![Page 1: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/1.jpg)
Infection in Surgical Patients
![Page 2: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/2.jpg)
![Page 3: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/3.jpg)
![Page 4: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/4.jpg)
![Page 5: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/5.jpg)
![Page 6: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/6.jpg)
![Page 7: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/7.jpg)
Defense Barriers
Physical Chemical Immunologic
![Page 8: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/8.jpg)
Host defense
Barrier Microbial flora Humoral Cellular cytokine
![Page 9: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/9.jpg)
Microbial flora
![Page 10: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/10.jpg)
Humoral defenses
Immunoglobulin Complement
![Page 11: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/11.jpg)
Immunoglobulin All Ig classes (IgM, G, A, E, D and igG
subclasses are composed of one type (M,G,A,E,D) of heavy (H) and one type of light (L) protein.
Each L chain is linked to an H chain, and H chains are interlinked.
H chain activate complement or bind to receptors of either macrophages or PMN leucocytes
The amino terminus of the H and L chains together forms antigen-binding site
![Page 12: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/12.jpg)
Immunoglobulin
![Page 13: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/13.jpg)
Complement system
Series of serum proteins that may became activated via either classic or alternative pathway
![Page 14: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/14.jpg)
![Page 15: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/15.jpg)
Cellular defense
Macrophage PMN leucocytes cytokines
![Page 16: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/16.jpg)
Surgical Site Infection ( SSI )
![Page 17: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/17.jpg)
Clinical criteria ( CDC )
A purulent exudate draining from the surgical site
A positive fluid culture obtained from a surgical site that was closed primarily
The surgeon’s diagnosis of infection A surgical site that requires reopening
![Page 18: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/18.jpg)
FACTS One out of every 24 patients who have
inpatient surgery in the United States has a postoperative SSI
The cost of SSIs are substantial: an increased total cost of more than 300%
SSIs increase the post operative length of hospital stay by 10-14 days
![Page 19: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/19.jpg)
Definition SSI is a difficult term to define
accurately because it has a wide spectrum of possible clinical features
“It’s hard to define, but I know it when I see it.”
SSI are classified into three categories, depending of which anatomic areas are affected
![Page 20: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/20.jpg)
![Page 21: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/21.jpg)
Definitions of SSI
Superficial incisional SSI: Infection involves only skin and subcutaneous tissue of incision.
Deep incisional SSI: Infection involves deep tissues, such as fascial and muscle layers. This also includes infection involving both superficial and deep incision sites and organ/space SSI draining through incision.
Organ/space SSI: Infection involves any part of the anatomy in organs and spaces other than the incision, which was opened or manipulated during operation.
![Page 22: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/22.jpg)
Causes Table 1. Pathogens
Commonly Associated with Wound Infections and Frequency of Occurrence*Pathogen Frequency (%) *NNIS System (CDC, 1996)
Staphylococcus aureus
20
Coagulase-negative staphylococci
14
enterococci 12
Escherichia coli
8
Pseudomonas 8
enterobacter 7
Proteus Mirabilis
3
Klebsiella pn. 3
Bact. fragilis 2
![Page 23: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/23.jpg)
Risk factors Decreased host resistance can be due to systemic factors
affecting the patient's healing response, local wound characteristics, or operative characteristics.
Systemic factors include age, malnutrition, hypovolemia, poor tissue perfusion, obesity, diabetes, steroids, and other immunosuppressants.
Wound characteristics include nonviable tissue in wound; hematoma; foreign material, including drains and sutures; dead space; poor skin preparation, including shaving; and preexistent sepsis (local or distant).
Operative characteristics include poor surgical technique; lengthy operation (>2 h); intraoperative contamination, including infected theater staff and instruments and inadequate theater ventilation; prolonged preoperative stay in the hospital; and hypothermia
![Page 24: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/24.jpg)
The type of procedure is a risk factor too
![Page 25: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/25.jpg)
Antimicrobial agents
Prophylaxis Empiric therapy Directed therapy
![Page 26: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/26.jpg)
Classes of Antimicrobial Agents Penicillins, Cephalosporins,
carbapenems inhibit cell wall synthesis, resulting in bacteriolysis
Tetracyclins, chloramphenicol, and macrolides inhibit bacterial ribosomal activities and thus overall protein synthesis
Vanco inhibits assembly of peptido glycan polymers
Quinolones inhibit bacterial DNA synthesis
![Page 27: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/27.jpg)
Prophylactic Antibiotics General agreement exists that prophylactic
antibiotics are indicated for clean-contaminated and contaminated wounds
Antibiotics for dirty wounds are part of the treatment because infection is established already.
