05 Infection Flashcards
If ascites culture is poly-microbial, what do you need to rule out if the patient is not getting better on antibiotics?
rule out intra-abdominal source (bowel perf)
what causes lower and upper GI bleeds in HIV pts?
lower: CMV, bacterial, HSV. upper: Kaposi’s sarcoma, lymphoma.
what is treatment for cat/dog/human bite?
broad-spectrum (augmentin)
what drug helps prevent development of cirrhosis in hep C pts?
interferon
what are the CD4 count ranges for normal, symptomatic, and opportunistic infections to occur?
800-1200 normal
300-400 symptomatic disease
<200 opportunistic infection
what are CT findings in sinusitis?
air-fluid levels in sinus
what can human bites do to joints?
cause permanent joint injury from eikenella
what is treatment for acute septic arthritis?
drainage (first), 3rd gen cephalosporin and vanc until cultures show organism
what is the treatment for brown recluse spider bite?
dapsone initially. may need resection of area and skin graft for large ulcers later
what is another name for unasyn?
ampicillin/sulfbactam
what type of lymphoma most commonly affects HIV pts?
non-hodgkin’s (B cell)
what bacteria causes impetigo, erysipelas, cellulitis, and folliculitis?
staph and strep most common
is fulminant hepatic failure common w/ hep C?
no. rare.
how do oyu treat peritoneal dialysis catheter infection if you find fecal products in peritoneal fluid?
laparotomy to find perforation
what is treatment for diabetic foot infectinos?
broad spectrum antibiotics (unasyn)
what are the bugs for acute septic arthritis?
gonococcus, staph, H. influenzae, strep
is lower or upper GI bleed more common in HIV pts?
lower
what is a carbuncle?
a multiloculated furuncle
what are risk factors for sinusitis?
nasoenteric tubes, intubation, pts with severe facial fxs
what bugs are involved in peritoneal dialysis catheter infections?
s. aureus and s. epi most common
what is the treatment for lymphoma in HIV pts?
chemotherapy usual; may need surgery w significant bleeding or perforation
what % of population is infected with hep C?
1-2%
what is treatment for peritoneal dialysis catheter infection?
intraperitoneal vanc and gent. increase dwell time and intraperitoneal heparin can help. remove catheter for peritonitis that lasts >4-5d.
what bugs cause cat/dog/human bite infections?
polymicrobial
which organ is most infected in lymphoma in HIV pts?
stomach, followed by rectum
is hepatitis C common with blood transfusion?
no. rare. 0.0001%/unit
what is treatment of a furuncle?
drainage +/- antibiotics
what is treatment for cat/dog/human bites?
eikenella in human bites. pasteurella in cat and dog bites
what is treatment for sinusitis?
broad-spec abx, rare to have to tap sinus percutaneously for systemic illness
how often to hep C pts get chronic infection, cirrhosis, and hepatocellular carcinoma?
chronic in 60%, cirrhosis in 15%, hepatocellular carcinoma in 1-5%.
what is another name for augmentin?
amoxicillin/clavulanate
what bugs cause sinusitis?
polymicrobial
what do you do if you grow fungus, TB, or pseudomonas from peritoneal dialysis catheter?
remove peritoneal dialysis catheter
what bugs cause diabetic foot infections?
mixed staph, strep, GNRs, anaerobes
what is a furuncle and what bug?
it is a boil caused by s. epidermidis or s. aureus
what causes fournier’s gangrene?
Next organisms (GPC’s, GNRs, anaerobes)
what is the 2nd most common reason for laparotomy?
neoplastic disease
Is actinomyces a true fungus?
no
what is the most common intestinal manifestation of AIDS? how does it present?
CMV colitis. Presents w/ pain, bleeding, or perforation
What are the signs and symptoms of c. perfringens infection?
Pain out of proportion to exam, may not show skin signs with deep infection. commonly myonecrosis and gas gangrene.
what are the different ways you can get HIV, and what is the risk of contracting?
HIV blood transfusion (70%), infant from positive mom (30%), needle stick from positive pt (0.3%), mucous membrane exposure (0.1%)
what is the most common opportunistic infection in HIV pts?
CMV
Is Nocardia a true fungus?
no
What is the treatment for aspergillosis?
Voriconazole for severe infections
What is the treatment for SBP?
Ceftriaxone or other third-generation cephalosporin
what is the most common neoplasm in AIDS pts?
kaposi’s sarcoma
What is the treatment for Cryptococcus?
