II. Definition: Community Acquired Pneumonia (CAP)

  1. Lower respiratory tract infection
  2. Develops in non-hospitalized patient
  3. May be Bacterial, viral, fungal or parasitic
  4. May be present despite normal Chest XRay

III. Epidemiology: Community acquired Pneumonia

  1. Incidence: 9.2 to 33 per 1000 person-years in U.S.
  2. Adult mortality: 60,000 deaths per year from Pneumonia or Influenza (8th leading cause of death)
  3. Most severe cases in very young and very old
  4. U.S. cost/year for community acquired Pneumonia: $10-17 billion (90% of cost is inpatient care)

V. Risk Factors

  1. Age over 65 years
  2. Recent antibiotics
  3. Immune compromised (e.g. HIV Infection)
  4. Respiratory illness (COPD, Asthma)
  5. Vascular disease (CHF, CVA)
  6. Diabetes Mellitus
  7. Chronic Liver Disease
  8. Chronic Kidney Disease
  9. Cancer

VI. Findings: Signs and Symptoms

  1. Bacterial Pneumonia
    1. Cough
      1. Productive of Purulent Sputum with typical Bacteria
      2. Non-productive in atypical cases
    2. Sudden onset
    3. Fever and Chills
    4. Fatigue
    5. Ill appearing patient
    6. Pleuritic Chest Pain
    7. Dyspnea
    8. Tachypnea
    9. Tachycardia
  2. Viral Pneumonia
    1. Non-productive cough
    2. Gradual Onset with prodrome (malaise and Headache)
    3. Chest XRay more impressive than exam
    4. Onset in fall or winter
    5. Wheezing more common in viral causes
    6. Low grade Temperature (<101.3 F)
  3. Mycoplasma pneumonia
    1. Constant, harsh, non-productive cough
    2. Wheezing may occur in Mycoplasma pneumonia
    3. Fever typically lasts longer than 3 days
    4. More common in age over 3 years
  4. Legionella
    1. Onset with myalgias and Headache
    2. Fever to 104 F for first few days
    3. Gastrointestinal symptoms predominate in up to 40%
    4. Cough is late onset, mild, often non-productive

VII. Signs

  1. General findings
    1. Fever
      1. Positive Likelihood Ratio: 2.1
      2. Negative Likelihood Ratio: 0.71
    2. Ill appearing patient
    3. Dyspnea
    4. Tachypnea
    5. Tachycardia
    6. Hypoxia (check Oxygen Saturation)
  2. Localized findings at involved lung region
    1. Egophony
      1. Positive Likelihood Ratio: 8.6
      2. Negative Likelihood Ratio: 0.96
    2. Dullness to percussion
      1. Positive Likelihood Ratio: 4.3
      2. Negative Likelihood Ratio: 0.79
    3. Rales
    4. Diminished breath sounds
    5. Bronchial breath sounds
    6. Tactile fremitus
  3. References
    1. Metlay (1997) JAMA 278(17): 1440-5 [PubMed]

VIII. Diagnosis

  1. See Diehr Rule to Diagnose Pneumonia
  2. Findings with highest Test Sensitivity for Pneumonia
    1. Fever and chills
    2. Pleuritic Chest Pain
    3. Cough productive of mucopurulent Sputum
    4. Dyspnea
    5. Tachypnea (especially in over age 65 years)
  3. Findings with highest Specificity
    1. Asymmetric breath sounds
    2. Pleural rubs
    3. Egophony
    4. Increased tactile fremitus

