Surgical Infections Flashcards
Pathogens vs Commensals
Concept of host defenses
A commensal could become a pathogen if it entered a sterile body cavity at time of surgery
Aerobes and Anaerobes
Can synergize with soft tissue infections and intra abdominal infections
Therapy is directed by both
Most surgical infections are caused by?
Polymicrobials
What are the host’s defenses?
Skin and mucosa Microflora of Resp. and GI tract Stomach pH Lactoferin and Fe chelators Innate immune system (macrophages) Adaptive immune system (T cells and B cells) Omentum
Why are surgical infections becoming a rising problem?
emerging resistant organisms
changing patient population (immunosupression and sicker patients in the ICU)
larger more invasive operations
Local manifestations
Fever
elevated WBC
tachycardia and tachypnea
altered mental status
What are the outcomes of microbial invasion?
erradication containment locoregional infection metastatic abscess systemic infection
What are examples of containment?
Abscess, pus, intermittent drainage
What are examples of locoregional infections?
cellulitis
lymphangitis
aggressive soft tissue infection
What are the types of surgical infections?
Soft tissue infections
Body cavity infections
Hospital acquired infections
What is significant about body cavity infections?
Usually iatrogenic (surgery), hard to see, no outward wound
Dehiscence
A surgical complication in which a wound breaks open along surgical suture. Risk factors are age, diabetes, obesity, poor knotting or grabbing of stitches, and trauma to the wound after surgery.
Evisceration
fascia falls apart, gut falls out of abdomen, surgical issue
Cellulitis
A diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin.
Gangrene
A serious and potentially life-threatening condition that arises when a considerable mass of body tissue dies after an injury, infection or ischemia, will not be treated with antibiolics since no blood flow goes to dead tissue
Abscess
A collection of pus in a newly formed cavity in any part of the body that is accompanied by swelling and inflammation.
Bacteremia
The presence of viable bacteria in the circulating blood that may or may not have any clinical significance;
Sepsis
response to infection, manifests as an increase in HR and a decrease in BP with a change in mental status
Cellulitis Treatment
Drainage of focal source, antibiotics, local wound care and control of complicating factors.
The underlying source of infection has to be removed
If abscess or necrotic tissue, cath and treat with antibiotics
Abscess Treaatment
Most commonly inappropriatley treated; many just give antibiotics BUT if there is pus you have to get it out!
Need to drain with a proper incision and then close it up from the bottom to avoid reformation
Abx not indicated for a straight forward abscess
complicating factors make a huge difference in how patient reacts to treatment
Necrotizing Fascitis
Flesh eating bacteria that spreads quickly along fascial planes with in minutes to hours
How do you treat necrotizing fascitis?
Have to treat aggressively, 1st surgical debridement. May have to amputate
Make a wide surgical debridement and treat with broad spectrum antibiotics, supportive care
May need serial debridements
Risk factors for a UTI
Instrument- foley (most common cause)
Elderly or debilitated
Pregnant
Urologic abnormalities
Treatment of a UTI
Antibiotics, early catheter removal and evaluate for complicating factors
Pneumonia- Hospital Acquired
Inhibition of normal cough reflex, can be due to anesthesia, narcotics, pain, ET intubation
Pt presents with fever, dyspnea, etc
How do you diagnose a patient with HA pneumonia?
No one thing:
elevated WBC, excess fluid accumulates in the lung bases (atelectasis), decrease in breath sounds, CXR findings, Hypoxia
What is a common cause of HA pneumonia?
Ventilators- bacteria grows in the lines
What is the treatment for HA pneumonia?
Antibiotics and breathing support
How do we prevent HA pneumonia?
early extubation, incentive spirometry/chest PT, OOB, oropharyngeal decontamination w/topical abx, limit narcotics
Intravenous catheter related infections
central venous lines vs peripheral IV lines
microorganisms from skin follow catheter into bloodstream
Main causative agents of IV cath related infections?
S. aureus and S. epidermis
What are the risks of IV cath related infections?
duration of cath number of cath manipulations violations of aseptic technique multi-lumen caths nontransparent bandages
How do we diagnose IV cath related infections?
frank pus around cath site
cellulitis around cath insertion
culture of blood from cath
How do we treat IV cath related infections?
remove cath, culture blood, cath free break, ABX, reinsert new cath
Surgical infections prevention includes:
good surgical technique
antibiotic prophylaxis
Good surgical technique
gentle traction, hemostasis, removal of devitalized tissue, no dead space, irrigation, monofilament vs braided suture, no tension and closed suction
Antibiotic prophylaxis
eradicate/retard growth of endogenous organisms
must be w/in 1 hr window prior to incision time
Cefazolin- most clean procedures
What antibiotic prophylaxis do you use in bowel surgery?
