Lower Respiratory Tract Infection Flashcards
What is the definition of acute bronchitis?
acute cough <3w due to inflammation of trachea and lower airways
are antibiotics recommended in the treatment of acute bronchitis?
No
How does acute bronchitis usually start?
from a viral URTI
What are the expected radiographic findings for pneumonia?
evidence of new infiltrates / dense consolidations, usually unilateral
What urinary antigen tests are available for pneumonia?
s. pneumonia, legionella
What are the limitations of urinary antigen tests for pneumonia?
only indicates exposure, remains positive even with appropriate treatment
For whom are urinary antigen tests recommended?
severe CAP or hospitalised patients
For whom should pre-treatment blood and respiratory cultures be obtained?
Patients in the hospital who have:
- Severe CAP
- have MRSA and pseudomonas risk factors (being empirically treated for either, infected with either in the past 1 year, hospitalised or received IV antibiotics in the last 90 days)
What are the risk factors for pneumonia?
- smoking
- chronic lung condition
- immunosuppression
- swallowing impairment (increased risk of aspiration)
What is the definition of community-acquired pneumonia?
Onset in the community / < 48H after admission
Outline the CURB-65 risk stratification tool.
Confusion
Urea > 7mm
Respiratory rate >=30
SBP < 90 / DBP < 60
Age >= 65
0-1: outpatient treatment
2: inpatient treatment
>=3: inpatient, consider ICU
What are the 2 major criteria for severe CAP?
- mechanical ventilation
- septic shock requiring vasoactive medications
What are the 8 minor criteria for severe CAP?
- Urea > 7
- Respiratory rate >= 30
- PaO2/FiO2 <= 250
- multilobar infiltrates
- confusion
- WBC < 4
- hypothermia < 36c
- hypotension requiring aggressive fluid resuscitation
What pathogen(s) is/are implicated in patients with CAP with no comorbidities treated in the outpatient setting?
s. pneumoniae
What are the recommended regimens for patients with CAP with no comorbidities treated in the outpatient setting?
PO amoxicillin 1g Q8H OR levofloxacin / moxifloxacin
What pathogen(s) is/are implicated in patients with CAP with comorbidities treated in the outpatient setting?
s. pneumoniae, h. influenzae, atypical bacteria
What are the recommended regimens for patients with CAP with comorbidities treated in the outpatient setting?
PO amox-clav / PO cefuroxime AND clarithromycin / azithromycin / doxycycline OR respiratory fluoroquinolones
What pathogen(s) is/are implicated in patients with non-severe CAP treated in the inpatient setting?
s. pneumoniae, h. influenzae, atypical bacteria
What are the MRSA risk factors for patients with non-severe CAP treated in the inpatient setting?
Respiratory isolation of MRSA in the past 1 year / prior hospitalisation or abx use in the last 90 days AND MRSA PCR screen positive
What are the pseudomonas risk factors for patients with non-severe CAP treated in the inpatient setting?
respiratory isolation of pseudomonas in the last 1 year
What agents should be included in the treatment of patients with non-severe / severe CAP with MRSA risk factors?
IV Vancomycin / IV/PO linezolid
What agents may be considered in the modification of treatment of patients with non-severe CAP with pseudomonas risk factors?
pip-tazo, meropenem, cefepime, ceftazidime, levofloxacin
What are the MRSA risk factors for patients with severe CAP treated in the inpatient setting?
respiratory isolation of MRSA in the past 1 year OR prior hospitalisation or abx use in the last 90 days
What are the pseudomonas risk factors for patients with severe CAP treated in the inpatient setting?
respiratory isolation of pseudomonas in the past 1 year OR prior hospitalisation or abx use in the last 90 days
What pathogen(s) is/are implicated in patients with severe CAP treated in the inpatient setting?
s. pneumoniae, h. influenzae, atypical, gram neg (klebsiella, burkholderia), s. aureus
What agents should be added in patients with lung abscess / empyema?
metronidazole (first choice) / clindamycin
what are the recommended treatment regimens for non-severe CAP treated in the inpatient setting?
- IV amox-clav / cefuroxime / ceftriaxone + azithromycin / clarithromycin / doxycycline
- respiratory fluoroquinolone
what are the recommended treatment regimens for severe CAP treated in the inpatient setting?
IV amox-clav / penicillin G + ceftazidime + azithromycin / clarithromycin OR
respiratory fluoroquinolone + ceftazidime
(ceftazidime is for burkholderia)
Why are respiratory fluoroquinolones not first-line for the treatment of pneumonia?
- high adverse effects
- mask symptoms of TB
- collateral damage with 3rd / 4th gen cephalosporins
What should be added to pneumonia treatment if influenza is suspected?
Oseltamivir
For CAP de-escalation, abx covers for which bacteria can be dropped, if there are no available cultures?
MRSA, pseudomonas, burkholderia
What is the recommended treatment duration for CAP?
minimum 5d, 7d for MRSA / pseudomonas suspected / proven
longer for deep-seated infections and uncommon pathogens
When should chest x-ray be repeated?
only if there is a deterioration in the patient’s condition
What is the definition of HAP / VAP?
onset >= 48H after admission / mechanical ventilation
What are the risk factors for HAP and VAP?
as per pneumonia + supine position, deep sedation, prior abx use, opiods, mechanical ventilation
What pathogens should be empirically covered for HAP / VAP?
pseudomonas and s. aureus
What are the MRSA risk factors for HAP / VAP?
- isolation of MRSA in the last 1 year
- prior IV abx use within the last 90 days
- hospital unit > 20% of s. aureus is MRSA
- patient is at high risk for mortality
When should double pseudomonal cover be considered?
- patient has risk factors for pseudomonal resistance (prior IV abx use, isolation of pseudomonas in the last 1 year, acute renal replacement therapy prior to VAP onset)
- hospital unit where >10% of pseudomonas is resistant to agent considered for monotherapy
- patient is at high risk for mortality
Should aminoglycosides be used as monotherapy?
no
What are the recommended regimens for HAP / VAP?
pip-tazo / cefepime / ceftazidime / meropenem / imipenem AND/OR anti-pseudomonal FQ OR amikacin
What is the recommended treatment duration for HAP / VAP?
7 days regardless of pathogen
For de-escalation in HAP / VAP, what pathogen cover should be maintained if culture / antibiogram is not available?
pseudomonas, s. aureus, enteric gram neg
(can drop MRSA if no MRSA in culture, unless patient very sick)
