Wound Care: Surgical Wound Classification
Surgical Wound Classification – CDC Definition
Class I: Clean
- Uninfected with No Inflammation
- Do Not Enter the Respiratory, Alimentary (GI) or Genitourinary (GU) Tracts
- Examples:
- Mastectomy
- Thyroidectomy
- Herniorrhaphy
- Nissen Fundoplication
- Vascular Procedures
- Cardiac Procedures
- Class ID: Otherwise Clean with a Prosthetic Graft
Class II: Clean-Contaminated
- No Unusual Contamination
- Enters the Respiratory, Alimentary (GI) or Genitourinary (GU) Tracts
- Under Controlled Conditions
- Examples:
- Bowel Resection
- Cholecystectomy
- Pancreatectomy
Class III: Contaminated
- Gross GI Spillage
- Major Break in Sterile Technique (Unsterile Instruments, Open Cardiac Massage, etc.)
- Acute Non-Purulent Inflammation
Class IV: Dirty
- Through Existing Clinical Infection (Purulence)
- Perforated Viscera
- Old Wound with Retained Devitalized Tissue (Gangrene/Necrosis)
- Trauma with Devitalized Tissue
Interpretation
Poor Reliability
- Classification Scheme Has Low Inter-Rater Reliability
- Abdominal Wounds are the Most Likely to Be Incorrectly Classified as Clean Wounds
Risk of Infection (Classic Teaching)
- Class I: 1-5%
- Most Common Source: The Patient Themselves
- Class II: 3-11%
- Class III: 10-17%
- Class IV: > 27%
Risk of Infection (Newer NSQIP Data)
- Newer Data Show Lower Rates Than Previously Seen
| Class | Superficial SSI | Deep SSI | Organ/Space SSI |
| I | 1.76% | 0.54% | 0.28% |
| II | 3.94% | 0.86% | 1.87% |
| III | 4.75% | 1.31% | 2.55% |
| IV | 5.16% | 2.1% | 4.54% |
Preoperative Antibiotics