What is the recommended management of acute hyperglycemia upon hospital admission?

Management of Acute Hyperglycemia on Hospital Admission

For acute hyperglycemia on admission, initiate insulin therapy immediately: use continuous intravenous insulin infusion for critically ill patients, and scheduled subcutaneous basal-bolus insulin (or basal insulin with correction) for noncritically ill patients, targeting blood glucose 100-180 mg/dL. 1

Critical Care Setting

If the patient is critically ill (ICU admission):

• Start continuous IV insulin infusion immediately using validated protocols that allow predefined adjustments based on glucose fluctuations 1
• Target glucose range: 100-180 mg/dL (5.6-10.0 mmol/L) 1, 2
• This is the most effective method for achieving glycemic goals while avoiding hypoglycemia in critical illness 1

Special considerations for DKA/HHS:

• Use fixed-rate IV insulin infusion or nurse-driven variable-rate protocols 1
• Mild, uncomplicated DKA can be managed with subcutaneous rapid-acting insulin every 1-2 hours 1

Noncritical Care Setting

For Patients WITHOUT Known Diabetes (New Hyperglycemia)

If admission glucose >140 mg/dL (7.8 mmol/L):

1. Start with correction insulin alone initially 3
2. Add scheduled insulin (basal or basal-bolus) if:
   • ≥2 point-of-care glucose measurements ≥180 mg/dL in 24 hours on correction insulin alone 3
   • Or confirmed admission glucose ≥180 mg/dL—consider starting scheduled insulin immediately 3

For Patients WITH Known Diabetes

Previously on diet or oral medications:

• Start with either correction insulin alone OR scheduled insulin therapy 3
• Add scheduled insulin if persistent hyperglycemia (≥2 readings ≥180 mg/dL in 24 hours) 3
• If admission glucose ≥180 mg/dL, strongly consider initiating scheduled insulin immediately 3

Previously on insulin therapy:

• Initiate scheduled subcutaneous insulin immediately 1
• Use basal-bolus regimen (basal insulin + prandial insulin before meals + correction doses) for patients eating 1
• Use basal insulin plus correction insulin every 4-6 hours for patients with poor/no oral intake 1

Type 1 diabetes:

• Never use correction insulin alone—always include basal insulin component 1
• Continue basal insulin even if NPO (nothing by mouth) 1
• Implement EHR alerts to prevent dangerous basal insulin omissions during care transitions 1

Insulin Dosing Principles

• Base initial basal insulin dose on body weight and expected insulin sensitivity 1
• Reduce doses in renal insufficiency 1
• Avoid prolonged use of correction/supplemental insulin alone (except mild type 2 diabetes or stress hyperglycemia in noncritical care) 1, 3
• Insulin analogs preferred over regular insulin due to lower hypoglycemia risk 1

Common Pitfalls to Avoid

1. Never use sliding-scale insulin (SSI) as monotherapy—this reactive approach without basal insulin is strongly discouraged and ineffective 1, 4
2. Never hold basal insulin in type 1 diabetes, even when NPO 1
3. Avoid dosing insulin solely on premeal glucose without accounting for basal requirements or caloric intake 1
4. Don't delay scheduled insulin in patients with confirmed severe hyperglycemia (≥180 mg/dL) 3

Monitoring Approach

• Standard: Point-of-care capillary glucose monitoring 1
• Consider real-time CGM with confirmatory POC-BG for high-risk patients (age ≥65, BMI ≤27, insulin dose ≥0.6 units/kg/day, CKD stage ≥3) in settings with available resources 3
• Measure HbA1c on admission to assess chronic control and guide discharge planning 5

The 2025 ADA guidelines 1 represent the most current evidence-based approach, emphasizing that insulin remains the cornerstone of inpatient hyperglycemia management, with the specific regimen determined by illness severity and oral intake status.