SURGICAL INFECTIONSUnder supervision of : Dr. MOHAMMED AL-AKEELY

infectionInvasion of the body by pathogenic microorganisms and reaction of the host to organisms and their toxins

A surgical infection is an infection which requires surgical treatment and has developed befor, or as a complication of surgical treatment.

could be life threatening

Accounts for 1/3 of surgical patients

Increased cost to healthcare

Some imp defin.Bacteremia: bacteria in bloodSIRS: systemic inflammatory response syndrome (fever, tachycardia, tachypnea, leukocytosis)Sepsis: documented infection & SIRASSeptic shock: sepsis & hypotension refractory to fluid resuscitation

Debridement- necrotic, injured, dead tissueDrainage- abscess, infected fluidRemoval- infection source, foreign bodySupportive measures: immobilization elevation antibiotics Principles of surgical treatment

Common organisms Gram positive bacteria:StreptococciStaphylococciClostridiaGram negative bacteria:PseudomonasE. coliBacteroid fragilis

Streptococcal infectionsCellulitisLymphangitisLymphadenitisNecrotizing faciitis

cellulitissevere inflammation of dermal and subcutaneous layers of the skin.caused by normal skin flora(group A strept /staph)or by exogenous bacteria.the bacteria can spread rapidly, entering the lymph nodes and the bloodstream and spreading throughout the body.In rare cases, the infection can spread to the deep layer of tissue (Necrotizing faciitis).often occurs in broken skin.

cellulitisSigns & symptoms: affected area is red, hot, and tender with vague borders.Most common sites : Face, hand and lower extremities.

RF: old age & immunodeficiency.

Diagnosis: clinically.

TX:1- resting, elevation of the affected limb, debridement.2- ampicillin/amoxicillin in moderate (suspected strept) + flucloxacillin or dicloxacillin for mild (staph)

cellulitis

ErysipelasErysipelas is the term used for a more superficial infection of the dermis and upper subcutaneous layer that presents clinically with raised surface and well defined edge.

Erysipelas and cellulitis often coexist, so it is often difficult to make a distinction between the two.

Erysipelas

Lymphangitis

Lymphangitis is an inflammation of the lymphatic channels that occurs as a result of infection at a site distal to the channel.

Streptococcus pyogenes.

Signs and symptoms: deep reddening of the skin, warmth, with moderate pain and swelling. Lymphadenitis, chills and a high fever along. ( appears as red streak).

LymphangitisTx: 1-elevate and immobilize affected areas to reduce swelling, pain, and the spread of infection.2- antibiotic.

Lymphangitis

LYMPHADENITISLymphadenitis is an infection of the lymph nodes.Lymphadenitis may occur after skin infections or other bacterial infections, particularly those due to streptococcus or staphylococcus.Swollen, tender, or hard lymph nodesRed, tender skin over lymph nodeLymph nodes may feel rubbery if an abscess has formed.

LYMPHADENITISTreatment may include:Antibiotics to treat any underlying infectionAnalgesics (pain killers) to control painAnti-inflammatory medications to reduce inflammation and swellingCool compresses to reduce inflammation and painSurgery may be needed to drain any abscess.

LYMPHADENITIS

Necrotizing fasciitis (flesh-eating disease)Infection and necrosis of the deeper layers of skin and subcutaneous tissues.

2 types: l:polymicrobial ll: monomicrobial (mostly group A strept)

Signs and symptoms: The infection begins locally, at a site of trauma>>intense pain>> then tissue becomes swollen (hrs.)

Common sites: abdominal wall, perineum, and limbs.

Diagnosis: visual examination & microscopic evaluation of tissue samples.

Necrotizing fasciitisRF: diabetes, abdominal surgery, drug addict and trauma.

Tx: 1-Early medical treatment (combination of intravenous antibiotics including penicillin, vancomycin, and clindamycin)2-Cultures are taken to determine appropriate antibiotic 3-aggressive surgical debridement ( no definitive boundries!!)

High mortality rate (75%) if left untreated.

