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4/28ABA-UMQU- Antibiotics in Surgical Practice 2.

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Presentation on theme: "4/28ABA-UMQU- Antibiotics in Surgical Practice 2."— Presentation transcript:

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2 4/28ABA-UMQU- Antibiotics in Surgical Practice 2

3 4/28ABA-UMQU- Antibiotics in Surgical Practice 3 Historical Overview  Contagious disease- The concept1830  Bacteria as a cause of disease, leeuwenhoek  Hand washing, Semmelweis  Introduction of the principle of aseptic surgery (Carbolic acid), Lister  Steam sterilization, Schimmelbusch & Octave 1990  Early 20 th century Halsted introduced the use of gloves.  1928 Alexander Fleming discovered Penicillin

4 4/28ABA-UMQU- Antibiotics in Surgical Practice 4

5 4/28ABA-UMQU- Antibiotics in Surgical Practice 5 Antisepsis OR environment. Drapes and instruments Hand washing Gloves and other barrier methods Short preoperative stay Treat remote infections Skin and bowel preparation Improved host defences Improved surgical technique Minimization of cross infection Infection control ? Hair removal

6 4/28ABA-UMQU- Antibiotics in Surgical Practice 6 Nasocomial)) Hospital Acquired Infections Infections that become clinically evident with in 48 hours of admission Found: a.Common postoperative infections b.In critically ill patients (ICU) Significance: a.Increased postoperative mortality b.Increased Hopspital stay c.Increased cost of surgical care d.Afflicated by multiresistanct organisms

7 4/28ABA-UMQU- Antibiotics in Surgical Practice 7 Hospital Acquired Infections Risk factors: 1.Age > 70 2.Shock 3.Steroids 4.Chemotherapy 5.ICU > 3 days 6.Mechanical ventilation 7.Invasive monitoring 8.Indwelling catheter > 10 days 9.Surgical 10.Acute renal failure

8 4/28ABA-UMQU- Antibiotics in Surgical Practice 8 Hospital Acquired Infections The most common infections 1.Blood stream infections 28% 2.Lower respiratory tract infections 21% 3.Wound Infections:7% 4.Urinary tract infections 15% 5.GI, Skin.. 10%

9 4/28ABA-UMQU- Antibiotics in Surgical Practice 9 Hospital Acquired Infections The most common organisms

10 4/28ABA-UMQU- Antibiotics in Surgical Practice 10 Hospital Acquired Infections The most common organisms

11 4/28ABA-UMQU- Antibiotics in Surgical Practice 11 Hospital Acquired Infections The most common infections Wound Infections  Present if: 1.Wound red or swollen 2.Requiring opening 3.Exudate: Serous or pus 4.Antibiotics are prescibed because of concerns over the wound  Clinically:  Cellulitis  Localized abscess  Non clostridial gangrene  Clostridial: gas and non gas forming gangrene  Wound culture:  A positive culture does not prove infection  A negative culture does not exclude infection

12 4/28ABA-UMQU- Antibiotics in Surgical Practice 12 Hospital Acquired Infections The most common infections Chest infection 1.Risk factors: 1.Age 2.Aspiration 3.Head injury 4.Smoking 5.Intubation 6.Lung injury 7.Upper abdominal incisions 8.Prolonged hospital preoperative hospital stay 2.Organism: 1. 75% gram negative, % S aureus, 3. 5% Candida

13 4/28ABA-UMQU- Antibiotics in Surgical Practice 13 Hospital Acquired Infections: The most common infections Others:  Central lines: Treat by  Course of antibiotics  Replacement, same site  Replacement different line  Always send tip for micro on removal  UTI: Associated with urinary catheters (10 5 OPM)  Intra-abdominal abscess  Infection at time of surgery  Contamination from perforation,trauma..etc  Tertiary peritonitis  Infected implants or prosthetic material

14 4/28ABA-UMQU- Antibiotics in Surgical Practice 14 Antibiotic resistance Up to 70% of hospital acquired infections are resistant to antibiotics Causes: 1.Previous exposure to antibiotics 2.Inappropriate use of antibiotics 3.Prolonged hospital stay 4.Poorly inforced infection control measures 5.Lack of nursing staff Mechanism : Beta lactemases DNA gyrases, topisomorase Point mutations…etc

15 4/28ABA-UMQU- Antibiotics in Surgical Practice 15 Hospital Acquired Infections Resistance: MRSA (Methicillin Resitant Staph Aureus) 1.Associated with morbidity, mortality, increased hospital stay and treatment cost. 2.Usually nasocomial but community accquied infections are now present. 3.Associated with; 1.Use of broad spectrum antibiotics 1.Macroloids, 2. fluroquinalones, 3. cephlosporins 2.Previous hospital admission 3.Prolonged hospital/ICU stay 4.Entral feeding 5.Surgery

16 4/28ABA-UMQU- Antibiotics in Surgical Practice 16 Hospital Acquired Infections Resistance: Others: 1.Pseudomonas aeruginosa 2.E Coli 3.Enterobacter cloacae 4.Kelbsiella spp

