Surgical Site Infections

Definition, Epidemiology, Types, Risk factors, Etiology, Pathophysiology, Clinical presentation, Complications, Diagnosis and Treatment of Surgical Site Infections

1. V. S.Swathi Assistant Professor VIPT, Duvvada SURGICAL SITE INFECTIONS

2. Definition According to Centers for Disease Control and Prevention (CDC), A surgical site infection is an infection that occurs after surgery in the part of the body where the surgery took place. Surgical site infections can sometimes be superficial infections involving the skin only. Other surgical site infections are more serious and can involve tissues under the skin, organs, or implanted material

3. Epidemiology (World and India) Globally SSIs estimation is 0.5%-15% and in India it is in higher rates ranging from 23%-38%.

4. Types According to CDC Superficial incisional Affects skin and subcutaneous tissue Deep incisional Affects fascial and muscle layers Organ/ space infection Affects any part of the body other than incision that is opened/ manipulated during the surgical procedure

5. Classification of surgical procedures based on risk of infection Clean Atraumatic No inflammation encountered No break in technique Gastro intestinal, genitourinary and respiratory tracts not entered Wound infection rate is 1.5-4.2% Need for prophylaxis not usually required Example: Inguinal hernia repair

6. Classification of surgical procedures based on risk of infection Contaminated Gastro intestinal tract/ respiratory tract entered but without spillage Minor break in technique Wound infection rate is less than 10% Prophylaxis is usually required Example: Cholecystectomy

7. Classification of surgical procedures based on risk of infection Clean- Contaminated Acute inflammation Infected bile or urine Gross spillage from gastro intestinal tract Major lapse in technique Fresh traumatic wound (12-24h) Wound infection rate is 10-20% Prophylaxis is usually required Example: Appendicectomy

8. Classification of surgical procedures based on risk of infection Dirty and infected established infection Transaction of clean tissue to enable collection of pus Traumatic wound with retained lifeless tissue Faecal contamination Delayed treatment Wound infection rate is 20-40% Prophylaxis is compulsorily required Example: Sigmoid colectomy

9. Risk factors Patient related risk factors Advanced age Malnutrition Obesity Concurrent infection Diabetes mellitus Liver impairment Renal impairment Immune deficiency status Prolonged preoperative stay Blood transfusion

10. Risk factors Operative risk factors Tissue ischemia Lack of haemostasis Tissue damage Presence of necrotic tissue Presence of foreign body including surgical material

11. Etiology Methicillin resistant Staphylococcus aureus -24% Methicillin sensitive Staphylococcus aureus -14% Enterobacteriaceae -21% Coagulase negative Staphylococci -10% Enterococcus -10% Pseudomonas -5% Streptococcus -3% Anaerobic bacilli -2% Anaerobic cocci -2% Candida -1% Acenobactor -1%

12. Pathogenesis Any surgery ↓ Breaching of protective barrier of any organ (epithelial tissue) and mucosa ↓ Entry of endogenous and exogenous micro organisms to that organ ↓ Inflammation ↓ Surgical site infection

13. Clinical Presentation Superficial incisional Affects skin and subcutaneous tissue Clinical presentation include redness, pain, heat/ swelling at site of incision and presence of pus within 30 days

14. Clinical Presentation Deep incisional Affects fascial and muscle layers Clinical presentation include presence of pus/ an abscess, fever with tenderness of wound, separation of the edges of the incision exposing the deeper tissues within 30 days and 1 year if implant is used

15. Clinical Presentation Organ/ space infection Affects any part of the body other than incision that is opened/ manipulated during the surgical procedure Clinical presentation include loss of function of a joint, abscess in an organ, localised peritonitis/ collection and ultrasound/ CT scan confirm infection within 30 days and 1 year if implant is used

16. Complications Sepsis Shock Death

17. Diagnosis Based on clinical presentation Culture test Complete blood count Erythrocyte sedimentation rate C reactive protein Procalcitonin Neutrophil CD64

18. Non Pharmacological Treatment Recommended steps to patients and care takers during different phases of surgery: Pre operative phase Patient preparation- Pre operative washing, hair removal, nasal MRSA decontamination, antimicrobial prophylaxis guidance, staff preparation and theatre movement Intra operative phase Operating team preparation, patient skin preparation, maintaining patient homeostasis and wound dressings Post operative phase Dressing and cleaning the wound, antimicrobial treatment for SSI, debridement of SSI  

19. Treatment Algorithm 1. Gastrointestinal surgery   a. Upper GIT ↓ Bowel flora/ Staphylococcus aureus / Gram negative bacilli ↓ Co amoxiclav / Cefuroxime/ Gentamycin

20. Treatment Algorithm 1. Gastrointestinal surgery b. Biliary surgery ↓ Staphylococcus aureus / Gram negative bacilli ↓ Co amoxiclav / Cefuroxime+ Metronidazole Gentamycin + Metronidazole  

21. Treatment Algorithm 1. Gastrointestinal surgery c. Colorectal surgery / Appendicectomy ↓ Staphylococcus aureus / Gram negative bacilli / Anaerobes ↓ Co amoxiclav / Cefuroxime+ Metronidazole Gentamycin + Metronidazole  

22. Treatment Algorithm 2. Urogenital a. Transrectal biopsy ↓ Staphylococcus aureus / Gram negative bacilli / Anaerobes ↓ Co amoxiclav / Cefuroxime+ Metronidazole Gentamycin + Metronidazole    

23. Treatment Algorithm 2. Urogenital b. Transurethral resection of prostrate ↓ Staphylococcus aureus / Gram negative bacilli ↓ Co amoxiclav / Cefuroxime/ Gentamycin  

24. Treatment Algorithm 3. Obstetric/ Gynaecological   a. Caesarean section ↓ Staphylococcus aureus / Gram negative bacilli/ Anaerobes ↓ Co amoxiclav / Cefuroxime + Metronidazole   b. Hysterectomy ↓ Staphylococcus aureus / Gram negative bacilli / Anaerobes ↓ Co amoxiclav / Cefuroxime + Metronidazole

25. Treatment Algorithm 4. Vascular a. Reconstructive arterial surgery ↓ Skin flora- Staphylococci ↓ Co amoxiclav / Cefuroxime   b. Amputation ↓ Staphylococcus aureus / Anaerobes ↓ Co amoxiclav / Cefuroxime + Metronidazole Vancomycin + Metronidazole

26. Treatment Algorithm 5. Orthopedic   Joint replacement surgery ↓ Skin flora- Staphylococci ↓ Co amoxiclav / Cefuroxime / Flucloxacillin + Gentamycin

27. Drug Category Mode of action Dose Adverse effects Cefuroxime Cephalosporin Inhibit cell wall synthesis 1.5g-IV Diarrhea Anemia Eosinophilia Vaginitis Tranaminitis Ciprofloxacin Fluroquinolone Inhibit DNA Gyrase 400mg-IV Abdominal pain Diarrhea Transaminitis Increased serum creatinine Rashes Co amoxiclav Pencillin+ Beta lactamase inhibitor Inhibit cell wall synthesis+ Reduce resistance power of microbes 1.2g-IV Diarrhea Mycosis Candidiasis Vaginitis Hypersensitivity reactions- if patient is allergic Cotrimazole Sulfonamide Inhibit folic acid synthesis 960mg-IV Anorexia Vertigo Peripheral neuritis Hyperkelemia Rashes Flucloxacillin Pencillin Inhibit cell wall synthesis 1g-IV Rashes Arthralgia Neutropenia Pseudomembranous colitis Transaminitis

28. Gentamycin Aminoglycoside Inhibit protein synthesis 5mg/kg-IV 1 hour prior to surgery Neurotoxicity Gait instability Ototoxicity Nephrotoxicity Edema Metronidazole Miscellaneous Inhibit nucleic acid synthesis 500mg-IV Anorexia Candidiasis Diarrhea Dark urine Furry tongue Vancomycin Glycopeptide Inhibit cell wall synthesis 1g-IV Redman syndrome Steven Johnsan’s Syndrome Acute kidney injury Tinnitus Hearing loss Muscle pain Teicoplainin Glycopeptide Inhibit cell wall synthesis 200mg-IV Redman syndrome Steven Johnsan’s Syndrome Acute kidney injury Tinnitus Hearing loss

29. Choice of antimicrobial agent should consider following Likely infecting organism Local susceptibility of potential pathogens to antimicrobials Pharmacokinetics Patient’s allergy status to antibiotics Administration time Drug cost Carriage of resistant organisms Prevalence of Clostridium defficile infection in hospital

30. Resources https://www.sciencedirect.com/science/article/pii/S1479666X1830074X https://www.sciencedirect.com/science/article/pii/S000296101830672X https://www.sciencedirect.com/science/article/pii/S1201971219300049 https://www.sciencedirect.com/science/article/pii/S000293781930432 https://www.sciencedirect.com/science/article/pii/S0195670119301124