IX. Labs

  1. General
    1. Consider specific testing based on risks
      1. See Pneumonia Causes (as well as indications below)
    2. Lab Indications
      1. Moderate or severe community acquired Pneumonia
      2. Patient with comorbid conditions
    3. Efficacy of Labs
      1. No value in non-severe community acquired Pneumonia
      2. Theerthakarai (2001) Chest 119:181-4 [PubMed]
  2. Sputum Gram Stain and Culture
    1. See Sputum Culture
    2. Adequacy
      1. Good quality sample: <25 epithelial cells/LPF and contains Neutrophils
    3. Indications (IDSA/ATA 2007)
      1. ICU Admission (consider endotracheal aspirate if intubated)
      2. Failed outpatient antibiotic therapy
      3. Cavitary infiltrates (obtain specific fungal and Tuberculosis cultures)
      4. Active Alcohol Abuse
      5. Severe COPD
      6. Pleural Effusion (also perform Thoracentesis for Pleural Fluid culture and analysis)
      7. Positive Legionella urine antigen (Legionella culture requires special media)
      8. Positive Pneumococcal urine antigen
    4. Efficacy
      1. Sputum has low diagnostic yield in Community acquired Pneumonia
        1. Not recommended in outpatient community acquired Pneumonia
        2. Ewig (2002) Chest 121:1486-92 [PubMed]
  3. Blood Culture
    1. Indications (IDSA/ATA 2007)
      1. Not indicated unless severe disease (highest yield in severe Pneumonia)
      2. Consider in hospitalized community acquired Pneumonia (especially if possible ICU patient)
      3. Intensive care unit admission
      4. Cavitary infiltrates
      5. Leukopenia
      6. Active Alcohol Abuse
      7. Chronic severe liver disease
      8. Asplenia
      9. Pleural Effusion
      10. Positive Pneumococcal urine antigen
    2. Efficacy
      1. Low sensitivity: Positive in only 5-10% of cases
      2. Does not predict severity or outcome
    3. References
      1. Campbell (2003) Chest 123:1142-50 [PubMed]
  4. Specific Testing with reasonable efficacy
    1. Influenza
      1. Rapid Influenza Test (Influenza DFA)
    2. Legionella pneumophila
      1. Rapid PCR of Sputum (80% Test Sensitivity)
      2. Urinary antigen
        1. Test Sensitivity 70-90% (for serogroup 1, responsible for >80% of cases)
        2. Test Specificity 99%
      3. Indications (Legionella UAT per IDSA/ATS 2007)
        1. Intensive care unit admission
        2. Failed outpatient antibiotic therapy
        3. Active Alcohol Abuse
        4. Travel within prior 2 weeks
        5. Pleural Effusion
    3. Mycoplasma pneumoniae
      1. Rapid PCR of Sputum (>30% Test Sensitivity)
    4. Chlamydia Pneumonia
      1. Rapid PCR (>30% Test Sensitivity)
    5. Streptococcus Pneumoniae (Pneumococcus)
      1. Pneumococcal Urine antigen Test (UAT)
        1. Test Sensitivity 60-80%
        2. Test Specificity >90%
      2. Indications (Pneumococcal UAT per IDSA/ATS 2007)
        1. Intensive care unit admission
        2. Failed outpatient antibiotic therapy
        3. Active Alcohol Abuse
        4. Chronic severe liver disease
        5. Leukopenia
        6. Asplenia
        7. Pleural Effusion
  5. Thoracentesis with fluid analysis
    1. Indicated for Pleural Effusion >5 cm
    2. Send for Gram Stain, aerobic and anaerobic culture
  6. Fungal and TB Culture
    1. Cavitary lesions
    2. Foreign travel or immigration
  7. References
    1. Mandell (2007) Clin Infect Dis 44:S27–72 [PubMed]

X. Imaging: Chest XRay

  1. Indications: All cases of suspected Community Acquired Pneumonia
    1. Any patient with at least 1 of the following
      1. Temperature >100 F (37.8 C)
      2. Heart Rate >100 beats/min
      3. Respiratory Rate >20 breaths/min
    2. Any patient with at least 2 of the following
      1. Decreased breath sounds
      2. Rales or crackles
      3. No Asthma history to explain findings
    3. Other indications (not included in Ebell protocol)
      1. Hypoxemia
      2. Confusion
      3. Known structural lung disease
      4. Age > 60 years old
      5. Systemic illness signs
    4. Ebell (2007) Am Fam Physician 76(4): 560-2 [PubMed]
  2. Precautions: False negatives in early presentation
    1. Serial Chest XRays may be needed
    2. Does not exclude Pneumonia in severe illness
      1. Positive in only 40% of acute pneumococcal community acquired Pneumonia (CAP)
  3. Precautions: Underlying malignancy
    1. Confirm infiltrate resolution at 6 weeks after management (especially in smokers, or those over age 50)
  4. Interpretation
    1. Lobar infiltrate suggests typical Bacterial community acquired Pneumonia (CAP)
    2. Diffuse, bilateral infiltrates suggests atypical community acquired Pneumonia (CAP)

