IC16 PR3151 LRTI Flashcards
describe acute bronchitis?
characterised by acute cough (usually ≤3 weeks) due to inflammation of the trachea and lower airway.
usually self-limiting.
usually starts from URTI.
cough lasts for more than 3 weeks.
ABX treatment is NOT recommended unless confirmed for bacterial infection. It will not change the resolution time.
what is the differential diagnosis for acute bronchitis?
need to rule out exacerbation of COPD, pneumonia, or acute asthma.
when should patients with acute bronchitis return to the clinic?
1) fever
2) cough with changing frequency and extent
3) cough that lasts more than 3 weeks
describe pneumonia
infection of the parenchyma of the lung
proliferation of microbial pathogen in the alveolar level
what is the pathophysiology of pneumonia
1) exposure to the host
2) susceptible host
3) proliferation
what are the methods of exposure to pneumonia pathogen (pathophysiology)
1) inhalation
2) aspiration of oropharyngeal secretions
3) hematogenous spreading: e.g., bacterimia from extra-pulmonary sources
What are the risk factors for pneumonia?
1) smoking: suppress neutrophils
2) immunosuppressed: e.g., glucocorticoids, chemotherapy, HIV, sepsis
3) chronic respiratory conditions e.g., COPD, asthma, and lung cancer that destroy lung tissue and allow for more space for pathogen proliferation.
what are the systemic clinical presentation for pneumonia
fever
chills
malaise
altered mental status (elderly)
hypotension
tachycardia
what are physical examination evidence for pneumonia (lung auscultation)
1) inspiratory crackling during lung expansion
2) diminished breath sounds over the affected area
what are the localised clinical presentation for pneumonia
localised ie lung conditions (not general)
tachypnoea
chest pain
SOB
cough
hypoxia
increased sputum production
what are the radiological methods for pneumonia detection?
chest x-ray
lung CT
lung ultrasonography
what are the radiological evidence for diagnosis of pneumonia?
PRESENCE of NEW infiltrates or dense consolidations
what are the methods for pneumonia laboratory testing?
1) urinary antigen tests
2) culture and gram staining
3) blood culture
- rule out bacterimia
describe the urinary antigen test for pneumonia
what it tests for and the limitations
tests for
- strep pnuemo
- legionella pneumo
limitations
- may remain positive for days-weeks after antibiotic treatment
when to perform urinary antigen test for pneumonia
for severe CAP or hospitalised patients
what are the risk factors for CAP
SAME as pneumonia
and
history of pneumonia
prevention methods for CAP?
vaccinations: pneumococcal and influenza
smoking cessation
what are the different culture and gram staining methods for pneumonia
1) sputum
- low yield and contaminated by saliva (if culture has high epithelial cell count)
2) lower respiratory tract
- invasive: BAL (bronchoalveolar lavage)
pneumonia classification?
1) CAP
- <48h after hospital admission
- onset in the community
2) HAP
- >48h after hospital admission
3) VAP
- >48h after mechanical ventilation
HAP and VAP = nosocomial
note that CAP and HAP are now treated together
when should you initiate culture(s) per the IDSA guidelines for pneumonia?
indicate the cultures required.
blood and sputum culture required before abx treatment for patients with
1) severe CAP
2) risk factors for resistant bacteria e.g., MRSA, psedumonas
what are the risk factors for drug resistant bacteria in pneumonia
1) iv abx or recent hospitalisation in the last 90 days
2) empiric treatment for mrsa or pseudomonas
3) recent infection from mrsa or psedumonas (in the last year)
what are the likely pathogens for inpatient (severe) CAP?
strep pneumo
haemo infl
atypicals (MCL)
add on MRSA, psedumonas depending on risk factors
ADD ON
- s. aureus
- gram negatives e.g., Burkholderia, klebsiella
what are the likely pathogens for outpatient and inpatient (nonsevere) CAP?
strep pneumo
haemo infl
atypicals (MCL)
add on MRSA, psedumonas depending on risk factors
what is Burkholderia -> describe the type of problems and location…
burkholderia causes melioidosis = severe CAP in tropical countries
what other condition should patients be tested for when diagnosed with CAP (and for whom)
influenza
for all inpatients
during circulating seasons
what is the classification for PSI (risk classification)
RISK I: 0 (outpatient)
RISK II: ≤70 (outpatient)
RISK III: 71-90 (inpatient, brief)
RISK IV: 91-130 (inpatient)
RISK V: >130 (inpatient)
what is the criterion for CURB65 CAP stratification?
