Pneumonia in Adults

Community Acquired Pneumonia (CAP)

Elderly pt with no h/o alcoholism, dysphagia, cardiopulmonary/liver/renal disease, DM, asplenia, malignancy, and immunosuppression including HIV and IV drug use presents from home with dyspnea. Reports malaise, fever/chills, productive cough, pleuritic chest pain, myalgias, and night sweats. Denies rhinorrhea, sore throat. Recently returned from a cruise. Fever, hypotension, tachycardia with increased work of breathing, pulmonary crackles, and egophony on exam.

• Labs

  • Obtain SPO2, BMP

  • Obtain CBC, blood cultures upon hospitalization

  • Consider obtaining pneumococcal/Legionella urine antigen test and procalcitonin for risk stratification

  • Recent high risk sexual exposure/IV drug use: Consider testing for HIV, TB, pneumocystis pneumonia (PCP)

• Imaging

  • Obtain EKG upon hospitalization to rule out QT prolongation

  • CXR showing pulmonary opacities and lobar infiltrate

• Calculate CURB-65 (confusion, BUN > 19, RR > 30, BP < 90/60, age 65+) to determine need for hospitalization

• Treatment

  • Outpatient: CURB-65 < 2

    • Start azithromycin 500 mg on day 1 followed by 250 mg days 2-5

    • Contact office if symptoms worsen or fail to improve with treatment

  • Hospitalized patient (CURB-65 2+) with no QTC prolongation and normal renal function:

    • Start ceftriaxone (CTX) 1g IV qd + azithromycin 500 mg IV qd x 5 days

    • Pseudomonas risk factors: Substitute piperacillin-tazobactam (Zosyn) 3.375g q6h x 7 days for CTX

    • MRSA risk factors: Add vancomycin 20 mg/kg/dose (max 2g) BID x 7 days

    • Admitted to ICU: Consider prednisone 50 mg qd x 5 days to decrease length of stay/ARDS risk

    • Age 65+ years: PCV13 vaccine prior to discharge and PPSV23 in 12 months

  • Alcoholism, dysphagia, and/or other aspiration risk factors

    • Outpatient: Amoxicillin-clavulanate ER 875 mg BID + azithromycin

    • Hospitalized: Ampicillin-sulbactam 1.5 g IV q6h + azithromycin

Notes

• The vignette presentation is a severe CAP case that would require hospitalization. It is written to help you take a more complete history.

  • For less severe presentations and CURB-65 < 2, treat as an outpatient. A BMP is required to calculate CURB-65 and should be obtained in more severe cases.

  • Patient without any of the risk factors mentioned in the vignette can be treated outpatient with azithromycin (see above)

• Clinical presentation

  • Pleuritic chest pain: Sharp stabbing/burning sensation present while inhaling (primarily) and exhaling

  • Fever (LR+ 2.7) and egophony (LR+ 5.3) are the most predicative physical findings

  • Rhinorrhea and sore throat may be present, but are more indicative of viral URI

• Treatment in hospital

  • IV antibiotics indicated if any are present: Cognitive impairment, inability to tolerate PO, HR > 100, SPO2 < 90%, RR > 25, T > 38.4

  • Alternative regimen for non-ICU patient without risk factors:

    • Ceftriaxone 2g BID x 5 days (beta-lactam) + azithromycin 500 mg qd x 5 days (macrolide)

    • If QTc elevated, substitute doxycycline 100 mg BID x 5 days for azithromycin

  • Pneumonia requiring ICU admission: 3rd generation cephalosporin (CTX) + macrolide (azithromycin) +/- respiratory fluoroquinolone (levofloxacin, moxifloxacin)

• Pneumonia subtypes

  • Aspiration pneumonia

    • Alcoholism and dysphagia increase risk

    • Require anaerobic coverage with a macrolide (e.g. azithromycin), fluoroquinolone (e.g. levofloxacin), or doxycycline

  • MRSA PNA: Risk factors include components of the Schorr score (consider MRSA coverage for ≥ 7 points)

  • Legionella pneumonia

    • Risk factors include cruise ship travel

    • May present with diarrhea and hyponatremia

    • Levofloxacin covers Legionella (do not obtain a urine Legionella NAAT if using this medication)

Hospital Acquired Pneumonia (HAP)

• When taking a history, the CAP vignette still applies with the exception of presenting from home

  • HAP definition: PNA occurring within 48 hours of admission that was not present at the time of admission

  • Healthcare associated pneumonia (HCAP) was not included in the 2016 IDSA guidelines

• Antibiotic selection: Refer to a local antibiogram for specific resistance patterns. One will generally be available through a hospital EMR or intranet page.

  • Levofloxacin 750 mg x 7 days

  • MRSA coverage

    • Start if risk factors for MRSA pneumonia are present or if local methicillin resistance is > 20% or unknown

    • Add linezolid 600 mg IV BID x 7 days

  • Structural lung disease, treatment with IV antibiotics during previous 90 days, and/or need for ventilatory support: Add Ceftazadime 2 g IV q8h x 7 days to levofloxacin and linezolid coverage

Differential Diagnosis

When evaluating for pneumonia, also consider acute lung injury including:

• Acute Respiratory Distress Syndrome (ARDS)

• E-cigarette or Vaping Product use Associated Lung Injury (EVALI)

• Transfusion Associated Lung Injury (TRALI)