Utilization patterns and yield of Computed Tomography Pulmonary Angiogram (CTPA) at a tertiary teaching hospital - Liverpool Hospital Poster No.: R-0017 Congress: Type: Authors: Keywords: DOI: 2014 CSM Scientific Exhibit T. C. Yeow, L. Lam; CAMPERDOWN/AU Respiratory system, Pulmonary vessels, CT, RIS, Audit and standards, Diagnostic procedure, Quality assurance, Embolism / Thrombosis 10.1594/ranzcr2014/R-0017 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 RANZCR/AIR/ACPSEM's endorsement, sponsorship or recommendation of the third party, information, product or service. RANZCR/AIR/ ACPSEM 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 RANZCR/AIR/ACPSEM 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,.doc documents and any other multimedia files are not available in the pdf version of presentations. Page 1 of 13
Aim Increased availability and sensitivty of Multi-detector CT to detect pulmonary emboli (PE) have led to an increased in the use of Computed Tomography Pulmonary Angiograms (CTPA) in detection of PE across the world 1,2,3. The current view suggests that CTPAs are over-utilised in the evaluation of patients with suspected PE. CTPAs bring with them risks of contrast-induced nephropathy and radiation exposure 4,5,6,7. The current guidelines from the Royal College of Radiologists suggest at a Tertiary level, CTPAs should detect PE between 15.4% - 37.4% based on published data 8. Thus the aim of the project is to identify the total number of CTPA studies performed in a Tertiary Teaching Hospital - Liverpool Hospital within a seven month period (June 2012 - December 2012). Assess the yield of positive studies of the Hospital and its comparison with the current guidelines. Methods and materials Retrospective audit was performed using the search identifier in RIS. The keywords for Procedure Name as "CT Pulmonary Angiogram" with the dates from "1-Jun-2012 to 31- Dec-2012". All scans were performed on either of the 2 CT machines in the department - 64 slice Siemens Somatom Definition or 128 slice Siemens Somatom Definition AS according to our standard CTPA department protocol. Each CTPA was divided into referrals from Emergency, Medical, Respiratory and Surgical teams. Positive yields were calculated for the hospital as a whole and for each individual department. Results Total of 491 CTPAs performed in the 7 month period. 5 CTPAs were excluded as 3 were previously known acute PE for progress imaging and 2 were deemed to be chronic PE. Page 2 of 13
This leaves a total of 486 CTPAs for analysis. There was a slightly higher female to male ratio, 259:232; 53% female. The age range was 18-96years with a mean age of 63.7 and a median age of 66years. The number of scans performed were fairly consistent from month to month, ranging between 61-80 studies each month Fig. 1 on page 3 Fig. 7 on page 9. Emergency accounted for the largest number of studies, with a total of 274 studies (56%) performed. They had a positive yield of 35 studies (13%) Fig. 3 on page 5. Medical performed 110 studies (22%) Fig. 2 on page 4 with a positive yield of 18 studies (16%) Fig. 4 on page 6. Respiratory performed 46 studies (10%) Fig. 2 on page 4 with 7 positive studies (15%) Fig. 5 on page 7. Surgical performed the least number of scans, 56 studies (12%) Fig. 2 on page 4 with 10 positive studies (18%) Fig. 6 on page 8. The average positive yield for the hospital was 14% Fig. 8 on page 10. Images for this section: Page 3 of 13
Fig. 1: Total CTPAs performed divided per month and positivity Page 4 of 13
Fig. 2: Total CTPAs performed divided by each Department Page 5 of 13
Fig. 3: Percentage Positive for ED Page 6 of 13
Fig. 4: Percentage Positive for Medical Page 7 of 13
Fig. 5: Percentage Positive for Respiratory Page 8 of 13
Fig. 6: Percentage Positive for Surgical Page 9 of 13
Fig. 7: Number ordered for each Department per month Page 10 of 13
Fig. 8: Total Percentage Positive Page 11 of 13
Conclusion The average positive yield of the hospital is 14%, approximately 1 in 7 studies. This falls just below the recommended guideline of 15.4%. Emergency performs the largest number of studies with the lowest yield. On the contrary, Surgical performs the least number of studies with the highest yield. This trend is also reflected in a large study from Long Island, New York 1. During the time of this study, there was no algorithm for the investigation of PE in the Emergency department. Several studies have shown that implementation of an algorithm has been beneficial in improving the positive yield of CTPAs 9, 10, 11. Since this study, Emergency department at Liverpool Hospital has implemented an algorithm for the investigation of PE. This would require further evaluation to assess the benefits of this algorithm. Personal information Dr T. C. Yeow Radiology Registrar, Liverpool Hospital Dr L. Lam Staff Specialist, Liverpool Hospital Head of Radiology Department, Fairfield Hospital References 1 Chandra,S, Sarkar PK, Chandra D, et al. Finding an alternative diagnosis does not justify increased use of CT-pulmonary angiography. BMC Pulmonary Medicine. 2013; 13:9 Page 12 of 13
2 Donohoo JH, Mayo-Smith WW, Pezzullo JA, et al. Consecutive multidetector row computed tomography Pulmonary Angiograms in a busy Emergency Department. J Comput Assist Tomogr. 2008; 32:421-5 3 Weir ID, Drescher F, Cousin D, Et al. Trends in use and yield of chest computed tomography with angiography for diagnosis of pulmonary embolism in a Connecticut hospital emergency department. Conn Med 2010; 74(1): 5-9 4 Newman DH, Schriger DL. Rethinking Testing for Pulmonary Embolism: Less is More. American College of Emergency Physicians. 2011 June; 57 (6): 622-7 5 Mitchell AM, Kline JA. Contrast nephropathy following computed tomography angiography of the chest for pulmonary embolism in the emergency department. J Thromb Haemost. 2007; 5:50-4 6 Mitchell, AM, Jones, AE, Tumlin, JA, Kline, JA. Prospective study of the incidence of contrast-induced nephropathy among patients evaluated for pulmonary embolism by contrast-enhanced computed tomography. Acad Emerg Med. 2012 June; 19(6):618-25 7 Reagle Z, Tringali S, Gill N, et al. Diagnostic yield and renal complications after computed tomography pulmonary angiograms performed in a community-based academic hospital. Journal of Community Hospital Internal Medicine Perspectives. 2012, 2: 17722 8 https://www.rcr.ac.uk/audittemplate.aspx?pageid=1020&audittemplateid=166 9 Ong, CW et al. Implementation of a clinical prediction tool for pulmonary embolism diagnosis in a tertiary teaching hospital reduces the number of computed tomography pulmonary angiograms performed. Internal Medicine Journal. 2012: 169-173 10 Stein EG, Haramati CL, Chamarthy M, et al. Success of a safe and simple algorithm to reduce use of CT Pulmonary Angiography in the Emergency Department. AJR. 2010; 194:392-7 11 Mamlouk MD, vansonnenberg E, Gosalia R, et al. Pulmonary Embolism at CT Angiography: Implications for appropriateness, cost and radiation exposure in 2003 patients. Radiology 2010 Aug; 256 (2): 625-32 Page 13 of 13