Role of Chest Low-dose Computed Tomography in Elderly Patients with Suspected Acute Pulmonary Infection in the Emergency Room

Transcription

1 Role of Chest Low-dose Computed Tomography in Elderly Patients with Suspected Acute Pulmonary Infection in the Emergency Room Poster No.: C-1461 Congress: ECR 2014 Type: Authors: Keywords: DOI: Scientific Exhibit M. Lee, Y. Kim, J. K. Lee, J. Cho, B. Lee; Seoul/KR Lung, Respiratory system, CT, Plain radiographic studies, Computer Applications-Detection, diagnosis, Computer Applications-General, Infection, Outcomes, Acute /ecr2014/C-1461 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 9

2 Aims and objectives With global ageing, population of elderly is increasing. Majority of acute pulmonary infection (API) in elderly are pneumonia, bronchitis, acute exacerbation of COPD/asthma. Despite advances in antimicrobial therapy, rates of mortality due to pneumonia have not decreased significantly [1-4]. IDSA/ATS consensus guidelines on the management of CAP(community acquired pneumonia). API(acute pulmonary infection) is usually diagnosed by both clinical features and chest radiographic or other imaging (CT) abnormality. However, both clinical features and physical exam findings may be lacking or altered in elderly patients. IDSA/ATS consensus guidelines on the management of CAP. Rarely, admission CXR is clear, but patient's toxic appearance suggests more than bronchitis. CT scan may be more sensitive, but the clinical significance of these findings when findings of CXR are negative is unclear [5]. The purpose of this study is to evaluate the role of low dose chest CT(LDCT) in elderly patients with suspected API at emergency room as well as to evaluate the clinical significance of abnormal LDCT when findings of CXR are negative. Methods and materials 205 patients (mean age, 75.9±9.2 yrs; range, years) are studied who underwent LDCT at ER from Jan to May LDCT were indicated the patients with acute fever or dyspnea, but neither definite CXR abnormality, underlying pulmonary diseases complicating CXR interpretation nor low confidence of CXR diagnosis by clinician. CXR were analyzed by two radiologists with consensus of presence of API. LDCT were analyzed by two radiologists with consensus of presence of findings of API. Other combined findings were indicated that pulmonary findings other than CAP, pleural effusion, etc. Findings of API on LDCT were decribed by consolidation, ground-glass opacity (GGO), gentrilobular nodules (CLN), diffuse bronchial wall thickening (DBWT). Diagnostic accuracy of CXR and LDCT were compared between CXR (+) API and CXR (-) LDCT(+) API. Age, sex, comorbidity, hospitalization and antibiotic therapy, mortality rate were also compared. Page 2 of 9

3 Results 205 patients (mean age, 75.9±9.2 yrs; range, years) are studied who underwent LDCT from Jan to May 2012 with suspicion of API at ER (Fig.1). Fig. 1: This flow chart shows the patients who had enrolled in this study. References: Ewha wamans university Mokdong hospital - Seoul/KR The number of patients who had abnormal finding on LDCT were 166 and amont them, only 160 patients were diagnosed acute API. In the API group, 111 patients had abnormal CXR findings due to acute exacerbation of COPD (1 patient) or pneumonia(110 patient). On the other hand, 49 patients were noted normal CXR with abnormal LDCT due to acute exacerbation of COPD/asthma (6 patient), bronchitis (17 patient) and pneumonia (26 patient). In the non-api group, the patients suffered from pulmonary edema (1 patient), pulmonary embolism(1 patient), lung cancer(1 patient), acute pyelonephritis(1 patient) and colitis(1 patient). Diagnostic accuracy for pneumonia which diagnosed by the presence of consolidation, GGO, CLN on LDCT were compared to CXR (Table 1). Page 3 of 9