17 4/28ABA-UMQU- Antibiotics in Surgical Practice 17 Hospital Acquired Infections 1The Fight:

18 4/28ABA-UMQU- Antibiotics in Surgical Practice 18 Hospital Acquired Infections 2The Fight:

19 4/28ABA-UMQU- Antibiotics in Surgical Practice 19 Hospital Acquired Infections The Fight: 3

20 4/28ABA-UMQU- Antibiotics in Surgical Practice 20 Hospital Acquired Infections The Fight: 4

21 4/28ABA-UMQU- Antibiotics in Surgical Practice 21 Antimicrobial Therapy Antibiotics in surgical practice are only an adjunct to treating surgical infection Before using an antibiotic ask the following Is an antibiotic required? Is it for treatment or prophylaxis? What is the likely pathogen (spectrum)? What is the site AB are required to reach (tissue penetration)? Route of administration? Resistance? Any Allergies? Is the patient Immunocompromised? Toxicity What is the cost?

22 4/28ABA-UMQU- Antibiotics in Surgical Practice 22 Classes of Antibiotics Beta-lactams Amoxicillin, penicillin Penicillins Cephalexin Cephalosporins Imipenem Carbopenems Erythromycin, clarithromycin, zithromycin Macroloids Ciprofloxacin Fluroqiunolons Trimaxazole, trimethoprim Sulphonomids Tetracyclin, doxacyclin Tetracyclins Gentamicin, tobromycin Aminoglycosids

23 4/28ABA-UMQU- Antibiotics in Surgical Practice 23 Target Sites CommentDrugTarget Bactericidal, Inhibit cell wall synthesis by preventing cross linkage of peptidogycans. Beta lactams (Penicillin, cephalosporins, carbapenems) Vancomysin Cell Wall Bacteriostatic Bacteriostatic/bacteriocidal Bacteriocidal All prevent bacterial protein synthesis Tetracyclin Erythromycin Aminglycosides Ribosomes DNA supercoiling RNA polymerase Ciprofluxacin Rifampacin Nucleic Acid

24 4/28ABA-UMQU- Antibiotics in Surgical Practice 24 Summary of Differences EukaryoticProkaryotic Multiple, non-circular Yes No Single and circular DS DNA No Yes Chromosome Nuclear Mem Mitochondria Plasmids

25 4/28ABA-UMQU- Antibiotics in Surgical Practice 25 Staphylococcus F.anaerob, Moist enviro. 1.Coagulase 2.Cell wall inhibit migration and phagocytosis of macrophages 3.Entrotoxin 4.Epidermotoxin Characteristc Pathogenicity Cellulitis, wound infections, infection of prosthesis. Disease

26 4/28ABA-UMQU- Antibiotics in Surgical Practice 26 Streptococcus Lancfeild A, B…… Alpha, Beta, Gamma Charecteristics 1.M protein & phagocytosis 2.Hyaluronidase & streptokinase 3.Stretolysins 4.Pyogenic exotoxins Pathogenicity Cellulitis, erysipilis, rhumatic fever……..etc Diseases

27 4/28ABA-UMQU- Antibiotics in Surgical Practice 27 Gram negatives Aerobic e.g. E.coli Obligate Aerobe. Pseudomonas Characteristics 1.Lipopolysaccharid entrotoxins 2.Adhesion molecules 3.Neuro & hemotoxins Pathogenicity Cephalosporins, Gentamicin …………etc Treatment Peritonitis, IP abscess, wound infections, post-op pneumonia, Necrotizing infections, Vasculitis Diseases

28 4/28ABA-UMQU- Antibiotics in Surgical Practice 28 Anaerobes Found mainly in GI, mouth, vagina, ischemic, trauma, devitalized tissue, foreign bodies & malignancies, aerobic bacterial growth Characteristics Bacteroides ( entrotoxins), Clostridia ( exotoxins) Pathogenicity Metronidazole Penicillins Treatment Abscess necrotizing fascitis pseudomembraneous colitis neurotoxins Diseases

29 4/28ABA-UMQU- Antibiotics in Surgical Practice 29 Beta lactams All have a beta lactam ring as a basic structure Penicillins Benzyle Penicillin……..Staph/Streps Flucloxcacillin…………Staph Co-amoxiclav………… Staph/G-ve/Bacteroids Pipracillin…………… Psuedomonas Cephalosporins 3 groups 10% Cross sensitivity in patients with penicillin allergy 3 generations with Increased G-ve & decreased G+ve in fourth generation. Carbapenenms Truly broad spectrum ( G negative, positive and anaerobes) May provoke seizures May promote highly resistant organisms

30 4/28ABA-UMQU- Antibiotics in Surgical Practice 30 Aminoglycosides Active against staph.aureus and aerobic G-ve Narrow theraputic ratio ( easily toxic) Monitor renal function and auto-toxicity Examples: Gentamicn Tobramicin Amicacin

31 4/28ABA-UMQU- Antibiotics in Surgical Practice 31 Macroloids & Quinalons Macroloids e.g. erythromicin, clarithromycin An alternative in penicillin sensitivity New generations have improved bioavailability, better oral absorbtion and fewer GI side effects. Quinalons e.g. Ciproflucloxacillin Good tissue penetration Gram negative activity Attains good levels on oral intake.

