What is the recommended acute management for an adult patient with a blood glucose concentration above 20 mmol/L?

Management of Blood Glucose Above 20 mmol/L (360 mg/dL)

Immediately administer 0.1-0.15 units/kg of rapid-acting insulin subcutaneously (approximately 7-10 units for a 70 kg patient) and verify the absence of ketosis before proceeding with isolated hyperglycemia management. 1

Immediate Assessment (First 15 Minutes)

Critical first step: Rule out diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS) before treating as isolated hyperglycemia. 1, 2

• Check blood β-hydroxybutyrate or urine ketones immediately in all patients with Type 1 diabetes and insulin-treated Type 2 diabetes when glucose exceeds 16.5 mmol/L (300 mg/dL). 3, 1
• Calculate effective osmolality using the formula: 2[measured Na (mEq/L)] + glucose (mg/dL)/18 to ensure <320 mOsm/kg. 3, 1
• If ketones are elevated (β-hydroxybutyrate >1.5 mmol/L or urine ketones 2+), this is DKA requiring ICU transfer and IV insulin infusion. 3, 4
• If osmolality ≥320 mOsm/kg with marked dehydration, this is HHS requiring ICU management. 3, 5

Treatment Protocol for Isolated Severe Hyperglycemia (No Ketosis/Normal Osmolality)

Insulin Administration

Give weight-based rapid-acting insulin subcutaneously as the primary intervention:

• Administer 0.1-0.15 units/kg of rapid-acting insulin (lispro, aspart, or glulisine) subcutaneously. 1
• For a 70 kg patient, this equals 7-10 units. 1
• Do not use sliding scale insulin alone as it provides inadequate correction for this degree of hyperglycemia. 1
• Avoid IV insulin infusion unless DKA/HHS develops or the patient cannot tolerate subcutaneous administration. 1

Hydration Strategy

Aggressive fluid replacement is essential:

• If the patient can drink, administer 500-1000 mL of water or sugar-free fluids over 1-2 hours. 1
• If oral intake is inadequate or patient is NPO, start IV 0.9% sodium chloride at 150-250 mL/hour. 1
• Fluid replacement helps lower glucose through dilution and improved renal perfusion. 3, 6

Monitoring Parameters

Hourly glucose monitoring is mandatory initially:

• Check capillary blood glucose every 1 hour until glucose reaches 11-14 mmol/L (200-250 mg/dL). 1, 4
• Expect glucose decline of 50-75 mg/dL (2.8-4.2 mmol/L) per hour with appropriate insulin dosing. 3, 1
• Once glucose stabilizes in the 11-14 mmol/L range, reduce monitoring to every 2 hours. 1
• Recheck ketones if glucose remains >16.5 mmol/L after 2 hours to ensure DKA has not developed. 3, 1

Identify and Address Precipitating Factors

Investigate why hyperglycemia occurred:

• Review recent insulin doses and adherence patterns to identify missed doses. 1
• Screen for infection (urinary tract infection, pneumonia, skin/soft tissue infection) as the most common precipitant. 2, 6, 7
• Check for concurrent illness or stress (myocardial infarction, stroke, pancreatitis). 8, 6
• Review medications for recent corticosteroid initiation or dose increase. 1
• If on insulin pump, check for malfunction (kinked tubing, site infection, pump failure). 1

Transition and Follow-Up Management

Once glucose reaches target range:

• Resume usual insulin regimen if patient was previously on basal-bolus therapy, ensuring basal insulin was not missed. 1, 4
• Consider temporary 10-20% increase in total daily insulin dose if no clear precipitant identified. 1
• Schedule follow-up within 24-48 hours to reassess glycemic control and adjust insulin doses. 1

Critical Pitfalls to Avoid

Common errors that worsen outcomes:

1. Never delay insulin administration while waiting for additional workup - glucose >20 mmol/L requires immediate treatment regardless of time of day. 1

2. Never assume absence of ketosis without verification - at glucose levels >16.5 mmol/L, ketone measurement is mandatory in Type 1 diabetes and insulin-treated Type 2 diabetes. 3, 1

3. Never use sliding scale insulin alone - weight-based dosing of rapid-acting insulin is far more effective than arbitrary sliding scales. 1

4. Never withhold fluids - dehydration from osmotic diuresis is universal at this glucose level and must be corrected. 3, 6, 5

5. Never stop monitoring prematurely - glucose can rebound after initial correction, requiring additional insulin doses. 1, 4

Special Considerations for DKA/HHS (If Ketosis or Hyperosmolarity Present)

If assessment reveals DKA or HHS, management changes dramatically:

• Transfer to ICU immediately for continuous IV insulin infusion and intensive monitoring. 3, 2
• Start IV regular insulin at 0.1 unit/kg/h (no bolus in pediatric patients; 0.15 unit/kg bolus in adults). 3
• Aggressive IV fluid resuscitation with 0.9% NaCl at rates determined by degree of dehydration and hemodynamic status. 3, 5
• Add dextrose 5% to IV fluids when glucose falls to 14 mmol/L (250 mg/dL) while continuing insulin to clear ketones. 3, 4
• Monitor electrolytes, pH, and osmolality every 2-4 hours until stable. 3, 4
• DKA resolution requires glucose <11 mmol/L (200 mg/dL), bicarbonate ≥18 mEq/L, and pH >7.3. 4
• HHS resolution requires osmolality <300 mOsm/kg, corrected hypovolemia, and glucose <15 mmol/L. 5