1. Preventing Surgical Site Infections for Gastrointestinal Surgery
Dr CHIA Chi Fung (Queen Elizabeth Hospital)
Joint Hospital Surgical Grand Round Jan 2017

2. Wound matters
M/70, Newly found Ca rectum Hx of lap R hemicolectomy for Ca caecum APR + Total colectomy + End-ileostomy done
Post-op discharge from laparotomy wound on D7 Wound C/ST: Proteus, E Coli, Pseudomonas Prolonged hospital stay for wound care till D23

3. Wound matters
F/83, Strangulated incisional hernia Hx of LAR for Ca rectum Small bowel resection and defect repair done
Gapping with purulent discharge on D6 Wound swab: Klebsiella, Enterococcus CT: Inflammatory change at wound Subcutaneous collection at abdominal wall Given TPN, daily dressings Meropenem, vancomycin

4. Surgical Site Infections (SSI)
Procedure-related infection at or near incision
Within 30 days (or within 90 days if prosthetic material)
Translates to morbidity, hospital stay, cost and mortality
Microbiology:
Skin flora
Endogenous flora of involved viscus / mucosa

5. Risk Factors Age Underlying Illness Obesity Smoking
Wound Classification
Clean: up to 3%
Clean-contaminated: up to 8%
Contaminated: up to 15%
Dirty: up to 40%

6. How to prevent SSIs? Pre-op preparation Peri-op care
Nutrition, S aureus decontamination, Bathing
Bowel Preparation
Peri-op care
Oxygenation, Perfusion
Sterile environment, Hand decontamination
Skin preparation
Antibiotics on induction and impregnated sutures
Wound protectors
Wound irrigation

7. Bowel Preparation Polyethylene glycol, Sodium phosphate Good or bad?
 Intraluminal faecal mass   Bacterial load
?? Liquefies faeces   Intra-op spillage

8. Bowel Preparation
Yes or No? NICE 2008: ✗ IDSA 2014: ? to combine with oral antibiotics WHO 2016: ✓ with oral antibiotics
If only bowel prep, worse than none
Meta-analysis 13 RCTs: OR 1.31 (95%CI )
Benefits other than SSI not taken into account

9. Oral Antibiotics with bowel prep
Better than bowel prep alone
Meta-analysis 11 RCTs: OR 0.56 (95%CI )
What type? What dose?
No conclusive evidence
High intraluminal concentrations, poor absorption
Against facultative Gram-ve & anaerobic bacteria
E.g. Neomycin + Metronidazole
? Oral antibiotics alone ? Side effect profile

10. Surgical Site Preparation
What to use? NICE 2013: Iodine or Chlorhexidine IDSA 2014: Alcohol-containing WHO 2016: Alcohol-based chlorhexidine
Limitation
Small effect size ~ 4 fewer in 100
? Cost-effective

11. Wound Protector Minimize wound-edge contamination
Yes or No? NICE 2013: ✓ abdominal IDSA 2014: ✓ GI & biliary WHO 2016: ✓ abdominal
Lower risk of SSI
~ 10 fewer in 100
Very low quality evidence
May not be cost-effective

12. Wound Irrigation
Physical removal + Dilution + Local antibacterial effect
How? Syringe pressure? Pulsed irrigation?
What? Saline? Povidine-iodine? Antibiotics?

13. Wound Irrigation
Yes or No? NICE 2008: ✗ IDSA 2014: ✓ povidine-iodine WHO 2016: ✓ povidine-iodine
Remains debate
Mainly based on old evidence or evidence from non-GI surgeries
? Wound irritation

14. What’s the trend? Oral antibiotics goes with bowel prep
Alcohol-based chlorhexidine for skin prep
Consider use of wound protectors
Wound irrigation with povidone-iodine

15. To know more
Thanks