Pneumonia (main): Difference between revisions
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[[File:PneumonisWedge09.jpg|thumb|[[CXR]] showing prominent wedge-shape area of airspace consolidation in the right lung, characteristic of bacterial [[pneumonia]].]]
[[File:PneumonisWedge09.jpg|thumb|[[CXR]] showing prominent wedge-shape area of airspace consolidation in the right lung, characteristic of bacterial [[pneumonia]].]]
[[File:RLLpneumonia.png|thumb|Right lower lobe pneumonia as seen on lateral CXR.]]
[[File:RLLpneumonia.png|thumb|Right lower lobe pneumonia as seen on lateral CXR.]]
[[File:XR chest - pneumonia with abscess and caverns - d0.jpg |thumb|[[CXR]] showing pneumonia with abscess.]]
[[File:XR chest - pneumonia with abscess and caverns - d0.jpg |thumb|[[CXR]] showing pneumonia with [[lung abscess]].]]
[[File:CT scan of the chest, demonstrating right-sided pneumonia.jpg|thumb|CT chest showing right sided pneumonia]]
[[File:CT scan of the chest, demonstrating right-sided pneumonia.jpg|thumb|CT chest showing right sided pneumonia]]
[[File:PNA_US.gif|thumb|Hepatization of the lung and dynamic air bronchograms present in patient with LLL pneumonia. Source: POCUS Atlas]]
[[File:PNA_US.gif|thumb|Hepatization of the lung and dynamic air bronchograms present in patient with LLL pneumonia. Source: POCUS Atlas]]

Revision as of 22:07, 13 December 2023

This page is for adult patients. For pediatric patients, see: pneumonia (peds)

Background

Lobes of the lung with related anatomy.
  • Definition: infection of lung parenchyma
  • Empirically classified based upon location/risk factors

Pneumonia Empiric Categories

The term "health care-associated pneumonia" (HCAP) is no longer used.[1] It previously referred to pneumonia acquired in any healthcare facility (e.g., nursing home, hemodialysis center, recent hospitalization) and was used to identify patients at risk for infection with multidrug-resistant pathogens. However, this inappropriately led to increased inappropriately broad antibiotic use and was thus retired. Patients previously classified as HCAP should in general be treated as CAP with exceptions as below under resistant pathogens.

  • Community-acquired pneumonia (CAP): Acquired outside of the hospital
  • Nosocomial pneumonia: Acquired in a hospital setting
    • Hospital-acquired pneumonia (HAP): Acquired ≥48 hours after hospital admission
    • Ventilator-associated pneumonia (VAP): Acquired ≥48 hours after endotracheal intubation

Resistant Pathogen Risk Factors

ISDA recommends covering empirically for resistant pathogens (e.g., MRSA, pseudomonas) in adults with CAP only if there is a treatment regimen based on "locally validated" risk factors. In that case, may give empiric coverage while awaiting culture results.

  • Commonly accepted risk factors historically include:
    • Recent hospital stay
    • Nursing home/long-term care residents
    • Recent antibiotics
    • Dialysis
    • Receiving chronic wound care
    • Receiving chemotherapy
    • Immunosuppression (including steroids)
    • Alcoholism
    • Structural lung disease
    • Malnutrition

Commonly Encountered Pathogens by Risk Factor

Risk Factor Associated Organism
Alcoholism
*Aspiration
COPD and/or Smoking
Nursing Home
Exposure to bird droppings
Exposure to birds
Exposure to rabbits
Exposure to farm animals
Exposure to southwestern US
Early HIV
Late HIV (as above, plus:)
Structural Lung Disease (CF, bronchiectasis)
Injection drug use
Influenza
Ventilator Associated Pneumonia


Causes of Pneumonia

Bacteria


Viral


Fungal


Parasitic

Clinical Features

Differential Diagnosis

Acute dyspnea

Emergent

Non-Emergent

Evaluation

CXR showing prominent wedge-shape area of airspace consolidation in the right lung, characteristic of bacterial pneumonia.
Right lower lobe pneumonia as seen on lateral CXR.
CXR showing pneumonia with lung abscess.
CT chest showing right sided pneumonia
Hepatization of the lung and dynamic air bronchograms present in patient with LLL pneumonia. Source: POCUS Atlas

