Download Surgical Infections

Surgical Infections
Joseph Castellano M.D.
9/29/09
Definition
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Infections that require surgical intervention to
resolve completely
Infections that develop as a complication of
surgery
Caused by the invasion, resident, and
proliferation of pathogens such as bacteria,
viruses and fungi.
Outcomes of Microbial Invasion
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Eradication
Containment leads to abscess (furuncle,
carbuncle, hidradenitis suppurativa, intraabdominal abscesses)
Locoregional infection (cellulitis, soft tissue
infection, lymphangitis)
Systemic infection (bacteremia, fungemia)
Furuncle
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Cutaneous staph
abscesses
Bacterial colinization
begins in hair follicles
and can cause cellulitis
and abscess formation
Treatment with surgical
drainage if large,
antibiotics +/-
Carbuncles
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Cutaneous abscess that spreads through the
dermis into subcutaneous region
Common with diabetics
Treatment with I & D, antibiotics +/-
Intra-abdominal infection
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Primary microbial peritonitis
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Ascities, peritoneal dialysis
Tx: antibiotics
Secondary microbial peritonitis: contamination of the
peritoneal cavity due to perforation or severe
inflammation and infection of an intra-abdominal organ
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Appendicitis, diverticulitis, perforation, etc.
therapy requires source control to resect the diseased organ;
débridement of necrotic, infected tissue and debris; and
administration of antimicrobial agents directed against
aerobes and anaerobes
Intra-abdominal infection
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Patients in whom standard therapy fails develop
an intra-abdominal abscess, leakage from a
gastrointestinal anastomosis leading to
postoperative peritonitis, or tertiary (persistent)
peritonitis.
Intra-abdominal abscess: perc drain vs. surgical
intervention, short course of antibiotics
Organ Specific Infections
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Hepatic abscesses
80% pyogenic, 20% parasitic and fungal
 Pyogenic abscess treated with sampling and 4-6
weeks of antibiotics, larger abscesses may need perc
drain.
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Organ Specific Infections
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Pancreatic necrosis
Develops in 10-15% of patients who develop severe
hemorrhagic pancreatitis
 Sterile and Infected necrosis
 empiric antibiotic therapy with carbapenems or
fluoroquinolones that achieve high pancreatic tissue
levels reduce the incidence and severity of pancreatic
infection
 enteral feedings initiated early, using nasojejunal
feeding tubes – prevents translocation of bacteria
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Organ Specific Infections
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Secondary pancreatic infection
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Suspected in patients whose systemic inflammatory response
(fever, elevated WBC count, or organ dysfunction) fails to
resolve, or in those individuals who initially recuperate, only
to develop sepsis syndrome 2 to 3 weeks later
CT-guided aspiration or identification of gas within the
pancreas on CT scan, mandate operative intervention
50% mortality if no surgical intervention if infected necrosis
Lower mortality in sterile necrosis
Cellulitis
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Inflammation of the dermal and subcutaneous
tissues secondary to nonsuppurative bacterial
invasion.
Redness, edema, and localized tenderness
May infect the lymphatics leading to
lymphangitis
Treatment against Group A strep
Necrotizing Fasciitis
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Rapidly progressive, multiple organisms, invades fascial
planes
Causes vascular thrombosis as it progresses, resulting in
necrosis of the tissues involved.
Overlying skin may be normal
Hemorrhagic bullae may develop from edema; crepitus;
systemic toxicity
“dishwater gray” discharge with anaerobic infection
Group A strep, mixed anaerobes + coliforms, MRSA
Treatment is surgical debridement, send gram stain
Vanc, carbapenems, and Pen G
Surgical Site Infection
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38% of nosocomial infections, 2-5% of patients
Factors:
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Health of the patient
Operative technique
Timely administration of preoperative antibiotics
No benefit to antiseptic bath over other wash products
No benefit to barrier devices except gloves
Good surgical techniques: gentle traction, hemostasis,
removal of devitalized tissue, obliteration of dead space,
irrigation, wound closure without tension
Risk Factors
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Microorganism: Remote site infection, long term
care facility, duration of the procedure, wound
class, ICU patient, prior antibiotic therapy, preop
shaving, bacterial number, virulence, and
antimicrobial resistance
Local Wound: Surgical technique – Hematoma/
seroma, necrosis, sutures, drains, foreign bodies
Patient: Age, immunosuppression, steroids,
malignancy, obesity, diabetes, malnutrition, multiple
comorbidities, transfusions, cigarette smoking,
oxygen, temperature, glucose control
Risk Factors
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Drains:
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Should be omitted after hepatic, colonic, or rectal
resection with primary anastomosis and after
appendectomy for any stage of appendicitis
Should be used after esophageal resection and total
gastrectomy
Contamination increases with duration of operation
Electrocautery: pinpoint coagulation, dividing tissue
under tension decreases tissue destruction
Surgical Site Infection
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Difference is SSI based on hand hygiene? Hand
rubbing vs. hand scrubbing
Compliance 44% vs 28%
Wound classification
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Clean wounds were defined as uninfected operative wounds in which no
inflammation was encountered and the wound was closed primarily. By
definition, a viscus (respiratory, alimentary, genital, or urinary tract) was not
entered during a clean procedure.
