LRTI; NAP Flashcards
what is classifed as nosocomial pneumonia?
Hospital-acquired pneumonia (HAP): onset >= 48hours after hospital admission
Ventilator-associated pneumonia (VAP): onset >= 48 hours after mechanical ventilation
Risk factors for HAP/VAP?
(1) patient-related factors
- elderly
- smoking
- COPD, cancer, immunocompression
- prolonged hospitalisation
- coma, impaired consciousness
- malnutrition
(2) infection control-related factors
- hand hygiene compliance
- contaminated respiratory care devices
(3) healthcare-related factors
- prior abx use
- sedatives
- opioid analgesic
- mechanical ventilation
- supine position
Prevention strategies for HAP/VAP
- practice consistent hand hygiene
- judicious use of abx and medication with sedative effects
Preventive strategies SPECIFIC to VAP:
- limit duration of mechanical ventilation
- minimise duration and deep levels of sedation
- elevate head of bed by 30 degrees
the microbiology (gram + and -ve) that can cause HAP/VAP
(1) gram +ve
- strep pneumoniae
- staphylococcus aureus
(2) gram -ve
- Haemophilus influenzae
- E.coli
- Proteus spp
- Serratia marcescens
- Enterobacter spp
- Klebsiella pneumonia (including MDR strains)
- Acinetobacter spp. (including MDR strains)
- Pseudomonas aeruginosa (including MDR strains)
what is the MINIMUM empiric coverage for HAP and VAP?
- empirically cover S.aureus (MSSA) and P.aeruginosa
- may need to additional coverage based on:
- MDR organism risk factors
- Mortality risk factors
- Hospital/unit’s bacteria susceptibility rates (i.e. antibiogram)
what are the MDRO risk factors of HAP/VAP?
for HAP:
- Prior IV abx within 90 days
for VAP (any ONE of the following): - prior IV abx within *90 days*
- septic shock at the time of VAP
~ septic shock: hypoTN which is caused by infection, requires support of vasoactive medications - Acute respiratory distress syndrome (ARDS) preceding VAP onset
~ acute inflammatory lung injury, usually due to infection, causes hypoxemic respiratory failure requiring mechanical ventilation, high mortality (40%) - > = 5 days of hospitalisation prior to VAP onset
-
Acute renal replacement therapy prior to VAP
~ acute is due to septic shock resulting from hypoTN
(note: if patient is CKD stage 5 (chronic), then not included in this point)
what are the mortality risk factors of HAP?
mortality risk only applies to HAP and not VAP
for HAP (any ONE of the following): - requiring mechanical ventilation as a result of HAP (note patient prev not on mechanical ventilation when they initially had HAP)
- in septic shock
how to additional coverage based on hospital/unit’s bacteria susceptibility rates (i.e. antibiogram)
e.g. if antibiogram says cloxacillin/cefazolin is 75%:
-75% of S.aureus (MSSA) is susceptible to cloxacillin/cefazolin,
that means 25% of S.aureus (MRSA) is susceptible to
cloxacillin/cefazolin
e.g. 84 means 84% of the P.aeruginosa isolates are susceptible to pip-tazo
what is the “backbone regimen” for HAP/VAP?
- refers to no MDRO risk factors, no mortality risk factors, no indication for MRSA coverage
- minimum coverage: S.aureus (MSSA), P.aeruginosa
Empiric therapy:
(1) anti-pseudomonal B-lactam
~ pip-tazo OR cefepime OR meropenem OR imipenem
(2) anti-pseudomonal FQ
~ levofloxacin
(note: cipro dont have good gram +ve coverage)
what microorganisms does the backbone regimen of HAP/VAP cover other than S.aureus (MSSA) and P.aeruginosa
- Strep pneumoniae
- Abx-SENSITIVE Enterobacteriaceae (E.coli, K. pneumonia, Enterobacter spp, Proteus spp, Serratia marcescens)
for HAP, what are the additional empiric coverage along with the backbone regimen?
(for empiric MRSA coverage)
(1) Empiric MRSA coverage Indication for empiric MRSA coverage: - MDRO risk factor OR - Mortality risk factor OR - MRSA prevalence >20% or *unknown*
then ADD:
- Vancomycin (more commonly used) OR
- Linezolid
for HAP, what are the additional empiric coverage along with the backbone regimen?
(for ADDITIONAL gram-ve coverage)
(2) Indication for additional gram -ve coverage:
- MDRO risk factor OR
- Mortality risk factor
then ADD:
- gentamicin OR
- amikacin OR
- tobramycin OR
- ciprofloxacin (good gram -ve coverage) OR
- levofloxacin
NOTE:
- add a drug that is of DIFFERENT class as backbone regimen
e.g. if B-lactam used for backbone, can use either AGs or FQs (AGs commonly chosen),
BUT
if FQ is used for backbone, only can use AGs
for VAP, what are the additional empiric coverage along with the backbone regimen?
(for empiric MRSA coverage)
(1) Empiric MRSA coverage
Indication for empiric MRSA coverage:
- MDRO risk factor OR
- MRSA prevalence >10-20% or unknown
then ADD:
- Vancomycin (more commonly used) OR
- Linezolid
for VAP, what are the additional empiric coverage along with the backbone regimen?
(for ADDITIONAL gram-ve coverage)
(2) Indication for additional gram -ve coverage:
- MDRO risk factor OR
- Single anti-pseudomonal agent with activity <90% or unknown (the anti-pseudomonal referring to the one used in backbone)
then ADD:
- gentamicin OR
- amikacin OR
- tobramycin OR
- ciprofloxacin (good gram -ve coverage) OR
- levofloxacin
NOTE:
- add a drug that is of DIFFERENT class as backbone regimen
e.g. if B-lactam used for backbone, can use either AGs or FQs (AGs commonly chosen),
BUT
if FQ is used for backbone, only can use AGs
why the need for additional gram -ve coverage for HAP/VAP treatment?
- proposed benefit: synergistic activity, prevent resistance, expand spectrum of coverage
(benefits from in vitro) - but potential risk: increase cost, increase adverse effects
BUT: this double coverage has NO difference in mortality, length of stay, treatment failure rates
BUT: we still have this additional gram -ve coverage to:
- empirically broaden spectrum of gram -ve coverage in patients who are at RISK for MDRO or death (in case, 1 agent does not provide adequate coverage)
