Antibiotics are crucial tools in surgery and there use has seen drastic reduction in morbidity and mortality in surgical patients. They are however only adjuncts to established surgical principles of sepsis and anti sepsis, and source control of infection.

1. ANTIBIOTICS USE IN SURGERY
DR. ALUMONA C.O.

2. OUTLINE
• INTRODUCTION
• CLASSIFICATION
• APPLICATIONS IN SURGERY
• DISEASE-, PATHOGEN-, AND ANTIBIOTIC-SPECIFIC
CONSIDERATIONS
• MONITORING OF ANTIBIOTICS THERAPY
• ANTIBIOTICS ABUSE
• ANTIBIOTICS RESISTANCE
• FUTURE TRENDS
• CONCLUSION
• REFRENCES

3. INTRODUCTION
• Antibiotics are substances that posses the
capacity to inhibit or kill micro-organisms.
– Antimicrobials is a broad term for both naturally
occurring and synthetic agents.
• Via interaction with key cell components of
the microorganisms.
• Minimal or no damage to normal body cells.

4. Surgical importance
• The proper use of antibiotics reduces surgical
morbidity and mortality by preventing the
development of surgical infections or
controlling established infection.
• Antibiotics are only adjuncts to sound surgical
technique, aseptic and antiseptic principles
and adequate source control.

5. History
• Louis Pasteur and
Robert koch (18th
century): Germ
theory of disease

6. Pharmacology
• MIC
• T1/2

7. Classification
• Based on Activity
– Bactericidal: penicillins, cephalosporins, flagyl,
aminoglycoside
– Bacteriostatic: macrolides, clindamycin, tetracycline,
chloramphenicol
• Based on Spectrum
– Narrow spectrum: macrolides, vancomycin, penicillin
G, gentamycin
– Broad spectrum: levofloxacin, ciprofloxacin,
cephalosporin, tetracycline
• Mechanism of action: Inhibitors of cell wall, protein,
and nucleic acid synthesis

8. Mechanism of action

9. Factors influencing choice of Antibiotics
• Activity against known or suspected
pathogens
• Antimicrobial resistance patterns
• Patient-specific factors
– Age, Severity of illness, co-morbidities/organ
dysfunction, immunosuppression, allergy, MRSA
infection
• Institutional guidelines or local policies

10. Applications in Surgery
• Prophylaxis
• Therapy
– Empirical therapy
– Definitive therapy
• Others
– Anti tumours: bleomycin, dactinomycin
– In radiotherapy as radiosensitizers: metronidazol
– Bowel preparation: neomycin
– Pleurodesis: tetracycline, neomycin
– Prokinetics: erythromycin

11. Antibiotics Prophylaxis
• The pre-emptive use of antibiotics to prevent
infection of a surgical site.
• Reduces rates of SSI.
• May increase rates of SSI when used
inappropriately.

12. • Indications
– Clean surgeries involving incision into a bone eg craniotomy,
sternotomy, amputations
– Clean surgeries in which an infection would be catastrophic eg
neurosurgeries
– Clean surgery with insertion of prosthesis eg vascular stents,
pacemaker insertions, ORIFs
– Others: breast cancer surgery without immediate reconstruction
– Clean surgeries with a break in asepsis
– Clean surgery in immunosuppressed patients
– Clean contaminated surgeries: high risk biliary surgery, elective colon
surgery, gastrectomy.

13. • Principles of Antibiotics Prophylaxis
– Safety
– An appropriate narrow spectrum of coverage of
relevant pathogens
– Little or no reliance on the agent for therapy of
infection
– Administration within 1hour before skin incision
– Should be intravenous
– Aim at a saturated tissue concentration above MIC
before skin incision
– Redosed if procedure exceeds the T1/2 of agent or when
there is greater than 1.5Litres of blood loss
– Must not exceed 24hours or 48hours for cardiac surg.)

14. Suggested antibiotic prophylaxis

15. Therapeutic use of Antibiotics
• Principles of therapeutic use of Antibiotics
– Establish a diagnosis and need for AB based on Hx
and clinical examination
– Obtain appropriate samples for cultures and
sensitivity prior to commencement
– Adequate source control via debridement, I&D,
– Agents selected based on most likely pathogens
and de-escalated based on culture results

16. Therapeutic use cont
• Empiric therapy comprises the use of an
antimicrobial agent or agents when the risk of
a surgical infection is high
Indications; - dirty wounds
– based on the underlying disease process (e.g.,
ruptured appendicitis),
– when significant contamination during surgery has
occurred (e.g., inadequate bowel preparation or
considerable spillage of colon contents).

