What is the best course of action for a patient with a rapidly progressing wound and potential severe infection, who was discharged from the emergency department (ED) without intervention, and may have underlying conditions such as diabetes or poor circulation?

Immediate Return to Emergency Department Required

This patient requires immediate return to the emergency department for urgent reassessment and likely hospital admission, as discharging a patient with a rapidly progressing wound and signs of severe infection without intervention represents a critical error in management that places the limb and potentially life at risk. 1, 2

Critical Red Flags Requiring Immediate ED Return

The following signs indicate a potentially limb- or life-threatening infection that mandates urgent surgical consultation and hospitalization:

• Rapid progression of infection over hours to days 1, 2
• Fever, tachycardia, or systemic signs of sepsis (temperature >38°C, heart rate >100 bpm) 1, 3
• Extensive erythema extending beyond the wound margins, especially if >2 cm 2
• Purulent drainage or foul odor suggesting wet gangrene or deep infection 2
• Crepitus or gas in tissues indicating gas gangrene (surgical emergency) 1, 2
• Pain out of proportion to clinical findings 1
• New onset wound anesthesia or loss of neurologic function 1

Immediate Actions Upon ED Return

Stabilization and Assessment

• Administer crystalloid fluid challenge of 30 mL/kg body weight immediately if hypotensive or showing signs of sepsis 3
• Obtain vital signs, assess for systemic inflammatory response (fever, tachycardia, hypotension, altered mental status) 3
• Check blood glucose immediately and correct severe hyperglycemia (target 7.8-10 mmol/L or 140-180 mg/dL if critically ill) 3
• Obtain blood cultures and wound cultures before antibiotics, but do not delay antibiotic administration 3

Urgent Surgical Consultation

Consult a surgical specialist immediately for all moderate to severe diabetic foot infections 1, 3. Emergent surgery (within 24-48 hours) is necessary for: 1

• Deep abscesses
• Compartment syndrome
• Necrotizing soft tissue infections
• Gas gangrene
• Systemic sepsis despite antibiotics

Early surgical debridement (within 24-48 hours) combined with antibiotics improves outcomes and reduces major amputation rates compared to delayed surgery 1, 4.

Immediate Antibiotic Therapy

For severe infection with systemic toxicity, initiate broad-spectrum IV antibiotics immediately: 3

• Piperacillin-tazobactam 4.5 grams IV every 6 hours as first-line 3
• Add vancomycin if MRSA is common in your institution or if patient has healthcare-associated risk factors 1, 3
• Duration: typically 7-10 days for soft tissue infection, longer if osteomyelitis present 3

Vascular Assessment

Assess for critical limb ischemia, which requires urgent vascular surgery consultation: 1, 2

• Palpate pedal pulses and assess capillary refill 2
• Document dependent rubor, pallor on elevation, or hair loss 2
• Obtain ankle-brachial index (ABI), though may be falsely elevated in diabetics with calcified vessels 2
• For severely infected ischemic foot, perform revascularization early rather than delaying for prolonged antibiotic therapy 1

Patients with chronic limb-threatening ischemia who don't receive revascularization face a 22% mortality and 22% major amputation rate at 12 months 2.

Admission Criteria

Hospitalization is mandatory for: 2, 3

• Severe infection indicators (cellulitis >2 cm, rapidly progressive inflammation, necrosis) 2
• Deep tissue involvement (penetration to fascia, tendon, muscle, joint, or bone) 2
• Severe ischemia (dependent rubor, pallor on elevation, critical limb ischemia) 2
• Need for IV antibiotics or surgical procedures 2
• Metabolic instability (severe hyperglycemia, acidosis, azotemia, electrolyte abnormalities) 2

Common Pitfalls to Avoid

The absence of fever or leukocytosis should not dissuade clinicians from considering surgical exploration of a diabetic foot infection 1. The most common site for severe foot infection is the plantar surface; a plantar wound with dorsal erythema or fluctuance suggests infection has passed through fascial compartments, requiring surgical intervention 1.

Do not delay debridement of necrotic infected material while awaiting revascularization 1. Optimal management may require combined multispecialty or staged procedures 1.

For patients with diabetes and poor circulation, even seemingly minor infections can rapidly progress to limb-threatening or life-threatening conditions 1, 4. The case example in the guidelines demonstrates a patient with similar presentation (fever 38°C, tachycardia 108 bpm, large ulcer with erythema, elevated WBC 26.1, CRP 260) who required immediate hospital admission, IV antibiotics, and surgical debridement 1.