
Avoid rapid overcorrection of hyperglycemia, which is the primary risk factor for cerebral edema 3, 5. Maintain glucose decline at 50-75 mg/dL per hour 1. If cerebral edema develops (altered mental status, headache, bradycardia), immediately administer mannitol or hypertensive saline 8.