SURGICAL INFECTIONS & ANTIBIOTICS M K ALAM MS, FRCS Prof. & Consultant Surgeon College of Medicine & RCH Done by : 428 surgery team surgery team

OBJECTIVES Definitions. Pathogenesis. Clinical features. Surgical microbiology. Common infections. Antibiotics use surgery team

INFECTION Invasion of the body by pathogenic microorganisms and reaction of the host to organisms and their toxins ( the def. its 2 part :1- invase of organism 2- body respond to it ) surgery team

SURGICAL INFECTIONS Infections that require surgical intervention as a treatment [1] or develop as a result of surgical procedure [2]. Appendicitis : 1- comes? the infection – need treatment by surgery 2- surgery – complictaion surgery team

Surgical Infection A major challenge Accounts for 1/3 of surgical patients Morbidity increase Mortality increase Increased cost to healthcare surgery team

Factors contributing to infections Microorganism related factors: -Adequate dose ( many organism ) -Virulence of microorganisms Host related factors: -Suitable environment ( closed space ) ( make an env. For the body to accept the organism ). -Susceptible host ( weak immunity ) surgery team

Pathogenicity of bacteria ( wt makes organism pathogen ?) -Exotoxins: specific effect for each bacteria type, soluble proteins, remote cytotoxic effect, released from intact bacteria e.g Cl.Tetani cause tetanus, Strep. Pyogenes cause infection having an acid -Endotoxins: part of gram-negative bacterial wall, released only after destruction of bacteria, lipopolysaccharides e.g., E coli Resist phagocytosis: Protective capsule Klebsiela and Strep. Pneumoniae -Explain: 1- toxin EX. Secretions ---- END. Part of the organism which distorted it 2- resist phagocytosis surgery team

Host Resistance  Intact skin / mucous membrane. (surgery/ trauma- causes breach) by breaking the skin during the surgery which is a defensive mechanism for the body.  Immunity: like patient who treated by cortisone, they have weak immunity Cellular (phagocytes ) Antibodies surgery team

Classification of infection - Autoinfection(endogenous) :pathogen from within the patient - Community acquired : e.g. flu -nosocomial : from hospital environment -iatrogenic : secondary to theraby e.g. cathters - From carrier - Opportunistic infection surgery team

Clinical features Local- pain, heat, redness, swelling, some times loss of function. (apparent in superficial infections) Systemic- ill, loss of appetite, fever, tachycardia, chills,rigors Like appendicitis when patient come after 3 days with high fever this indicate as infection surgery team

Principles of surgical treatment Debridement- necrotic, injured tissue [a] Drainage- abscess, infected fluid [b] Removal- infection source, foreign body[c] Supportive measures: to stop the spread of infection a- immobilization “ bed rest “ b- elevation “ swell less, rest elevation “ c- antibiotics “ for appendicitis “ surgery team

STREPTOCOCCI Gram positive, manily aerobe/anaerobe Flora of the mouth and pharynx oral cavity, ( bowel ) Streptococcus pyogenes –( β hemolytic) 90% - 95% of infections e.g.,lymphangitis, cellulitis, rheumatic fever,pharyngitis Strep. viridens- subacute bacterial endocarditis, urinary infection Strep. Fecalis (bowel ) – urinary infection, pyogenic infection Strep. pneumonae – pneumonia, meningitis not commonly seen surgery team

STAPHYLOCOCCI “ surgical wound infections “ Inhabitants of skin, Gram positive anaerobes Infection characterized by suppuration like HAI, immune weak Staph.aureus- the most common, most pathogen SSI, nosocomial,superficial infections Staph. epidermidis- opportunistic ( wound, endocarditis ) surgery team

CLOSTRIDIA Gram positive, anaerobe Rod shaped microorganisms Live in bowel & soil Produce exotoxin for pathogenicity Important members: Cl. Perfringens, Cl. Septicum ( gas gangrene ) Cl. Tetani ( tetanus ) Cl. Difficile ( pseudomembranous colitis ) surgery team

GRAM NEGATIVE ORGANISMS ( Enterobactericiae ) Escherichia coli ( bowel infections ) Facultative anaerobe, Intestinal flora Produce exotoxin & endotoxin Endotoxin produce Gram-negative shock Wound infection, abdominal abscess, UTI, meningitis, endocarditis Treatment- ampicillin, cephalosporin, aminoglycoside surgery team

GRAM NEGATIVE ORGANISMS Pseudomonas most come in ICU patient aerobes, occurs on skin surface opportunistic pathogen may cause serious & lethal infection colonize ventilators, iv catheters, urinary catheters Wound infection, burn, septicemia Treatment: aminoglycosides, piperacillin, ceftazidime surgery team

