How to manage severe hyperglycemia?

Management of Blood Glucose 50 mmol/L (900 mg/dL)

This represents a life-threatening hyperglycemic emergency requiring immediate intravenous insulin infusion, aggressive fluid resuscitation, and intensive care unit admission to prevent death from hyperosmolar hyperglycemic state (HHS) or diabetic ketoacidosis (DKA). 1, 2, 3

Immediate Emergency Assessment (First 60 Minutes)

Assess for hyperglycemic crisis immediately:

• Check for altered mental status, severe dehydration (dry mucous membranes, poor skin turgor), Kussmaul respirations, fruity breath odor, abdominal pain, nausea/vomiting 2, 3
• Measure serum or urine ketones urgently - presence of ketones ≥3.0 mmol/L indicates DKA rather than pure HHS 4
• Calculate serum osmolality using [(2×Na+) + glucose + urea] - osmolality ≥320 mOsm/kg confirms HHS 4
• Obtain arterial blood gas - pH <7.3 and bicarbonate <15 mmol/L indicates DKA 4
• Check serum potassium immediately before starting insulin - severe hypokalemia (<2.5 mEq/L) occurs in ~50% of cases and is associated with increased mortality 1

Immediate Treatment Protocol

Start continuous intravenous insulin infusion immediately:

• Begin IV insulin at 0.1 units/kg/hour (typically 5-10 units/hour for adults) using regular insulin diluted to 1 IU/mL 1, 3
• Do NOT delay insulin therapy - at glucose levels this extreme, insulin must be started urgently regardless of potassium unless <3.3 mEq/L 1, 2
• Target glucose reduction of 50-70 mg/dL per hour initially, NOT faster - overly rapid correction increases risk of cerebral edema and osmotic demyelination 1, 4

Aggressive fluid resuscitation is critical:

• Administer 0.9% normal saline at 15-20 mL/kg/hour (typically 1-1.5 L) in the first hour 4
• Total fluid deficit is typically 100-220 mL/kg (8-15 liters in adults) 4
• Aim to replace approximately 50% of fluid deficit in first 12-24 hours 4
• Monitor for fluid overload, especially in elderly patients and those with heart failure 1, 4

Potassium replacement protocol:

• If K+ <3.3 mEq/L: hold insulin and give 20-30 mEq/hour potassium until >3.3 mEq/L 1
• If K+ 3.3-5.0 mEq/L: add 20-40 mEq potassium to each liter of IV fluid 1
• If K+ >5.0 mEq/L: do not give potassium but recheck every 2 hours 1

Glucose Management During Crisis

Once glucose falls to 14-16 mmol/L (250-300 mg/dL):

• Add 5% or 10% dextrose infusion at 100-150 g/day to prevent hypoglycemia while continuing insulin 1, 3
• Continue insulin infusion to clear ketones (if DKA) and normalize osmolality 4
• Target glucose 10-15 mmol/L (180-270 mg/dL) for first 24 hours 2, 4

Monitoring requirements:

• Measure blood glucose hourly until stable, then every 2 hours 1, 3
• Check serum potassium every 2-4 hours 1, 4
• Monitor osmolality every 4-6 hours - aim for decline of 3-8 mOsm/kg/hour 4
• Reassess mental status, vital signs, and urine output hourly 4

Resolution Criteria and Transition

HHS is resolved when ALL of the following are met:

• Osmolality <300 mOsm/kg 4
• Patient alert and oriented to baseline mental status 4
• Adequate urine output (≥0.5 mL/kg/hour) 4
• Blood glucose <15 mmol/L (270 mg/dL) 4

Transition to subcutaneous insulin:

• Administer subcutaneous basal insulin (glargine or NPH) 2-4 hours BEFORE stopping IV insulin 1, 3
• Calculate total daily insulin dose based on IV insulin requirements over previous 6-12 hours 1
• Give 50% as basal insulin and 50% as prandial insulin divided before meals 3

Critical Pitfalls to Avoid

Common errors that increase mortality:

• Never use sliding scale insulin alone - this approach is ineffective and strongly contraindicated in hyperglycemic crisis 3
• Never correct glucose too rapidly - aim for gradual decline to prevent cerebral edema, especially in HHS where osmolality has been elevated for days 4
• Never stop IV insulin before giving subcutaneous insulin - this causes immediate rebound hyperglycemia 1, 3
• Never ignore potassium - insulin drives potassium intracellularly and can precipitate fatal cardiac arrhythmias 1

Identify and Treat Precipitating Cause

Common triggers requiring specific treatment:

• Infection (pneumonia, UTI, sepsis) - most common precipitant 2, 4
• Acute myocardial infarction or stroke 1, 4
• Medication non-adherence or new diagnosis of diabetes 1, 4
• Corticosteroid therapy or other diabetogenic medications 1, 5

Post-Crisis Management

Once stabilized (24-72 hours):

• Initiate or resume metformin if eGFR ≥30 mL/min/1.73 m² 1
• Continue basal-bolus insulin regimen with daily dose adjustments based on glucose patterns 3
• Target glucose 7.8-10.0 mmol/L (140-180 mg/dL) for hospitalized patients 1, 2
• Arrange diabetes education and close outpatient follow-up within 1 week of discharge 3