Necrotizing fasciitis

Abscess: is a collection of pus (dead neutrophils) that has accumulated in a cavity formed by the tissue

It is a defensive reaction of the tissue to prevent the spread of infectious materials to other parts of the body

As Staphylococcus aureus bacteria is a common cause, an anti-staphylococcus antibiotic such as flucloxacillin or dicloxacillin is usedIncision and drainage is a common surgical intervention in case of abscess

Staphylococcal Infections

Staphylococcal InfectionsFuruncle- infection of one hair follicle / sweat glands

Carbuncle- extension of furuncle into subcut. Tissue with possible formation of abscess. usually more than one furuncle common in diabetic patient common sites- back, back of neck Treatment: drainage, antibiotics, control diabetes

Staphylococcal Infections

Clostridial infectionsGas gangreneTetanusPseudomembranous colitis

GAS GANGRENEis a bacterial infection that produces gas in gangrenous tissues usually caused by Clostridium perfrengins bacteria.

It is a medical emergency (Progression to toxemia and shock is often very rapid)

Large wounds contaminated by soil.

It results in rapid myonecrosis, swelling, seropurulent discharge, foul smelling wound, crepitus in subcutaneous tissue.

GAS GANGRENEX-ray: gas in muscle and under skin.

Tx: 1-Wound exposure, debridement , drainage.2-Penicillin, clindamycin, metronidazole3-Hyperbaric oxygen chamber

GAS GANGRENE

TETANUSCl. Tetani, produce neurotoxinPenetrating wound ( rusty nail, thorn )Incubation period: 7-10 daysUsually wound healed when symptoms appearTrismus- first symptom, stiffness in neck & backAnxious look with mouth drawn up ( risus sardonicus)Progressive dysphasia, dysphagia, dyspnea & tonic convulsion

Death by exhaustion, aspiration or asphyxiation

TETANUSTreatment:wound debridementMuscle relaxants, penicillinventilatory support

Prophylaxis:vaccination by HTIG & T toxoid in tetanus prone wound in patient with unknown or incomplete history of immunization.If it is more than 5 years since last dose of tetanus immunization give only T toxoid.

Superinfection in patients in long term oral antibiotic therapyCl. DifficileWatery diarrhea, abdominal pain, feverDiagnosis needs Sigmoidoscopy, stool- culture and toxin assay

Treatment : stop offending antibiotic oral vancomycin/ metronidazole rehydration, isolate patient PSEUDOMEMBRANOUS COLITIS

PseudomonasOpportunestic bacteria that may cause surface infections, but may also cause serious and lethal infection.

Enter the body through minor skin abrasion, ventilator tubes, urinary catheters and IV lines >>> therefore it is common in ICU.

Can cause septecimia (particularly in burn wounds)

Tx: aminoglycosides, piperacillin, ceftazidine.

E. coliNormal intestinal flora, facultative anearobes.

May cause circulatory collapse (due to endotoxin), wound infections, meningitis, endocarditis, abdominal abscess & UTI.

Tx: ampicillin, aminoglycosides, cephalosporine.

Bacteroides fragilisNormal flora of mouth and colon, anearobic.Produce foul smelling pus, gas in surrounding tissues & necrosis.Responsible for intraabdominal & gyne. infection.Causes spiking fever, jaundice & leukocytosis.Tx: Surgical drainage, excision.Clindamycin, metronidazole.

Hospital aquired infectionsThe most common is UTIThe most common causing death is pneumonia.

38% of all surgical infectionsInfection within 30 days of operationClassification: Superficial: Superficial SSIinfection in subcutaneous plane (47%) Deep: Subfascial SSI- muscle plane (23%) Organ/ space SSI- intra-abdominal, other spaces (30%)Staph. aureus- most common organism E coli, Entercoccus ,other Entetobacteriaceae- deep infections B fragilis intrabd. abscess

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. Surgical site infection (SSI)

Intra-abdominal infectionsGeneralizedLocalizedPrevention- good tech., avoid bowel injury, good anastomosis.Diagnosis- History, exam., investigations CT scan.Treatment- surgery/ intervention Antibiotics (aerobe+ anaerobe)

Surgical site infection (SSI)

UTIUTI are usually consequences of foley cathetar. The most common symptoms of a bladder infection are burning with urination (dysuria), frequency of urination and an urge to urinate.may also present with flank pain and a fever.

