Case Summary

Click here to print this page.

Chest Pain: Case 3



Chest Pain: Case 3 History

A 52 year old man presents to the emergency room with a 1 day history of fever, chills, rigors, cough productive of yellowish but slightly blood-tinged sputum and pleuritic left chest pain.

Recommended Initial Workup

A PA and lateral chest radiograph is the first radiological study recommended for evaluation of suspected pulmonary infection.


Patient 1 Frontal & Lateral CXR: Please click on the abnormality on frontal or lateral CXR

Image


Click on the abnormality on this patient's chest X-ray.

Correct. Please continue.


Patient 1: Which Lobe is Involved?

Which lobe is involved with this classic air-space consolidation?

 a. Left upper lobe
Incorrect. The correct answer is c. Lingula. Please continue.
 b. Left lower lobe
Incorrect. The correct answer is c. Lingula. Please continue.
 c. Lingula
Correct. Please continue.

Patient 1 Film Findings: Lingular Pneumonia on CXR


chest3_new3A3B_ann Please click to enlarge. ©

Film Findings:

  1. There is lingular opacification, with the aerated airways standing out as an air-bronchogram.
  2. There is sharp demarcation of the consolidation inferoposteriorly by the major fissure confirming the location of this process in the lingula of the left upper lobe.

Dense consolidation, often with air bronchograms in lobar or segmental distribution suggests bacterial pneumonia.



Patient 2: Suggest Location of the Pneumonia

The next patient also received a CXR for suspected pneumonia:


new_3C3D_noann ©


Which lobe(s) show an infiltrate?

 a. Right upper lobe
Incorrect. Please continue.
 b. Right middle lobe
Incorrect. Please continue.
 c. Right lower lobe
Incorrect. Please continue.
 d. Right upper lobe & right lower lobe
Correct. Please continue.
 e. Right middle lobe & right lower lobe
Incorrect. Please continue.

Patient 2 Film Findings: RUL and RLL Pneumonia


chest_c3p2_ff ©
Film Findings:

  1. There is consolidation of the right upper lobe and superior segment of right lower lobe. Its inferior margin is sharply defined by the minor fissure anteriorly and by a superior accessory fissure inferoposteriorly.
This patient had a confirmed community acquired pneumococcal pneumonia.


DIFFERENTIAL DIAGNOSIS OF LOBAR CONSOLIDATION

1. Lobar pneumonia (see Discussion for causes)
2. Pulmonary hemorrhage/contusion
3. Pulmonary embolism
4. Bronchioloalveloar cell carcinoma
5. Lymphoma
6. Non-infectious pneumonitis (e.g. SLE)
7. Sarcoidosis (very rare)



Patients 3, 4, and 5: Different Patterns of Infiltrate on CXR

Infiltrate patterns on chest X-ray may suggest etiology but are too variable to be reliable.

The following patients all have acute pneumonia with patterns on CXR suggesting the etiology:


chest_c3p3p4p5_ul ©


Patient 3 Film Findings: Viral Pneumonia on CXR

CXR of a symptomatic patient with AIDS


chest_c3p3_ff Please click to enlarge ©

Film Findings:

  1. There are diffuse bilateral patchy infiltrates with bronchial thickening.
    The patchy interstitial nature suggests a viral etiology.

Diagnosis:

The patient has Pneumocystis Carinii Pneumonia.



Patient 4 Film Findings: Round Pneumonia on CXR

CXR of a 61-year-old woman with fever and cough:


3f&3g Please click to enlarge ©

Film Findings:

  1. There is a roundish infiltrate in the left midlung zone (arrows).

    The round shape suggests a tumor. A CT scan was obtained which showed the area to be an airspace process with air bronchograms. There was no lymphadenopathy or other abnormalities. In view of the patient's acute febrile illness, antibiotics were administered with the presumptive diagnosis of Round pneumonia. In view of the mass-like appearance, a follow up CXR is indicated. The follow up showed complete resolution of the Round infiltrate confirming this as a "Round Pneumonia".



Patient 5 Film Findings: Viral Pneumonia on Frontal CXR

CXR of our last patient in this series with fever, cough and flu symptoms:


chest_c3p5_ff  ©

Film Findings:

  1. There are diffuse bilateral infiltrates.
  2. Peribronchial cuffing (box) and kerley lines are seen (arrow).

The bilateral patchy distribution with interstitial features - thickened bronchial walls and kerley lines coupled with the clinical presentation favor a viral etiology. These infiltrates are more confluent than most viral pneumonias.

