Surgical Infection, C27 P170-180 Flashcards
What are the classic signs/ symptoms of inflammation/ infection?
P170
Tumor (mass = swelling/edema)
Calor (heat)
Dolor (pain)
Rubor (redness = erythema)
Define:
Bacteremia
P170
Bacteria in the blood
Define:
SIRS
P170
Systemic Inflammatory Response Syndrome (fever, tachycardia, tachypnea, leukocytosis)
Define:
Sepsis
P170
Documented infection and SIRS
Define:
Septic shock
P170
Sepsis and hypotension
Define:
Cellulitis
P170
Blanching erythema from superficial
dermal/epidermal infection (usually strep
more than staph)
Define:
Abscess
P170
Collection of pus within a cavity
Define:
Superinfection
P170
New infection arising while a patient is
receiving antibiotics for the original infection at a different site (e.g., C. difficile colitis)
Define:
Nosocomial infection
P170
Infection originating in the hospital
Define:
Empiric
P170
Use of antibiotic based on previous sensitivity information or previous experience awaiting culture results in an established infection
Define:
Prophylactic
P170
Antibiotics used to prevent an infection
What is the most common nosocomial infection?
P170
Urinary tract infection (UTI)
What is the most common nosocomial infection causing death?
P170
Respiratory tract infection (pneumonia)
URINARY TRACT INFECTION (UTI)
What diagnostic tests are used?
P171
Urinalysis, culture, urine microscopy for WBC
URINARY TRACT INFECTION (UTI)
What constitutes a POSITIVE urine analysis?
P171
Positive nitrite (from bacteria)
Positive leukocyte esterase (from WBC)
>10 WBC/HPF
Presence of bacteria (supportive)
URINARY TRACT INFECTION (UTI)
What number of colonyforming units (CFU)
confirms the diagnosis of UTI?
P171
On urine culture, classically 100,000 or
105 CFU
URINARY TRACT INFECTION (UTI)
What are the common organisms?
P171
Escherichia coli, Klebsiella, Proteus
Enterococcus, Staphylococcus aureus
URINARY TRACT INFECTION (UTI)
What is the treatment?
P171
Antibiotics with gram-negative spectrum
(e.g., sulfamethoxazole/trimethoprim
[Bactrim™], gentamicin, ciprofloxacin,
aztreonam); check culture and sensitivity
URINARY TRACT INFECTION (UTI)
What is the treatment of bladder candidiasis?
P171
- Remove or change Foley catheter
- Administer systemic fluconazole or
amphotericin bladder washings
CENTRAL LINE INFECTIONS
What are the signs of a central line infection?
P171
Unexplained hyperglycemia, fever,
mental status change, hypotension,
tachycardia → shock, pus, and erythema
at central line site
CENTRAL LINE INFECTIONS
What is the most common cause of “catheter-related bloodstream infections”?
P171
Coagulase-negative staphylococcus (33%),
followed by enterococci, Staphylococcus
aureus, gram-negative rods
CENTRAL LINE INFECTIONS
When should central lines be changed?
P171
When they are infected; there is NO
advantage to changing them every 7 days
in nonburn patients
CENTRAL LINE INFECTIONS
What central line infusion increases the risk of
infection?
P171
Hyperal (TPN)
CENTRAL LINE INFECTIONS
What is the treatment for central line infection?
P172
- Remove central line (send for culture)
+/- IV antibiotics - Place NEW central line in a different site
CENTRAL LINE INFECTIONS
When should peripheral IV short angiocatheters be changed?
P172
Every 72 to 96 hours
WOUND INFECTION (SURGICAL SITE INFECTION)
What is it?
P172
Infection in an operative wound
WOUND INFECTION (SURGICAL SITE INFECTION) When do these infections arise? P172
Classically, PODs #5 to #7
WOUND INFECTION (SURGICAL SITE INFECTION)
What are the signs/symptoms?
P172
Pain at incision site, erythema, drainage,
induration, warm skin, fever
WOUND INFECTION (SURGICAL SITE INFECTION)
What is the treatment?
P172
Remove skin sutures/staples, rule out
fascial dehiscence, pack wound open, send
wound culture, administer antibiotics
WOUND INFECTION (SURGICAL SITE INFECTION)
What are the most common bacteria found in postoperative wound infections?
P172
Staphylococcus aureus (20%) Escherichia coli (10%) Enterococcus (10%) Other causes: Staphylococcus epidermidis, Pseudomonas, anaerobes, other gram-negative organisms, Streptococcus
WOUND INFECTION (SURGICAL SITE INFECTION)
Which bacteria cause fever and wound infection in the first 24 hours after surgery?
