Author:
Jamie L.Adler
Jason C.Imperato
Description
- Epidemiology:
- Seventh leading cause of death and leading cause from infectious disease in the U.S.
- Highest mortality in elderly and patients with the following coexisting conditions:
- Chronic heart, lung, liver, and kidney disease
- Diabetes mellitus
- Alcoholism
- Malignancy
- Asplenia
- Immunosuppression
- Use of antimicrobials within last 3 mo
- Classifications:
- Source based:
- Community acquired (CAP)
- Hospital acquired (HAP)
- Ventilator associated (VAP)
- Symptom based:
- Complications:
- Bacteremia
- Sepsis
- Abscess
- Empyema
- Respiratory failure
Etiology
- CAP (typicals):
- CAP (atypicals):
- Mycoplasma pneumoniae
- Chlamydophila pneumoniae
- Legionella pneumophila
- Viral
- HCAP/HAP/VAP:
- Gram negatives (Pseudomonas, Stenotrophomonas)
- Methicillin-resistant S. aureus (MRSA)
- Immunosuppressed:
- Aspiration:
- Chemical pneumonitis ± oral and gastric anaerobes
Signs and Symptoms
History
- Typical:
- Acute onset
- Fever
- Chills
- Rigors
- Cough
- Purulent sputum
- Shortness of breath
- Pleuritic chest pain
- Atypical:
- Subacute onset
- Viral prodrome
- Nonproductive cough
- Low-grade fever
- Headache
- Myalgias
- Malaise
- Absence of pleurisy and rigors
Physical Exam
- Vital signs:
- Tachypnea
- Tachycardia
- Hypoxia
- Fever
- Pulmonary exam:
- Dullness to percussion
- Tactile fremitus
- Egophony
- Rales
- Rhonchi
- Decreased breath sounds
- Note that pneumonia may be present in the absence of the above signs of consolidation
Geriatric Considerations |
- Elderly patients have higher morbidity and mortality from pneumonia
- Atypical presentations are more common
|
Essential Workup
Combination of clinical and radiographic diagnosis
Diagnostic Tests & Interpretation
Lab
- General:
- CBC with differential
- Serum chemistry
- Others:
- Blood cultures (ICU only)
- Sputum cultures and Gram stain (ICU only)
- Urine antigen tests for S. pneumoniae and Legionella
- C-reactive protein possibly helpful
- Lactate may be helpful
- Influenza viral test
Imaging
Chest radiograph:
- General:
- Findings are nonspecific for particular infectious etiologies
- May be deferred in young, healthy patients receiving empiric outpatient management
- Negative imaging should not preclude antimicrobial therapy in patients with clinical diagnosis
- Suggestive findings:
- Silhouette sign (R. heart border = RML, L. heart border = lingula, R. hemidiaphragm = RLL, L. hemidiaphragm = LLL)
- Air bronchograms
- Segmental or subsegmental consolidation
- Diffuse interstitial opacities
- Pleural effusion
- Empyema
- Abscess
- Cavitation
Diagnostic Procedures/Surgery
Thoracentesis:
- For large effusions, enigmatic pneumonia, and patients who fail to respond to stand ard therapy
Differential Diagnosis
- Asthma
- Bronchitis
- CHF
- COPD
- Foreign-body aspiration
- Occupational or environmental exposure
- Pneumothorax
- Pulmonary embolism
- Tumor
Prehospital
- IV access
- Supplemental oxygen
- Cardiac monitor
- Consider inhaled bronchodilators
- Consider endotracheal intubation in cases of severe respiratory distress
Initial Stabilization/Therapy
- IV access and fluid resuscitation as needed
- Supplemental oxygen
- Cardiac monitor
- Inhaled bronchodilators
- Endotracheal intubation in cases of severe respiratory distress as indicated
ED Treatment/Procedures
- American Thoracic Society guidelines for empiric therapy
- Outpatient:
- Previously healthy, no coexisting conditions:
- Significant coexisting conditions (see above):
- Inpatient:
- Noncritical care:
- Combination β-lactam PLUS macrolide OR
- Respiratory fluoroquinolone alone
- Critical care:
- Combination β-lactam PLUS macrolide OR respiratory fluoroquinolone
- For Pseudomonas, consider adding antipseudomonal agent (piperacillin/tazobactam, imipenem, meropenem, cefepime) PLUS antipseudomonal fluoroquinolone (high-dose levofloxacin) OR antipseudomonal agent (see above) PLUS aminoglycoside (gentamicin) PLUS macrolide (azithromycin)
- For MRSA, consider adding vancomycin or linezolid