32 4/28ABA-UMQU- Antibiotics in Surgical Practice 32 The Use of Antibiotics Prophylaxis 1.When anatomical barriers are breached leading to contamination: faeces, bile..etc. 2.When the consequence and risks are unacceptably high 3.In traumatic wounds 4.In immunocompromised 5.Age> 70 Theraputic 1.Emperical therapy –The likely organism & antibiotic susceptibility –Avoid using a single agent –Avoid using agents with inadequate cover –Avoid AB with serious side effects. 1.Definitive therapy

33 4/28ABA-UMQU- Antibiotics in Surgical Practice 33 Drug administration 1. Route Intravenous if: Patient is seriously ill with inconsistent intestinal absorption or inability to oral medication. IV ensures rapid adequate serum levels. Be aware of theraputic window. Oral step down if : T < 38, Oral intake is tolerated, Good absorbtion, No unexplained tachycardia, No need for high tissue concentrations suitable oral prep available

34 4/28ABA-UMQU- Antibiotics in Surgical Practice 34 Drug administration Duration Treatment failure: Wrong AB/ Wrong dosing Other causes of infection Fungal superinfection Inappropriate administration Persistent source of infection

35 4/28ABA-UMQU- Antibiotics in Surgical Practice 35 Scenario 1 A 65 year old diabetic gentleman presented with swelling, erythema of his R leg. Clinically he was in septic shock with fowl smell and areas of necrosis, gangrene and crepitation noted on the leg

36 4/28ABA-UMQU- Antibiotics in Surgical Practice 36 Scenario 2 A 75 year old gentleman was admitted to ICU following major laparotomy. He was intubated, had a central line and a urinary catheter. 1 weeks following his admission he developed a fever there was a green discharge around the CVP line with areas of consolidation on the R lung base

37 4/28ABA-UMQU- Antibiotics in Surgical Practice 37 Principles of Antibiotics Prophylaxis Choose an AB against the most likely organism AB with low toxicity. Monotherapy A single dose minutes pre-op. A second dose if OP lasts > 4 hours Add 2-3 doses post-op Prolonged use is appropriate when infection is likely or it’s consequence is devastating.

38 4/28ABA-UMQU- Antibiotics in Surgical Practice 38 Scenario 3 A 35 year old lady presented with R hypochondrial pain. The diagnosis of cholecystitis is confirmed and laparoscopic cholecystectomy is planned

39 4/28ABA-UMQU- Antibiotics in Surgical Practice 39 Scenario 4 An elderly lady is undergoing a total hip replacement for severe osteoarthritis of her hip.

40 4/28ABA-UMQU- Antibiotics in Surgical Practice 40 Prophylaxis CoverOrganismOperationType 3 rd generation Cephs or vancomycin Staphs, StrepsCardiac Vascular Ortho Ophthalmic Breast & thyroid Clean 3 rd generation Cephs Cipro 3 rd generation Cephs & metronidazole Staphs, streps, anaerobe G- bacilli, enteroccoci G- bacilli, enteroccoci, clostridia G- bacilli, anaerobe Oropharynx Gastric Biliary Colonic Clean contaminated 3 rd generation Cephs G- bacilli, anaerobe, enteroccoci, clostridia Perforation Traumatic Abscess Dirty

41 4/28ABA-UMQU- Antibiotics in Surgical Practice 41 Distribution of Anti-microbial Agents CommentArea Levels are determined by rate of excretion & protein binding. Efficacy depends on the minimum inhibitory concentration and the time spent above that level. Blood Most agents achieve a urine concentration the serum concentration Ph may influence the spectra of agents Urine Most achieve concentration higher than serum May be influenced by liver disease Bile High concentrations favored by low albumin, prolonged use Interstitial fluids May achieve theraputic levels Low Ph, low oxidative potential, large number of microbes and tissue products all serve to reduce the efficacy of AB Abscesses

42 4/28ABA-UMQU- Antibiotics in Surgical Practice 42 Pseudomembraneous colitis

43 4/28ABA-UMQU- Antibiotics in Surgical Practice 43 Pseudomembraneous colitis Cause: clostridium difficile Risk factors: Broad spectrum antibiotics Proton pump inhibitors Clinical features: Voluminous diarrhea colitis Diagnosis: endoscopic veiw, stool toxin ESR/ WBC/ CT Treatment: Vancomicin/ Metronidazole

44 4/28ABA-UMQU- Antibiotics in Surgical Practice 44 Allergy 2-3% of patients Anaphylaxis 0.1% Need detailed history of positive reactions Cross-reaction: 8-10% Skin reaction not needed Atopy may an independent risk factor

45 4/28ABA-UMQU- Antibiotics in Surgical Practice 45 Miscellaneous 1.Hair removal Shave on morning of surgery, use clippers 2.Hypothermia Avoid 1.Bowel preparation No difference 1.Hyperglycaemia Avoid


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