Lower Respiratory Tract Infections Flashcards
What organism etiologies are in CAP?
Strep pneumo H. Influenzae Staph aureus Mycoplasma pneumoniae PSA Legionella
How do you define severe CAP?
Major Criteria (at least 1 major) Septic shock with need for vasopressors Resp failure needing mechanical ventilation
Minor criteria (at least 3 minor) RR > 30 FaO2/FiO2 < 250 Multilobar infiltrates Confusion/disorientation BUN > 20 WBC > 4000 Plt < 100000 Hypothermia < 36C Hypotension requiring aggressive fluid resuscitation
1 major or 3 minor consider ICU admission
What classifications are there for Pneumonia severity index or Pneumonia Outcomes Research Team and how to they determine outpatient or inpatient management?
Risk class I or II - outpatient Risk class III - observation Risk class IV or V - inpatient
What is CURB-65?
Confusion BUN > 20 RR > 30 BP < 90/60 Age > 65
What is first line empiric adult outpatient CAP?
HD Amoxicillin 1 g TID is preferred
Doxycycline
Macrolide - only if amox or doxy are CI and macrolide resistant S. Pneumoniae known to be infrequent
What comorbidies are considered for poor CAP outcomes or resistant strep pneumo?
Heart disease Lung disease Liver disease Renal disease Diabetes Alcoholism Malignancy Asplenia
What empiric therapy should be considered in a patient with comorbidies to CAP?
B lactam (augmentin, cefpodoxime, cefuroxime) + macrolide OR doxycycline Levofloxacin or moxifloxacin
When should anaerobic coverage be used for aspiration pneumonia?
Empyema
Lung abscess
What other treatment considerations should be made for CAP?
Give neuromidase inhibitor regardless of time
Give steroids only in shock
What directed therapy is preferred in common CAP organisms?
S. Pneumo PCN S - Amoxicillin
S. Pneumo PCN R - Cefotaxime, CTX, FQs
H. Influenzae non B lactamase producing - Amoxicillin
B lactamase producing - 2nd or 3rd generation cephalosporins
Legionella - FQs, macrolides
MRSA - vancomycin, linezolid
MSSA - anti-Staph PCN
What antibacterial coverage is for omadacycline?
MRSA and drug resistant S. Pneumo
H. Influenzae
M. Catarrhalis
No coverage in Proteus, PSA, morganella or providencia
What is the preferred duration of therapy for CAP?
Minimum 5 days
7 days if suspected or proven MRSA or PSA
Serial PCT can be used to support d/c
When should a patient receive influenza treatment?
Outpatient, uncomplicated, no risk factors - Tamiflu or Zanamivir x 5 days
- < 2 days since onset
- household contact with patients high risk of complications such as immunocompromised
Outpatient, risk factor for complications
Tamiflu or inhaled Zanamivir for 5 days
Consider longer duration if complicated/immunocompromised
- Tamiflu preferred in pregnancy and COPD/asthma
Inpatient
Tamiflu or IV prramivir if unable to absorb PO for 5 days
*Risk factors Age < 2 or age > 65 Chronic pulmonary Cardiovascular Renal or hepatic disease DM Immunosuppression Pregnancy or <2 weeks postpartum Nursing home Obesity BMI > 40
What CAP organisms are expected for pediatric patients?
Strep pneumo
Mycoplasma pneumoniae
Staph aureus
Strep viridans
How do you treat pediatric CAP?
< 5 years Amoxicillin, alternative: augmentin
> 5 years Amoxicillin, alternative: augmentin and add macrolide if no data to differentiate typical from atypical
Atypical bacteria: azithromycin or clarithromycin
What are the common pathogens for HAP and VAP?
- PSA
- Acinetobacter spp.
- Enteric GNR
- MSSA
- MRSA
When should double PSA coverage be used in HAP?
- High mortality risk
- IV abs in prior 90 days
- Structural lung disease (bronchiectasis or CF)
What are risk factors for MDR VAP?
- IV antibiotics in past 90 days
- Septic shock
- ARDs preceding VAP
- > 5 days of hospitalization prior to VAP
- Acute renal replacement therapy prior to VAP
- GNR resistance > 10%
For HAP/VAP, when should PSA directed therapy be de-escalated to monotherapy?
Septic shock or high mortality risk resolution
What is the AUC/MIC goal for vancomycin for complicated S. aureus infections?
400 mgxhr/L with MIC of 1 mg/L
How to calculate dosing interval change in individualized vancomycin dosing?
tau(new) x Css (new) = tau (old) X Css (old)
How to calculate both change in dose and interval for vancomycin?
Css new divided 24 hr dose new = Css (old) divided 24 hr dose old
What are the advantages of polymyxin B over colistin?
Polymyxin has less acute kidney injury and PK optimization is more likely (Css of 2 mg/L or AUC = 50)
What to HAP/VAP guidelines say about using polymyxin?
Avoid when possible since exposure required for success in lower respiratory tract infection is above max tolerable range. Always use polymyxin with systemic agent even if resistant and use inhaled polymyxin for XDR GNR
What diagnostic considerations should be considered to discontinue HAP/VAP?
- Clinical criteria
- Procalcitonin