P172
- Streptococcus
- Clostridium
(bronze-brown weeping tender wound)
CLASSIFICATION OF OPERATIVE WOUNDS
What is a “clean” wound?
P172
Elective, nontraumatic wound without acute inflammation; usually closed primarily without the use of drains
CLASSIFICATION OF OPERATIVE WOUNDS
What is the infection rate of a clean wound?
P172
< 1.5%
CLASSIFICATION OF OPERATIVE WOUNDS
What is a clean-contaminated wound?
P173
Operation on the GI or respiratory tract
without unusual contamination or entry
into the biliary or urinary tract
CLASSIFICATION OF OPERATIVE WOUNDS
Without infection present, what is the infection rate of a clean-contaminated wound?
P173
< 3%
CLASSIFICATION OF OPERATIVE WOUNDS
What is a contaminated wound?
P173
Acute inflammation, traumatic wound,
GI tract spillage, or a major break in sterile technique
CLASSIFICATION OF OPERATIVE WOUNDS
What is the infection rate of a contaminated wound?
P173
≈5%
CLASSIFICATION OF OPERATIVE WOUNDS
What is a dirty wound?
P173
Pus present, perforated viscus, or dirty
traumatic wound
CLASSIFICATION OF OPERATIVE WOUNDS
What is the infection rate of a dirty wound?
P173
≈33%
CLASSIFICATION OF OPERATIVE WOUNDS
What are the possible complications of wound
infections?
P173
Fistula, sinus tracts, sepsis, abscess,
suppressed wound healing, superinfection
(i.e., a new infection that develops during
antibiotic treatment for the original infection), hernia
CLASSIFICATION OF OPERATIVE WOUNDS
What factors influence the development of infections?
P173
- Foreign body (e.g., suture, drains, grafts)
- Decreased blood flow (poor delivery of PMNs
and antibiotics) - Strangulation of tissues with excessively tight
sutures - Necrotic tissue or excessive local tissue
destruction (e.g., too much Bovie) - Long operations (2 hrs)
- Hypothermia in O.R.
- Hematomas or seromas
- Dead space that prevents the delivery of
phagocytic cells to bacterial foci - Poor approximation of tissues
CLASSIFICATION OF OPERATIVE WOUNDS
What patient factors influence the development
of infections?
P173
Uremia Hypovolemic shock Vascular occlusive states Advanced age Distant area of infection
CLASSIFICATION OF OPERATIVE WOUNDS
What are examples of an immunosuppressed state?
P174
Immunosuppressant treatment Chemotherapy Systemic malignancy Trauma or burn injury Diabetes mellitus Obesity Malnutrition AIDS Uremia
CLASSIFICATION OF OPERATIVE WOUNDS
Which lab tests are indicated?
P174
CBC: leukocytosis or leukopenia (as an abscess may act as a WBC sink), blood cultures, imaging studies (e.g., CT scan to locate an abscess)
CLASSIFICATION OF OPERATIVE WOUNDS
What is the treatment?
P174
Incision and drainage—an abscess must be
drained (Note: fluctuation is a sign of a
subcutaneous abscess; most abdominal
abscesses are drained percutaneously)
Antibiotics for deep abscesses
CLASSIFICATION OF OPERATIVE WOUNDS
What are the indications for antibiotics after drainage of a subcutaneous abscess?
P174
Diabetes mellitus, surrounding cellulitis,
prosthetic heart valve, or an immunocompromised state
PERITONEAL ABSCESS
What is a peritoneal abscess?
P174
Abscess within the peritoneal cavity
PERITONEAL ABSCESS
What are the causes?
P174
Postoperative status after a laparotomy,
ruptured appendix, peritonitis, any
inflammatory intraperitoneal process,
anastomotic leak
PERITONEAL ABSCESS
What are the sites of occurrence?
P174
Pelvis, Morison’s pouch, subphrenic,
paracolic gutters, periappendiceal, lesser sac
PERITONEAL ABSCESS
What are the signs/symptoms?
P174
Fever (classically spiking), abdominal pain, mass
PERITONEAL ABSCESS
How is the diagnosis made?
P174
Abdominal CT scan (or ultrasound)
PERITONEAL ABSCESS
When should an abdominal CT scan be obtained looking for a postoperative abscess?
P175
After POD #7 (otherwise, abscess will not be “organized” and will look like a normal postoperative fluid collection)
PERITONEAL ABSCESS
What CT scan findings are
associated with abscess?
P175
Fluid collection with fibrous rind, gas in
fluid collection
PERITONEAL ABSCESS
What is the treatment?
