Lower Respiratory Infections: CAP

Question 1

How is CAP defined?

Answer 1

Pneumonia with onset outside hospital, or < 48 hours after admission (they brought it with them)
-Leading infectious cause of hospitalizations and death.

Question 2

Etiology of CAP?

Answer 2

Viral 14-27% (Mainly rhinovirus and influenza)
Bacterial 15-29%
-Mainly strep pneumo (becoming less common) and H flu, then S. aureus (usually MSSA).
-Atypicals: mycoplasma pneumoniae, chlamydophila pneomoniae. Less severe. “Walking pneumonia.” Legionella pneumophila is atypical but severe.
-Unidentifiable cause most of the time.

We can’t reliably differentiate between viral and bacterial, so we always assume bacterial for treatment.

Question 3

Diagnosis of CAP

Answer 3

Clinical features (cough, fever, sputum production, pleuritic chest pain) plus infiltrate on chest radiograph.

Cultures are not routine. Consider in severe cases, or those at risk for MRSA, Pseudomonas, or Legionella pneumophila.

Question 4

Diagnostic testing for severe CAP?

Answer 4

Gram stain + sputum cx, blood cx x2, Pneumococcal and Legionella urinary antigens, legionella selective media or nucleic acid amplification test (e.g. test for everything)

Question 5

Diagnostic testing for pts needing empiric MRSA or Pseudomonas coverage?

Answer 5

For pts with prior MRSA/Pseudomonas in last 12 months (by documented culture), or those with hospitalization in prior 90 days:

• Gram stain and sputum cx
• Blood cx x2
• Notice hospitalization in last 90 days but still CAP.

Question 6

Who gets Legionella testing for CAP?

Answer 6

If there’s a local outbreak or recent travel, get urinary antigen test or selective media, or nucleic acid amplification test.
Public health reportable disease. Need to track outbreaks.

Question 7

When to test for influenza?

Answer 7

If it’s circulating in community.

Question 8

How is Severe CAP defined and what relevance is it?

Answer 8

Need at least 1 major criteria, or at least 3 minor. Determines need for higher level of care (ICU).

Question 9

What are the CAP “Major Criteria” for defining severe CAP?

Answer 9

Septic Shock with need for vasopressors

Respiratory failure requiring mechanical ventilation

Question 10

What are the CAP “Minor Criteria” for defining severe CAP?

Answer 10

• Resp rate > 30 breaths per min
• PaO2/FIO2 ratio < 250 (partial pressure arterial O2 divided by the (f)raction of (i)nspired O2)
• Multilobar infiltrates
• Confusion/disorientation
• Uremia (BUN > 20 mg/dL)
• Leukopenia (WBC < 4,000), if due to infection, not chemo.
• Thrombocytopenia (plt < 100,000)
• Hypothermia (core temp < 36 C)
• Hypotension requiring aggressive fluid resuscitation

Question 11

What is the role of procalcitonin in CAP?

Answer 11

Empiric abx should be started regardless of initial PCT

Question 12

How to decide site of care?

Answer 12

Use the PSI (pneumonia severity index) to calculate a PORT score.

• Class I or II (70 points or less) = outpatient
• Class III (71-90 points) = observation
• Class IV or V (> 90 points) = Inpatient
• Preferred over the “CURB-65” score now
• Don’t use to decide if ICU or not ICU

CURB-65 was previously used: 1 point for each of (C)onfusion, (U)remia, (R)R>30, (B)P < 90/60, Age 65 or higher.
< 2 pts = outpatient
2 points or more = admission

*Most likely, if you have “Severe Cap” as defined by the major and minor criteria, you should probably be in the ICU.

Question 13

Empiric Therapy for outpatient treatment of CAP?

Answer 13

No Comorbids:

• High dose Amoxicillin (1 gram TID) is now preferred.
• Doxycycline is next.
• Macrolides only when preferred agents CI and when macrolide resistant S. pneumo is infrequent (wow!)

Comorbids: (Heart, lung, liver, kidney dx, diabetes, alcoholism, malignancy, asplenia)

• Beta-lactam (augmentin, cefpodoxime, cefuroxime) plus either macrolide or doxy.
• Levaquin or Moxiflox (these are antipneumococcal)

Question 14

Empiric therapy for inpatient treatment of non-severe CAP or severe CAP?

Answer 14

• Beta-lactam Plus (Macrolide OR Doxy (if mac CI))
• Levaquin or Moxy

If prior year MRSA: cover and obtain cx +/- nasal swab and de-escalate in 48 hours if no growth.
If prior year Pseudomonas: ADD cefepime, Zosyn, Merrem, ceftaz, Imipenem, or Aztreonam. Cx and de-escalate in 48 hours if no psuedomonas.
If recent (90 day) hospitalization, obtain Cx +/- nasal swab, and escalate if needed.

Question 15

What about aspiration pneumonia?