GRAM NEGATVE ANAEROBES Bacteroides fragilis ( bowel surgery, investigation by abscess with bad smell ) Normal flora in oral cavity, colon Intra-abdominal & gynecologic infections ( 90% ) Foul smelling pus, gas in surrounding tissue, necrosis Spiking fever, jaundice, Leukocytosis No growth on standard culture Needs anaerobe culture media Treatment: Surgical drainage Antibiotics- clindamycin, metronidazole surgery team

TYPES OF SURGICAL INFECTION A. Surgical Site Infection B. Soft Tissue Infection C. Body Cavity Infection D. Prosthetic Device related Infection E. Miscellaneous surgery team

Surgical site infection (SSI) 38% of all surgical infections Infection within 30 days of operation Classification: - Superficial: Superficial SSI–infection in subcutaneous plane (47%) - Deep: Subfascial SSI- muscle plane (23%) Organ/ space SSI- intra-abdominal, chest infections,other spaces (30%) Staph. aureus- most common organism E coli, Entercoccus,other Entetobacteriaceae- deep infections B fragilis – intrabd. abscess surgery team

Surgical site infection (SSI) Risk factors: age, malnutrition, obesity, immunocompromised, poor surg. tech, prolonged surgery, preop. shaving and type of surgery. Diagnosis: Sup.SSI- erythema, oedema, discharge and pain Deep infections- no local signs, fever, pain, hypotension. need investigations. Treatment: surgical / radiological intervention surgery team

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Prevention of SSI Pre-op: Treat pre-existing infection Improve general nutrition Shorter hospital stay Pre-op. shower Hair removal timing? Should if the surgery take long time, or the area need to shave. Intraoperative: Antiseptic technique Surgical technique Post-operative: Hand hygiene surgery team

STREPTOCOCCAL INFECTIONS Erysipelas Superficial spreading cellulitis & lymphangitis Area of redness, sharply defined irregular border Follows minor skin injuries Strep pyogenes Common site: around nose extending to both cheeks Penicillin, Erythromycin surgery team

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SREPTOCOCCAL INFECTION Cellulitis Inflammation of skin & subcutaneous tissue Non-suppurative Strep. Pyogenes Common sites- limbs Affected area is red, hot & indurated Treatment : Rest, elevation of affected limb Penicillin, Erythromycin Fluocloxacillin ( if staph. suspected ) surgery team

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NECROTIZING FASCIITIS Necrosis of superficial fascia, overlying skin Polymicrobial : Streptococci (90%), anaerobic Grampositive Cocci, aerobic Gram-negative Bacilli, and the Bacteroides spp. Sites- abd.wall (Meleny’s), perineum (Fournier’s), limbs, Usually follows abdominal surgery or trauma surgery team

NECROTIZING FASCIITIS we have 2 do the investigation 2 differentiated from simple crllulitis Diabetics more susceptible Starts as cellulitis, edema, systemic toxicity Appears less extensive than actual necrosis Investigation: Aspiration, Gram’s stain, CT, MRI Treatment: IV fluid, IV antibiotics (ampicillin, clindamycin l metronidazole, aminoglycosides ) Debridement, repeated dressings, skin grafting surgery team

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STAPHYLCOCCAL INFECTIONS Abscess- localized a lot creamy pus collection Treatment- drainage, antibiotics Furuncle- infection of hair follicle / sweat glands Carbuncle- extension of furuncle into subcut. tissue common in diabetics common sites- back, back of neck Treatment: drainage, antibiotics, control diabetes surgery team

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GAS GANGRENE grame (+) anaerobe Cl. Perfringens, Cl. Septicum Exotoxins: lecithinase, collagenase, hyaluridase Large wounds of muscle ( contaminated by soil, foreign body ) Charcterized by progressive,rapidly spreading edema Rapid myonecrosis (Affect mainly muscle and cause muscle necrosis), crepitus in subcutaneous tissue Seropurulent discharge, foul smell, swollen Toxemia, tachycardia, ill looking X-ray: gas in muscle and under skin Treatment : - Penicillin, clindamycin, metronidazole -Wound exposure, debridement, drainage, amputation -Hyperbaric oxygen chamber surgery team

TETANUS gram +, not seen recently unless u didn’t get the vaccine, or didn’t take the booster Cl. Tetani, produce neurotoxin Penetrating wound ( rusty nail, thorn ) Usually wound healed when symptoms appear Incubation period: 7-10 days Trismus- first symptom, stiffness in neck & back muscle spasm Anxious look with mouth drawn up ( risus sardonicus) Respiration & swallowing progressively difficult Reflex convulsions along with tonic spasm Death by exhaustion, aspiration or asphyxiation surgery team

risus sardonicus Contraction of jaws >> become closed.. While the lips >> open & tooth visible surgery team

