Surgical Site Infections

• Definition:

• Infection of the tissues ,organs or spaces exposed by surgeons during performance of an invasive procedure.

• Classification:

• Incisional:

• a. Superficial

• b. Deep

• Organ/Space

• Factors involved:

• 1.The degree of bacterial contamination of the wound during surgery.

• 2. The duration of the procedure

• 3. Host factors

• Host factors:

• a. General:

• Diabetes

• Malnutrition

• Obesity

• Immune suppression

• Old age

• Chronic inflammatory process

• Smoking

• Renal failure

• Anemia

• Radiation

• Chronic skin disease

• Host factors ……continued,

• b. Local:

• Open compared to laparoscopic procedures

• Poor skin preparation

• Contamination of the instruments

• Inadequate antibiotic prophylaxis

• Prolonged procedures

• Local tissue necrosis

• Hypoxia and hypothermia

• c. Microbial:

• Prolonged hospitalization leading to nosocomial infections

• Classification of surgical wounds:

• Clean (class 1) 1-2%

• (class1 D) ….Insertion of prosthetic device

• Clean contaminated (class 11) 2-10%

• Contaminated (class 111 ) 3-14%

• Dirty (class 1V ) 3-20%

• Intraabdominal infections:

• 1. Primary microbial peritonitis:

• ( Hematogenous dissemination from a distant source)

• Direct inoculation Ascites

• Peritoneal dialyses

• Monomicrobial

• Rarely require surgical intervention

• More than 100 WBCs/mL

• Microbes with a single morphology on Gram stain

• Treatment: 14-21 days of antibiotic therapy,

• Removal of indwelling devices( VP or PD)

• Rarely require surgical intervention.

• Intraabdominal Infections…..continued

• 2. Secondary microbial peritonitis:

• Peritoneal contamination:

• a. Perforated viscus

• b. Inflamed intraabdominal organ.

• Treatment:

• 1 Antimicrobial therapy

• 2 Abscess treatment is drainage

• Facts:

• The most morbid form is colonic perforation

• With source control, mortality 5-6%

• Without source control, mortality 40%

• If therapy fails, think of :

• Abscess formation

• Presence of anastomosis leak (tertiary peritonitis),mortality here increase to50%.

• Diagnosis of intraabdominal abscesses is by CT scan

• Sites:

• Pelvic

• Subdiaphragmatic

• Subhepatic

• Paracolic

• Interloop

• Abscess treatment:

• Drainage:

• a. Percutaneous

• b. Surgical, for Multiple abscesses

• Abscess in proximity to a vital structure

• Ongoing source of contamination(enteric leak)

• Drain is kept until Cavity collapse

• Output less than 10-20 mL per day

• No evidence of ongoing source of contamination

• The patient general condition improve

• Organ Specific Infections:

• Liver abscess:

• 1. Pyogenic 80%

• 2. Parasitic 10%

• 3. Fungal 10%

• Pyogenic liver Abscesses:

• Caused by pyelophlebitis(neglected appendicitis or diverticulitis)

• Recently, from manipulation of the biliary tree

• In 50% of cases, no source can be identified

• Treatment:

• Less than 1 cm multiple abscesses are treated by Antibiotics for 4-6 weeks

• Large abscess Drainage.

• Organ Specific Infections……continued • Splenic Abscess: • Rare • Same approach as in liver abscesses • If recurrent , treated surgically by deroofing or splenectomy. • Pancreatic Abscess: • Occur in 10-15% of patients with severe pancreatitis and necrosis • prognosis depends on Scoring systems • CT findings • Diagnosis is by CT guided aspiration and positive Gram stain or the

presence of gas in the pancreatic bed.

• Infections Of Skin And Soft Tissues:

• Skin Superficial

• Cellulitis

• Erysipelas

• Lymphangitis

• All are caused by Gram positive cocci and are treated by antibiotics.

• Furuncles and boils ,may drain spontaneously or surgically.

• Aggressive Soft Tissue Infections:

• Rare

• Difficult to diagnose

• Require immediate surgical intervention and administration of antibiotics

• Failure to do so…..high mortality (80-100%)

• Even with rapid recognition and intervention mortality rates are high (16-24%)

• 1. Meleneys synergistic gangrene

• 2. Rapidly spreading cellulitis

• 3. Gas gangrene

• 4.Necrotising faciitis

• Aggressive Soft Tissues Infections……continued

• Predisposing factors:

• Elderly patients

• Diabetics

• Peripheral vascular disease

• Combination of all

• The common thread …compromise to the fascial blood supply coupled with introduction of exogenous microbes

• Streptococcal fasciitis can occur in healthy individuals

• Patients often develop sepsis or septic shock without an obvious cause

• Necrotising Fasciitis….. Continued

• Sites in order,

• Extremities

• Perineum (Fournier gangrene)

• Trunk

• Torso

• Approach:

• Careful exam for an entry point( small break or sinus )

• Drainage of greyish turbid semiperulent material can be expressed (dishwasher pus)

• Skin changes:

• Bronze or brawny induration

• Plebs

• Crepitus

• The striking feature is that pain at the site is out of proportion to any of the physical manifestations.

• Necrotising Fasciitis….. Continued

• Treatment:

• Immediate surgical intervention

• Exposure and direct visualisation of potentially infected tissue

• Radical resection

• During the procedure , Gram stain should be performed on tissue fluid.

• Post Op.Nosocomial Infections:

• 1. Surgical site infections

• 2. Urinary tract infections

• 3. Pneumonia

• 4. Bacteremia

• Sepsis

• Prophylactic Antibiotics:

• The use of antibiotics before surgery or dental procedures to prevent bacterial infection

• Patient selection:

• a. If the procedure is associated with a considerable risk of infection

• b. If postop infection would pause a serious hazard to the patient recovery and well-being.

• Effective

• Cephalosporins

• Hospital policies and guidelines

• Given no more than 30-60 minutes before surgery

• No longer than 24 hours

• Therapeutic concentration to be present throughout the period the wound is open

• Asplenic patients

• Post Operative fever:

• Definition

• Temperature more than 38.5 C on 2 consequtive post op days or , more than 39 C on any postop day.

• Fever might be ……benign

• self limited

• unrelated to the surgical procedure or,

• indicative of a surgical complication.

• Possibilities:

• 1-2 days Pneumonia or Atelectasis

• 3-5 days UTI

• 5-7 days Infected surgical wound (superficial or deep)

• space infection

• Organ abscess

• 5 days to months DVT or PE

• Anytime Drug fever

• Febrile nonhemolytic transfusion reaction

• TRALI

• Anytime Blood stream infection

• Phlebitis or cellulitis related to IV lines