Liposomal amphotericin for severe infections
What are the findings of histoplasmosis?
Pulmonary symptoms are usual, Mississippi and Ohio River valleys
What is the treatment for necrotizing fasciitis?
Early debridement, high-dose penicillin, broad spectrum if poly-organismal
What is the treatment for histoplasmosis?
Liposomal amphotericin for severe infections
What are the findings of Cryptococcus and who gets it?
CNS symptoms most common, usually in AIDS patients
what are the most common bugs in secondary bacterial peritonitis?
B. fragilis, e. coli, enterococcus
when should antivirals be given after exposure?
1-2hrs
What are the risk factors for fournier’s gangrene?
Diabetes mellitus and immunocompromised state
What causes spontaneous bacterial peritonitis?
Decreased host defenses (intrahepatic shunting, impaired bactericidal activity in ascites), not due to transmucosal migration
What is the treatment for actinomyces infection?
Drainage and penicillin G
What is a major risk factor for spontaneous bacterial peritonitis?
low protein (<1 g/dL) in peritoneal fluid
What bacteria causes necrotizing fasciitis?
beta-hemolytic group A strep, can be poly organismal
What are fluid cultures in SBP?
negative in many cases
What are the findings of coccidioidomycosis? where in the USA is it located?
pulmonary sx, southwest.
how many weeks after exposure does seroconversion occur?
6-12 weeks
What toxin does C. perfringens have?
alpha toxin
what is the treatment for fournier’s gangrene?
early debridement, preserve testicles, antibiotics
What are the findings in necrotizing tissue infection?
Pain out of proportion to skin findings wbc's greater than 20 thin grey drainage blistering/necrosis induration and edema crepitus or soft tissue gas on XR can be septic
What are the findings of nocardia infection?
Pulmonary and CNS symptoms most common
What is the treatment for c. perfringens infections?
Early debridement, high-dose penicillin
what is treatment for secondary bacterial peritonitis?
usually need laparotomy to find source
what is the treatment for coccidioidomycosis?
liposomal amphotericin for severe infections.
what meds do you use to decrease seroconversion after exposure?
AZT (zidovudine, reverse transcriptase inhibitor), and ritonavir (protease inhibitor)
is surgery needed for kaposi’s sarcoma?
No
what does the gram stain show in c. perf infections?
GPRs without WBCs.
How many PMNs in ascitic fluid is diagnostic of SBP?
> 500cells/cc
What bacteria are present in spontaneous bacterial peritonitis?
monobacterial (50% e.coli, 30% strep, 10% kleb)
what causes necrotizing fasciitis?
beta-hemolytic group A strep has exotoxin
What is the treatment for Candida infection?
Fluconazole, anidulafungin for severe infections
What are the findings in necrotizing fasciitis?
Overlying skin may be pale red and progress to purple with blister or bullae development, overlying skin can look normal in the early stages, thin, gray, foul-smelling drainage; crepitus
In a patient with active infection, can you give liver transplantation?
No
What symptoms does Actinomyces cause?
pulmonary symptoms most common; can cost tortuous abscesses in cervical, thoracic, and abdominal areas.
What is a good antibiotic for prophylaxis for SBP?
fluoroquinolones (norfloxacin)
When is a fungal infection real?
Positive blood cultures, two sites other than blood, one site with severe symptoms, endophthalmitis, or patients on prolonged bacterial antibiotics with failure to improve
What is the treatment for nocardia infection?
Drainage and sulfonamides (bactrim)
what is the most common cause for laparotomy in HIV pts?
opportunistic infections
what is fournier’s gangrene?
Severe infection in perineal and scrotal region
How does the patient get c. perfringens infection?
Necrotic tissue decreases oxidation-reduction potential, setting up environment for bacteria
When do you know you need a new central line and that this line is currently infected?
> 15 colony forming units
What percent of abdominal abscesses have both anaerobic and aerobic bacteria?
80%
What percentage of clean surgeries get infected? And what is an example of the surgery?
2%, hernia
When you have to give antibiotics for abscesses?
Give antibiotics for patients with diabetes, cellulitis, clinical signs of sepsis, fever, elevated WBC, or who have bioprosthetic hardware
what does endotoxin do?
endotoxin triggers release of TNF-a from macrophages, activates, complement, and activates coagulation cascade.
What is the definition of line infection?