Cefazolin/metronidazole OR cefotetan
What antibiotic prophylaxis do you use in an appendectomy or biliary tract surgery?
Timentin
What antibiotic prophylaxis do you use for a penicillin allergy?
Clindamycin or Levofloxacin
What antibiotic prophylaxis do you use for in-patients?
Vancomycin
Where else do we use vancomycin?
prevention of MRSA
prosthtic valves and vascular grafts
History of broad spectrum antibiotic therapy
preoperative study longer than 1 week in the hospital
With the removal of hair, what does shaving increase?
SSI
How do we prevent this with hair removal?
Remove just prior to incision
use clippers or creams
What do we do if our patient develops hyperglycemia?
Tight glucose control below 150
continuous iv insulin decrease SSI and better than SQ
What is perioperative normothermia? And how do we prevent it?
vasoconstrictibe response leading to skin ischemia
a temperature above 36.5 C reduces the risk of a SSI
What is a SSI?
Surgical site of infection- infections related to the operative procedure that occur near or at the surgical incision w/in 30 days of a year if an implant is left
What are the top two most common nosocomial infections?
UTIs
SSIs
What is the breakdown of incidence of SSIs in non-teaching vs teaching hospitals?
non: 4.6
small teaching: 6.4
large teaching: 8.2
What classifies an incisional deep SSI?
Surgical site of infection w/in 30 days of a year if an implant is left, that involves deep soft tissues, fascia, and muscle and at least 1:
purulent drainagge
fever >38C, spontaneous or intentional wound opening, pain and localized tenderness
visual, radiological or histological evidence of an abscess
surgeons diagnosis
What classifies an organ/space SSI?
Surgical site of infection w/in 30 days of a year if an implant is left, that involves any part of the anatomy list that was manipulated and at least 1:
purulent drainage from the rgan/space
positive culture
visual, radiological or histological evidence of organ/space
surgeons diagnosis
What are the procedure types and their corresponding degrees of contamination?
clean- <3% infection rate
clean contaminated- 1-3% infection rate
contaminated - 6.4-15.2% infection rate
dirty- up to 40% infection rate
Clean
a surgical procedure with prepped skin not infected no pre existing skin inflammatioin no resp, GI or GU tract involved primary closure
What are organisms that can cause an infection in a clean procedure?
S. aureus and S. epidermis
What are examples of a clean procedure?
hernia, thyroidectomy, vagotomy, neurosurgery
Clean-contaminated
A surgery involving the resp, GI or GU tract
mechanical and antibacterial preparation
no evidence of active infection
minor sterile technique errors
What are organisms that can cause an infection in a clean-contaminated procedure?
endogenous flora
What are examples of a clean-contaminated procedure?
cholecystectomy, appendectomy, colonic resection, adenoidectomy
Contaminated
involves a surgery with an acute non-purulent inflammation traumatic open wound major failure of sterile technique significant GI leak (colonic, biliary) secondary or delayed closure
What are organisms that can cause an infection in contaminated procedure?
endogenous flora
What are examples of a contaminated procedure?
gangrenous cholecystitis, enterectomy
Dirty
a surgery that involves an old traumatic wound (except in the face) >6hr necrotic or infected wound hollow organ perforation active infection delayed closure
What are organisms that can cause an infection in a dirty procedure?
mixed
What are examples of a dirty procedure?
perforated abscess, perforated diverticulitis, infected mesh
What are surgical management techniques in the acute care setting?
resuscitate
open wound
obtain cultures from deeper wound
antibiotic therapy
What are surgical management techniques in the long-term care setting?
improve patient condition
dry vs moist dressing changes
wound VAC
What are the classifications of wounds by color?
pink red yellow green black
What is a red classification?
granulated
What is a pink classification?
epithelialized
What is a yellow classification?
needs debridement
What is a green classification?
infection/Pseudomonas
What is a black classification?
necrosis
What classification is the ultimate goal in wound care?
granulated
What are side effects of dry dressing changes?
contact dermatitis and skin damage
What are side effects of moist therapy?
bleeding
hypergranulation
skin maceration
allergic reactions
What are types of moist therapy?
opsite/tegaderm hydrocolloids, hydropolymers, hydrocellular hydrogels calcium/collagen alginates activated charcoal/silver alginates collagenase
What is a VAC?
vacuum assisted closure
Emphyema
A collection of pus within a naturally existing anatomical cavity, such as the lung pleura.
Septicemia
Septicemia is bacteria in the blood that often occurs with severe infections and may be life-threatening.
