What is the management approach for a patient presenting with high-grade fever, vomiting, and ketosis, potentially indicating diabetic ketoacidosis (DKA)?

Management of High-Grade Fever, Vomiting, and Ketosis

The management of a patient with high-grade fever, vomiting, and ketosis should focus on immediate assessment for diabetic ketoacidosis (DKA), which is a life-threatening condition requiring prompt fluid resuscitation, insulin therapy, and electrolyte management. 1

Initial Assessment and Diagnosis

• Assess for DKA diagnostic criteria: blood glucose >250 mg/dL, arterial pH <7.3, bicarbonate <15 mEq/L, and moderate ketonemia or ketonuria 1
• Direct measurement of β-hydroxybutyrate in blood is preferred over urine ketones for monitoring DKA 1
• Evaluate for precipitating factors such as infection (common with fever), medication non-adherence, or new-onset diabetes 1, 2
• The combination of vomiting illness accompanied by ketosis strongly suggests DKA, which requires immediate medical attention 2

Immediate Management

Fluid Resuscitation

• Begin with isotonic saline (0.9% NaCl) at 15-20 mL/kg/hr (approximately 1-1.5 L) in the first hour to restore circulatory volume and tissue perfusion 1
• After the first hour, continue fluid replacement based on hemodynamic status, typically at 4-14 mL/kg/hr 1
• Adequate fluid intake must be assured as dehydration is more likely to necessitate hospitalization in patients with diabetes 2

Insulin Therapy

• Start continuous intravenous regular insulin at 0.1 units/kg/hr after fluid resuscitation has begun 1
• 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 (D5W or D10W) while continuing insulin infusion to prevent hypoglycemia 1, 3
• Continue insulin infusion until DKA resolves (pH >7.3, bicarbonate ≥18 mEq/L, and anion gap normalized) 1

Electrolyte Management

• Monitor serum potassium levels every 2-4 hours as insulin therapy can cause hypokalemia 1, 3
• Begin potassium replacement when serum levels fall below 5.2 mEq/L, provided the patient has adequate urine output 1
• Typical potassium replacement is 20-30 mEq per liter of IV fluid 1
• Monitor phosphate levels and consider replacement if <1.0 mg/dL 1

Ongoing Monitoring

• Check blood glucose every 1-2 hours until stable 1
• Monitor electrolytes, blood urea nitrogen, creatinine, and venous pH every 2-4 hours 1
• Assess for signs of cerebral edema, particularly in children and adolescents (headache, altered mental status, seizures, bradycardia) 1, 2
• Monitor for hypoglycemia, which is the most common adverse reaction of insulin therapy 3

Treatment of Precipitating Factors

• Identify and treat underlying causes such as infection (likely with high-grade fever), trauma, or medication non-compliance 1, 4
• Aggressive glycemic management with insulin may reduce morbidity in patients with severe acute illness 2
• The stress of illness frequently aggravates glycemic control and necessitates more frequent monitoring of blood glucose and ketones 2

Transition to Subcutaneous Insulin and Discharge Planning

• Once DKA has resolved (glucose <200 mg/dL, bicarbonate ≥18 mEq/L, pH >7.3), transition to subcutaneous insulin 1
• Administer subcutaneous basal insulin 2-4 hours before discontinuing IV insulin to prevent recurrence of ketoacidosis 1, 2
• Continue IV insulin infusion for 1-2 hours after starting subcutaneous insulin to ensure adequate plasma insulin levels 1
• Ensure clear communication with outpatient providers about medication changes and follow-up needs 1

Prevention of Future Episodes

• Review sick-day management with patients, including when to contact healthcare providers, blood glucose goals, and use of supplemental short-acting insulin during illness 2
• Advise patients never to discontinue insulin during illness and to seek professional advice early 2
• Educate patients on monitoring blood glucose, urine ketones when blood glucose is >300 mg/dL, and recording insulin administered 2
• Address potential barriers to insulin adherence, as stopping insulin for economic reasons is a common precipitant of DKA 2

Special Considerations

• Be aware of euglycemic diabetic ketoacidosis risk in patients taking SGLT2 inhibitors, which requires the same urgent management despite potentially lower blood glucose levels 2
• Patients should be advised to seek immediate care if they develop symptoms potentially associated with diabetic ketoacidosis (nausea, vomiting, abdominal pain, generalized weakness) 2
• Hypoglycemia risk increases when adding newer antihyperglycemic therapies; consider reducing doses of insulin secretagogues or insulin 2

DKA is a medical emergency with significant mortality risk if not promptly recognized and treated. The combination of high-grade fever, vomiting, and ketosis strongly suggests this diagnosis and requires immediate intervention to prevent complications and death 5, 6, 7.