What is the initial management for a patient presenting with Diabetic Ketoacidosis (DKA)?

Initial Management of Diabetic Ketoacidosis (DKA)

Begin immediate fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour for the first hour, followed by continuous IV regular insulin at 0.1 units/kg/hour once potassium is ≥3.3 mEq/L, while aggressively replacing potassium to maintain levels between 4-5 mEq/L. 1, 2

Immediate Diagnostic Workup

Obtain the following laboratory tests immediately upon presentation 1, 2:

• Plasma glucose, arterial blood gases (or venous pH), serum ketones, electrolytes with calculated anion gap, and serum osmolality 1
• Complete blood count with differential, blood urea nitrogen, creatinine, urinalysis with urine ketones, and electrocardiogram 1, 2
• Bacterial cultures (blood, urine, throat) if infection is suspected as the precipitating cause 1, 3

Diagnostic criteria for DKA: Blood glucose >250 mg/dL, arterial pH <7.3, serum bicarbonate <15 mEq/L, and presence of ketonemia or ketonuria 1

Fluid Resuscitation Protocol

First hour: Administer isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adults) to restore circulating volume and tissue perfusion 1, 2, 3

Subsequent fluid management depends on hydration status, electrolyte levels, and urine output, with total fluid replacement aimed at correcting estimated deficits within 24 hours 1

When glucose reaches 250 mg/dL: Switch to 5% dextrose with 0.45-0.75% NaCl to prevent hypoglycemia while continuing insulin therapy 1

Critical pitfall: Do not allow serum osmolality to decrease faster than 3 mOsm/kg/h, as overly rapid correction increases cerebral edema risk, particularly in children 2

Insulin Therapy

DO NOT start insulin if potassium <3.3 mEq/L - this is an absolute contraindication that can cause life-threatening cardiac arrhythmias and death 1, 3

Once potassium ≥3.3 mEq/L 1, 2:

• Administer IV bolus of regular insulin at 0.1-0.15 units/kg body weight 2, 3
• Follow immediately with continuous IV infusion at 0.1 units/kg/hour 1, 2
• Target glucose decline of 50-75 mg/dL per hour 1, 2

If glucose does not fall by 50 mg/dL in the first hour: Check hydration status; if adequate, double the insulin infusion rate hourly until steady glucose decline is achieved 1, 2

Continue insulin infusion until complete resolution of ketoacidosis (pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L) regardless of glucose levels 1

Critical pitfall: Never stop insulin when glucose falls below 250 mg/dL - instead add dextrose to IV fluids and continue insulin until ketoacidosis resolves 1

Potassium Management

Universal truth in DKA: Total body potassium is always depleted, even if initial serum levels appear normal or elevated due to acidosis 1, 2

Algorithm for potassium replacement 1, 2, 3:

• If K+ <3.3 mEq/L: HOLD insulin, aggressively replace potassium until ≥3.3 mEq/L to prevent fatal arrhythmias
• If K+ 3.3-5.5 mEq/L: Add 20-40 mEq/L potassium to each liter of IV fluid (use 2/3 KCl and 1/3 KPO₄) once adequate urine output confirmed
• If K+ >5.5 mEq/L: Withhold potassium initially but monitor closely every 2 hours, as levels will drop rapidly with insulin therapy

Target serum potassium: Maintain 4-5 mEq/L throughout treatment 1, 2

Bicarbonate Therapy

Bicarbonate is NOT recommended for pH >6.9-7.0 - studies show no benefit in resolution time or outcomes, and it may worsen ketosis, cause hypokalemia, and increase cerebral edema risk 1, 2

Only consider bicarbonate if pH <6.9: Administer 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/h 2

Monitoring Protocol

Draw blood every 2-4 hours to measure serum electrolytes, glucose, blood urea nitrogen, creatinine, osmolality, and venous pH 1, 2

Continuous cardiac monitoring is crucial in severe DKA to detect arrhythmias from electrolyte shifts 2

Preferred ketone monitoring: Direct measurement of β-hydroxybutyrate in blood (not nitroprusside method which only measures acetoacetic acid and acetone) 1, 2

Identification of Precipitating Causes

Search for and treat underlying triggers concurrently 1, 2:

• Infections (most common) - obtain cultures and start appropriate antibiotics
• Myocardial infarction or stroke - obtain ECG, consider troponin
• Insulin omission or inadequacy (especially in known diabetics)
• SGLT2 inhibitors - can cause euglycemic DKA; discontinue immediately 1, 2
• Other causes: pancreatitis, trauma, alcohol abuse, new diabetes diagnosis

Resolution Criteria

DKA is resolved when ALL of the following are met 1, 2:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L

Transition to Subcutaneous Insulin

Critical timing: Administer basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin infusion to prevent recurrence of ketoacidosis and rebound hyperglycemia 1, 2, 3

Once patient can eat: Start multiple-dose regimen using combination of short/rapid-acting and intermediate/long-acting insulin 1, 2

Most common error leading to DKA recurrence: Stopping IV insulin without prior basal insulin administration 3

Special Consideration for Mild-Moderate DKA

For uncomplicated mild-to-moderate DKA: Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be equally effective, safer, and more cost-effective than IV insulin 1, 2

However, continuous IV insulin remains standard of care for: Critically ill patients, mentally obtunded patients, and severe DKA 1, 2