Diagnosis:

The patient had Influenza Pneumonia.



Summary of Interactive Portion on Pneumonia

You have seen classic lobar consolidation due to bacterial pneumonia, patchy interstitial infiltrates due to viral pneumonia and an uncommon but well-recognized rounded configuration, the aptly named “round pneumonia”. In practice, the infiltrates are often nonspecific, correlating poorly with the etiologic agent.

Specifically, you saw the classic appearance of lingular, RUL and RLL bacterial pneumonia on CXR. You saw the less common round infiltrate of a patient also with bacterial pneumonia and learned the Differential Diagnosis of lobar consolidation.

You saw the typical appearance of viral pneumonia due to PCP in an AIDS patient and influenza pneumonia in a previously well patient.

Continue to view detailed Discussion notes, the Image Gallery, Differential Diagnosis lists and Bibliography.


DISCUSSION I: Pneumonia

PNEUMONIA
Pneumonia refers to inflammation of the pulmonary parenchyma distal to the terminal bronchioles and usually implies acute infection. The microbiology of pneumonia includes all types of bacteria, viruses, rickettsia, protozoa, mycobacteria and parasites. The patient's age, immune status, geographical location, occupation and socio-economic status strongly influence the likelihood of a specific organism causing the infiltrate.
Clinical features of fever, cough and auscultatory findings, in conjunction with a new opacity on chest radiograph and documentation of a pathogen are diagnostic of infectious pneumonia. Although the clinical presentation may suggest a specific cause, findings often overlap too much for reliable identification of the specific pathogen on clinical or radiological grounds alone. Isolation of the microorganism or serologic studies is necessary. However, even after extensive studies are performed, the pathogen remains unidentified in 30-50% of cases.
 
COMMON ETIOLOGIES ACCORDING TO AGE:

Neonate (birth to 1 month)

  1. First 3 days: Group B Streptococci, Escherichia coli, Klebsiella
  2. After 3 days: Pseudomonas & other Gram negative flora
  3. Viral: Influenza, Parainfluenza, Respiratory Syncitial virus (RSV), Adenovirus.
     
  Infants (1 month to 1 year)
  1. Viral: RSV (25%), Influenza A & B, Parainfluenza, Adenovirus.
  2. Bacterial: Hemophilus influenzae, Pneumococcus, Streptococci A & B
  3. Aspiration
     
  Preschool (1 year to 5 years)
  1. Viral: RSV (50% of pneumonia in ages 1-3 years)
  2. Bacterial: Hemophilus. influenzae, Pneumococcus, Streptococci
  3. Aspiration
  4. Hydrocarbon ingestion
     
School Age (5 years to 18 years)
1. Mycoplasma Pneumoniae ( 75% of pneumonia in age 9-15,
50% in age 5-9)
  2. Bacterial: Hemophilus influenzae, Pneumococcus, Streptococci A&B
     
  Adults (18 years and older) Community Acquired Pneumonia
  1. Bacterial: Pneumococcus, H. influenzae
  2. Mycoplasma
  3. Viral: Influenza, Parainfluenza, RSV, Adenovirus
     
  Pneumococcal pneumonia classically follows an upper respiratory infection and presents with abrupt onset of fever, chills, rigors, pleuritic chest pain and a cough productive of purulent, often bloody, sputum. Typically it presents as a lobar pneumonia but bronchopneumonia may occur. Cavitation is rare. Parapneumonic effusion or empyema occur in up to 50% of patients. These complications are more common in Staphylococcal pneumonia and pneumonia caused by Gram-negative or anaerobic organisms.
     
  The pulmonary infiltrates of pneumonia follow 3 patterns:
  1. Lobar pneumonia (typical pneumonia)
  2. Bronchopneumonia
  3. Interstitial pneumonia.
 
This distinction can be used as an imprecise guide to determine the likely pathogens:
  1. Lobar Pneumonia: Pneumococcus, Klebsiella, Legionella, Mycoplasma, TB, (almost anything from bronchopneumonia list)
  2. Bronchopneumonia: Staphylococcus, Streptococcus, Hemophilus, Tuberculosis, Viral, Pneumocystis (almost anything from lobar pneumonia list)
  3. Interstitial: Viral, Tuberculosis, Fungi, Toxoplasmosis
  4. Nodules and Masses: Mycobacteria, Fungi, Protozoa.
     