Workup

  • CXR
    • May have negative CXR early in disease or in cases of dehydration; infiltrate may "blossom" after providing rehydration and repeat imaging[2]
    • Absence of CXR findings does not preclude diagnosis; high clinical suspicion with adventitious breath sounds can be consistent with pneumonia despite negative imaging
    • Immunocompromised patients may not manifest radiographic evidence of pneumonia despite suggestive clinical findings
    • Clinical and radiographic findings do not necessarily correspond: the patient may be improving cliniclly despite having a worsening appearance on the CXR
  • Ultrasound
    • Can be considered as an alternative to CXR
    • Sensitivity 82% and specificity 94%[3]
  • CBC
  • Chemistry
  • IDSA does not support using initial serum procalcitonin levels to determine whether empiric antibiotics should be initiated.
    • Clinical judgement plus radiographic evidence alone should guide therapy (strong recommendation, moderate quality of evidence)


If patient will be admitted:

  • Blood Cultures are ONLY indicated for CAP patients with:
    • ICU (required)
    • Multi-lobar
    • Pleural effusion
    • Cavitary lesions
    • Leukopenia
    • Prosthetic valves
    • IV drug users
    • Parenteral antibiotics in the last 90 days
    • Consider for higher-risk patients admitted with CAP
      • Liver disease
      • Immunocompromised
      • Significant comorbidities
      • Other risk factors
  • Sputum staining
    • If concern for particular organism

Chest X-Ray Mimics

  • Legionella urine antigen test
    • ICU patients
    • Alcoholics
    • Outbreaks
    • Recent (within 2 weeks) travel history

IDSA Severe Pneumonia Criteria

Severe pneumonia can be diagnosed with either one major criterion or three or more minor criteria.[4]

Minor criteria

  • Respiratory rate > 30 breaths/min
  • PaO2/FiO2 ratio < 250
  • Multi-lobar infiltrates
  • Confusion/disorientation
  • Uremia (blood urea nitrogen level > 20 mg/dl)
  • Leukopenia (WBC < 4,000 cells/µL)
  • Thrombocytopenia (platelet count 100,000 cells/µL)
  • Hypothermia (<36.8C)
  • Hypotension requiring aggressive fluid resuscitation

Major criteria

  • Septic shock with need for vasopressors
  • Respiratory failure requiring mechanical ventilation
  • Leukopenia due to infection alone (i.e., not due to chemotherapy)

Management

Outpatient

Coverage targeted at S. pneumoniae, H. influenzae, M. pneumoniae, C. pneumoniae, and Legionella

Healthy[5]

No comorbidities (chronic heart, lung, liver, or renal disease; diabetes mellitus; alcoholism; malignancy; or asplenia) and no risk factors for MRSA or Pseudomonas aeruginosa (include prior respiratory isolation of MRSA or P. aeruginosa or recent hospitalization AND receipt of parenteral antibiotics (in the last 90 d))

  • Amoxicillin 1 g three times daily (strong recommendation, moderate quality of evidence), OR
  • Doxycycline 100 mg twice daily (conditional recommendation, low quality of evidence), OR
  • Macrolide in areas with pneumococcal resistance to macrolides <25% (conditional recommendation, moderate quality of evidence).
  • Duration of therapy 5 days minimum

Unhealthy[5]

If patient has comorbidities or risk factors for MRSA or Pseudomonas aeruginosa

  • Combination therapy:
    • Amoxicillin/Clavulanate
      • 500 mg/125 mg TID OR amox/clav 875 mg/125 mg BID OR 2,000 mg/125 mg BID. Duration is for a minimum of 5 days and varies based on disease severity and response to therapy; patients should be afebrile for ≥48 hours and clinically stable before therapy is discontinued[6]
    • OR cephalosporin
    • AND macrolide
      • Azithromycin 500 mg on first day then 250 mg daily
      • OR clarithromycin 500 mg BID OR clarithromycin ER 1,000 mg daily (strong recommendation, moderate quality of evidence for combination therapy)
    • OR doxycycline 100 mg BID (conditional recommendation, low quality of evidence for combination therapy)
  • Monotherapy: respiratory fluoroquinolone (strong recommendation, moderate quality of evidence):

