What is the management of Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycemic State (HHS) according to Tintinalli?

Management of DKA and HHS According to Tintinalli's Emergency Medicine

Initial Fluid Resuscitation

Begin aggressive fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hour during the first hour (approximately 1-1.5 liters in the average adult) to restore intravascular volume and renal perfusion. 1, 2, 3

• After the initial hour, switch to 0.45% NaCl at 4-14 mL/kg/hour if corrected serum sodium is normal or elevated 1, 2
• Continue 0.9% NaCl at the same rate if corrected serum sodium is low 1, 2
• Correct the serum sodium for hyperglycemia: add 1.6 mEq to the measured sodium value for each 100 mg/dL glucose above 100 mg/dL 1
• Fluid replacement should correct estimated deficits within 24 hours, with serum osmolality changes not exceeding 3 mOsm/kg/hour 1

Common pitfall: Avoid fluid overload in patients with cardiac or renal compromise—monitor hemodynamics, mental status, and serum osmolality frequently 1

Pediatric Fluid Management (<20 years)

• Start with 0.9% NaCl at 10-20 mL/kg/hour for the first hour 1
• Initial reexpansion should not exceed 50 mL/kg over the first 4 hours to minimize cerebral edema risk 1

Insulin Therapy

Start continuous IV regular insulin at 0.1 units/kg/hour WITHOUT an initial bolus as the standard approach for critically ill patients. 2, 3, 4

• An alternative approach uses an IV bolus of 0.15 units/kg followed by continuous infusion at 0.1 units/kg/hour 1, 4
• 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, double the insulin infusion every hour until steady decline is achieved 1, 4

Critical: Never interrupt insulin infusion when glucose reaches 250 mg/dL in DKA or 300 mg/dL in HHS—instead add 5% dextrose with 0.45-0.75% NaCl to maintain glucose 150-200 mg/dL while continuing insulin to clear ketosis. 1, 2, 3

• Continue insulin until complete resolution: pH >7.3, bicarbonate ≥18 mEq/L, anion gap ≤12 mEq/L, and glucose <200 mg/dL 2, 3, 4

Common pitfall: Premature termination of IV insulin is a frequent management error that leads to rebound ketoacidosis 5

Potassium Management

Check potassium immediately—if K+ <3.3 mEq/L, DELAY insulin therapy until potassium is repleted above 3.3 mEq/L to prevent life-threatening arrhythmias and cardiac arrest. 2, 3, 4

• Once K+ falls below 5.5 mEq/L and renal function is assured (adequate urine output), add 20-40 mEq/L potassium to IV fluids 1, 2
• Use 2/3 KCl and 1/3 KPO4 for replacement 1, 2
• Target serum potassium 4-5 mEq/L throughout treatment 2, 4

Rationale: Total body potassium deficits are substantial (3-5 mEq/kg in DKA, 5-15 mEq/kg in HHS) despite potentially normal or elevated initial levels due to acidosis-induced transcellular shifts 1, 4

Bicarbonate Therapy

Bicarbonate is generally NOT recommended for pH >6.9, as studies show no benefit on clinical outcomes and potential harm including worsening ketosis, hypokalemia, and increased cerebral edema risk. 2, 3, 4

• Consider bicarbonate ONLY if pH <6.9: give 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/hour 2, 4
• For pH 6.9-7.0: give 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/hour 4

Initial Laboratory Evaluation

Obtain immediately upon presentation 1, 3, 4:

• Plasma glucose, blood urea nitrogen, creatinine
• Serum ketones (β-hydroxybutyrate preferred over nitroprusside method) 4
• Electrolytes with calculated anion gap
• Serum osmolality
• Arterial blood gases (or venous pH, which is typically 0.03 units lower) 1, 2, 4
• Complete blood count with differential
• Urinalysis with urine ketones
• Electrocardiogram with continuous cardiac monitoring 4
• Bacterial cultures (blood, urine, throat) if infection suspected 1, 3, 4
• Chest X-ray if clinically indicated 1

Monitoring Protocol

Draw blood every 2-4 hours for electrolytes, glucose, BUN, creatinine, osmolality, and venous pH. 2, 3, 4

• Check blood glucose every 1-2 hours 2, 3
• Venous pH and anion gap can be followed instead of repeated arterial blood gases 2, 4
• Monitor fluid input/output, blood pressure, mental status, and cardiac rhythm continuously 1, 4

Transition to Subcutaneous Insulin

Administer subcutaneous basal insulin (intermediate or long-acting) 2-4 hours BEFORE stopping IV insulin to prevent rebound ketoacidosis and hyperglycemia. 2, 3, 4

• For newly diagnosed patients, initiate multidose regimen at approximately 0.5-1.0 units/kg/day 4
• Ensure patient can tolerate oral intake before transition 1

Common pitfall: Insufficient timing or dosing of subcutaneous insulin before discontinuing IV insulin is a frequent cause of treatment failure 5

Identifying and Treating Precipitating Causes

Search for and address 1, 3, 4:

• Infection (most common): obtain cultures and start antibiotics if suspected 1, 3, 4
• Insulin omission or inadequate dosing 3
• New-onset diabetes 3
• Medications: SGLT2 inhibitors (discontinue 3-4 days before surgery), corticosteroids, thiazides, sympathomimetic agents 3, 4
• Acute stressors: myocardial infarction, stroke, pancreatitis 4
• HHS-specific: inadequate fluid intake in elderly or nursing home residents 3

Special Considerations for Mild DKA

For uncomplicated mild DKA (glucose >250 mg/dL, pH 7.25-7.30, bicarbonate 15-18 mEq/L) 4:

• Subcutaneous rapid-acting insulin analogs may be used in emergency department or step-down units 4
• Give subcutaneous regular insulin every 4 hours (5-unit increments for every 50 mg/dL increase above 150 mg/dL, up to 20 units for glucose 300 mg/dL) 4
• Fluid therapy at 1.5 times 24-hour maintenance requirements (5 mL/kg/hour) 4

Complications to Monitor

DKA-specific complications 3, 4:

• Cerebral edema (0.7-1.0% in children, rare but frequently fatal) 4
• Hypoglycemia
• Hyperchloremic non-anion gap metabolic acidosis

HHS-specific complications 3:

• Vascular occlusion (thrombotic events)
• Seizures
• Central pontine myelinolysis
• Higher mortality rate compared to DKA

Typical Deficits

Total body deficits in DKA 1:

• Water: 6 liters (100 mL/kg)
• Sodium: 7-10 mEq/kg
• Potassium: 3-5 mEq/kg
• Chloride: 3-5 mEq/kg
• Phosphate: 5-7 mEq/kg

Total body deficits in HHS 1:

• Water: 9 liters (100-200 mL/kg)
• Sodium: 5-13 mEq/kg
• Potassium: 5-15 mEq/kg
• Chloride: 5-15 mEq/kg
• Phosphate: 3-7 mEq/kg