UTIDiagnostic test: -urinalysis (nitrate, estrase) -culture -urine microscopy (WBC>10)

The common org. is: - E. coli, klebsiella, enterococcus & staph. aureus

TREATMENTAb.with gram (-) spectrum -sulphamethoxasole -trimethoprim -gentamycin -ceprofloxacinCheck culture &sensitivity

pneumonia

Rout of infection:

-gross aspiration during anesthesia or intubation. Pathogen includes anaerobic organism & gram(-) bacilli.

- Atelectasis: the collapsed lung may become secondarily infected

-contiguous spread from another site.

pneumonia

Sing & symptoms :

People with pneumonia often have one or more of these symptoms: Fever, productive cough, shortness of breath, hypoxia and chest pain.

Chest x-ray & sputum culture are important to confirm the diagnose.

treatmentHospital acquired pneumonia generally treated by cefuroxime, ceftriaxone for the usual pathogen( gram(-), s.aureus , strept.pn, & H. influenzae) + treatment of other pathogen.if there is recent Hx of abd.surg the infectious org. is anaerobes we should add clindamycin

If the pt. is comatose or has head trauma, DM, or renal failure the org. usually is s.aureus & there is risk of MRSA we add vancomycin

If the pt. take high dose of glucocorticoides the org. usually is legionella we add macrolide (azithromycin)

If the pt. has malnutrition, structural lung disease, glucocorticoid therapy the org. usually is pseudomonas.a

Also if the pt. has Hx of neuro.surg. ,head trauma, ARDS, aspiration the org. usually is acinetobacter spp.

All of them treated by the standard treatment + aminoglycoside or ciprofloxacin IV + antipseudomonal penicillin or imipenem.

Sterilization and DisinfectionSterilization means ERADICATING all microorganisms and SPORES.Disinfection means the eradication of vegetative form only leaving SPORES.For sterilization, autoclave is the most common instrument used.Antiseptic is used on the surface of the body like alcohol, chlorohexidineDisinfectent is applied on metals and other instruments like formaldehyde = formalinPlastic materials are best sterilized using chemicals while metalic instrument can be safely sterilized in the autoclave.

antibioticsChemotherapeutic agents that act on organisms

Bacteriocidal: Penicillin,Cephalosporin, Vancomycin, Aminoglycosides

Bacteriostatic: Erythromycin,Clindamycin,Tetracycline

COMMON ANTIBIOTICSPenicillins- penicillin G

Cephalosporins (II, III)-Cefruoxime, Ceftriaxone

Aminoglycosides- Gentamycin

Fluoroquinolones- Ciprofloxacin

Glycopeptides- Vancomycin

Macrolides- Erythromycin,

Tetracyclines-, Doxycycline

Prophylactic ab.Prophylaxis in clean-contaminated or high risk clean wounds. Antibiotic is given just before patient sent for surgery. Duration of antibiotic is controversial (one dose-or more , should not be used more than 24 hour regimen )

Wound Classification

Wound class

Definition

Example

Infection rate (%)

Clean

Nontraumatic, elective surgery. GI tract, respiratory tract, GU tract not entered

Mastectomy Vascular

Hernias

2%

Clean-contaminated

Respiratory, GI, GU tract entered with minimal contamination

Gastrectomy

Hysterectomy

< 10%

Contaminated

Open, fresh, traumatic wounds, uncontrolled spillage, minor break in sterile technique

Rupture appy

Emergent bowel resect.

20%

Dirty

Open, traumatic, dirty wounds; traumatic perforation of hollow viscus, frank pus in the field

Intestinal fistula resection

28-70%

Thank u

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