4 The sensitivity in diagnosing pneumonia were 80.9% on CXR and 100 % on LDCT. The specificity were 92.8% on CXR and 89.9% on LDCT. Positive predictive value were 95.7% on CXR and 95.1 % on LDCT. Negative predictive value in diagnosing pneumonia is much higher on LDCT of 100%, compared to CXR of 71.1%. The diagnostic accuracy for pneumonia were 84.9% on CXR and 96.6% on LDCT. Equivocal CXR was interpreted as negative for pneumonia (Fig.2). Fig. 2: A 94-year-old woman with aspiration pneumonia. (a) Supine chest radiograph is equivocal for pneumonia. (b) LDCT shows consolidation and GGO in dependent areas of BLL. References: Ewha wamans university Mokdong hospital - Seoul/KR Diagnostic accuracy CXR* LDCT Sensitivity 80.9% 100% Specificity 92.8% 89.9% Positive predictive value 95.7% 95.1% Negative predictive value 71.1% 100% Accuracy 84.9% 96.6% <Table.1> Diagnostic accuracy for pneumonia on LDCT were compared to on CXR. Diagnostic accuracy of LDCT for API including the disease such as acute exacerbation of COPD/asthma, bronchitis, pneumonia were compared to CXR on table 2. The sensitivity in diagnosing API were 69.9% on CXR and 100 % on LDCT. The specificity were 91.9% on CXR and 86.7% on LDCT. Positive predictive value were 96.5% on CXR Page 4 of 9

5 and 96.4 % on LDCT. Negative predictive value in diagnosing pneumonia is much higher on LDCT of 45.6%, compared to CXR of 100%. The diagnostic accuracy for pneumonia were 74.1% on CXR and 97.1% on LDCT. Diagnostic accuracy CXR LDCT Sensitivity 69.9% 100% Specificity 91.9% 86.7% Positive predictive value 96.5% 96.4% Negative predictive value 45.6% 100% Accuracy 74.1% 97.1% <Table.2> Diagnostic accuracy of LDCT for API including the disease such as acute exacerbation of COPD/asthma, bronchitis, pneumonia were compared to CXR. Among the 160 API patients, abnormal CT or CXR patterns noted by two radiologists for each clinical diagnosis were compared in table 3. Figure 3 shows a 91-year-old woman with bronchitis without abnormality on CXR and with diffuse bronchial wall thickening in both lower lungs on LDCT. CXR(-)LDCT(+) (n=49) CXR(+) (n=111) Clinical diagnosis Acute exacerbation of COPD/asthma (n=6) Bronchitis (n=17) CT pattern DBWT DBWT Pneumonia (n=17) GGO, CLN, small consolidation Aspiration pneumonia (n=9) Acute exacerbation of COPD (n=1) Consolidation in dependent lung Consolidation pulmonary edema) (d/t Pneumonia (n=110) Consolidation >>GGO, CLN, DBWT <Table.3> Among the 160 API patients, abnormal CT or CXR patterns noted by two radiologists for each clinical diagnosis were compared in table 3. (DBWT = diffuse bronchial wall thickening, GGO = ground-glass opacity, CLN = centrilobular nodule) Page 5 of 9

6 Fig. 3: A 91-year-old woman with bronchitis. Supine chest radiograph shows cardiomegaly. LDCT shows diffuse bronchial wall thickening in both lower lungs. References: Ewha wamans university Mokdong hospital - Seoul/KR The age, sex, comorbidity rate, admission rate in ICU or non-icu in the patients who had abnormal LDCT or CXR findings were reported in table 4. Note that the abnormal LDCT group were reported lower admission rate than the abnormal CXR group. CXR(-) LDCT(+) CXR(+) P-value (n=49) (n=111) Age 77.0±9.4 yrs 75.1±9.5 yrs Sex (M:F) 17:32 69: Comorbidity 19/49 (38.8%) 66/111 (59.5%) Admission 27/49 (55.1%) 83/94* (88.3%) Non-ICU 23/49 (46.9%) 49/94 (52.1%) ICU 4/49 (8.2%) 34/94 (36.1%) <Table.4> The age, sex, comorbidity rate, admission rate in ICU or non-icu in the patients who had abnormal LDCT or CXR findings were reported. * Self discharge or transfer : 17 of total 111 CXR(-)LDCT(+) patients. The rate of using oral or intravenous antibiotic treatment in the patient with abnormal LDCT or CXR findings were reported in table 5. Page 6 of 9