17. – in situations in which the risk of infection
increases markedly because of intraoperative
findings.
– in critically ill patients in whom a potential site of
infection has been identified and severe sepsis or
septic shock occurs.
– Duration: 3 to 5 days
• Definitive treatment: Therapy should be de-
escalated based on culture results and clinical
response

18. Monitoring of antibiotics Therapy
• Patient parameters
– Clinical
– Laboratory (EUCR, LFT)
• Infection parameters
– Repeat cultures
– Inflammatory makers (ESR,CRP, serum procalcitonin)
• Drug parameters
– Serum concentration
– Toxicity/adverse effect

19. Antibiotics Abuse
• The wrong use of antibiotics.
– Unnecessary use, under/overuse, wrong dosage
• Constitutes potential harm to patients
• Contributes to development of MDR bacteria
• Increases health care cost
• Healthcare workers and patients culpable
• Requires committed governmental and
institutional policy to curb

20. Antibiotics Resistance
• The development of a new capacity to resist
antibiotic inhibition/kill.
• One of the biggest threats to global health.
• Occurs naturally but misuse of antibiotics
accelerates the process.
• Eg: MRSA, MRSE, ESBL,

21. • Mechanisms of Antibiotics resistance
– Production of enzymes eg b-lactamases
– Alteration in the number and type of target sites
eg penicillin binding proteins
– Blockage of drug penetration via changes in the
outer membrane pores
– Formation of bio films
– Acquisition of antibiotics resistant genes via
plasmid transfer

22. DISEASE-, PATHOGEN-,
AND ANTIBIOTIC-SPECIFIC CONSIDERATIONS
• Pneumonia: VAP
– Lower respiratory tract samples taken for cultures
– Empirical AB therapy with broad spectrum AB
– Culture result scenarios
• No growth of pathogenic org: discontinue AB
• Substantial growth of susceptible org.: De-escalate to a
narrow spectrum agent active against pathogen
• Growth of MDR pathogen: continue with initial broad
spectrum if active against the org. or escalate to cover for
the MDR org.
– Determine duration of therapy (6,8,15) and monitor
pt.
– Non improving clinical state: re-evaluate pt, consider
empyema, lung abscess

23. • Central Line-Associated Bloodstream
Infection
– MRSE, MRSA, Enterococci most implicated
– Blood culture and catheter tip MCS
– Trx: catheter removal and parenteral Abs
– Vancomycin, linezolid or daptomycin
– Duration of therapy: at least 2weeks for S. aureus

24. • Intra Abdominal infection
– Secondary peritonitis from penetrating abd
wounds, dehiscence of bowel anastomosis, intra
abdominal abscess
– Poly microbial cause: CA- anaerobic Gram –ve bacilli eg
Bacteroides fragilis, E coli, Klbsiella spp
• HA- MDR pathogens, Enterobacter, Pseudomonas
– Appropriate initial empirical therapy with
subsequent adjustment
– Source control
– Tertiary Peritonitis

25. • Complicated Soft Tissue Infections
– Diabetic Foot Infections: usu polymicrobial
• Adequate source control and tissues cultures
• De-escalated therapy following cultures
• Cefazolin, ceftriazone, ampicilin sulbactam
• Vancomycin, linezolid, tigecylin for MRSA
– Necrotizing Soft Tissue Infection: anaerobic, G+ve/-ve
• Early antibiotics coverage
• Timely wide local excision (repeated if necessary)
• Anti MRSA AB: Vancomycin, telavancic, ceftaroline,
daptomycin, tigecyline, linezolid

26. Prevention and control of Antibiotics resistance
• Individuals: should use only antibiotics prescribes by
physicians for them
• Policy makers: should develop and implement
national action plan via surveillance, prevention and
control of AB resistant infection, regulation of AB
prescription and use and public awareness
• Health care workers: should ensure proper use of
antibiotics
• Drug firms: should invest in research for new ABs

27. Future trends
• New sources of antibiotics: Endophytes,
thermophiles, animal venoms.
• Genomic sequencing of bacteria to identify
new targets for new antibiotics
• Novel antibiotics from combinatorial
biosynthesis
• Lantibiotics: synthesized from ribosomes
• New molecules

28. Conclusion
• Antibiotics are useful tools in the hands of the
surgeon to prevent and treat surgical infections.
• They however are adjuncts to established surgical
principles of asepsis & antisepsis, good surgical
technique and proper source control in the
management of surgical infections.
• Abuse of antibiotics poses serious threats to both
patients and global health.

29. References
• Sergio Sanchez and Arnold L. Demain.(2015).
Antibiotics; Current Innovations And Future Trends.
Retrieved from caister.com/antibiotics
• 5/02/2018. Antibiotics Resistance. Accessed
25/01/2020. retrieved from who.int/news-room/fact-
sheets/details/antibiotic-resistance
• Brunicardi, F. et al (2014) Schwartz’s principle of
Surgery. 10th Edition, McGraw-Hill Education, New York
• Sabiston, David C. Townsend, Courtney M., eds.
Sabiston Textbook of Surgery: The Biological basis of
modern Surgical Practice. 20th Edition. Philadelphia, PA:
Elsevier Saunders 2017

30. Miscellaneous Causes of Fever
Related to Noninfectious States
• Acalculous cholecystitis
• Acute myocardial infarction
• Acute respiratory distress
syndrome (fibroproliferative
phase)
• Adrenal insufficiency
• Cytokine release syndrome
• Fat embolism
• Gout
• Hematoma
• Heterotopic ossification
• Immune reconstitution
inflammatory syndrome
• Infarction of any tissue
• Intracranial hemorrhage (trauma
or vascular cause)
• Myocardial infarction
• Pancreatitis
• Pericarditis
• Pulmonary infarction
• Stroke
• Thyroid storm
• Transfusion of blood or blood
products
• Transplant rejection
• Tumor lysis syndrome
• Venous thromboembolic disease
• Withdrawal syndromes (e.g.,
drug, alcohol

33. Antibacterial agents
for empirical use
• cc