Pneumonia

Pulmonary Infections – VASP, Evan Schwartz

Acute Bronchitis

Background

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  • 1-3 wks productive cough, often preceded by URI, may have wheezing/rhonchi
  • Distinct from chronic bronchitis (>3 mos of consecutive cough x 2 consecutive yrs)
  • Distinct from PNA (parenchymal consolidation, fever >100.4F, hypoxia, tachypnea)
  • DDx: COVID19, post-nasal drip, GERD, undertreated/new asthma, ACE-i induced bradykinin cough, undertreated CHF, acute PE, or new lung cancer
  • Typically clinical dx; CXR/labs not necessary unless PNA suspected

 

Management

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  • Supportive: lozenges, cough suppressants (guaifenesin or dextromethorphan), smoking cessation. Consider albuterol inhaler for wheezing
  • No indication for antibiotics

 

Influenza

Background

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  • Dx often clinical w/cough, sore throat, #sputum/nasal discharge, HA, fever, myalgias, and malaise; ± N/V/D. Exam with increased flushing, rarely with lower respiratory symptoms

 

Evaluation

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  • During flu season: Obtain RPP or dedicated Influenza PCR in pts w/immunocompromise, acute hypoxic respiratory failure, respiratory distress, worsening of COPD, asthma, CAD/CHF; testing more accurate if obtained within 96 hour of symptom onset
  • CXR if concerned for bacterial superinfection

 

Management

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  • Antivirals most effective when given <48 hours from symptom onset; however, recommended to be given if symptomatic despite duration
  • Oseltamivir 75mg BID x 5 days or peramivir 600mg IV x 1 (needs renal adjustment)
  • Pain and fever: high-dose acetaminophen 1g TID are most effective; avoid aspirin, especially in children due to risk of Reye syndrome
  • There is emerging resistance to amantadine and rimantadine, and are no longer employed

 

Community Acquired Pneumonia (CAP)

Background

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  • All PNA that does not otherwise meet criteria for Hospital Acquired Pneumonia (PNA that develops ≥48 hours after hospital admission), Ventilator Associated Pneumonia (PNA that develops ≥48-72 hours after endotracheal intubation), or aspiration PNA
  • Healthcare-associated pneumonia is no longer a clinical entity per 2016 IDSA guidelines
  • MRSA Risk Factors: recent history, cavitary lesion, post-influenza bacterial PNA, pts with IDU, severe hypoxemia requiring intubation
  • Pseudomonas: Double coverage is not indicated in general population; LQ has 82% sensitivity so not recommended unless isolate proven susceptible

 

Evaluation

  • Resting pulse oximetry, ± ambulatory pulse oximetry
  • Sputum cultures prior to abx, BCx prior to abx in select groups (severe pneumonia, ICU admission, cavitary disease, immunosuppression).
  • Rule out flu if the right season, COVID-19, consider RVP if it will change management
  • CURB-65 or PSI can aid in decision between outpatient vs inpatient therapy
    • CURB65: Confusion, Uremia (BUN >=19 mg/dL), RR (>30/min), BP(<90/60 mmHg), Age ≥ 65 If ≥ 2, hospitalization is recommended.
        • Consider urine pneumococcal Ag, urine Legionella Ag in severe CAP and in certain pts (e.g., neutropenia, asplenia, obstructive lung disease, hyponatremia, diarrhea, or heavy alcohol use); these are performed at reference labs and will take several days to return.
        • CRP, ESR, and pro-calcitonin have not been shown to reliably improve outcomes; however, pro-calcitonin < 0.25 suggests against bacterial respiratory infection and antibiotic discontinuation is encouraged     
        • PA/ lateral CXR to evaluate for and localize infiltrate. If immunocompromised, consider CT chest w/o contrast (does not improve outcomes)
    • Lobar Consolidation - likely bacterial
    • Interstitial Infiltrate - likely atypical vs. viral vs. non-infectious
    • Cavitation - concerning for fungal vs. necrotizing vs. mycobacterial

 

Management

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  • Duration: 5-7 days (at least 5 days and improvement with clinical stability)

 

 

Outpatient

Inpatient (Non- ICU & ICU)

No MRSA or Pseudomonas suspected

Low Risk*: Amoxicillin 1g TID

High Risk:

- Amoxicillin-clavulanate 875/125 BID OR Cefdinir 300 BID + Macrolide

- Amoxicillin 1g TID + Macrolide

- Levofloxacin 750 daily

CTX 2g q24 + Azithromycin 500 daily OR Levofloxacin 750 daily

 

MRSA or Pseudomonas suspected

 

MRSA: Vancomycin OR Linezolid

  (if no bacteremia)

Pseudomonas: Cefepime 2g q8h

 

         

*No chronic heart, lung, liver, renal disease, DM, alcoholism, immunocompromise

 

Additional Information

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  • CTX is generally adequate coverage for aspiration PNA without evidence of abscess, empyema, or cavitary lesion on imaging
  • There is low sensitivity of S. pneumoniae to azithromycin (42%) and doxycycline (72%), so these should not be used as monotherapy
  • Check for DDI with Linezolid (e.g., SSRI)

 

 

Hospital Acquired Pneumonia (HAP) and Ventilator Associated Pneumonia (VAP)

Background

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  • HAP: Pneumonia that develops >48 hours after admission
  • VAP: Pneumonia that develops >48 hours after endotracheal intubation

 

Evaluation

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  • Cultures of blood, sputum, endotracheal aspirate and/or bronchoscopy specimen
  • Consider MRSA nares to help with de-escalation
  • If there is concern for respiratory viruses, influenza, COVID send RVP

 

Management

          •  
  • Duration: 7 days in uncomplicated cases, although specific pathogens (e.g., Pseudomonas) may require longer duration and ID guidance
  • Consider ID consultation if the patient is not clinically improving on empiric therapy or if an MDR pathogen grows from culture
  • If no MRSA isolated and pt is improving, consider stopping vancomycin ASAP
  • Some concern for nephrotoxicity with combination Vancomycin and piperacillin-tazobactam, but data controversial

 

 

MRSA Coverage

Pseudomonas Coverage

First Line

Vancomycin (PMCY dosing)

Cefepime 2g q8h OR Piperacillin-tazobactam 3.375 q8h extended infusion OR Ceftazidime 2g q8h

Alternative

Vancomycin allergy: Linezolid 600 mg PO q12h

PCN allergy*: Aztreonam 2g q8h