Management of Random Blood Glucose 300 mg/dL
A random blood glucose of 300 mg/dL requires immediate clinical assessment for symptoms, ketones, and precipitating factors, with prompt initiation of treatment to prevent progression to life-threatening hyperglycemic crisis.
Immediate Assessment Required
Check for ketones immediately to differentiate between simple hyperglycemia and impending diabetic ketoacidosis (DKA), as vomiting with ketosis indicates DKA requiring emergency management 1, 2. Obtain vital signs, assess hydration status, mental status, and look for signs of infection or other precipitants 3, 4.
Key laboratory tests to order STAT include:
- Blood or urine ketones 1, 2
- Complete metabolic panel with electrolytes, BUN, creatinine 3, 4
- Arterial blood gas if ketones present or patient appears ill 4
- Complete blood count 3
Clinical Decision Algorithm
If Ketones Present (>3.0 mmol/L) or pH <7.3:
This is DKA—initiate emergency hyperglycemic crisis protocol immediately with IV insulin infusion (0.15 units/kg bolus, then 0.1 units/kg/hour continuous infusion) and aggressive fluid resuscitation 3, 4.
If No Ketones and Patient Symptomatic:
Contact the provider immediately as glucose >300 mg/dL over 2 consecutive days warrants urgent intervention per standardized alert protocols 1. The patient requires:
- Increased insulin dosing or initiation of insulin therapy 3, 2
- IV fluids if dehydrated 3
- Blood glucose monitoring every 1-2 hours initially 3, 2
If No Ketones and Patient Asymptomatic:
Still requires same-day provider contact and intervention, as persistent hyperglycemia >300 mg/dL indicates inadequate diabetes control and risk for progression to hyperosmolar hyperglycemic state (HHS) 1, 2.
Treatment Approach Based on Setting
Outpatient/Long-Term Care Setting:
- Never discontinue insulin even if oral intake is poor 1, 2
- Increase blood glucose monitoring frequency to every 4-6 hours 2
- Adjust insulin doses based on current readings—typically requires 20-50% increase in total daily dose 2
- Ensure adequate hydration with sugar-free fluids 1
- Identify and treat precipitating causes (infection, medication non-adherence, steroid use) 1, 2
Hospital/ICU Setting:
If glucose remains >300 mg/dL despite initial interventions or patient develops altered mental status, initiate IV insulin infusion protocol 1, 3, 4:
- Start continuous IV regular insulin at 0.1 units/kg/hour (approximately 5-7 units/hour in adults) 3, 4
- Target glucose decline of 50-75 mg/dL per hour 3, 4
- Begin IV fluid resuscitation with 0.9% normal saline at 10-20 ml/kg/hour for first hour if dehydrated 3, 4
- Monitor glucose hourly and electrolytes every 2-4 hours 3, 4
For critically ill patients, target glucose 140-180 mg/dL once initial hyperglycemia controlled to balance glycemic control against hypoglycemia risk 1, 4. More aggressive targets (110-140 mg/dL) increase hypoglycemia risk without mortality benefit 1.
Critical Monitoring Parameters
Monitor for complications during treatment:
- Hypoglycemia (most common complication)—treat immediately if glucose <70 mg/dL 1
- Hypokalemia—add 20-40 mEq/L potassium to IV fluids once renal function confirmed; do not start insulin if K+ <3.3 mEq/L 3, 4
- Fluid overload—especially in elderly or those with heart/kidney disease 3, 4
- Mental status changes—may indicate cerebral edema or worsening hyperosmolality 4
Common Pitfalls to Avoid
Do not use sliding-scale insulin alone—this approach is associated with poor outcomes and fails to address basal insulin needs 2, 4. Do not stop IV insulin abruptly when transitioning to subcutaneous—overlap by 1-2 hours to prevent rebound hyperglycemia 3, 4. Do not ignore persistent hyperglycemia >300 mg/dL—this represents a quality measure for hospital-acquired events and requires intervention 1.
Transition and Follow-up
Once glucose stabilizes below 200 mg/dL and patient can eat: