Pneumonia

Community Acqired Pneumonia (CAP)

CAP is usually caused by S. pneumonia, H. influenza, S. aureus, legionella (usually more severe), mycoplasma and Chlamydophila (less severe), and pseudomonas and Enterobacteriaceae sometimes isolated 

You don’t usually do cultures in CAP.  Chest infiltrate and cough/sputum are diagnostic. Don’t go by procalcitonin to diagnose or to discontinue therapy.

For CAP, there are a few “scores” you should be familiar with. The CURB-65 has fallen out of favor, but it’s quick and easy and still may be tested. However, we usually don’t use it to determine ICU admission anymore (I left that in because some practitioners still do), it’s sometimes used for inpatient vs outpatient. To determine whether to admit to ICU or the floor, you should use clinical criteria and provider judgment.

• 1 point each: Confusion, Urea >19, Respiratory Rate >=30, Blood pressure <90 SBP or <=60 DBP, age >=65
• Score = 0 or 1: can treat as outpatient
• Score = 1: consider admission, but can closely watch as outpatient
• Score = 2: Inpatient admission, consider ICU

Generally, the Pneumonia Severity Index is preferred, but it’s far more complicated. It predicts patients who can be treated as outpatients better, saving unnecessary hospitalizations. A tool or scorecard must be used to obtain this score.

• <=70 outpatient
• 71-90-Inpatient observation
• >=91-Admission

Outpatient treatment:  

• No comorbidities: Amoxicillin TID
• Can use doxy 
• Macrolide only if above are contraindicated AND resistance infrequent 

• Comorbities: B-lactam PLUS macrolide or doxy 
• Can use levo or moxifloxacin 
• *Consider MRSA if IV antibiotics in last 90 days or pseudo/MRSA in last year 

Inpatient Treatment:

• No comorbidities: B-lactam PLUS macrolide or doxy 
• Can use levofloxacin or moxifloxacin 
• If prior MRSA (1 year): add vanc or linezolid 
• If prior pseudo (1 year): add cefepime, pip-tazo, ceftazidime, imipenem, meropenem or azetronam 
• If prior hosp. and IV antibiotics or locally validated resistance factors: add drugs after cultures 
• Comorbidities: CHF, lung, liver, renal disease, diabetes, alcoholism, malignancies, asplenia, immunosuppression, antimicrobial in past 3 months

• Severe: B lactam plus either a macrolide or FQ.  No FQ alone 
• Add on as above 
• Severe is: septic shock, respiratory failure/ventilation or 3 of: rr > 30 breaths, PaO2/FI02<250, multilobar infiltrates, confusion, uremia (>20), leukopenia (<4000), thrombocytopenia (<100,000), hypothermia or hypotension requiring aggressive resuscitation 

• Deescalate 48 hours after cultures or MRSA swab
• Do not add coverage for aspiration or corticosteroids 
• Give all CAP patients with flu Tamiflu, no matter how long they’ve had flu symptoms
• Duration: continue until clinically stable, minimum of 5 days, 7 days if suspected MRSA or pseudo.  Serial procalcitonin can support discontinuation.  If 80% drop, may DC
• Transition to PO when able to oral and clinically stable/improving 
• Treat for 7-10 days.

• Pediatric: if not immunized against strep and H. influenza, cefotaxime or ceftriaxone.   

Directed Therapy

If cultures grow something specific, you can treat just for that and DC any antibiotics that don’t treat (ie: vanc, anti-pseudomonas)

• S. Pneumo: PenG or Amoxil  ALT: macrolide, ceph, clinda, doxy, FQ 
• Resistant S. Pneumo: cefotaxime, ceftriaxone, Levo ALT: vanc, linezolid, high dose Amoxil 
• H. Influenza: Amoxil ALT: FQ, doxy, azithromycin, clarithromycin 
• Resistant H. Influenza: 2^nd or 3^rd gen ceph ALT: FQ, doxy, azithromycin, clarithromycin 
• Legionella: FQ, macrolide ALT: Doxy 
• MRSA: van, linzesolid ALT: Bactrim 
• MSSA: Antistaph PCN (methicillin nafcillin oxacillin cloxacillin dicloxacillin) ALT: cefazolin, clindamycin
• New CAP agents: Omadecycline and Lefamulin: approved for adult CAP. No clinical data for MRSA. 

Hospital Associated Pneumonia (HAP):

HCAP is no longer a category. See CAP.

Hospital-Acquired or Ventilator-Associated Pneumonia (HAP/VAP):

• Pathogens: Pseudomonas, Acinetobacter, staph, MRSA 
• HAP = pneumonia 48 hours admission, VAP= pneumonia 48 hours after ventilation 
• Get blood cultures for HAP/VAP. Non-invasive is preferred. Do not diagnose based on procalcitonin. Clinical criteria is more important than biomarkers 
• If morbidity risk is high: MRSA and Double Pseudo from 2 classes (Only risk factors are IV antibiotics in last 90 days or structural lung disease) 
• NO AMINOGLYCOSIDE MONOTHERAPY 

Treatment:

• In VAP, if the MRSA and Gram Negative Bacterial Resistance (GNBR) rates are <10 or < 20 in HAP: B-lactam only (cefepime, imipenem, meropenem, pip-tazo) OR Levaquin only 
• In VAP, if the MRSA/GNBR>10 or >20 in HAP: ADD vanc or linezolid (you can use aztreonam as your beta-lactam or cipro as your FQ in addition to the above) 
• High Risk (structural lung disease or IV antibiotics) ADD extra antipseudomonal.  Can be above or aminoglycoside (or polymyxins in VAP) 
• In VAP, one of the two must have s. aureus coverage 
• B-Lactam should have antipseudomonal coverage: ceftazidime, cefepime, imipenem, meropenem, pip/tazo or aztreonam 
• Inhaled antibiotics can be used in combo (not alone) in VAP due to Gram – bacilli being susceptible only to AGS or polymyxins 
• Avoid polymyxin unless no other choice, Polymyxin B causes less kidney damage than colistin 
• Escalation with cultures or an 80% drop in procalcitonin (this is the best use of procalcitonin in pneumonia).
• If morbidity risk is high: MRSA and Double Pseudo from 2 classes (Only risk factors are IV antibiotics in last 90 days or structural lung disease). The first agent should be a B-lactam unless contraindicated. B-lactams are almost always preferred in pneumonia.
• Everyone with HAP/VAP needs at least 2 agents.  Most patients (patients with MDRs) will need at least 3.
• ***Linezolid causes thrombocytopenia, check CBC*** 

• Treatment Duration:  7 days 

Newer Agents

• Ceftolozone-tazobactam: MDR Gram – coverage, including ESBL and AmpC producers, CTX-M, pseudomonas but no activity against carbapenemase producers/CRE, no enterococcus, no anaerobes, NO KPC 
• Ceftazidime-avibactam: MDR Gram – including ESBL, AmpC, most CRE, including KPC and OXA-48, limited gram, no STAPH, no pseudomonas, no enterococcus, no anaerobes 
• Meropenem-vaborbactam – MDR Gram – including ESBL, AMPC, CRE including KPC, and NON-MDR STAPH