It must be emphasized that there is considerable overlap in these patterns- especially amongst the various bacterial pathogens. Studies in children have shown that radiographic findings are poor indicators of microbiological diagnosis and are insufficient for making therapeutic decisions.
With appropriate therapy, complete clearing may be seen in 10-14 days. In older patients, or in those with underlying disease, complete resolution may take 8-10 weeks. Radiographic findings in Legionella pneumonia may persist for months despite clinical resolution.
     
The following risk factors have been identified for delayed resolution of pneumonia:
  1. History of smoking
  2. Advanced age
  3. Multilobar involvement
  4. Diabetes
  5. Chronic obstructive pulmonary disease
  6. Renal failure
  7. Alcohol abuse
  8. Uncommon infectious agents
Conditions that mimic pneumonia e.g. neoplasms, congestive heart failure and complications such as lung abscess or effusion can also result in delayed resolution.
     
Usual Treatment:
Pneumonia is treated by oral or intravenous antibiotics, together with supportive care and chest physical therapy if needed. Parapneumonic effusions are often tapped to exclude empyema. This complication should be suspected when there is prolonged fever without the usual defervescence, or a large or loculated effusion. Contrast-enhanced CT is the best imaging modality to evaluate for empyema, demonstrating a loculated fluid collection in the pleural space, with enhancing rim and possibly containing gas. Loculation not evident on CT, is often detectable by ultrasound.
     

Although the frequency of community-acquired pneumonia caused by Pneumococcus continues to be high, studies show that Mycoplasma pneumoniae, Chlamydia pneumoniae or Legionella pneumophila are the etiologic agents in 20-40% of cases in adults. The clinical presentations may be indistinguishable. Separation into typical and atypical pneumonias is not always helpful in planning therapy. Community-acquired pneumonia can have a high morbidity and mortality in patients who are very young or elderly, immune compromised or have other comorbid conditions. In choosing appropriate empiric antimicrobial therapy, Erythromycin and other macrolides have the advantage of being effective against a wide range of causative pathogens. In other patients, the selection of antibiotic therapy can be based on age, clinical suspicion, epidemiologic data, and laboratory test results. Antimicrobial therapy can be directed at specific organisms when they are identified.

In our institution, risk stratification according to an established algorithm is used to decide upon inpatient or outpatient therapy. First-line outpatient therapy is with oral Erythromycin. Oral Levofloxacin is recommended as first-line inpatient therapy for community acquired pneumonia.

     
Prognosis:
Usually excellent. 1/4 of all patients with pneumococcus requiring hospitalization develop sepsis. More aggressive Staphylococcal or Gram negative pneumonia may cause significant lung destruction and long-term sequelae.



IMAGE GALLERY


Chest Pain Case 3 ©


DIFFERENTIAL DIAGNOSIS LISTS

DIFFERENTIAL DIAGNOSIS OF LOBAR CONSOLIDATION:

1. Lobar pneumonia (see discussion for causes)
2. Pulmonary hemorrhage/contusion
3. Pulmonary embolism
4. Bronchioloalveolar cell carcinoma
5. Lymphoma
6. Non-infectious pneumonitis (e.g. SLE)
7. Sarcoidosis (very rare)

COMMON ETIOLOGIES ACCORDING TO AGE:


Neonate (birth to 1 month)
1. First 3 days: Group B Streptococci, Escherichia coli, Klebsiella
2. After 3 days: Pseudomonas & other Gram negative flora
3. Viral: Influenza, Parainfluenza, Respiratory Syncitial virus (RSV), Adenovirus.
Infants (1 month to 1 year)
1. Viral: RSV (25%), Influenza A & B, Parainfluenza, Adenovirus.
2. Bacterial: Hemophilus influenzae, Pneumococcus, Streptococci A & B
3. Aspiration
Preschool (1 year to 5 years)
1. Viral: RSV (50% of pneumonia in ages 1-3 years)
2. Bacterial: Hemophilus. influenzae, Pneumococcus, Streptococci
3. Aspiration
4. Hydrocarbon ingestion
School Age (5 years to 18 years)
1. Mycoplasma Pneumoniae (75% of pneumonia in age 9-15,
50% in age 5-9)
2. Bacterial: Hemophilus influenzae, Pneumococcus, Streptococci A&B
Adults (18 years and older) Community Acquired Pneumonia
1. Bacterial: Pneumococcus, H. influenzae
2. Mycoplasma
3. Viral: Influenza, Parainfluenza, RSV, Adenovirus