> 15 CFU
list the parts of GI tract with types of bacteria.
stomach: sterile, some GPCs, some yeast.
proximal small bowel: 10^5 bacteria, mostly GPC.
distal small bowel: 10^7 bacteria, GPC, GPR, GNR.
colon: 10^11 bacteria, almost all anaerobes, some GNRs, GPCs
what is the most common organism in the GI tract?
anaerobes, 1000:1
what causes c.diff colitis?
c.diff toxin
What percentage of gross contamination surgeries get infected? What are examples of these surgeries?
30%, abscess
What is the most common anaerobe in the colon?
bacteroides fragilis
How do you treat abscess?
drainage
What are the risk factors for wound infection?
Long operations, hematoma or seroma around that formation, advanced age, chronic disease, malnutrition, immunosuppressive drugs.
What happens just before the patient becomes clinically septic?
hyperglycemia
When do necrotizing soft tissue infections present?
Very quickly after surgical procedures, within hours
What bacteria are the most common causes of line infection?
1 s. epi, #2 s. aureus, #3. yeast
What is the most common gram-negative rod in surgical wound infections?
E. coli
what is nosocomial pneumonia related to?
length of time on vent, aspiration from duodenum thought to have role
What is the most common infection in surgery patients?
Urinary tract infection. The most common risk factor is urinary catheters, commonly e. coli
What percentage of contaminated surgeries get infected? What are examples of these surgeries?
5 to 10%, gunshot wound to colon with repair
What is the optimal glucose level in the septic patient?
100-120 mg/dL
What endotoxin is released from gram-negative sepsis?
lipopolysaccharide lipid A
How many bacteria are needed for wound infection?
> 10^5
What is exoslime?
released by staph species, a exopolysaccharide matrix
What are the time periods for fever? What are the sources of infection?
Atelectasis: 2d
UTI: 2-5d.
Wound: >5d
What are the risk factors for necrotizing soft tissue infection?
Immunocompromised, diabetes mellitus, patients who have poor blood supply
What should you do if you’re worried about line infection?
Pull the central line in, place IVs if central lines not needed
Which bacteria can cause infection within hours postoperatively? How does it do it?
c. perfringens and beta-hemolytic strep can present within hours postop by producing exotoxins
When should your central line be moved to a new site?
Site shows signs of infection, >15 CFU
What is the most common anaerobe in surgical wound infections?
B. fragilis
What percent of abdominal abscesses have anaerobes?
90%
What bacteria cause necrotizing soft tissue infection?
beta hemolytic strep (group A), C. perfringens, or mixed organisms.
what is the treatment for c. diff colitis?
oral: vanc or flagyl. IV: flagyl. lactobacillus can help. stop other antibiotics or change them
What is the line salvage rate with anabiotics?
50%, less with yeast infection
What are the most common organisms in ICU pneumonia?
1 s. aureus, #2 PSA. GNRs are #1 class of organisms in ICU PNA
if there is b. fragilis in wound, what does it imply?
traslocation from gut and if there is recovery from tissue, there is likely necrosis or abscess (b. fragilis only grows in low redox state)
What percent of clean-contaminated surgeries get infected? What are some examples of surgeries?
3 to 5%, elective colon resection with prepped bowel.
What happens to insulin and glucose in early gram-negative sepsis?
dec insulin, inc glucose (impaired utilization)
how long do you give postop prophylactic antibiotics? Which type of surgery is there an exception?
Stop within 24 hours of and operation time, except cardiac, which is Stotzer than 48 hours of an operation time
what is the most common cause of immune deficiency?
malnutrition
What is the most common cause of gram-negative sepsis?
e.coli
Of Staphylococcus aureus and staphylococcus epidermidis, which are coagulase positive in which I coagulase negative?
s. aureus is coag+, s. epi is coag-
What is the most common organism in surgical wound infections?
Staphylococcus aureus
What kind of line is at highest risk for infection?
femoral lines
When do abscesses occur after operation?
7-10d
What surgical infections occur within 48 hours of procedure?
Injury it’s a bell with leak, invasive soft tissue infection.
What happens to an slim and glucose in late gram-negative sepsis?
inc insulin, inc glucose secondary to insulin resistance
What are the different types of contaminations during surgery?
Clean, clean contaminated, contaminated, gross contamination
What is the most common aerobic bacteria in the colon?
e. coli
What is the leading cause of infectious death after surgery?
nosocomial pneumonia
