What is the management for a patient with severe hyperglycemia (elevated blood glucose)?

Management of Blood Glucose 576 mg/dL

For a blood glucose of 576 mg/dL, immediately initiate insulin therapy while simultaneously starting metformin, and urgently evaluate for diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS) to determine whether intravenous or subcutaneous insulin is required. 1, 2

Immediate Assessment (First 30 Minutes)

Evaluate for hyperglycemic crisis by checking for:

• Mental status changes, confusion, or altered consciousness 2, 3
• Signs of severe dehydration (dry mucous membranes, poor skin turgor, hypotension, tachycardia) 3, 4
• Fruity breath odor (acetone), Kussmaul respirations (deep, rapid breathing) 5, 3
• Abdominal pain, nausea, or vomiting 3, 5
• Blood glucose ≥600 mg/dL suggests possible HHS 3

Obtain stat laboratory tests:

• Serum or urine ketones (critical for distinguishing DKA from HHS) 2, 3
• Complete metabolic panel (sodium, potassium, chloride, bicarbonate, BUN, creatinine) 1, 2
• Arterial blood gas if DKA suspected (pH <7.3, bicarbonate <18 mEq/L indicates DKA) 3, 4
• Anion gap calculation 3
• HbA1c to assess chronicity 1

Treatment Algorithm Based on Clinical Presentation

If DKA or HHS Present (Ketones Positive, pH <7.3, or Severe Dehydration/Mental Status Changes)

Start continuous intravenous insulin infusion immediately - this is the standard of care for critically ill patients with hyperglycemic crisis 3, 2:

• Use validated written or computerized protocols 3
• Target glucose range of 140-180 mg/dL 3, 2
• Monitor blood glucose every 1-2 hours during IV insulin 1

Aggressive fluid resuscitation is essential to restore circulatory volume and tissue perfusion 3, 2:

• Begin with 0.9% normal saline 1-1.5 L in first hour 4, 6
• Continue fluid replacement based on hydration status and electrolytes 3

Potassium replacement is critical - hypokalaemia occurs in approximately 50% of patients during treatment and severe hypokalaemia (<2.5 mEq/L) increases mortality 3:

• Check potassium before starting insulin 3
• Add potassium to IV fluids once levels are <5.2 mEq/L and urine output is adequate 4
• Monitor potassium every 2-4 hours 3

Do not use bicarbonate - studies show no benefit in resolution of acidosis or time to discharge 3, 2

Transition from IV to subcutaneous insulin requires careful timing to prevent rebound hyperglycemia 3, 2:

• Administer basal insulin 2-4 hours before stopping IV insulin 3, 2, 4
• Calculate subcutaneous dose as 60-80% of total daily IV insulin dose from the 12 hours before transition 3
• Common pitfall: premature termination of IV insulin leads to recurrent ketoacidosis 4

If No DKA/HHS (Asymptomatic or Mildly Symptomatic, Ketones Negative)

Start basal insulin immediately at 0.5 units/kg/day subcutaneously while initiating metformin 1:

• This applies to patients with glucose ≥250 mg/dL even without symptoms 1, 2
• Administer insulin subcutaneously, not IV, for stable non-critically ill patients 3

Initiate metformin 500 mg twice daily with meals if renal function is normal (eGFR >45 mL/min/1.73 m²) 1:

• Titrate up to 2000 mg per day as tolerated 1
• Continue metformin long-term 1

Adjust insulin dose every 2-3 days based on fasting blood glucose monitoring 1:

• Increase by 10-20% if fasting glucose remains elevated 1
• Target pre-meal glucose <140 mg/dL and random glucose <180 mg/dL 1

Monitor blood glucose every 2-4 hours initially until stable 3

Identify and Treat Precipitating Causes

Search for underlying triggers that caused the hyperglycemia 3, 2:

• Infection (most common precipitant - check for pneumonia, UTI, skin infections) 4, 6
• Myocardial infarction or stroke 3
• Medication non-adherence (omitted insulin doses) 5, 7
• New diagnosis of diabetes 7
• Corticosteroid therapy 3
• Pancreatitis 6

Insulin Tapering (Once Glucose Controlled)

Taper insulin over 2-6 weeks once glucose targets are consistently met on home blood glucose monitoring 3, 2:

• Decrease insulin dose by 10-30% every few days 3, 2
• Continue metformin throughout the taper 1, 2
• If glycemic targets are not maintained on metformin alone, consider adding a GLP-1 receptor agonist before reintroducing insulin 1

Critical Pitfalls to Avoid

Common errors that worsen outcomes:

• Stopping IV insulin before subcutaneous basal insulin has been given (causes rebound hyperglycemia and recurrent ketoacidosis) 4
• Using sliding-scale insulin alone without basal insulin (strongly discouraged and associated with poor glycemic control) 3
• Inadequate potassium monitoring and replacement (severe hypokalaemia increases mortality) 3
• Failing to identify and treat the precipitating cause (leads to recurrence) 3, 7
• Premature discharge without ensuring patient has access to insulin and follow-up 7

Disposition and Follow-Up

Admission criteria:

• All patients with DKA or HHS require ICU admission 3, 8
• Patients with severe hyperglycemia (>600 mg/dL) or significant symptoms require hospitalization 3
• Stable patients with glucose 250-600 mg/dL without ketoacidosis may be managed as outpatients with close follow-up 1

Schedule follow-up within 1-2 weeks to reassess glycemic control and adjust therapy 2

Provide diabetes self-management education before discharge to prevent recurrence 2, 7