- For aspiration, consider adding clindamycin or metronidazole
- For drug-resistant S. pneumoniae, consider adding vancomycin
Medication
- Amoxicillin-clavulanate (Augmentin): 500 mg PO q12h
- Ampicillin-sulbactam (Unasyn): 1.5-3 g IV q6h
- Azithromycin: 500 mg PO on day 1 and 250 mg PO on days 2-5 OR 500 mg PO daily for 3 d OR 500 mg IV daily
- Aztreonam: 1-2 g IV q12h
- Cefepime: 2 g IV q12h
- Cefotaxime: 1-2 g IV q8h
- Cefpodoxime: 200 mg PO q12h
- Ceftazidime: 2 g IV q12h
- Ceftriaxone: 1-2 g IV daily
- Cefuroxime: 0.75 and 1.5 g IV q8h
- Doxycycline: 100 mg PO/IV q12h
- Ertapenem: 1 g IV daily
- Levofloxacin: 500-750 mg PO/IV daily
- Linezolid: 600 mg PO/IV q12h
- Imipenem: 500 mg IV q6h
- Meropenem: 1 g IV q8h
- Moxifloxacin: 400 mg IV daily
- Piperacillin-tazobactam (Zosyn): 3.375-4.5 g IV q6h
- Vancomycin: 1 g IV q12h
First Line
- Outpatient:
- Healthy:
- Azithromycin 500 mg PO day 1, 250 mg PO days 2-5 OR 500 mg PO daily for 3 d
- Comorbidities:
- Levofloxacin 750 mg PO daily for 5 d
- Inpatient:
- Non-ICU:
- Levofloxacin 750 mg IV daily
- ICU:
- Ceftriaxone 1 g IV daily and levofloxacin 750 mg IV daily ± piperacillin-tazobactam 4.5 g IV q6h ± vancomycin 1g IV q12h
Second Line
Aztreonam may be substituted for β-lactams in confirmed penicillin-allergic patients for the above ICU regimens
Disposition
Admission Criteria
- Based on severity of illness, coexisting conditions, ability of home care, and follow-up
- Clinical decision-making rules may aid in stratifying patients but should not supersede clinical judgment
- Pneumonia severity index:
- Demographics:
- If male: + age (yr)
- If female: + age (yr) - 10
- If nursing-home resident: +10
- Comorbid illness:
- Neoplastic disease: +30
- Liver disease: +20
- Congestive heart failure: +10
- Cerebrovascular disease: +10
- Renal disease: +10
- Physical exam findings:
- Altered mental status: +20
- Pulse ≥125/min: +20
- Respiratory rate >30/min: +20
- SBP <90 mm Hg: +15
- Temperature <35°C or ≥40°C: +10
- Lab and radiographic findings:
- Arterial pH <7.35: +30
- BUN ≥30 mg/dL: +20
- Sodium <130 mmol/L: +20
- Glucose ≥250 mg/dL: +10
- Hematocrit <30%: +10
- PaO2<60 mm Hg: +10
- Pleural effusion: +10
- Interpretation:
- 0: Class I (outpatient)
- <70: Class II (outpatient vs. short observation)
- 71-90: Class III (home with IV antibiotics vs. short observation)
- 91-130: Class IV (inpatient)
- >130: Class V (inpatient)
- Additional considerations:
- Previous hospitalization within last year for pneumonia
- Failed outpatient therapy
- Social conditions preventing safe outpatient disposition
- CURB-65 rule:
- Criteria:
- Confusion (abbreviated mental test ≤8)
- Urea >7 mmol/L OR BUN >19
- Respiratory rate ≥30/min
- BP with SBP <90 mm Hg, DBP <60 mm Hg
- Age ≥65 yr
- Interpretation:
- 0-1: Outpatient treatment
- 2: Close outpatient vs. brief inpatient
- 3-5: Inpatient with ICU consideration
Discharge Criteria
- Age <65 yr
- No comorbid illnesses
- Nontoxic appearance
- Normal vital signs
- Normal lab studies
- Primary care follow-up within 72 hr
Issues for Referral
Follow-up with primary care within 72 hr
Follow-up Recommendations
Primary care follow-up within 72 hr
- KalilAC, MeterskyML, KlompasM, 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 Infec Dis. 2016;63(5):e61-e111.
- Mand ellLA, WunderinkRG, AnzuetoA, et al. Infectious Disease Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults . Clin Infect Dis. 2007;44(suppl 2):S27-S72.
- MoranGJ, TalanDA. Pneumonia. In: MarxJA, HockbergerRS, WallsRM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed.St. Louis, MO: Mosby; 2009:927-938.
- MoranGJ, TalanDA, AbrahamianFM. Diagnosis and management of pneumonia in the emergency department . Infect Dis Clin North Am. 2008;22(1):53-72.
- NazarianDJ, EddyOL, LukensTW, et al. Clinical policy: Critical issues in the management of adult patients presenting to the emergency department with community-acquired pneumonia . Ann Emerg Med. 2009;54(5):704-731.
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