What is the appropriate management for a diabetic patient with poor compliance, presenting with hyperglycemia, metabolic acidosis, ketonuria, and an infected wound?

Management of Diabetic Ketoacidosis with Severe Infection

This patient requires immediate hospitalization for aggressive management of diabetic ketoacidosis (DKA) with concurrent severe foot infection, as the combination of metabolic instability (pH 6.85, ketonuria, severe hyperglycemia) and infected wound constitutes a life-threatening emergency requiring intensive monitoring and parenteral therapy. 1

Immediate Hospitalization is Mandatory

This patient meets multiple criteria for severe infection requiring hospitalization 1:

• Metabolic instability with severe acidosis (pH 6.85), severe hyperglycemia (CBG 428 mg/dL), and ketonuria
• Systemic manifestations including dyspnea, weight loss, and polyuria/polydipsia indicating DKA
• Infected wound in the setting of metabolic decompensation
• Poor compliance history making outpatient management unsafe

The presence of acidosis and severe hyperglycemia in a patient with infection classifies this as a severe diabetic foot infection requiring immediate inpatient care 1.

Step 1: Metabolic Stabilization Takes Priority

Before addressing the wound infection surgically, metabolic stabilization must be achieved 1:

Fluid Resuscitation

• Restore circulating volume and tissue perfusion with aggressive intravenous fluids 1, 2, 3
• Correct dehydration, electrolyte imbalances (particularly potassium), and acidosis 1

Insulin Therapy

• Continuous intravenous insulin is the standard of care for critically ill patients with DKA 1
• Administer intravenous insulin to resolve hyperglycemia and ketoacidosis 1, 2, 4
• Monitor blood glucose frequently (every 2-4 hours minimum) 1

Electrolyte Management

• Aggressive potassium replacement is critical, as insulin therapy will drive potassium intracellularly 1, 2, 3
• Monitor and correct other electrolyte abnormalities 1

Critical timing note: Surgery should not be delayed more than 4-8 hours after hospital presentation, but the patient should be stabilized first 1.

Step 2: Management of Infected Foot Wound

Obtain Cultures Before Antibiotics

• Blood cultures are mandatory given systemic illness and metabolic instability 1
• Obtain deep tissue specimens from the debrided wound base via curettage or biopsy (not swabs of undebrided wounds) 1
• Cleanse and debride the lesion before obtaining specimens 1

Empirical Antibiotic Therapy

Initiate broad-spectrum parenteral antibiotics immediately after obtaining cultures 1:

• Coverage must include gram-positive cocci (including MRSA if prevalent locally), gram-negative organisms, and obligate anaerobes 1
• Parenteral route is mandatory initially to ensure adequate tissue concentrations 1
• This is a severe infection requiring broad coverage, not narrow-spectrum therapy 1

Surgical Consultation

• Immediate podiatric/surgical consultation for wound debridement 1
• Assess for deep-tissue involvement, abscess, gangrene, or bone/joint involvement 1
• Consider need for urgent surgical intervention or amputation 1

Step 3: Transition from IV to Subcutaneous Insulin

Administer basal insulin subcutaneously 2-4 hours before stopping IV insulin to prevent rebound hyperglycemia and recurrent ketoacidosis 1. This is a critical step that is frequently missed and leads to metabolic decompensation.

Common Pitfalls to Avoid

• Do not use bicarbonate therapy for DKA management, as studies show no difference in outcomes 1
• Do not stop IV insulin abruptly without prior subcutaneous basal insulin administration 1
• Do not use narrow-spectrum antibiotics in this severe infection with metabolic instability 1
• Do not delay surgical consultation beyond 4-8 hours, even if metabolic stabilization is incomplete 1
• Do not culture undebrided wounds with swabs, as this provides inaccurate results 1

Monitoring Requirements

• Hourly vital signs and neurological assessment 1
• Blood glucose monitoring every 2-4 hours 1
• Serial electrolytes (especially potassium) 1, 2, 3
• Daily reassessment of wound and infection status 1
• Monitor for complications including cerebral edema, hypoglycemia, and hypokalemia 1, 5, 2

Addressing the Underlying Cause

Infection is the precipitating factor for DKA in 30-50% of cases 6, 2, 3. The infected foot wound combined with poor insulin compliance triggered this patient's DKA 6, 2, 3. Both issues must be addressed simultaneously to prevent mortality, which is higher when infection accompanies DKA 6.

Discharge Planning Considerations

Once metabolically stable and infection controlled 1:

• Structured diabetes education focusing on insulin adherence 2, 3
• Clear wound care instructions and follow-up plan 1
• Appropriate basal-bolus insulin regimen (not just oral agents given type 1 presentation) 1
• Close outpatient follow-up within 1-2 weeks 1