What are the current management guidelines for diabetic ketoacidosis in type 1 diabetes and hyperosmolar hyperglycemic state in type 2 diabetes?

Management of Diabetic Ketoacidosis and Hyperosmolar Hyperglycemic State

For critically ill patients with DKA or HHS, continuous intravenous insulin is the standard of care, with fluid resuscitation being the first and most critical intervention. 1

Diagnostic Criteria

DKA (occurs in both Type 1 and Type 2 diabetes)

• Plasma glucose: ≥250 mg/dL
• Arterial pH: <7.30
• Serum bicarbonate: <15 mEq/L
• Positive serum/urine ketones
• Anion gap: >10 mEq/L 2

HHS (predominantly Type 2 diabetes)

• Plasma glucose: ≥600 mg/dL
• Arterial pH: >7.30
• Serum bicarbonate: >15 mEq/L
• Small or absent ketones
• Effective serum osmolality: ≥320 mOsm/kg
• Often presents with stupor/coma 2

Important caveat: Up to one-third of patients present with overlapping features of both DKA and HHS, which carries higher mortality than either condition alone 3.

Initial Management Algorithm

Step 1: Fluid Resuscitation (FIRST PRIORITY)

Isotonic saline (0.9% NaCl) at 15-20 mL/kg/h (1-1.5 L in average adult) during the first hour 2, 4. This is the single most important initial intervention, as both conditions involve massive fluid deficits:

• DKA: ~6 L total water deficit (100 mL/kg)
• HHS: ~9 L total water deficit 2, 4

After the first hour:

• If corrected serum sodium is normal or elevated: use 0.45% NaCl at 4-14 mL/kg/h
• If corrected serum sodium is low: continue 0.9% NaCl at similar rate 4

Correct serum sodium for hyperglycemia: add 1.6 mEq to measured sodium for each 100 mg/dL glucose above 100 mg/dL 2

Step 2: Insulin Therapy

For critically ill and mentally obtunded patients: Continuous IV insulin infusion is mandatory 1.

For mild-to-moderate uncomplicated DKA: Subcutaneous rapid-acting insulin analogs combined with aggressive fluid management are equally effective and may be safer and more cost-effective 1, 5.

IV Insulin Protocol:

• Initial bolus: 0.1 units/kg IV (optional, can start infusion directly)
• Continuous infusion: 0.1 units/kg/h for DKA; 0.05 units/kg/h for HHS (increase by 1 unit/h as needed) 6
• Goal: Decrease glucose by 50-75 mg/dL/h
• When glucose reaches 200 mg/dL in DKA or 250-300 mg/dL in HHS: Add dextrose to IV fluids and reduce insulin rate to maintain glucose 150-200 mg/dL until acidosis resolves 2

Subcutaneous Protocol (mild DKA only):

• Priming dose: 0.4-0.6 units/kg (half IV bolus, half SC/IM)
• Maintenance: 0.1 units/kg SC or IM every hour 2

Step 3: Potassium Replacement

Critical monitoring required: Hypokalaemia occurs in ~50% of patients during treatment and severe hypokalaemia (<2.5 mEq/L) increases mortality 7.

• **If K+ <3.3 mEq/L:** Hold insulin, give potassium 20-30 mEq/h until K+ >3.3 mEq/L
• If K+ 3.3-5.3 mEq/L: Add 20-30 mEq/L to IV fluids (2/3 KCl, 1/3 KPO4)
• If K+ >5.3 mEq/L: Do not give potassium, check levels every 2 hours 2, 4

Step 4: Monitoring

Laboratory checks every 2-4 hours:

• Point-of-care glucose
• Serum electrolytes (calculate anion gap)
• Venous pH (arterial blood gases not routinely needed after initial assessment)
• BUN, creatinine
• Serum osmolality 2

Do NOT use nitroprusside method for ketone monitoring during treatment - it only measures acetoacetate and acetone, not β-hydroxybutyrate (the predominant ketone). β-hydroxybutyrate blood measurement is preferred 2.

Resolution Criteria

DKA Resolution:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3
• Anion gap ≤12 mEq/L 2

HHS Resolution:

• Normal osmolality
• Patient mentally alert
• Adequate oral intake 2

Transition to Subcutaneous Insulin

Critical timing: Administer basal insulin 2-4 hours BEFORE stopping IV insulin to prevent rebound hyperglycemia and recurrent ketoacidosis 1, 8, 1, 5. This is a common pitfall that leads to treatment failure.

Recent evidence suggests: Adding low-dose basal insulin analog during IV insulin infusion may prevent rebound hyperglycemia without increasing hypoglycemia risk 1.

Calculate subcutaneous dose: Use average insulin infusion rate over the last 12 hours × 24 hours for total daily dose. Example: 1.5 units/h × 24 = 36 units/day total 7.

Special Considerations

Bicarbonate Therapy

Generally NOT recommended - multiple studies show no difference in resolution of acidosis or time to discharge 1, 8, 5. May be considered only if pH <6.9, but evidence is weak 2.

Phosphate Replacement

Not routinely necessary despite theoretical concerns. Consider only if:

• Serum phosphate <1.0 mg/dL
• Cardiac dysfunction present
• Respiratory depression
• Severe anemia 2

Precipitating Factors

Always identify and treat underlying causes:

• Infection (most common)
• Myocardial infarction
• Stroke
• Medication non-compliance
• New-onset diabetes 1

SGLT2 Inhibitor Consideration

Be aware of euglycemic DKA in patients on SGLT2 inhibitors - glucose may be only mildly elevated despite severe ketoacidosis 3.

Mortality and Prognosis

• DKA mortality: ~5% in experienced centers
• HHS mortality: ~15% (substantially higher)
• Overlap syndrome mortality: Higher than either alone
• Worst prognosis: Extremes of age, coma, hypotension 2, 3