What is the immediate management for a patient with a history of diabetes presenting with a hyperglycemic crisis, potentially complicated by diabetic ketoacidosis (DKA) or hyperglycemic hyperosmolar nonketotic syndrome (HHNS)?

Immediate Management of Hyperglycemic Crisis

A patient with diabetes presenting in hyperglycemic crisis requires immediate intravenous fluid resuscitation with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hr, followed by continuous IV insulin infusion at 0.1 units/kg/hr after initial fluid bolus, with aggressive potassium monitoring and replacement to prevent life-threatening complications. 1, 2

Initial Assessment and Diagnostic Confirmation

Rapidly assess for DKA versus HHS by checking blood glucose, arterial or venous pH, bicarbonate, and ketones (preferably β-hydroxybutyrate in blood rather than urine ketones). 1, 2

• DKA criteria: Blood glucose >250 mg/dL, arterial pH <7.3, bicarbonate <15 mEq/L, and moderate ketonemia or ketonuria 1
• HHS presentation: More gradual onset over days to a week with severe dehydration, altered mental status, and extreme hyperglycemia (often >600 mg/dL) but minimal ketosis 3, 4
• The combination of vomiting with ketosis strongly indicates DKA requiring immediate intervention 1, 3

Identify precipitating factors immediately: infection (most common), medication non-adherence, new-onset diabetes, myocardial infarction, or stroke. 1, 5

Step 1: Aggressive Fluid Resuscitation (FIRST PRIORITY)

Begin isotonic saline (0.9% NaCl) at 15-20 mL/kg/hr during the first hour to restore circulatory volume and tissue perfusion. 1, 2

• After the first hour, continue at 4-14 mL/kg/hr based on hemodynamic status 1
• Dehydration is a critical factor that increases hospitalization risk and mortality 6
• Critical pitfall: Do not delay fluid resuscitation while waiting for laboratory results 4

Step 2: Insulin Therapy (After Initial Fluid Bolus)

Start continuous IV regular insulin at 0.1 units/kg/hr after fluid resuscitation has begun. 1, 2, 7

• If glucose does not fall by 50-75 mg/dL in the first hour, double the insulin infusion rate 1
• Once blood glucose reaches 200-250 mg/dL, add dextrose to IV fluids while continuing insulin infusion to prevent hypoglycemia and allow continued clearance of ketones 1
• Critical pitfall: Never discontinue IV insulin prematurely—continue until ketones clear, not just until glucose normalizes 1, 4

Step 3: Potassium Management (ESSENTIAL)

Monitor serum potassium every 2-4 hours as insulin therapy drives potassium intracellularly, causing potentially fatal hypokalemia. 1, 7

• Begin potassium replacement when serum levels fall below 5.2 mEq/L, provided adequate urine output is present 1
• Typical replacement is 20-30 mEq per liter of IV fluid 1
• Critical warning: Untreated hypokalemia can cause respiratory paralysis, ventricular arrhythmia, and death 7

Ongoing Monitoring Requirements

Check blood glucose every 1-2 hours until stable and monitor electrolytes, BUN, creatinine, and venous pH every 2-4 hours. 1, 2

• Assess for cerebral edema (especially in children and adolescents): headache, altered mental status, seizures, bradycardia 1
• Monitor for signs of treatment complications including hypoglycemia and hypokalemia 7, 4

Transition to Subcutaneous Insulin

Administer subcutaneous basal insulin 2-4 hours BEFORE discontinuing IV insulin to prevent rebound hyperglycemia and recurrent ketoacidosis. 1, 2

• Critical pitfall: Premature termination of IV insulin or insufficient overlap with subcutaneous insulin is a common management error that leads to recurrence 4
• Target pre-meal glucose <140 mg/dL and random glucose <180 mg/dL for non-critically ill patients 2

Special Populations Requiring Modified Approach

Pregnant patients: Any concern for DKA requires immediate medical attention due to significant feto-maternal harm risk; may present with euglycemic DKA (glucose <200 mg/dL). 3

SGLT2 inhibitor users: Can develop euglycemic DKA with normal or near-normal glucose levels, requiring the same urgent management despite lower glucose readings. 1, 3

Children: Higher risk of cerebral edema during treatment, requiring closer monitoring during fluid resuscitation. 3

Critical Management Pitfalls to Avoid

• Never discontinue insulin during illness, even if the patient is not eating—this precipitates DKA 6, 3
• Do not stop IV insulin when glucose normalizes; continue until ketones clear 1, 4
• Do not forget potassium replacement—insulin therapy without potassium monitoring is dangerous 1, 7
• Ensure adequate overlap between IV and subcutaneous insulin (2-4 hours) 1, 2, 4

Treatment of Underlying Precipitating Factors

Identify and aggressively treat infection or other stressors that triggered the crisis. 6, 1

• Aggressive glycemic management with insulin may reduce morbidity in severe acute illness 6
• A physician with expertise in diabetes management should oversee hospitalized patient care 6

Prevention of Recurrence

Review sick-day management: Never discontinue insulin during illness, monitor blood glucose and ketones when glucose >200-300 mg/dL, seek professional advice early. 1, 3

• Educate on when to check ketones: glucose >200 mg/dL, illness symptoms (nausea, vomiting, abdominal pain), missed insulin doses, or unexplained hyperglycemia 3
• Blood ketone testing is preferred over urine testing for more accurate real-time assessment 3