Surgical Wounds and Antimicrobial prophylaxis

Dr. Philip G. Murphy

Consultant in Medical Microbiology

Adelaide and Meath Hospitals incorporating the National Children’s Hospital.

History

• 1862 Pasteur

• 1865 Lister

• 1866 Semmelweiss

• 1940’s Antibiotic era

• Today ?? Postantibiotic era

• <2 %

Pathogenesis

• Skin flora into wound margins / deep sites

• risk factors eg haematoma, ischaemia, prostheses

• Bacterial virulence eg GNB + anerobes

Definitions

• Spectrum from wound margin erythema through local invasion, abscess, bacteraemia

Classifiaction and Rates

• Clean - no intrinsic bacterial flora <2 %• Clean / contaminated - involving

a viscus with bacterial flora 8%• Contaminated - involves spillage

of viscus content 15%• Dirty - involves inflamation or

viscus perforation 40%

Bacteriology

• UK Survey:

Staphylococci 40-45 %

GNB 40-45 %

other aerobes 6 %

anaerobes 5 %

• Specific surgery types have different rates:

Bacteriology

• Staphylococci and skin flora in bone and cardiac surgery

• GNB in biliary surgery

• Streptococci and anaerobes in gynae

• Colonic surgery:aerobic GNB 10 6-7 / G

Enterococci 10 5-6 / G

Bacteroides 10 9-11 /G

anaerobic cocci 10 10 / G

Prevention• Skin preparation:

skin cleaning, disinfection, opsite

• Bowel preparation:

No irrigation, diets, or non- absorbable antibiotics

• Theatre technique:

workflow zoning, air flow, CSSD, restricted staffing, aseptic technique etc.

• Wound managementDressing, no touch technique, closed drainage

Prophylaxis - principles

• First dose immediately pre-op

• maximum of 3 doses or 24h period

• Rarely > 24h

• parenteral, PR

• No non-absorbables

• Rarely required in clean or clean/contaminated

Prophylaxis - specific

Indication Antibiotic Durationabove knee amputation benzyl penicillin 1 dose

Cholecystectomy cefuroxime 1 dose

Appendicectomy metronidazole 3 doses

Colectomy Cefuroxime + 3 doses

metronidazole

vaginal hysterectomy as above as above

or augmentin

Prosthetic hip replacement cefuroxime 2 doses

Prosthetic heart valve cefuroxime or fluclox tid <48h

Vascular prosthesis as above as above

Treatment

• Topical Vs systemic

• Saline Vs disinfectant Vs antibiotic

• Target organisms Vs culture

• empirical Vs culture targetted

• one drug Vs two

• Remove all prostheses / implants

• pus collection drainage

Surveillance

• Infection Control Team

• Link nurses

• Databases

• Early discharge, day surgery

• Post discharge