1) confusion
2) urea >7
3) RR ≥30
4) BP
SBP <90
DBP <60
5) Age ≥65
what is the point system for CURB65
0-1: outpatient
2: inpatient non severe
≥3 inpatient severe
what are the criteria in IDSA/ATS CAP classification?
major factors:
- mechanical ventilation
- septic shock requiring vasoactive medications
minor factors
- RR ≥ 30 breaths/min
- PaO2/FiO2 ≤ 250
- Multilobar infiltrates
- Confusion/disorientation
- Uremia (urea > 7 mmol/L)
- Leukopenia (WBC < 4 x 109/L)
- Hypothermia (core temperature < 36ºC)
- Hypotension requiring aggressive fluid resuscitation
what is the empiric treatment for OUTPATIENT CAP with no comorbidities?
beta lactam:
- PO amoxicillin 1g q8
respiratory FQ
- PO moxi or levo
what is the empiric treatment for OUTPATIENT CAP with comorbidities?
beta lactam + macrolides/doxycycline
- PO amoxiclav
- PO cefuroxime
ADD
- PO azithromycin/clarithromycin + doxycycline.
respiratory FQ
- PO moxi or levo
what is the (standard) empiric treatment for INPATIENT NON-SEVERE CAP?
beta lactam + macrolides/doxycycline
- IV amoxiclav
- IV cefuroxime
- IV ceftriaxone
ADD
- IV azithromycin/clarithromycin + doxycycline.
respiratory FQ
- IV moxi or levo
what is the (PSEDUMONAL risk factor COVER) empiric treatment for INPATIENT NON-SEVERE CAP?
modify regimen to
IV piptazo (add atypical coverage)
IV ceftazidime (add strep pneumo coverage)
IV cefepime (add atypical coverage)
IV meropenem (add atypical coverage)
IV levofloxacin
what is the (MRSA risk factor COVER) empiric treatment for INPATIENT NON-SEVERE CAP
add
IV vancomycin or IV/PO linezolid
what is the (standard) empiric treatment for INPATIENT SEVERE CAP?
beta lactam + ceftazidime (burkholderia) + macrolides (atypicals)
- IV amoxiclav
- IV pen G
ADD
- IV ceftazidime
ADD
- IV azithromycin or clarithromycin
OR
respiratory FQ + ceftazidime
- IV cipro or moxi
ADD
- IV ceftazidime
what is the (MRSA risk factor COVER) empiric treatment for INPATIENT SEVERE CAP
ADD
IV vancomycin OR
IV/PO linezolid
what is the (pseudomonas risk factor COVER) empiric treatment for INPATIENT SEVERE CAP
same as the empiric general regimen already covers for pseudomonas
why is daptomycin not used for LRTI (compared to vancomycin)?
it will get destroyed in the lung tissue
what is the dosing for amoxicilin in general CAP regimen for outpatient without comorbidities?
need to increase to a higher dose of
1g Q8 (take note)
what additional agents should be added when there is anaerobes present in CAP
1st line: metronidazole
2nd line: clindamycin
when to initiate anaerobic coverage for CAP?
during radiological investigations showing:
a) lung abscess
b) empyema
what are some regimens that do not require additional anaerobe coverage?
piptazo and amoxiclav
what additional agents to include if patient has influenza on top of CAP.
and what to do if positive PCR
start course of oseltamivir
- x5 days
- 75mg BD
if positive influenza PCR
- complete course
- may discontinue if patient reaches early clinical stability, low procalcitonin (<0.25ug/ml), OR has negative culture.
why is respiratory FQ secondline for CAP treatment
high ADR profile
delay diagnosis of TB
develop resistance
only PO agent for Pseudomonas
- preserve therapy
what is an adjunctive therapy to CAP
- purpose
- indication
- precautions
corticosteroids
- reduce inflammation in lungs
- MOSTLY ICU = add if shock refractory to fluid resuscitation or vasopressor support.
- avoid routine use
when to de-escalate for CAP?
Hemodynamic stability
Improving clinically
For IV-to-Oral -able to ingest oral medications
how to deescalate for CAP?
if positive culture:
- use AST and select for narrower/PO drugs
if no positive culture
- remove agents for burkholderia, Pseudomonas and MRSA in 48 hours if patient is improving
- change from IV to oral (maintain atypical, strep pneumo and haem cover)
what is the treatment duration for CAP (if suspected or proven mrsa or pseudmonas )
7 days
what is the treatment duration for CAP (minimally)
5 days
when should treatment be stopped for CAP?
