Principle of antibiotic prophylaxis

Principle of antibiotic prophylaxis

1. Principle of Antibiotic Prophylaxis Short Note 2014

2. Outline Introduction What is antibiotic What is antibiotic prophylaxis Indication Potential benefit Potential harm Antibiotic Choice Timing Redosing Consideration to continue as therapeutic

3. Introduction Antibiotic is any substance of natural, synthetic or semi-synthetic origin which kill (bactericidal) or inhibit ( bacteriostatic ) the growth of bacteria Prophylactic antibiotic is the use of antibiotic to prevent infections at the surgical site The risk of surgical site infection reduce to 0.5-1%

4. Indication of Prophylactic Antibiotic Clean contaminated surgery Risk of surgical site infection 10% Clean surgery with insertion of an artificial device or prosthetic material E.g : hernioplasty , chemoport insertion Patient in whom the consequences of infection may be catastrophic E.g : neurosurgery, open heart surgery, opthamic surgery

5. Impaired immune status Poor nutrition state Morbid Obesity Poor control diabetes mellitus Taking immunosuppression drug

6. Potential Benefit Prevent surgical site infection (SSI) Prevent SSI-related morbidity and mortality Reduce the duration and cost of health care

7. Potential Harm Risk of allergic reaction Risk of contributing to antimicrobial resistance Specific risk related to antibiotic E.g : aminoglycoside - renal toxicity, erythromycin – GI upset

8. Choice of Antibiotic Avoid antibiotic that can cause allergy Active against pathogen most likely to contaminate the surgical site Narrow spectrum antibiotic

9. Common Antibiotic Used Condition Antibiotic Upper GI IV Cefobid 1g Distal GI and colorectal IV cefobid 1g and IV flagyl 500mg Hernioplasty IV cloxacillin 1g or IV augmentin 1.2g Cholecystectomy IV cefobid 1g or IV zinacef 1.5g Vascular Surgery IV Augmentin / IV Unasyn IV Vancomycin when prosthetic graft in patients at risk

10. Route and Timing Been given bolus intravenously 30 minutes before skin incision or upon induction (induction to skin incision take 20-30 minutes) To provide serum and tissue concentration exceeding the minimum inhibitory concentration (MIC)

11. Redosing Redosing needed to keep antibiotic concentration within therapeutic range for entire surgery Indication Excessive blood loss >1.5L Prolong surgery > 4 hours Single dose of antibiotic is adequate if the condition above not present Continuation of prophylactic antibiotic post op doesn’t show any benefit.

12. Consideration to Continue as Therapeutic Breach of sterility during surgery Extensive contamination during surgery

13. Thank You

14. References Antibiotic for Surgical Prophylaxis, Australian prescriber, 2005 SIGN antibiotic prophylaxis in Surgery, 2014 ASHP Therapeutic Guideline