What is the Southampton wound‑scoring system (Southampton SSI grade) for surgical‑site infection, what are its grades, and how should each grade be managed?

Southampton Wound Scoring System for Surgical Site Infection

Definition and Grading System

The Southampton wound scoring system is a validated classification tool that grades surgical wounds from 0 (normal healing) to V (deep or severe infection), providing a standardized method to assess and document surgical site infections. 1, 2

The Southampton SSI grading system includes the following categories:

• Grade 0: Normal healing with no complications 1, 2
• Grade Ia: Minor bruising or minor asymmetry 1
• Grade Ib: Minor bleeding 1
• Grade Ic: Minor separation of wound edges (≤2 cm) 1
• Grade II: Erythema plus other signs of inflammation 1, 2
• Grade IIIa: Clear or serous discharge 1
• Grade IIIb: Serosanguinous discharge 1
• Grade IV: Purulent discharge 1, 2
• Grade V: Deep or severe wound infection with or without tissue breakdown, requiring debridement 1, 2

Clinical Application

The Southampton system facilitates standardized evaluation of wound healing outcomes and allows for systematic comparison between different surgical techniques and closure methods. 1 This scoring system should be applied at multiple postoperative time points (typically days 1,7, and 30) to track wound healing progression. 1

Management Based on Grade

Grades 0-Ic (Normal Healing to Minor Complications)

• No intervention required beyond standard wound care and observation 1, 2
• Continue routine postoperative wound management 3
• Remove dressing after minimum 48 hours unless leakage occurs 3
• No antibiotics indicated 3, 4

Grade II (Erythema with Inflammation)

• Assess for systemic signs of infection before initiating antibiotics 3, 4
• If erythema extends >5 cm from wound edge, temperature >38.5°C, heart rate >110 beats/minute, or WBC >12,000/µL, add systemic antibiotics 3, 5
• For isolated erythema without systemic signs, continue close observation 3
• First-generation cephalosporin or antistaphylococcal penicillin for MSSA coverage 3
• Add vancomycin, linezolid, or daptomycin if MRSA risk factors present (nasal colonization, prior MRSA infection, recent hospitalization, recent antibiotics) 3

Grades IIIa-IIIb (Serous or Serosanguinous Discharge)

• Open wound if discharge is copious or accompanied by systemic signs 3, 4
• Obtain Gram stain and culture before initiating antibiotics 5, 6
• Antibiotics NOT routinely required if adequately drained and patient lacks systemic inflammatory signs 5, 6
• Add antibiotics only when temperature >38.5°C, heart rate >110 beats/minute, or erythema >5 cm beyond wound margins 3, 5

Grade IV (Purulent Discharge)

• Immediate surgical opening and drainage is mandatory—this is the primary treatment 3, 4, 5, 6
• Open incision widely, evacuate all purulent material, and perform thorough irrigation 5, 6
• Continue wet-to-dry dressing changes until wound heals by secondary intention 5
• Obtain Gram stain and culture before initiating antibiotics 5, 6
• Add systemic antibiotics for brief course (24-48 hours) if systemic signs present 3, 5
• For clean operations (trunk, head/neck, extremities): first-generation cephalosporin or antistaphylococcal penicillin 3
• For operations on axilla, GI tract, perineum, or female genital tract: add coverage for gram-negatives and anaerobes (cephalosporin or fluoroquinolone plus metronidazole) 3

Grade V (Deep or Severe Infection)

• Immediate surgical consultation for extensive debridement and drainage 3, 4
• Broad-spectrum IV antibiotics required 3, 5
• Coverage must include MRSA (vancomycin, linezolid, or daptomycin) PLUS gram-negative and anaerobic coverage (piperacillin-tazobactam or carbapenem) 3, 5
• Monitor for necrotizing fasciitis, gas gangrene, or septic shock requiring escalation to ICU 5, 6
• Prolonged antibiotic course may be necessary based on clinical response 3

Critical Pitfalls to Avoid

• Never rely on antibiotics alone without surgical drainage for purulent infections (Grades IV-V)—this is the most common error leading to treatment failure 5, 6
• Do not continue antibiotics beyond 48 hours if patient is clinically improving after adequate drainage 5
• Do not use advanced dressings over standard dressings for primarily closed surgical wounds—they do not reduce SSI rates 3
• SSIs rarely occur in first 48 hours; fever during this period usually has noninfectious causes unless streptococcal or clostridial infection present 3