Answer 15

Probably don’t need anaerobic coverage, unless there’s an abscess or empyema.

Question 16

What about if pt has flu?

Answer 16

Give neuraminidase inhibitor (e.g. oseltamivir, zanamivir), but keep abx on board, and de-escalate after a few days if pt stable, low procalcitonin (possibly), cx neg.

Question 17

What about adjunctive corticosteroids?

Answer 17

Not routinely. Add if shock refractory to fluids and vasopressors. No benefit in non-severe CAP.

Question 18

What if you culture S. pneumo (PCN susceptible)?

Answer 18

First line: PCN or Amoxicillin

Second Line alternatives: Mac, ceph, clind, doxy, FQ

Question 19

What if you culture S. pneumo PCN resistant?

Answer 19

First Line: Cefotax, rocephine, or FQ

Alternatives: Vanc, zyvox, high-dose amox (if MIC 4 or less)

Question 20

What if you culture H. Flu (non-beta-lactamase)

Answer 20

First: Amoxicillin
Second: FQ, doxy, azith, clarith

Question 21

What if you culture H. Flu (beta-lactamase producer)

Answer 21

First: second or third gen ceph
Second: FQ, doxy, azith, clarith

Question 22

What if you culture Legionella?

Answer 22

First: Macrolide, FQ
Second: Doxy

Question 23

What if you culture MRSA?

Answer 23

First: Vanc or Zyvox
Second: Bactrim

Question 24

What if you culture MSSA?

Answer 24

First: antistaph PCN (nafcillin)
Second: Ancef, clindamycin

Question 25

What about Omadacyline?

Answer 25

New FQ that covers most G+ (MRSA effectiveness unclear), and drug-resistant S. pneumoniae, and most gram (-) such as H flu and M cat. Also covers many enterobacterieae and acinetobacter spp. Also covers atypicals (M pneumo, chlamydophila pneumo, and legionells pneumo)

Does not cover Proteus, Providencia, Morangella, or Pseudomonas.

FDA approved for CAP: 200 mg IV x 1, or 100 mg IV q12h x 2, then 100 mg IV q24h or 300 mg PO q24h.

Also approved for ABSSSI in adults.

Question 26

What about Lefamulin?

Answer 26

New drug. Inhibits protein synth via 50S ribosomal peptidyl transferase interference. Covers most G+, including MRSA (but these pt’s weren’t included in studies), and drug resistant S pneumo.

No activity against E. feacalis.

Covers common CAP G- like H flu and M cat, but does not cover enterbacters, psuedomonas, or A. baumannii.

Covers atypicals: M pneumo, C pneumo, L pneumo

Approved by FDA for CAP: 150 mg IV q12h and PO q12h

Question 27

What about IV to PO and Duration of therapy?

Answer 27

IV to PO: hemodynamically stable, clinically improving, able to take PO

Duration: Continue until clinically stable (afebrile, HR < 100, RR < 24, SBP > 90, OSAT > 90 or pO2 > 60 on RA, able to maintain oral intake, normal mental status).

• Minimum 5 days.
• 7 days suspected or proven MRSA or Pseudomonas
• Serial procalcitonin may help support discontinuation

Question 28

Who should get the flu vaccine?

Answer 28

All people over 6 months, who don’t have a CI.

Question 29

How should you treat the flu?

Answer 29

Outpatient, uncomplicated, no risk factors for complications: Tamiflu PO or inhaled Zanamivir for 5 days OR IV peramivir x 1.
-If started within 48 hours of onset or if household contact with patients at high risk.

Outpatient with risk factors for complications: PO Tamiflu OR inhaled Zanamivir for at least 5 days. Regar

Inpatient: PO Tamiflu OR IV peramivir if unable to obsorb PO meds, for 5 days.

Question 30

What are risk factors for complications from the Flu?

Answer 30

Age < 2, or 65 or older, chronic pulmonary, CVD (not HTN), renal, hepatic, hematologic, or metabolic (including DM), immunosuppression, pregnancy (or less than 2 week post partum), nursing home resident, extreme obesity (BMI > 40).

Question 31

Make cards for Pediatrics (last 5 minutes of video)

Answer 31

Do it.

Question 32

What is CURB-65?

Answer 32

Confusion
bUn > 19
Resp Rate > 30
BP < 90/60
Age > 65

You get 1 point for each thing

Question 33

If treating outpatient CAP with levaquin, what’s the dose?

Answer 33

750 mg Daily for at least 5 days (and patient is clinically improving)

Question 34

Who should get neuramidase inhibitors?

Answer 34

Outpatient pts with no risk factors: If within 2 days of symptom onset: oseltamivir or inhaled zanamivir for 5 days or IV peramivir x 1.

Outpatient with risk factors for complications: give regardless of when onset was: oseltamivir or inhaled zanamivir for 5 days:

Inpatient: give it. Oseltamivir if can take PO. Else, IV peramivir. Give either one for 5 days!