XI. Imaging: Lung Ultrasound

  1. May be more accurate than Chest XRay in the diagnosis of Pneumonia
  2. Also defines other respiratory conditions at the bedside (e.g. Pneumothorax, Pleural Effusion)
  3. Test Sensitivity: 94 to 95%
  4. Test Specificity: 90 to 96%
  5. Chavez (2014) Respir Res 15:50 [PubMed]
  6. Ye (2015) PLoS One 10(6): e0130066 [PubMed]

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Related Studies (from Trip Database) Open in New Window

Ontology: Pneumonia, Bacterial (C0004626)

Definition (MSH) Inflammation of the lung parenchyma that is caused by bacterial infections.
Definition (NCI) Acute infection of the lung parenchyma caused by bacteria (e.g., Streptococcus pneumoniae, Haemophilus influenzae, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila). Signs and symptoms include productive cough, fever, chills, shortness of breath, and chest pain.
Definition (CSP) pneumonia caused by various species of bacteria; commonly results from bronchogenic spread of infection following microaspiration of secretions.
Concepts Disease or Syndrome (T047)
MSH D018410
ICD9 482.9
ICD10 J15.9
SnomedCT 195891009, 195892002, 155553007, 53084003
English Bacterial Pneumonia, Bacterial Pneumonias, Pneumonia, Bacterial, Pneumonias, Bacterial, Bacterial pneumonia, unspecified, Pneumonia due to bacteria NOS, BACT PNEUMONIA, PNEUMONIA BACT, bacterial pneumonia (diagnosis), bacterial pneumonia, Pneumonia bacterial NOS, Bacterial pneumonia NOS, Unspecified bacterial pneumonia, Pneumonia, Bacterial [Disease/Finding], Pneumonia;bacterial, pneumonia bacterial, Pneumonia due to bacteria NOS (disorder), Bacterial pneumonia NOS (disorder), Pneumonia bacterial, Bacterial pneumonia, Bacterial pneumonia (disorder), bacterial; pneumonia, pneumonia; bacterial, Bacterial pneumonia, NOS
Dutch bacteriële pneumonie NAO, bacteriële pneumonie, niet-gespecificeerd, bacterieel; pneumonie, pneumonie; bacterieel, Bacteriële pneumonie, niet gespecificeerd, bacteriële pneumonie, Bacteriële pneumonie, Pneumonie, bacteriële
French Pneumonie bactérienne non précisée, Pneumonie bactérienne SAI, Pneumonie bactérienne, Pneumopathie bactérienne
German Pneumonie bakteriell NNB, bakterielle Pneumonie, unspezifisch, Bakterielle Pneumonie, nicht naeher bezeichnet, Pneumonie durch Bakterien, Pneumonie, bakterielle
Italian Polmonite batterica NAS, Polmonite batterica, non specificata, Polmonite batterica
Portuguese Pneumonia bacteriana NE, Pneumonia bacteriana, Pneumonia Bacteriana
Spanish Neumonía bacteriana no especificada, Neumonía bacteriana NEOM, neumonía bacteriana, SAI, neumonía bacteriana, SAI (trastorno), neumonía debida a bacterias, SAI (trastorno), Bacterial pneumonia NOS, neumonía debida a bacterias, SAI, neumonía bacteriana (trastorno), neumonía bacteriana, neumonía bactérica, Neumonía bacteriana, Neumonía Bacteriana
Japanese 細菌性肺炎、詳細不明, 細菌性肺炎NOS, サイキンセイハイエンショウサイフメイ, サイキンセイハイエン, サイキンセイハイエンNOS, 肺炎-細菌性, 細菌性肺炎
Swedish Lunginflammation, bakteriell
Finnish Bakteeripneumonia
Russian PNEVMONIIA BAKTERIAL'NAIA, ПНЕВМОНИЯ БАКТЕРИАЛЬНАЯ
Czech Bakteriální pneumonie, Bakteriální pneumonie, blíže neurčená, Bakteriální pneumonie NOS, bakteriální pneumonie, pneumonie bakteriální
Korean 상세불명의 세균성 폐렴
Croatian PNEUMONIJA, BAKTERIJSKA
Polish Zapalenie płuc bakteryjne
Hungarian bacterialis pneumonia, bacterialis pneumonia k.m.n., bacterialis tüdőgyulladás, nem meghatározott
Norwegian Bakteriell lungebetennelse, Lungebetennelse, bakteriell, Bakteriell pneumoni, Pneumoni, bakteriell

Ontology: capsule (pharmacologic) (C0006935)

Definition (HL7V3.0) <p>A solid dosage form in which the drug is enclosed within either a hard or soft soluble container or "shell" made from a suitable form of gelatin.</p>
Definition (HL7V3.0) <p>A solid dosage form in which the drug is enclosed within either a hard or soft soluble container or "shell" made from a suitable form of gelatin.</p>
Definition (NCI) A drug packaging type usually in a cylindrical shape with rounded ends. Capsule shells may be made from gelatin, starch, or cellulose, or other suitable materials, may be soft or hard, and are filled with solid or liquid drug products.
Definition (NCI) A solid contained within either a hard or soft soluble shell, usually prepared from gelatin.
Definition (NCI_CDISC) A solid pharmaceutical dosage form that contains medicinal agent within either a hard or soft soluble container or shell, usually used for the oral administration of medicine. The shells are made of a suitable form of gelatin or other substance. (NCI)
Definition (NCI_NCI-GLOSS) A form for medicine that is taken by mouth. It usually has a shell made of gelatin with the medicine inside.
Definition (MSH) Hard or soft soluble containers used for the oral administration of medicine.
Concepts Biomedical or Dental Material (T122)
MSH D002214
SnomedCT 385049006, 40973004
HL7 2.16.840.1.113883.1.11.14507, CAP
English Capsules, Capsule, Capsule Dosage Form, Capsule Dose Form, Capsule (product), Capsule dose form (qualifier value), Capsule dose form (product), capsule (pharmacologic), Cap, Capsule [Dose Form], capsule drugs, capsule, capsule drug, capsules, drug capsule, CapsuleDrugForm, Drug capsule, Drug capsule (product), Capsules (Pharmacy), CAPSULE, CAP, Capsule-Container, cap, Drug capsule (substance), Caps, CAPS
Swedish Kapslar
Spanish cápsula - forma farmacéutica, cápsula (producto), cápsula - forma farmacéutica (calificador), cápsula - forma farmacéutica (producto), cápsula medicamentosa, fármaco en cápsula, medicamento en cápsula, cápsula medicamentosa (producto), cápsula medicamentosa (sustancia), cápsula, Cápsulas
Czech tobolky, kapsle
Finnish Kapselit
Russian KAPSULY, MIKROKAPSULY, КАПСУЛЫ, МИКРОКАПСУЛЫ
French Capsule, Capsules
Croatian KAPSULE
Polish Kapsułki, Mikrokapsułki
Norwegian Kapsler
German Kapseln
Italian Capsule
Portuguese Cápsulas

Ontology: Pneumonia (C0032285)

Definition (MSH) Inflammation of any part, segment or lobe, of the lung parenchyma.
Definition (MEDLINEPLUS)

Pneumonia is an infection in one or both of the lungs. Many germs, such as bacteria, viruses, and fungi, can cause pneumonia. You can also get pneumonia by inhaling a liquid or chemical. People most at risk are older than 65 or younger than 2 years of age, or already have health problems.

Symptoms of pneumonia vary from mild to severe. See your doctor promptly if you

  • Have a high fever
  • Have shaking chills
  • Have a cough with phlegm that doesn't improve or gets worse
  • Develop shortness of breath with normal daily activities
  • Have chest pain when you breathe or cough
  • Feel suddenly worse after a cold or the flu

Your doctor will use your medical history, a physical exam, and lab tests to diagnose pneumonia. Treatment depends on what kind you have. If bacteria are the cause, antibiotics should help. If you have viral pneumonia, your doctor may prescribe an antiviral medicine to treat it.

Preventing pneumonia is always better than treating it. Vaccines are available to prevent pneumococcal pneumonia and the flu. Other preventive measures include washing your hands frequently and not smoking.