P175
Percutaneous CT–guided drainage
PERITONEAL ABSCESS
What is an option for
drainage of pelvic abscess?
P175
Transrectal drainage (or transvaginal)
PERITONEAL ABSCESS
All abscesses must be
drained except which type?
P175
Amebiasis!
NECROTIZING FASCIITIS
What is it?
P175
Bacterial infection of underlying fascia
spreads rapidly along fascial planes
NECROTIZING FASCIITIS
What are the causative agents?
P175
Classically, group A Streptococcus
pyogenes, but most often polymicrobial
with anaerobes/gram-negative organisms
NECROTIZING FASCIITIS
What are the signs/symptoms?
P175
Fever, pain, crepitus, cellulitis, skin discoloration, blood blisters (hemorrhagic bullae), weeping skin, increased WBCs, subcutaneous air on x-ray, septic shock
NECROTIZING FASCIITIS
What is the treatment?
P175
IVF, IV antibiotics and aggressive early
extensive surgical débridement, cultures,
tetanus prophylaxis
NECROTIZING FASCIITIS
Is necrotizing fasciitis an
emergency?
P175
YES, patients must be taken to the O.R.
immediately!
CLOSTRIDIAL MYOSITIS
What is it?
P175
Clostridial muscle infection
CLOSTRIDIAL MYOSITIS
What is another name for
this condition?
P175
Gas gangrene
CLOSTRIDIAL MYOSITIS
What is the most common
causative organism?
P176
Clostridium perfringens
CLOSTRIDIAL MYOSITIS
What are the signs/symptoms?
P176
Pain, fever, shock, crepitus, foul-smelling
brown fluid, subcutaneous air on x-ray
CLOSTRIDIAL MYOSITIS
What is the treatment?
P176
IV antibiotics, aggressive surgical
débridement of involved muscle, tetanus
prophylaxis
SUPPURATIVE HIDRADENITIS
What is it?
P176
Infection/abscess formation in apocrine
sweat glands
SUPPURATIVE HIDRADENITIS
In what three locations does
it occur?
P176
Perineum/buttocks, inguinal area, axillae
site of apocrine glands
SUPPURATIVE HIDRADENITIS
What is the most common
causative organism?
P176
Staphylococcus aureus
SUPPURATIVE HIDRADENITIS
What is the treatment?
P176
Antibiotics
Incision and drainage (excision of skin
with glands for chronic infections)
PSEUDOMEMBRANOUS COLITIS
What is it?
P176
Antibiotic-induced colonic overgrowth
of C. difficile, secondary to loss of
competitive nonpathogenic bacteria that
comprise the normal colonic flora
(Note: it can be caused by any antibiotic,
but especially penicillins, cephalosporins,
and clindamycin)
PSEUDOMEMBRANOUS COLITIS
What are the signs/symptoms?
P176
Diarrhea (bloody in 10% of patients),
± fever, ± increased WBCs, ± abdominal
cramps, ± abdominal distention
PSEUDOMEMBRANOUS COLITIS
What causes the diarrhea?
P176
Exotoxin released by C. difficile
PSEUDOMEMBRANOUS COLITIS
How is the diagnosis made?
P176
Assay stool for exotoxin titer; fecal leukocytes may or may not be present; on colonoscopy you may see an exudate that looks like a membrane (hence, “pseudomembranous”)
PSEUDOMEMBRANOUS COLITIS
What is the treatment?
P177
PO metronidazole (Flagyl®; 93% sensitive)
or PO vancomycin (97% sensitive);
discontinuation of causative agent
Never give antiperistaltics
PROPHYLACTIC ANTIBIOTICS
What are the indications for
prophylactic IV antibiotics?
P177
Accidental wounds with heavy contamination and tissue damage Accidental wounds requiring surgical therapy that has had to be delayed Prosthetic heart valve or valve disease Penetrating injuries of hollow intra-abdominal organs Large bowel resections and anastomosis Cardiovascular surgery with the use of a prosthesis/vascular procedures Patients with open fractures (start in ER) Traumatic wounds occurring > 8 hours prior to medical attention
PROPHYLACTIC ANTIBIOTICS What must a prophylactic antibiotic cover for procedures on the large bowel/abdominal trauma/appendicitis? P177
Anaerobes
PROPHYLACTIC ANTIBIOTICS What commonly used antibiotics offer anaerobic coverage? P177
Cefoxitin (Mefoxin®), clindamycin,
metronidazole (Flagyl®), cefotetan,
ampicillin-sulbactam (Unasyn®), Zosyn™,
Timentin®, Imipenem®
PROPHYLACTIC ANTIBIOTICS What antibiotic is used prophylactically for vascular surgery? P177
Ancef (if patient is significantly allergic
to PCN—hives/swelling/shortness of
breath—then erythromycin or
clindamycin are options)
PROPHYLACTIC ANTIBIOTICS When is the appropriate time to administer prophylactic antibiotics? P177
Must be in adequate levels in the blood
stream prior to surgical incision!