TETANUS Treatment: wound debridement, penicillin Muscle relaxants, ventilatory support Nutritional support Prophylaxis: wound care, antibiotics Human tetanus immunglobulin (HTIG )in high risk ( un-immunized ) Commence active immunization ( T toxoid) Previously immunized - booster >10 years needs a booster dose booster <10 years- no treatment in low risk wounds surgery team

PSEUDOMEMBRANOUS COLITIS gram + Cl. Difficile Overtakes normal flora in patients on antibiotics Watery diarrhea, abdominal pain, fever Sigmoidoscopy show: membrane of exudates (pseudomembranes) Diagnosis :Stool- culture and toxin assay Treatment : stop offending antibiotic oral vancomycin/ metronidazole rehydration, isolate patient surgery team

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Body Cavity Infection abdominal and Primary peritonitis: Spontaneous, weak immune. Children, Ascitic immuno Haematogenous/ lymphatic route Tt /Antibiotic Secondary peritonitis: infection one of the organ in abdomen Inflam./ rupture of viscera Polymicrobial Investigations: blood, radiological Tt/ of original cause surgery team

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Prosthetic Device Related Infection Artificial valves and joints Peritoneal and haemodialysis catheters Vascular grafts patient may have hernia repair Staphylococcus aureus Antibiotics, washing of prosthesis or removal surgery team

Hospital Acquired Infection Occurring within 48 h of hospital admission, three days of discharge or 30 days following an operation 10% of patients admitted to hospitals Spent 2.5-times longer in hospital - UK Highest prevalence in ICU- Enterococcus, Pseudomonas spp.,E coli(exo & endo toxin), Staph. aureus. Sites: Urinary, surg. Wounds, resp., skin, blood, GIT Wt is the most common site in HAI ? surgery team

ANTIBIOTICS Chemotherapeutic agents that act on organisms Bacteriocidal: Penicillin, Cephalosporin, Vancomycin Aminoglycosides refers to the treatment of a bacterium such that the organism is killed Bacteriostatic: Erythromycin, Clindamycin, Tetracycline refers to a treatment that restricts the ability of the bacterium to grow surgery team

ANTIBIOTICS THE DOC SAID READ IT Penicillins- Penicillin G, Piperacillin Penicillins with β-lactamase inhibitors- Tazocin Cephalosporins (I, II, III)- Cephalexin, Cefuroxime, Ceftriaxone Carbapenems- Imipenem, Meropenem Aminoglycosides- Gentamycin, Amikacin Fluoroquinolones- Ciprofloxacin Glycopeptides- Vancomycin Macrolides- Erythromycin, Clarithromycin Tetracyclines- Minocycline, Doxycycline surgery team

ROLE OF ANTIBIOTICS “ given a scenario and ask if its therapeutic or prevention” Therapeutic: To treat existing infection Prophylactic ( PREVENTION ) : To reduce the risk of wound infection surgery team

ANTIBIOTIC THERAPY Pseudomembranous colitis- oral vancomycin/ metronidazole Biliary-tract infection- cephalosporin or gentamycin Peritonitis- cephalosporin/ gentamycin + metronidazole/ clindamycin Septicemia- aminoglycoside + ceftazidime, Tazocin or imipenem, ( may add metronidazole ) Septicemia due to vascular catheter- Flucloxacillin/ vancomycin or Cefuroxime Cellulitis- penicillin, erythromycin ( flucloxacillin if Staphylococcus infection. Suspected ) surgery team

ANTIBIOTIC PROPHYLAXIS BASED ON SURGICAL WOUND CLASSIFICATION Clean wound no organism present - e.g., thyroid surgery ( 2% ), repair of hernia, removing a laparotomy(NOT in GIT,Resp. Sys., or GU sys). Typically an elective surgery in a non-contaminated, non-traumatic and non-inflamed surgical site Clean-contaminated- minimal contamination e.g., biliary, urinary, GI tract surgery ( 5-10% ) Here surgery involves the respiratory, GI or genitourinary system, ie often a hollow organ Contaminated-gross contamination e.g., during bowel surgery- (up to 20% ) Similar surgeries, but with leakage or a major break in aseptic technique Dirty- surgery through established infection e.g., peritonitis ( up to 50% ) NOT prophylaxis BUT antibiotic A hollow organ is ruptured surgery team

ANTIBIOTIC PROPHYLAXIS (IMP ) * Prophylaxis in clean-contaminated/ high risk clean wounds * Antibiotic is given just before patient sent for surgery *Duration of antibiotic is controversial ( one dose- 24 hour regimen ) *Hernia- one dose preoperatively, can be pre and post operative or for 24hrs or even days surgery team

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