NIH: National Heart, Lung, and Blood Institute

Definition (NCI_NCI-GLOSS) A severe inflammation of the lungs in which the alveoli (tiny air sacs) are filled with fluid. This may cause a decrease in the amount of oxygen that blood can absorb from air breathed into the lung. Pneumonia is usually caused by infection but may also be caused by radiation therapy, allergy, or irritation of lung tissue by inhaled substances. It may involve part or all of the lungs.
Definition (NCI) An acute, acute and chronic, or chronic inflammation focally or diffusely affecting the lung parenchyma, due to infections (viruses, fungi, mycoplasma, or bacteria), treatment (e.g. radiation), or exposure (inhalation) to chemicals. Symptoms include cough, shortness of breath, fevers, chills, chest pain, headache, sweating, and weakness.
Definition (CSP) inflammation of the lungs with consolidation and exudation.
Concepts Disease or Syndrome (T047)
MSH D011014
ICD10 J18.9
SnomedCT 274103002, 155552002, 155558003, 266391003, 155548002, 60363000, 205237003, 233604007
LNC LP21407-9, MTHU020831, LA7465-3
English Pneumonitis, Pneumonia, Pneumonias, Pneumonia, unspecified, Pneumonitides, Pneumonia NOS, pneumonia (diagnosis), pneumonia, Pneumonitis NOS, Pneumonia [Disease/Finding], Pneumoniae, inflammation lungs, unspecified pneumonia, pneum, pulmonary inflammation, lung inflammation, Inflammation, Lung, Inflammation, Pulmonary, Inflammations, Lung, Inflammations, Pulmonary, Lung Inflammation, Lung Inflammations, Pulmonary Inflammation, Pulmonary Inflammations, Pneumonia NOS (disorder), Pulmonary inflammation, Lung inflamed, Pulmonitis, PNEUMONIA, Pneumonia (disorder), Pneumonia, NOS, Pneumonia (disorder) [Ambiguous], pneumonitis
French PNEUMONIE, Congestion pulmonaire SAI, Pneumonite, Pneumonie SAI, Pneumopathie infectieuse, Pneumonie
Portuguese PNEUMONIA, Pneumonite NE, Pulmonite, Pneumonia NE, Pulmonia, Pneumonia, Inflamação do Pulmão, Inflamação Pulmonar, Pneumonite
Spanish NEUMONIA, Neumonitis NEOM, Neumonía NEOM, neumonia, SAI (trastorno), Pneumonia NOS, neumonia, SAI, Pneumonía, Pulmonía, neumonía (concepto no activo), neumonía (trastorno), neumonía, Neumonitis, Inflamación del Pulmón, Inflamación Pulmonar, Neumonía
German PNEUMONIE, Pneumonie NNB, Pulmonitis, Pneumonitis NNB, Pneumonie, nicht naeher bezeichnet, Lungenentzuendung, Pneumonie, Pneumonitis, Lungenentzündung
Italian Infezione polmonare, Polmonite aspecifica, Infezione dei polmoni, Infezione polmonare aspecifica, Pneumonite, Infiammazione del polmone, Infiammazione polmonare, Polmonite
Dutch pneumonie NAO, pneumonitis NAO, pulmonitis, Pneumonie, niet gespecificeerd, pneumonie, Pneumonie, Longontsteking, Pneumonitis
Japanese 肺炎NOS, 肺臓炎, 肺臓炎NOS, ハイエンNOS, ハイエン, ハイゾウエンNOS, ハイゾウエン, 肺炎
Swedish Lunginflammation
Czech pneumonie, Pneumonie, Pulmonitida, Pneumonie NOS, Pneumonitida NOS, zápal plic, zánět plic
Finnish Keuhkokuume
Russian PNEVMONIIA, ПНЕВМОНИЯ
Korean 상세불명의 폐렴
Croatian PNEUMONIJA
Polish Zapalenie płuc
Hungarian pneumonia, Pneumonitis k.m.n., pneumonia k.m.n., Pulmonitis
Norwegian Pneumoni, Lungebetennelse

Ontology: Atypical pneumonia (C1412002)

Concepts Disease or Syndrome (T047)
SnomedCT 195932001, 233606009, 35037009
English Atypical pneumonia, Pneumonia;atypical, atypical pneumonia (diagnosis), Atypical pneumonia (disorder), atypical; pneumonia, pneumonia; atypical, atypical pneumonia
Czech Atypická pneumonie
Dutch atypische pneumonie, atypisch; pneumonie, pneumonie; atypisch
French Pneumonie atypique
German atypische Pneumonie
Hungarian atípusos pneumonia
Italian Polmonite atipica
Japanese イケイハイエン, 異型肺炎
Portuguese Pneumonia atípica
Spanish Neumonía atípica, neumonía atípica (trastorno), neumonía atípica