PAROTITIS
What is it?
P178
Infection of the parotid gland
PAROTITIS
What is the most common
causative organism?
P178
Staphylococcus
PAROTITIS
What are the associated risk
factors?
P178
Age older than 65 years, malnutrition,
poor oral hygiene, presence of NG tube,
NPO, dehydration
PAROTITIS
What is the most common
time of occurrence?
P178
Usually 2 weeks postoperative
PAROTITIS
What are the signs?
P178
Hot, red, tender parotid gland and
increased WBCs
PAROTITIS
What is the treatment?
P178
Antibiotics, operative drainage as
necessary
MISCELLANEOUS
What is a “stitch” abscess?
P178
Subcutaneous abscess centered around a
subcutaneous stitch, which is a “foreign
body”; treat with drainage and stitch
removal
MISCELLANEOUS
Which bacteria can be found
in the stool (colon)?
P178
Anaerobic—Bacteroides fragilis
Aerobic—Escherichia coli
MISCELLANEOUS
Which bacteria are found in
infections from human bites?
P178
Streptococcus viridans, S. aureus,
Peptococcus, Eikenella (treat with
Augmentin®)
MISCELLANEOUS
What are the most common
ICU pneumonia bacteria?
P178
Gram-negative organisms
MISCELLANEOUS
What is Fournier’s
gangrene?
P178
Perineal infection starting classically in
the scrotum in patients with diabetes;
treat with triple antibiotics and wide
débridement—a surgical emergency!
MISCELLANEOUS Does adding antibiotics to peritoneal lavage solution lower the risk of abscess formation? P178
No (“Dilution is the solution to
pollution”)
MISCELLANEOUS What is the classic finding associated with a Pseudomonas infection? P179
Green exudate and “fruity” smell
MISCELLANEOUS What are the classic antibiotics for “triple” antibiotics? P179
Ampicillin, gentamycin, and
metronidazole (Flagyl®)
MISCELLANEOUS
Which antibiotic is used to
treat amoeba infection?
P179
Metronidazole (Flagyl®)
MISCELLANEOUS Which bacteria commonly infect prosthetic material and central lines? P179
Staphylococcus epidermis
MISCELLANEOUS
What is the antibiotic of
choice for Actinomyces?
P179
Penicillin G (exquisitely sensitive)
MISCELLANEOUS
What is a furuncle?
P179
Staphylococcal abscess that forms in a hair follicle (Think: Follicle = Furuncle)
MISCELLANEOUS
What is a carbuncle?
P179
Subcutaneous staphylococcal abscess
(usually an extension of a furuncle), most
commonly seen in patients with diabetes
(i.e., rule out diabetes)
MISCELLANEOUS
What is a felon?
P179
Infection of the finger pad
Think: Felon = Finger printing
MISCELLANEOUS
What microscopic finding is
associated with Actinomyces?
P179
Sulfur granules
MISCELLANEOUS
What organism causes
tetanus?
P179
Clostridium tetani
MISCELLANEOUS
What are the signs of
tetanus?
P179
Lockjaw, muscle spasm, laryngospasm,
convulsions, respiratory failure
MISCELLANEOUS What are the appropriate prophylactic steps in tetanus-prone (dirty) injury in the following patients:
Three previous
immunizations?
P179
None (tetanus toxoid only if >5 years
since last toxoid)
MISCELLANEOUS What are the appropriate prophylactic steps in tetanus-prone (dirty) injury in the following patients:
Two previous
immunizations?
P180
Tetanus toxoid
MISCELLANEOUS What are the appropriate prophylactic steps in tetanus-prone (dirty) injury in the following patients:
One previous
immunization?
P180
Tetanus immunoglobulin IM and tetanus toxoid IM (at different sites!)
MISCELLANEOUS What are the appropriate prophylactic steps in tetanus-prone (dirty) injury in the following patients:
No previous
immunizations?
P180
Tetanus immunoglobulin IM and tetanus toxoid IM (at different sites!)
MISCELLANEOUS
What is Fitz-Hugh-Curtis
syndrome?
P180
Right upper quadrant pain from
gonococcal perihepatitis in women