Inpatient

  • Monotherapy or combination therapy is acceptable
  • Combination therapy includes a cephalosporin and macrolide targeting atypicals and Strep Pneumonia[7]
  • Adjunctive corticosteroids in severe CAP: The SCCM 2024 Focused Update strongly recommends corticosteroids for hospitalized adults with severe bacterial CAP (strong recommendation, moderate certainty)[8]
    • CAPE COD trial (NEJM 2023): Hydrocortisone 200 mg IV daily (50 mg q6h) in severe CAP requiring ICU/intermediate care → ↓ 28-day mortality (6.2% vs 11.9%, NNT ~18), ↓ intubation, ↓ vasopressor use[9]
    • Duration: 200 mg/day for 4–7 days based on clinical improvement, then tapered (total 8–14 days)
    • Excluded patients already in septic shock
    • No recommendation for or against steroids in less severe CAP[8]
    • Avoid in influenza pneumonia (without bacterial superinfection)[5]
  • Duration: Minimum 5 days; continue until clinically stable (temp ≤37.8°C, HR ≤100, RR ≤24, SBP ≥90, SpO2 ≥90% on RA, tolerating PO, baseline mental status) for ≥48 hours[5]
  • De-escalation: If empiric MRSA or Pseudomonas coverage was started, de-escalate to standard CAP therapy within 48 hours if cultures/MRSA nasal PCR are negative and patient is improving[5]

Community Acquired (Non-ICU)

Coverage against community acquired organisms plus M. catarrhalis, Klebsiella, S. aureus[5]

ICU, Low Risk of MRSA/Pseudomonas

ICU, Risk of Pseudomonas (without MRSA risk)

2019 guidelines recommend single antipseudomonal β-lactam (changed from double gram-negative coverage in 2007 guidelines)[5]

ICU, Risk of MRSA

Add MRSA coverage to appropriate regimen above[5]

  • Vancomycin 15–20 mg/kg IV q8-12h (target AUC/MIC 400-600) OR Linezolid 600 mg IV q12h
  • MRSA nasal PCR has a high negative predictive value (~95%); if negative, MRSA coverage can be safely discontinued[10]

Hospital Acquired Pneumonia (HAP)

Pneumonia developing ≥48 hours after hospital admission in non-intubated patients[11]

High risk of MRSA or high mortality risk (ventilatory support for HAP or septic shock)
Low risk of MRSA and low mortality risk

Ventilator Associated Pneumonia (VAP)

Pneumonia developing ≥48 hours after endotracheal intubation[11]

High risk of MRSA or IV antibiotics in the last 90 days or unit MRSA prevalence >10-20% or unknown
Low risk of MRSA and Pseudomonas (no risk factors for antimicrobial resistance, unit MRSA <10-20%)
  • Single antipseudomonal β-lactam monotherapy (from list above) is acceptable[11]
  • Duration: 7 days recommended[11]


Disposition

IDSA 2019 guidelines recommend clinical judgement plus PSI over CURB-65. [13]

Pneumonia severity index (Port Score)

Risk Factors

Points
Demographic Factors
Age for men
 Age
Age for women
 Age -10
Nursing home resident
 +10
Coexisting Illnesses

Neoplastic disease (active)
 +30
Chronic liver disease
 +20
Heart Failure
 +10
Cerebrovascular disease
 +10
Chronic renal disease
 +10
Physical Exam

AMS
 +20
RR > 30/min
 +20
Sys BP < 90
 +20
Temp <35 or >40
 +15
Pulse > 125
 +10
Lab and xray findings
Arterial pH < 7.35
 +30
BUN > 30
 +20
Na <130
 +20
Glucose > 250
 +10
Hematocrit <30%
 +10
PaO2 < 60 or SpO2 < 90%
 +10
Pleural effusion
 +10

