Transcript 03. surgical infection team 428

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SURGICAL INFECTIONS
&
ANTIBIOTICS
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M K ALAM
MS, FRCS
Prof. & Consultant Surgeon
College of Medicine & RCH
Done by : 428 surgery team
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OBJECTIVES
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• Definitions.
• Pathogenesis .
• Clinical features .
• Surgical microbiology.
• Common infections.
• Antibiotics use.
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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 )
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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
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Surgical Infection
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• A major challenge
• Accounts for 1/3 of surgical patients
• Morbidity increase
• Mortality increase
• Increased cost to healthcare
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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 )
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Pathogenicity of bacteria
( wt makes organism pathogen
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-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
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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
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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
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Clinical features
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• 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 .
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Principles of surgical treatment
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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 “
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STREPTOCOCCI
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• 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
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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. epidermidisopportunistic ( wound, endocarditis )
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CLOSTRIDIA
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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 )
GRAM NEGATIVE ORGANISMS
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( 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
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GRAM NEGATIVE ORGANISMS
Pseudomonas most come in ICU patient
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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
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GRAM NEGATVE ANAEROBES
Bacteroides fragilis ( bowel surgery , investigation
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by
abscess with bad smell )
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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
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TYPES OF SURGICAL INFECTION
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A. Surgical Site Infection
B. Soft Tissue Infection
C. Body Cavity Infection
D. Prosthetic Device related Infection
E. Miscellaneous
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Surgical site infection (SSI)
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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
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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.
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Prevention of SSI
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• 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
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STREPTOCOCCAL INFECTIONS
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Erysipelas
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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
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SREPTOCOCCAL INFECTION
Cellulitis
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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 )
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NECROTIZING FASCIITIS
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• 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
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NECROTIZING FASCIITIS
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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
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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
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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 :
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- Penicillin, clindamycin, metronidazole
-Wound exposure, debridement , drainage, amputation
-Hyperbaric oxygen chamber
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TETANUS gram + , not seen recently unless u didn’t get
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the vaccine , or didn’t take the booster
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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
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risus sardonicus •
Contraction of jaws >> become closed..
While the lips >> open & tooth visible .
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TETANUS
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• 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 immunizedbooster >10 years needs a booster dose
booster <10 years- no treatment in low risk wounds
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PSEUDOMEMBRANOUS COLITIS
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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
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Body Cavity Infection
abdominal and
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• 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
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Prosthetic Device Related Infection
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Artificial valves and joints
Peritoneal and haemodialysis catheters
Vascular grafts patient may have hernia repair
Staphylococcus aureus
Antibiotics, washing of prosthesis or removal
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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 ?
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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
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ANTIBIOTICS
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THE DOC SAID READ428IT
• 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
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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
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ANTIBIOTIC THERAPY
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• 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
• Cellulitis- penicillin, erythromycin
( flucloxacillin if Staphylococcus infection. Suspected )
or Cefuroxime
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ANTIBIOTIC PROPHYLAXIS
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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
peritonitis ( up to 50% ) NOT prophylaxis BUT antibiotic
• A hollow organ is ruptured
e.g.,
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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.
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