Chest Ctscan Project

CT Scan Within 6 Hours of Admission Versus Plain X-ray of The Chest For Immunocompetent Patient Admitted With Community Acquired Pneumonia, A Retrospective Observational Study M Chadi Alraies M.D., Samer Alhindi M.D., Abdul Hamid Alraiyes M.D., Joseph Sopko MD, FCCP Department of Internal Medicine - St. Vincent Charity Hospital / Case Western Reserve University - Cleveland, Ohio Introduction 

Clinical suspicion for pneumonia is one of the most common indications for chest imaging1.  According to the guidelines from the American Thoracic Society, postero-anterior and if possible lateral chest radiographs should be obtained if pneumonia is suspected in adults2.  The chest radiograph (CXR) continues to be the initial imaging tool to assess the lung parenchyma because its yield in relation to cost, radiation dose, availability, and ease of performance is unmatched by other modalities.  In immunocompromised patients with suspected pneumonia, CT has been shown to improve pretest probability when forming a differential diagnosis and strengthen clinical decision making3.  There is a paucity of literature regarding the utility of chest CT in immunocompetent patients with chest radiographic findings of pneumonia4.

Hypothesis Chest CT scan in immunocompetent patient will make no change in diagnosis and clinical management comparing to plain chest x-ray for patient admitted with pneumonia.

Method  





Study type: Observational retrospective case-controlled study Inclusion criteria: 1. Immunocompetent patients with chest radiographic findings of pneumonia. 2. Subsequent evaluation by chest CT within 24 hours.

Discussion

Statistical Analysis Patient and control groups were compared using Fisher exact and paired Student’s t tests.

 

Results

 

Clinical history, presentation, and management variables for cases (n=37) and controls (n=37)

Variables

Cases (%)

Controls (%)

p value

56

55.4

0.497

Smoking history

28 (78%)

26 (72%)

0.999

Fever

17 (46%)

7 (18%)

0.086

Chest pain

14 (38%)

5 (13%)

0.103

Cough

31 (84%)

33 (89%)

0.834

Hypoxemia

21 (57%)

11 (29%)

0.004

Weight loss

4 (11%)

0 (0)

0.088

Night sweats

8 (22%)

1 (2%)

0.006

Leukocytosis

19 (54%)

2 (5.4%)

0.093

Auscultation abnormalities

35 (95%)

25 (67%)

0.044

Abnormal sputum

15 (41%)

0 (0)

<0.001

Initiation of antibiotics

37 (100%)

18 (47%)

<0.001

Change of antibiotics based on CT findings

3 (8%)

0 (0)

0.094

Procedures

5 (14%)

2 (6%)

0.467

Additional/alternative diagnosis based on CT findings

4 (11%)

0 (0)

0.03

Mean length of stay

6.5 days

<1 day

<0.005

Age (years)

Study Limitations •Small population •Teaching hospital •Observational retrospective study •Majority of low socioeconomic African American population.

Conclusion We conclude that chest CT was of minimal value in a group of clinically ill, immunocompetent patients with chest radiographic findings of pneumonia. Physician experience and clinical skills play a major role in ordering CT of the chest as a further work up of CAP (communityacquired pneumonia) which might help guiding therapy, or providing an alternative diagnosis in only (11%) percent of cases.

References 1. 2.

Exclusion criteria: 1. Immunocompromised patients. 2. Further imaging was recommended by radiologist. 3. CT chest done to role out pulmonary embolism. 538 patients from our admissions that underwent chest CT between 1/05 and 1/07. 37 patient matched our inclusion criteria. Age and sexmatched controls from the floor admissions with pneumonia that did not undergo CT were identified.

Study patients were sicker than control group. Clinical presentation not radiological report should guide further workup. Future criteria for CT use in immunocompetent CAP patients. Importance of: 1. Radiation safety. 2. Cost effectiveness. 3. Identify the group of patients who will benefit from CT 4. Identify the group of patients in whom chest CT is not required.

3. 4. 5. 6. 7.

Study patients’ clinical presentation

8.

Adams PF, Marano MA (1995) Current estimates from the National Health Interview Survey, 1994. Vital Health Stat 10 1995:1–260. Niderman MS, Bass JB Jr, Campbell GD (1993) Guidelines for the initial management of adults with community-acquired pneumonia: diagnosis, assessment of severity, and initial antimicrobial therapy. American Thoracic Society. Medical Section of the American Lung Association. Am Rev Respir Dis 148 (5):1418–1426 Pulmonary complications in immunocompromised non-AIDS patients: comparison of diagnostic accuracy of CT and chest radiography. Clin Radiol 47(3):159–165, Mar Syrjala H, Broas M, Suramo I et al (1998) High-resolution computed tomography for the diagnosis of community-acquired pneumonia. Clin Infect Dis 27:358. Dimarco AF, Briones B (1993) Is chest CT performed too often? Chest 103:985–986. Reittner P, Ward S, Heyneman L, Johkoh T, Muller NL (2003) Pneumonia: high-resolution CT findings in 114 patients. Eur Radiol 13(3):515–521, Ma Kang EY, Staples CA, McGuinness G, Primack SL, Muller NL (1996) Detection and differential diagnosis of pulmonary infections and tumors in patients with AIDS: value of chest radiography versus CT. Am J Roentgenol 166(1):15–19, Ja Diehl SJ, Lehmann KJ, Thienel F, Georgi M (1997) Value of highresolution CT of the lungs in acute pulmonary symptoms of patients with HIV infections. Rofo 167(3):227–233, Sep.