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35 Cards in this Set
- Front
- Back
Important factors when differentiating Pneumonia Categories include:
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Environment of patient when infection occurred (Hospital verses community; Intensive care unit versus general patient unit)
Time when infection occurs (Especially important for nosocomial infection) Patient confounding factors [Other important disease states (ex. HIV, cancer, etc)] |
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what is the time frame/definition of HAP (hospital acquired pneumonia)?
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Pneumonia occurring 48 hours or more after admission, not incubating at time of admission
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what is the time frame/definition of ventilator-associated pneumonia (VAP)?
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Pneumonia that arises more that 48-72 hours after endotracheal intubation
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what is the time frame/definition of Health-care associated pneumonia (HCAP)?
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Includes patients:
-hospitalized within an acute care hospital for 2 plus days within 90 days of admission -residing in nursing home or long-term care facility prior to admission -who have received IV antibiotics, chemotherapy, or wound care with 30 days of admission -who attend a hospital or hemodialysis clinic |
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why is it important to differentiate place of infection?
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1. different microbiological pathogens
2. different therapy guidelines |
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what is the difference btwn microbiological pathogens in community vs. hospital acquired pneumonia?
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Community: Streptococcus, atypical bacteria
Hospitals: more resistant gram negative pathogens; Staphyloccocus aureus |
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what is the difference btwn therapy guidelines in community vs. hospital acquired pneumonia?
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Community: Streptococcus pneumoniae most important; less emphasis on gram-negative pathogens
Hospital: typically need to utilize more “big-gun” gram-negative antibiotics to deal with the possible pathogens seen |
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how is early onset of hospital acquired pneumonia defined?
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Occurring within 4 days of hospitalization
Patients who have received prior abx or who have been hospitalized within past 90 days should be treated similar to late-onset patients (even if hospitalized <5 days) |
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how is late onset of hospital acquired pneumonia defined?
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Occurring 5 or more days after hospitalization
Associated with increased presence of multi-drug resistant (MDR) pathogens Associated with higher crude mortality |
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what causes nosocomial pneumonia?
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Answer: Bacteria!!
Aerobic-gram-negative bacilli Gram-positive cocci Fungi and viruses are much less common pathogens |
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3 Factors associated with increased mortality associated with nosocomial pneumo?
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Bacteremia, especially with Pseudomonas aeruginosa or Acinetobacter species
Medical rather than surgical illness Treatment with ineffective or delayed antibiotic therapy! |
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non-MDR pathogens associated with nosocomial pneumo?
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Streptococcus pneumoniae
Haemophilus influenzae Methicillin-sensitive Staphylococcus aureus Antibiotic-sensitive enteric gram-negative bacilli -Escherichia coli -Klebsiella pneumoniae -Enterobacter species -Proteus species -Serratia marcescens |
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MDR pathogens associated with nosocomial pneump
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Gram-negatives:
Pseudomonas aeruginosa Extended spectrum B-lactamase producing gram negative rods (Klebsiella, Ecoli, Enterobacter, Serratia Acinetobacter species) Gram-positive Methicillin-resistant Staphyloccus aureus (MRSA) Other: Legionella pneumophila |
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Risk factors for MDR pathogens:
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JUST KNOW HOSPTALIZATION OF 5 DAYS or more*** (everything else is FYI)
Antimicrobial therapy in preceding 90 days Current hospitalization of *5 days* or more High frequency of antibiotic resistance in the community or in the specific hospital unit Presence of risk factors or HCAP: Hospitalization for 2 days or more in the preceding 90 days, Residence in a nursing home or extended care facility, Home infusion therapy (including antibiotics), Chronic dialysis within 30 days, Home wound care, Family member with multidrug-resistant pathogen, Immunosuppressive disease and/or therapy |
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what is the most common MDR gram-negative bacterial pathogen?
It is also: Very virulent organism (high mortality risk) Highly resistant (Intrinsic resistance to many antimicrobials, Capacity to develop resistance to all known classes of antibiotics, Resistance rates increasing within the U.S.) |
pseudomonas aeruginosa
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List the antibiotics that generally cover Pseudomonas aeruginosa
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Piperacillin/tazobactam
Ticarcillin/clavulanate Ceftazidime Cefepime Meropenem Imipenem-cilastatin Ciprofloxacin* Levofloxacin (750mg)* Tobramycin Gentamicin Amikacin Aztreonam |
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is Acinetobacter an MDR or a non-MDR? what are the most effective ab's against it?
