W13 Pneumonia Flashcards
CAP S/S
5
SIRS criteria (+/-):
○ Heart rate
○ Temperature
○ Respiratory rate
○ WBC
● Increased sputum production
● Cough
● Decreased oxygen saturation
● Pleuritic chest pain
● Physical exam: rales, crackles, diminished breath sounds over affected area
What is the difference between
CAP
HAP/VAP
● Community-acquired pneumonia (CAP):
—patient presents from the community or disease develops < 48 hours from hospital admission
● Nosocomial pneumonia:
○ Hospital-acquired pneumonia (HAP): develops ≥ 48 hours after hospital admission
○ Ventilator-associated pneumonia (VAP): develops ≥ 48 hours after being mechanically ventilated
CAP risk factors -
● Age > 65 yo
● Alcohol or tobacco use disorder
● Comorbidities, esp. pulmonary (i.e. asthma, COPD)
● Immunosuppression
● Viral influenza
CAP
How do you diagnose pneumonia
Are respiratory or blood cultures required?
What is the most common isolate?
Which test is highly specific?
What else should you test for?
● ⭐️ Signs & symptoms + evidence of infiltrates/opacities on chest X-ray
● ⭐️ Positive resp. cultures are NOT needed for definitive diagnosis of CAP
○ Often contaminated with normal oropharyngeal flora
○ Low sensitivity and specificity for Strep
● Blood cultures only positive in CAP 5-14% of the time → consider if severe CAP (more likely to yield S. aureas, P. aeruginosa, and other GNR)
○ Most common isolate still Strep. pneumo
● Urinary antigen assays: Legionella and Strep pneumo
○ High specificity and moderate sensitivity + very quick
○ Strep recommended in all cases except for severe CAP
○ Legionella recommended if recent travel, associated with Legionella outbreak, in adults with severe CAP
● Don’t forget to test for influenza (if flu season) and COVID!
CAP
Likely pathogens
⭐️ Which abx with atypical coverage?
2 “other” organisms
● Streptococcus pneumoniae
○ Up to 75% of CAP cases
● Atypical organisms:
○ Mycoplasma pneumoniae
○ Chlamydophila pneumoniae
○ Legionella species (more likely in elderly or patients with chronic diseases)
● Others: Moraxella catarrhalis, Haemophilus influenzae
● ICU: Strep pneumo, Legionella spp, S. aureus, GNR
⭐️ Antibiotics with atypical coverage:
● Macrolides
● Tetracyclines
● Respiratory FQs
CAP Determining risk/level of care
Which system?
Which score determines in patient treatment
—PSI/PORT preferred over CURB-65 because it considers more factors that CURB-65
— ≤70: low risk, outpatient
—71-90: moderate risk, outpatient or observation
—≥91: high risk, treat in patient
CAP supportive care
● Hydration
● Nutrition
● Fever control
● Bronchodilators if bronchospasm present
● Chest physiotherapy with postural drainage if evidence of secretions
● Humidified oxygen if hypoxic
CAP
Considering MRSA or Pseudomonas
What are 2 risk factors?
Which conditions would make you cover pseudomonas
Which would make you cover MRSA
Which test has a high negative predictive value for MRSA
Treatment duration
● More of a concern in hospitalized patients
● Risk factors:
○ Prior respiratory isolate with either pathogen
○ Hospitalization and treatment with IV antibiotics within past 90 days
○ Recommendations per Sharp infectious disease:
■ Pseudomonas: structural lung disease (i.e. cystic fibrosis, pulmonary fibrosis, bronchiectasis); recurrent COPD exacerbations requiring steroids and/or antibiotics;
immunosuppression
■ MRSA: post-influenza with severe or necrotizing pneumonia
● If treating empirically for either organism:
○ Get a sputum & blood culture + MRSA nares if MRSA → de-escalate/narrow abx
■ MRSA nares high negative predictive value (if neg, can rule out MRSA)
● Less positive predictive value → if positive, doesn’t mean they have MRSA pneumonia
○ Treat for 7 days
CAP
What is the empiric therapy for outpatient ?
No risk factors for MRSA/pseudo/comorbs
No risk factors BUT has comorbs
no risk factors for MRSA, pseudo or comorbs
1. Amoxicillin 1g TID
OR
2. Doxy 100mg BID
OR
3. Macrolide (i.e. azihromycin 500 mg x1, then 250 mg daily; clairthromycin 500 mg BID; clarithromycin XR 1000 mg daily)
no risk factors for MRSA, pseudo, BUT has comorbs (heart, liver, lungs, DM etc)
—Beta-lactam (i.e. Augmentin, cefuroxime or cefpodoxime)
PLUS
—doxycycline 100 mg BID/macrolide (same dosing as above)
OR
—Respiratory fluoroquinolone (i.e. levofloxacin 750 mg daily)
CAP Pneumonia
Outpatient bug drug chart
CAP
Pneumonia empiric treatment inpatient
Non severe?