Clean procedures might be an issue of debate. No doubt exists regarding the use of prophylactic antibiotics in clean procedures in which prosthetic devices are inserted because infection in these cases would be disastrous for the patient.
![Page 28: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/28.jpg)
Systemic preventive antibiotics should be used in the following cases
A high risk of infection is associated with the procedure (eg, colon resection).
Consequences of infection are unusually severe (eg, total joint replacement).
The patient has a high NNIS risk index.
![Page 29: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/29.jpg)
The antibiotic should be administered preoperatively but as close to the time of the incision as is clinically practical. Antibiotics should be administered before induction of anesthesia in most situations.
The antibiotic selected should have activity against the pathogens likely to be encountered in the procedure.
Postoperative administration of preventive systemic antibiotics beyond 24 hours has not been demonstrated to reduce the risk of SSIs
![Page 30: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/30.jpg)
Intraoperative re-dosing
Operation is prolong If massive blood loss occurs The patient is obese
![Page 31: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/31.jpg)
Colorectal Surgery
Recommended oral prophylaxis consist of Neomycin plus erythromycin or Neomycin plus Flagyl, along with administration of mechanical bowel preparation
Intravenous cefoxitin or cefazolin preoperatively and continued 2 doses or 24 hrs postoperatively
![Page 32: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/32.jpg)
Intraabdominal Infection Usually polymicrobial
There is synergism between aerobic and anaerobic organisms
Peritonitis vs abscesses formation Abscesses
Determined by gravity and the physiologic drainage basins of the abdomen
Subphrenic space, pelvic space, subhepatic space, paracolic gutter, lesser sac, subfascial area
![Page 33: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/33.jpg)
Primary Peritonitis
Microorganisms lodge in the peritoneal cavity without a fundamental intraabd. Process Previously occurred in miliary TB, but
now commonly occurs in ascites Most common organism in ascties is S.
pneumoniae
![Page 34: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/34.jpg)
Secondary peritonitis Usually begins with perforation of the GI tract
From inflammatory or neoplastic process One major factor in determining severity is the
size of the bacterial inoculum Perforated appendix has 106 to 107 bacteria per g Sigmoid colon has 1010 to 1011 bacteria per g
Anaerobes exceed aerobes 1,000-fold Adjuvant factors are also important
Food, fiber, exfoliated cells, blood, dead tissue Bacteria that are eliminated are either
phagocytized or removed into the lymphatic system
![Page 35: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/35.jpg)
Tertiary Peritonitis
recurrent intra-abdominal infection after initial surgical and antimicrobial therapy of secondary bacterial peritonitis.
![Page 36: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/36.jpg)
Nosocomial Pneumonia Comes from
atelectasis, aspiration, and contamination from ventilation
Most common bacteria Pseudomonas, Klebsiella,
Staph, E. coli, Proteus, Enterobacter, Pneumococcus, Serratia, group A Strep, H. flu
Host defenses Glottis Cilia Mucus Secretory IgA and IgG Surfactant Transferrin Alveolar macrophages
![Page 37: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/37.jpg)
Urinary Tract Infections Foley catheterization is usually the
culprit Host defenses
Urine flow, antireflux, epithelium, mucus, IgA, urethral length
Common organisms E. coli, Klebsiella, Pseudomonas, Proteus,
Enterobacter, Enterococcus, Serratia, Citrobacter, Staph epidermidis
![Page 38: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/38.jpg)
Catheter and Prosthetic Device Infection The trauma of the catheter
placement, the foreign body itself, and the contaminating bacteria lead to an inflammatory response
Eradication cannot be achieved because of the persistence of the foreign body
Intimal vein disruption and clot formation also lead to bacterial proliferation
Removal should never be delayed nor should antimicrobial agents be withheld
![Page 39: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/39.jpg)
Other Specific Site Infection
Parotitis Sinusitis Pseudomembranous colitis
![Page 40: Infection in Surgical Patients. Defense Barriers Physical Chemical Immunologic](https://reader030.vdocuments.mx/reader030/viewer/2022033103/56649f445503460f94c65c2d/html5/thumbnails/40.jpg)