Classification

Class
Points
Mortality
I
 <51 0.1%
II
 51-70 0.6%
III
 71-90
 0.9%
IV
 91-130
 9.3%
V
 >130
 27%

Disposition Pathway

  • Classes I and II: consider discharge
  • Class III: discharge verus admit based on clinical judgment
  • Classes IV and V: consider admission

CURB-65

  1. Confusion
  2. bUn > 19 mg/dl
  3. RR > 30
  4. BP < 90 SBP, or < 60 DBP
  5. Age > 65
  • Approximate 30-day mortalities and Tx considerations
    • +1 --> 3%, outpt tx
    • +2 -->7%, inpt, possible outpt
    • +3 --> 14% inpt, possible ICU
    • +4-5 --> 30% ICU

Prognosis

  • Half of patients are still symptomatic at 30 days, with a significant minority of patients experiencing chest pain, malaise or mild dyspnea even 2 to 3 months after treatment
  • In adults with CAP whose symptoms have resolved within 5-7 days, it is not recommended to routinely obtain follow-up chest imaging

See Also

External Links

References

  1. ↑ Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America Am J Respir Crit Care Med. 2019 Oct 1;200(7):e45-e67
  2. ↑ Feldman C. Pneumonia in the elderly. Clin Chest Med. 1999;20(3):563-573. doi:10.1016/s0272-5231(05)70236-7
  3. ↑ Staub LJ, Mazzali Biscaro RR, Kaszubowski E, Maurici R. Lung Ultrasound for the Emergency Diagnosis of Pneumonia, Acute Heart Failure, and Exacerbations of Chronic Obstructive Pulmonary Disease/Asthma in Adults: A Systematic Review and Meta-analysis. J Emerg Med. 2019;56(1):53-69. doi:10.1016/j.jemermed.2018.09.009
  4. ↑ Severe pneumonia can be diagnosed with either one major criterion or three or more minor criteria. Neth J Med. 1999 Sep;55(3):110-7 10.1016/s0300-2977(99)00071-6
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America Am J Respir Crit Care Med. 2019 Oct 1;200(7):e45-e67
  6. ↑ IDSA. Mandell 2007
  7. ↑ Chokshi R, Restrepo MI, Weeratunge N, Frei CR, Anzueto A, Mortensen EM. Monotherapy versus combination antibiotic therapy for patients with bacteremic Streptococcus pneumoniae community-acquired pneumonia. Eur J Clin Microbiol Infect Dis. Jul 2007;26(7):447-51
  8. ↑ 8.0 8.1 Chaudhuri D, Nei AM, Rochwerg B, et al. 2024 Focused Update: Guidelines on Use of Corticosteroids in Sepsis, Acute Respiratory Distress Syndrome, and Community-Acquired Pneumonia. Crit Care Med. 2024;52(5):e219-e233.
  9. ↑ Dequin PF, Meziani F, Quenot JP, et al. Hydrocortisone in Severe Community-Acquired Pneumonia. N Engl J Med. 2023;388(21):1931-1941.
  10. ↑ Parente DM, Cunha CB, Engemann AM, et al. The Clinical Utility of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Screening to Rule Out MRSA Pneumonia: A Diagnostic Meta-analysis With Antimicrobial Stewardship Implications. Clin Infect Dis. 2018;67(1):1-7.
  11. ↑ 11.0 11.1 11.2 11.3 11.4 11.5 Kalil AC, Metersky ML, Klompas M et al. Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016 Sep 1;63(5):e61-e111.
  12. ↑ Luther MK, Timbrook TT, Caffrey AR, Dosa D, Lodise TP, LaPlante KL. Vancomycin Plus Piperacillin-Tazobactam and Acute Kidney Injury in Adults: A Systematic Review and Meta-Analysis. Crit Care Med. 2018;46(1):12-20.
  13. ↑ Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America AJRCCM Vol. 200, No. 7, Oct 01, 2019
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