What is the management approach for a patient with urine ketones greater than 150?

Management of Urine Ketones Greater Than 150

For patients with urine ketones greater than 150, immediate implementation of sick day management protocols is required, including increased fluid intake, insulin administration, and frequent monitoring of blood glucose and ketones to prevent progression to diabetic ketoacidosis (DKA). 1

Assessment of Ketosis Severity

Elevated urine ketones (>150) indicate a state of increased fat metabolism where the body is producing ketone bodies as an alternative energy source due to insufficient glucose utilization. This can signal impending or established diabetic ketoacidosis in diabetic patients 1.

Key assessments to perform:

• Blood glucose levels
• Venous blood gases (pH and bicarbonate)
• Electrolytes (sodium, potassium, chloride)
• Blood urea nitrogen and creatinine
• Blood ketone levels (if available)

Blood ketone testing is more accurate than urine ketone testing for diagnosis and monitoring of DKA, as it measures β-hydroxybutyrate directly and provides quantitative results 1.

Management Algorithm

1. For Diabetic Patients with Hyperglycemia and Elevated Ketones

• Fluid replacement:

  • Increase oral fluid intake to at least 150-200 g of carbohydrate-containing fluids daily
  • If unable to maintain oral hydration, IV fluid therapy with isotonic saline (0.9% NaCl) is indicated 2

• Insulin therapy:

  • For mild ketosis: Administer supplemental insulin as needed
  • For moderate to severe ketosis (blood ketones >3.0 mmol/L):
    • Adults: IV bolus of regular insulin at 0.15 units/kg followed by continuous infusion at 0.1 unit/kg/hr
    • Children: Avoid initial insulin bolus and start continuous infusion at 0.1 unit/kg/hr 2, 1

• Monitoring:

  • Check blood glucose every 1-2 hours
  • Monitor blood or urine ketones every 2-4 hours
  • Target glucose decrease of 50-75 mg/dL/hr
  • Add 5-10% dextrose to IV fluids when glucose reaches 200 mg/dL 2, 1

2. For Patients with Type 1 Diabetes During Acute Illness

• Continue insulin therapy - never omit insulin during illness 2
• Test blood glucose and blood/urine ketones frequently
• Drink adequate amounts of fluids
• Ingest 150-200 g carbohydrate daily (45-50 g every 3-4 hours) to prevent starvation ketosis 2
• Replace fluids containing sodium (broth, tomato juice, sports drinks) to prevent dehydration 2

Resolution Criteria

DKA is considered resolved when:

• Glucose <200 mg/dL
• Serum bicarbonate ≥18 mEq/L
• Venous pH >7.3 2, 1

Once ketoacidosis is resolved and the patient can eat, transition to a multiple-dose insulin regimen, continuing IV insulin for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels 2.

Special Considerations

• Non-diabetic causes of elevated ketones should be considered, including:

  • Prolonged fasting
  • Very low carbohydrate diets
  • Prolonged exercise
  • Alcoholic ketoacidosis 1

• SGLT2 inhibitor use increases risk of euglycemic DKA, where ketone levels may be high despite relatively normal blood glucose levels 1, 3

• Monitoring limitations: The nitroprusside method (used in most urine ketone tests) only measures acetoacetic acid and acetone, not β-hydroxybutyrate (the strongest and most prevalent acid in DKA). During therapy, β-hydroxybutyrate is converted to acetoacetic acid, which may lead to the false impression that ketosis has worsened 2.

Prevention of Future Episodes

• Educate patients on sick day management
• Ensure patients have ketone testing supplies at home
• Instruct patients to test for ketones during illness, with unexplained hyperglycemia, or when experiencing symptoms of ketosis 1

By following this management approach, you can effectively treat elevated ketone levels and prevent progression to more severe diabetic ketoacidosis.