Clean-contaminated wounds were defined as operative wounds in which a
viscus was entered under controlled conditions and without unusual
contamination.
Contaminated wounds included open, fresh accidental wounds, operations
with major breaks in sterile technique or gross spillage from a viscus. Wounds
in which acute, purulent inflammation was encountered also were included in
this category.
Dirty wounds were defined as old traumatic wounds with retained devitalized
tissue, foreign bodies, or fecal contamination or wounds that involve existing
clinical infection or perforated viscus.
Antibiotic Prophylaxis
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Timing: Percent of SSI for dose given early,
preoperative, perioperative, and postop are 3.8,
0.6, 1.4 and 3.3 respectively
Prophylaxis with cefazolin has been effective for
most clean procedures. Cefuroxime can be given
for thoracic and ortho procedures.
For procedures that might involve bowel
anaerobes, cefoxitin is more effective than
cefazolin.
ABX Recs
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Colon/Whipple: Bowel prep/oral prophylaxis/ IV prophylaxis
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Neomycin, Erythromycin, Cefoxitin
Cholecystectomy open or laparoscopic prophylaxis
recommended for pt age>60, previous biliary surgery, acute
symptoms, jaundice (benefit less clear with lap): cefoxitin or
unasyn
Uncomplicated appendectomy: cefoxitin or unasyn
Penetrating abdominal trauma: Cefoxitin or Unasyn – continue
post op for 24 hours
IHR: uncomplicated, no prophylaxis; complicated, cefoxitin
Mastectomy: no abx recommended
Vascular cases: Cefazolin
Other Recs
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Esophageal and gastroduodenal: Cefazolin
ERCP: routine abx prophylaxis does not reduce
sepsis/cholangitis
Repeat dosing: Procedure lasting more than 4 hours
or when major blood loss occurs
Continuation of Abx past 24 hours post op is not
recommended
Hair removal with clippers immediately preop
Preop or postop hyperglycemia increase risk of SSI
Perioperative normothermia
Postoperative Nosocomial
Infections
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UTI
Pneumonia
Bacteremic Episodes
Sepsis Syndrome
UTI
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Diagnosis should be considered with urinalysis
positive for WBCs, bacteria, or a positive leukocyte
esterase.
Confirmed with culture > 10K colonies in
symptomatic patient or > 100K colonies in
asymptomatic patient
Treatment with 10-14 days with a single antibiotic
that achieves high levels in the urine is appropriate
Remove catheter
Pneumonia
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High risk with prolonged mechanical ventilation
Frequently multi-resistant organisms
Diagnosis by Xray
BAL with gram stain and culture
Antibiotics based on local antibiogram with
beta-lactam, aminoglycoside or fluoroquinolone,
and vanc or linezolid.
Treat for 7-8 days
Bacteremic Episodes
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Indwelling catheters
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25% of catheters will become colonized, and 5% will be
associated with bacteremia
Prolonged insertion, insertion under emergency conditions,
manipulation under nonsterile conditions, and perhaps the
use of multilumen catheters increase the risk of infection.
Confirmed with blood culture from peripheral site and
catheter that grow same bacteria
Treatment is removal of catheter.
In patients with difficult access and grow low virulence bugs,
such as S. epidermidis, treatment with 14-21 days of
antibiotics is effective 50-60% of the time.
Sepsis Syndrome
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Empiric antimicrobial therapy, institution specific
Fluid rescucitation
Metabolic support
Site specific infection control
Appropriate therapy associated with two to three fold reduction in
mortality
Low dose steroid for patients with hypotension refractory to
vasopressors
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STIM test
Hydrocortisone 100mg/8hr vs. continuous infusion
Xigris associated with 6% reduction in mortality
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antithrombotic, profibrinolytic, and anti-inflammatory properties
Consider in patients with severe infection and at least one organ failing