RISK FACTORS FOR DELAYED RESOLUTION OF PNEUMONIA:
1. History of smoking
2. Advanced age
3. Multilobar involvement
4. Diabetes
5. Chronic obstructive pulmonary disease
6. Renal failure
7. Alcohol abuse
8. Uncommon infectious agents



BIBLIOGRAPHY

1. Braunwald E. Chest discomfort and Palpitation. In: Fauci AS, Braunwald E, Isselbacher KJ, et al. Harrison’s Principles of Internal Medicine, 14th ed. New York: McGraw-Hill 1998; 1229-1231.
2. Brant W, Helms C. fundamentals of Diagnostic Radiology; Williams and Wilkins 1994.
3. Armstrong P, Wilson AG, Dee P. Infections of the lung and pleura. In: Imaging of Diseases of the Chest. 1st ed. Year Book, 1990; 405-462.
4. Jawetz, Melnick, Adelberg. Review of Medical Microbiology. 17th ed. Appleton and Lange 1987.
5. Sue DY. Community-acquired pneumonia in adults. West J Med 1994; 161(4):383-389.
6. Scanlon GT, Unger JD. The radiology of bacterial and viral pneumonias. Radiol Clin North Am 1973; 11(2):317-338.
7. McCarthy PL, Spiesel SZ, Stashwick CA, et al. Radiographic findings and etiologic diagnosis in ambulatory childhood pneumonias. Clin Pediatrics 1981; 20(11):686-691.
8. Cunha BA, Ortega AM. Atypical pneumonia. Extrapulmonary clues guide the way to diagnosis. Postgrad Med 1996; 99(1):123-128, 131-132.
9. Cabreros LJ, et al. Radiographic mimics of pneumonia. Pulmonary conditions to consider in the differential diagnosis. Postgrad Med 1996; 99(1):139-142,145-146.
10. Cassiere H, Rodrigues JC, Fein AM, et al. Delayed resolution of pneumonia. When is slow healing too slow? Postgrad Med 1996; 99(1):151-154, 157-158.
11. File TM Jr, Tan JS, Plouffe JF, et al. Community-acquired pneumonia. What's needed for accurate diagnosis. Postgrad Med 1996; 99(1):95-102, 105-107.
12. Lieberman D, Porath A, Schlaeffer F, et al. Legionella species community-acquired pneumonia. A review of 56 hospitalized adult patients. Chest 1996; 109(5):1243-1249.
13. Fine MJ, Auble TE, Yealy DM, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. NEJM 1997; 336(4):243-250.
14. Thomas CF Jr, Limper AH. Medical Progress: Pneumocystis Pneumonia. NEJM 2004; 350:2487-2498.
15. McIntosh K. Current Concepts: Community-Acquired pneumonia in children. NEJM 2002; 346:429-437.
16. Marik PE. Primary Care: Aspiration pneumonitis and aspiration pneumonia. NEJM 2001; 344:665-671.
17. Dowell SF, Kupronis BA, Zell ER, et al. Mortality from pneumonia in children in the United States, 1939 through 1996. NEJM 2000; 342:1399-1407.
18. Ledergerber B, Mocroft A, Reiss P, et al. Discontinuation of secondary prophylaxis against Pneumocystis carinii pneumonia in patients with HIV infection who have a response to antiretroviral therapy. NEJM 2001; 344:168-174.
19. Whitney CG, Farley MM, Hadler J, et al. Increasing prevalence of multidrug-resistant Streptococcus pneumonia in the United States. NEJM 2000; 343:1917-1924.
20. Halm EA, Teirstein AS. Management of community-acquired pneumonia. NEJM 2002; 347:2039-2045.
21. Davidson R, Cavalcanti R, Brunton JL, et al. Brief report: Resistance to Levofloxacin and failure to treatment of pneumococcal pneumonia. NEJM 2002; 346:747-750.
22. Thomas CF Jr, Limper AH. Medical Progress: Pneumocystis Pneumonia. NEJM 2004; 350:2487-2498.
23. Waxman AB, Shepard J-AO, Mark EJ. Case 14-2003: A 73 year old woman with Pneumonia and Progressive Respiratory Failure. NEJM 2003; 348:1902-1912.
24. Halm EA, Teirstein AS. Management of Community-Acquired Pneumonia. NEJM 2002; 347:2039-2045.





The End