7 Note that the abnormal LDCT group had lower antibiotic treatment rate than the abnormal CXR group. Table 6 shows the combined abnormality in 160 patients with API on current study. Fig.4 are the case of 72-year-old man with pneumonia with abnormal CXR findings. CXR(-)LDCT(+) CXR(+) P-value (n=49) (n=111) Antibiotic Tx 32/49 (65.3%) 104/105* (99.0%) P.O. 5/49 (10.2%) 8/105 (7.6%) I.V. 27/49 (55.1%) 96/105 (91.4%) Mortality 1/49 (2.0%) 16/88# (18.2%) <Table.5> The rate of using oral or intravenous antibiotic treatment in the patient with abnormal LDCT or CXR findings were reported. * Self discharge or transfer without medication : 6 of total 111 patients # F/U loss due to self discharge or transfer : 23 of total 111 patients API related findings Pulmonary edema 20 Pleural effusion 37 Pre-existing pulmonary diseases Emphysema 27 Bronchiectasis 16 Fibrosis due to previous infection, etc. 26 Incidental findings Lung cancer 2 Active pulmonary TB 1 Asbestosis 1 <Table.6> shows the combined abnormality in 160 patients with API on current study. Page 7 of 9

8 Fig. 4: A 72-year-old man with pneumonia. (a) Supine chest radiograph shows suspicious opacity in right lower lung zone. (b) LDCT shows consolidation in RML. She had oral antibiotic therapy at outpatient clinic. References: Ewha wamans university Mokdong hospital - Seoul/KR Conclusion There are several limitations in this study. First, supine CXR was obtained in most elderly with toxic appearance at ER and this caused decreasing diagnostic accuracy of CXR. Second, because of short period of this study (winter and spring in Korea), seasonal variation in incidence of URI or bronchitis may have influence on diagnostic accuracy of CXR and LDCT. Finally, non-contrast enhancement of LDCT were evaluated and misdiagnosis of pulmonary embolism might be occurred (Elderly patients with PE or CHF may have similar clinical feature to API). In conclusion, for the elderly patients with suspected API and CXR(-) at ER, LDCT was helpful for differential diagnosis between bronchitis, acute exacerbation of COPD/ asthma, and pneumonia. LDCT was useful especially for the diagnosis of aspiration pneumonia or pneumonia with small lesion. Although the patients with CXR(-)LDCT(+) API had better prognosis than those with CXR(+)API, antibiotic therapy and admission were needed in 65.3% and 55.1% of them, respectively. Page 8 of 9

9 Personal information References 1. Banker PD, Jain VR, Haramati LB. Impact of chest CT on the clinical management of immunocompetent emergency department patients with chest radiographic findings of pneumonia. Emerg Radiol 2007; 14: Hayden GE, Wrenn KW. Chest radiograph vs. computed tomography scan in the evaluation for pneumonia. J Emerg Med 2009; 36: Esayag Y, Nikitin I, Bar-Ziv J, et al. Diagnostic value of chest radiographs in bedridden patients suspected of having pneumonia. Am J Med 2010; 123:88.e1-88.e5 4. Syrjala H, Broas M, Suramo I, Ojala A, Lahde S. High-resolution computed tomography for the diagnosis of community-acquired pneumonia. Clin Infect Dis 1998; 27: Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/ American Thoracic Society consensus guidelines on the management of communityacquired pneumonia in adults. Clin Infect Dis 2007; 44 Suppl 2:S27-72 Page 9 of 9