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Inherent resistance to many classes of antibiotics
(Increasing resistance seen in the U.S.) Generally less virulent in comparison to Pseudomonas aeruginosa Most consistently effective antibiotics include: -Carbapenems -Ampicillin-sulbactam -The polymyxins (colistin) |
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Extended-spectrum B-lactamase-producing Enterobacteriaceae (ESBL’s) typically include what pathogens?
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Klebsiella, E.coli, Enterobacter, and Serratia species
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most reliable treatment choice for extended-spectrum B-lactamase-producing Enterobacteriaceae (ESBL’s)is:
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carbepenems
(ESBL's are typically resistant to most abs) |
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what are some therapy options for Methicillin-Resistant Staphylococcus aureus (MRSA)?
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Vancomycin
Aggressive dosing recommended; Keep trough level between 15-20 mcg/mL Linezolid Data exist suggesting mortality benefit for MRSA pneumonia |
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what is one of the most important things to do when diagnosing a nosocomial infection???
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get a lower respiratory tract culture before antibiotics started or changed (1. endotracheal aspirate 2. bronchoalveolar lavage 3. potected specimen brush)
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what is the main difference on x-rays btwn nosocomial vs. community acquired pneumo
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w/nosocomial –usually bilateral (on both sides) b/c people are usually laying in bed when they acquire it
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1. suspect HAP, VAP, or HCAP
2. obtain lower respiratory tract sample for culture and microscopy 3. what next? |
being empiric treatment!!!!!!
(unless there is both a low clinical suspicion for pneumo and negative microscopy or LRT sample) |
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general treatment principles w/nosocomial pneumo
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Early antibiotics therapy key
Broad spectrum up front COMBINATION therapy should be utilized for patients at risk for MDR pathogens ...If aminoglycoside used, may be stopped after 5-7 days May utilize monotherapy once cultures available If on previous antibiotics (within 2 weeks), should try to utilize different antibiotic class due to resistance risk |
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should initial therapy for nosocomial infections be PO or IV?
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IV
- switch to PO therapy with good clinical response; depends on bioavailability of agents |
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when should LONGER therapy be used?
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if pathogen is Pseudomonas or Acinetobacter
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specific treatment for NON-MDR pathogens:
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Ceftriaxone ; cefotaxime
Levofloxacin, moxifloxacin, or (ciprofloxacin* -- not recommended) Ampicillin/sulbactam Ertapenem |
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treatment for MDR pathogens
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minimum of 1 antibiotic from each of 3 classes:
Group 1: Antipseudomonal cephalosporin (cefepime, ceftazidime) Antipseudomonal carbapenem (imipenem, meropenem) b-Lactam/b-lactamase inhibitor (piperacillin-tazobactam) AND Group 2: Antipseudomonal fluoroquinolone (ciprofloxacin, levofloxacin) or aminoglycosides (genta, tobra, amik) AND Group 3: (directed towards MRSA) Vancomycin, linezolid |
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how should aminoglycosides be dosed? why?
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QD
improved PK/PD, improved safety (kidney, oto-toxicity risk decr) higher peak concentrations, longer period of time w/o drug exposure to kidney takes advantage of post=antibiotic effect |
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why use combination therapy?
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Provide broad-spectrum empiric coverage of MOST possible pathogens
Less important reasons: Antibiotic synergy Decrease risk for resistance emergence |
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when should combination therapy be used?
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Use in patients at risk for MDR pathogens
Monotherapy is adequate otherwise |
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rules for combination therapy
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For high risk patients, use combination therapy up front and then scale back based upon culture results
Not just any combination is o.k. Use separate classes utilizing different mechanisms of action b-lactam + aminoglycoside b-lactam + fluoroquinolone |
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duration of therapy
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Most antibiotic killing and clinical improvements occur in the 1st 6 days of therapy
In patients given initial appropriate antibiotic therapy: Make effort to shorten duration from 14 to 21 days to periods as short as 7 days If pathogen is Pseudomonas aeruginosa or Acinetobacter species, longer therapy (14 days+) duration still advised |
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Consequences of prolonged therapy include:
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Colonization with new, more resistant bacteria
Risk for recurrent pneumonia with these bugs |
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response to therapy? when is it seen?
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Clinical improvement typically takes at least 48 hour to see
Unless there is a rapid clinical decline, continue therapy without alteration until day 3 at least Day 3 and beyond: Responding patient Continue therapy and consider de-escalation Non-responding patient Broaden coverage if possible Consider other diagnosis |