ICU?
non-severe in patient
—Beta-lactam PLUS Macrolide
Or
—Respiratory fluoroquinolone
Example:
—Ceftriaxone, Unasyn, cefotaxime, ceftaroline PLUS
azithromycin/clarithromycin
OR
—Levofloxacin or moxifloxacin
ICU patient
—Beta-lactam PLUS Macrolide
Or
—Beta-lactam PLUS Respiratory fluoroquinolone
—same meds as above
CAP
Criteria for ICU admission
● ≥ 1of the following major criteria::
○ septic shock on pressors
○ respiratory failure requiring intubation and mechanical ventilation
● OR ≥ 3 of the following minor criteria:
○ RR > 30 bpm
○ PaO2/FiO2 < 250
○ Confusion
○ Multilobar infiltrates
○ Uremia
○ Leukopenia
○ Thrombocytopenia
○ Hypothermia
○ Hypotension
CAP
When are corticosteroids recommended? 3
● Not recommended unless:
○ Concomitant asthma/COPD exacerbation
○ Adrenal insufficiency
○ Certain cases of severe/refractory septic shock
CAP, duration of therapy
What are you hoping to see at the end of therapy in terms of fever and CAP-associated clinical instability ?
● Minimum of 5 days (or 7 if complicated requiring longer course or severe CAP)
● Afebrile for 48-72 hours
● No more than one sign of CAP-associated clinical instability (take into account status at baseline):
○ Febrile
○ HR > 100 beats/min
○ RR > 24 breaths/min
○ Systolic BP < 90 mmHg
○ O2 sat < 90%
○ Inability to maintain oral intake
○ Altered mental status
CAP
Macrolides, which is most used?
Dosing
ADR
Clinical pearls
● Available agents: ⭐️azithromycin, clarithromycin, or erythromycin
○ Azithromycin better tolerated and has less drug-drug interactions
● Dosing:
○ Azithromycin “Z-pak” has unique dosing (500 mg x1, then 250 mg daily)
○ Different dosing for clarithromycin vs clarithromycin XR
● Adverse effects:
○ 🔺QTc prolongation (potentially additive with other medications)
○ 🔺 Diarrhea
○ 🔺 Hearing loss
● Clinical pearls:
○ 25% resistance reported in AK, CA, OR, WA between 2018-2019
○ Macrolide monotherapy is guideline recommended only in areas with < 25% pneumococcal resistance to macrolides
HAP & VAP
Likely pathogens
HAP
● Non-enteric GNR: 15-24%
—Pseudomonas: 10-17%
—Acinetobacter: 2-6%
● Enteric GNR (i.e. PEK): 13-20%
● Staph. Aureus: 12-21%
—MRSA: 6-14%
HAP is mainly GNRs and then staph aureus
VAP
● Staph aureus: 20-30%
● Non-enteric GNR: Pseudomonas aeruginosa: 10-20%
● Enteric GNR: 20-40%
● Acinetobacter baumannii: 5-10%
VAP is mainly staph aureus then enteric GNR (PEK) which might make sense why you add MRSA coverage on when local prevalence is >10% as opposed to HAP, when you add on when prevalence is 20%
GNR = gram negative rods
HAP & VAP
Empiric treatment regimen
What must you always cover for, for both HAP and VAP?
For HAP:
—which 3 instances do you double cover for pseudomonas?
—which 3 instances would you cover for MRSA?
they share 2 in common
For VAP
—which 7 instances do you double cover pseudomonas
—which 7 instances do you cover for MRSA
they share 6 in common
HAP
⭐️Always cover Pseudomonas and MSSA
—assess the need for MDR coverage
Double cover pseudomonas for:
1. high mortality risk (ventilator support due to PNA OR septic shock)
2. or IV abx in past 90 days
3. 🔸structural lung disease (cystic fibrosis or bronchiectasis)
Cover MRSA for:
1. high mortality risk (ventilator support due to PNA OR septic shock)
2. or IV abx in past 90 days
3. 🔸 if local MRSA prevalence > 20%
VAP
⭐️Always cover Pseudomonas and MSSA
—Assess the need for MDR coverage
—Cover MRSA and double cover pseudomonas for:
1. septic shock
2. ARDS preceding VAP,
3. IV abx in past 90 days
4. acute renal
5. replacement therapy prior to VAP
6. ≥ 5 days of hospitalization prior to VAP
—local MRSA prevalence >10%:
1. add MRSA coverage
—local GNR resistance to monotherapy agents > 10%
1. double cover for Pseudomonas
MDR = multiple drug resistance
HAP & VAP
Calculating local abx susceptibility
For reference
When you’re looking at an antibiotic susceptibility table, the number given is the % susceptible that organism is to that antibiotic, the ∆ from 100 is the resistance.
If the resistance is >20% for MRSA in HAP, need to treat for MRSA, or >10% for VAP
Prevalence = resistance (I think)