Resolution of vital sign abnormalities ie heart rate, respiratory rate, blood pressure, oxygen saturation, and temperature
Ability to maintain oral intake
Baseline mental status
how to monitor response for CAP (step 4)
Most patients will achieve clinical stability within the first 48 to 72 hours
- Elderly patients and/or those with multiple co‐morbidities may take longer
Should not escalate antibiotic therapy in the first 72hours
- Unless culture‐directed or significant clinical deterioration
Radiographic improvement lags behind clinical improvement for resolution
- Repeat only if clinical deterioration
No need to repeat microbiological tests as well.
Adverse drug reactions of antibiotics
when should treatment for CAP be extended?
1) CAP complicated with other deep-seated infections (e.g.meningitis, lung abscess)
2) Infection with other, less-common pathogens (e.g., Burkholderia pseudomallei (up to 3-6weeks), Mycobacterium tuberculosis (up to 3-6months) or endemic fungi)
how long does it take for radiological findings to be cleared of CAP
ABOUT 6WEEKS TO 2MTHS
what are the HAP/VAP patient-related risk factors
ECCSPM
elderly
COPD/cancer/immunosuppression
coma/impaired consciousness
smoking
prolonged hospitalisation
malnutrition
what are the HAP/VAP infection control-related risk factors
lack of hand hygiene compliance
contaminated respiratory devices
what are the HAP/VAP healthcare-related risk factors
prior abx use
mech ventilation
supine position
opioid analgesics
sedative (unable to breathe properly)
HAP/VAP prevention methods?
include VAP specific methods
1) hand hygiene
2) judicious use of sedatives and abx
3) mech ventilator
- minimise prolonged or deep sedation
- minimise prolonged ventilation
- tilt head 30º (to facilitate breathing)
what to cover empirically for VAP/HAP?
pseudomonas
enterobacterales
s.aureus
when to cover MRSA empirically for VAP/HAP?
iv use in last 90 days
isolation of mrsa in last 1 year
hospitalisation in unit with >20% s.aureus is MRSA
if prevalence unknown but patient at high risk of mortality (ventilatory support due to HAP and septic shock)
VAP/HAP abx selection should be guided by _____
Choice of antibiotics for HAP/VAP should be guided by local distribution of pathogens associated with HAP/ VAP and their antimicrobial susceptibilities.
If possible, obtain ICU-specific antibiogram for VAP
when to use double pseudomonal agents for VAP/HAP?
use double pseudomonal agents from different classes if
a risk factor for antimicrobial resistance (prior intravenous antibiotic use within 90 d; acute renal replacement therapy prior to VAP onset; isolation of P. aeruginosa in last 1 year)
hospitalization in a unit where >10% of Pseudomonas isolates are resistant to an agent being considered for monotherapy
if prevalence of PA is not known but patient at high risk for mortality (include need for ventilatory support due to HAP and septic shock)
what is the MRSA cover on top of double antipseudomonal regimen for VAP/HAP?
IV vancomycin
IV/PO linezolid
what is the double antipseudomonal regimen for VAP/HAP?
1) ANTIPSEUDOMONAL B-LACTAM
- cefepime, piptazo, (ceftazidime), imipenem, meropenem
AND/OR
2) ANTIPSEUDOMONAL FQ
- (ciprofloxacin) or levofloxacin
OR
3) aminoglycosides: amikacin (DO NOT USE AS MONOTHERAPY)
- bracket = AVOID use without MRSA cover
when to deescalate for VAP/HAP
when
1) hemodynamically stable
2) improving clinically
3) able to take oral (from iv)
treatment duration for VAP/HAP?
7 days
how to deescalate for VAP/HAP
positive culture
- iv to oral and/or based on AST.
- change from double to single anti-pseudomonal
no positive culture
- maintain coverage according to local HAPVAP antibiogram
OR if not available, for psuedomonas, MSSA, MRSA, enteric GNR (do not do this for severe MDRO infection or if severely ill)
- change to oral from iv if possible
which MRSA agents do we not use in VAP/HAP and why?
clindamycin
cotrimoxazole
doxycycline
BECAUSE these are more for community acquired MRSA.
when to stop tx for VAP/HAP
resolution of vital sign abnormalities
for HAP: baseline mental status
why should the course of abx be limited for VAP HAP
STUDIES show it is related to more deep seated infections like
meningitis
lung abscess
monitoring symptoms for VAP HAP? (step 4)
Most patients will achieve clinical stability within the first 48 to 72 hours
Elderlypatients and/or those with multiple co‐morbidities may take longer
Should not escalate antibiotic therapy in the first 72hours UNLESS culture‐directed or significant clinical deterioration
Radiographic improvement lags behind clinical improvement for resolution
- Repeat only if clinical deterioration
No need to repeat microbiological test as well.
Adverse drug reactions of antibiotics
