What is the treatment plan for a patient presenting with Diabetic Ketoacidosis (DKA)?

Treatment Plan for 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 after an initial bolus of 0.1 units/kg, while aggressively replacing potassium once levels fall below 5.3 mEq/L. 1

Initial Assessment and Laboratory Evaluation

Obtain the following labs immediately to confirm DKA diagnosis and guide management 1, 2:

• Diagnostic criteria: Blood glucose >250 mg/dL, arterial pH <7.3, bicarbonate <15 mEq/L, and moderate ketonuria or ketonemia 2
• Plasma glucose, arterial blood gases, serum ketones (preferably β-hydroxybutyrate), electrolytes with calculated anion gap, osmolality 1
• Blood urea nitrogen/creatinine to assess renal function, complete blood count, electrocardiogram 1
• Urinalysis and urine ketones 1
• If infection suspected: bacterial cultures of urine, blood, and throat; chest X-ray if clinically indicated 1

Calculate corrected sodium: For every 100 mg/dL glucose above 100 mg/dL, add 1.6 mEq/L to the measured sodium value 3, 2. This is critical because most DKA patients appear hyponatremic due to hyperglycemia-induced water shifts, not true sodium depletion 3.

Fluid Resuscitation Protocol

Hour 1: Aggressive Initial Resuscitation

• Isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour (approximately 1-1.5 L in average adult) regardless of measured sodium 1, 3, 2
• This restores intravascular volume and renal perfusion 3

Subsequent Fluid Management

• Total fluid replacement goal: Approximately 1.5 times the 24-hour maintenance requirements, typically correcting an estimated deficit of 6L or 100 mL/kg within 24 hours 1, 2
• Critical pitfall: Ensure the induced change in serum osmolality does not exceed 3 mOsm/kg H₂O per hour to prevent osmotic demyelination syndrome 3

Insulin Therapy

Absolute Contraindication

Do not start insulin if serum potassium is <3.3 mEq/L 1. This is a life-threatening threshold that can cause cardiac arrhythmias and death 1. Continue aggressive potassium repletion until K+ ≥3.3 mEq/L before initiating insulin 1.

Insulin Initiation (once K+ ≥3.3 mEq/L)

• IV bolus: 0.1 units/kg regular insulin 1, 2
• Continuous infusion: 0.1 units/kg/hour regular insulin 1, 2
• Target glucose decline: 50-75 mg/dL per hour 1

Adjusting Insulin Infusion

• If glucose does not fall by 50 mg/dL in the first hour, verify adequate hydration status 1
• Double the insulin infusion rate every hour until achieving steady decline of 50-75 mg/dL/hour 1

Potassium Replacement

This is the most critical electrolyte management issue in DKA 1. Total body potassium is severely depleted despite potentially normal or elevated initial serum levels due to acidosis 2.

Potassium Management Algorithm

• If K+ <3.3 mEq/L: Hold insulin, aggressively replace potassium until ≥3.3 mEq/L 1
• If K+ 3.3-5.3 mEq/L: Add 20-30 mEq/L potassium to each liter of IV fluid once renal function is confirmed 1, 2
• Formulation: Use 2/3 KCl (or potassium-acetate) and 1/3 KPO₄ 1, 2
• Monitor closely: Insulin therapy drives potassium intracellularly, causing rapid serum level drops 1

Monitoring Requirements

Frequent Laboratory Monitoring

• Blood glucose: Every 1-2 hours initially, then every 2-4 hours 1, 3
• Serum electrolytes, glucose, BUN, creatinine, osmolality, venous pH: Every 2-4 hours 1, 3
• Direct measurement of β-hydroxybutyrate in blood is preferred for ketone monitoring 1

DKA Resolution Criteria

All of the following must be met simultaneously 1:

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

Transition to Subcutaneous Insulin

Critical Timing to Prevent DKA Recurrence

Administer basal insulin (glargine or detemir) subcutaneously 2-4 hours BEFORE stopping the IV insulin infusion 1. This is the most common error leading to DKA recurrence 1.

Transition Protocol

• Patient must be able to tolerate oral intake 1
• Start multiple-dose insulin schedule using combination of short/rapid-acting and intermediate/long-acting insulin 1
• Continue IV insulin for 1-2 hours after subcutaneous insulin is given to allow for absorption 1
• Monitor glucose every 2-4 hours during transition 1

Alternative Approach for Mild-Moderate Uncomplicated DKA

For hemodynamically stable, alert patients with mild-moderate DKA, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management can be as effective and more cost-effective than IV insulin 1. This requires frequent monitoring of capillary glucose levels 1.

Bicarbonate Therapy

Bicarbonate administration is controversial and should be restricted to patients with arterial pH <7.0 and/or cardiogenic shock 4. It is not recommended for most patients 5.

Identification and Treatment of Precipitating Causes

Common precipitating factors include 2, 4, 6:

• Infection (most common precipitating cause) 2, 4
• New-onset diabetes 2
• Insulin omission or nonadherence 2, 6
• Drugs affecting carbohydrate metabolism (corticosteroids, thiazides, sympathomimetic agents, SGLT-2 inhibitors) 2, 6

Administer appropriate antibiotics if infection is suspected 1, 2.

Common Pitfalls to Avoid

• Never stop IV insulin without prior basal insulin administration—this causes DKA recurrence 1
• Never start insulin if K+ <3.3 mEq/L—this can be fatal 1
• Never treat measured sodium without calculating corrected value—leads to inappropriate fluid selection 3
• Never initiate subcutaneous insulin before complete resolution of metabolic acidosis 1
• Never discontinue monitoring after initial correction—continued vigilance prevents overcorrection 3

Discharge Planning

Begin structured discharge planning at admission, including 1:

• Patient education on insulin administration
• Glucose monitoring techniques
• Sick day management protocols
• Improved access to medical providers to prevent future episodes 6