Back to Basics: Increasing the use of Posteroanterior Chest Radiograph to Aid Assessment of Chest Pain for Aortic Dissection

Transcription

1 Back to Basics: Increasing the use of Posteroanterior Chest Radiograph to Aid Assessment of Chest Pain for Aortic Dissection Dr Sachintha Perera, Dr S Cookson Royal Surrey County Hospital

2 Why is this relevant? 46 admitted with sudden onset chest pain and hypotension. CXR (AP projection) - widened mediastinum noted. Disregarded due to projection Initially treated as ACS Likely pericarditis/musculoskeletal pain Discharged home on analgesia with a plan for outpatient CT-Coronary Angiogram, echocardiogram and follow up in 6-8 weeks Died suddenly at home ruptured thoracic aortic aneurysm

3 Outline Value of CXR in aortic dissection Aims of study Methods Results Discussion

4 Aortic dissection A life threatening event Dissection typically presents with pain (90%) 1 sudden onset severe tearing/sharp pain radiating to the back A challenging diagnosis many present with non-specific signs and symptoms

5 Imaging Modalities High risk cases: CT aortography is the gold standard 2 Intermediate/ low risk: CXR to aid diagnosis Members et al ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease

6 PA vs AP Less magnification of the mediastinum and heart due to divergence of the X-ray beam 3 BUT requires patient to stand AP PA 90% of aortic dissections have some abnormality on chest radiograph 4 Most common abnormality: mediastinal widening, 60-90% of cases 5 PA chest radiograph is more sensitive and specific for aortic dissection than AP view 6 90% specificity and 88% sensitivity for maximal mediastinal width 90% sensitivity and specificity for left mediastinal width

7 Aims Evaluate the proportion of PA chest radiographs performed for Emergency Department (ED) patients presenting with chest pain Identify reasons why PA radiographs not performed Increase the proportion of PA chest radiographs performed

8 Methods Cross sectional study identified 80 ED patients presenting with chest pain/tightness/discomfort Two-pronged intervention: Radiographers: Education on importance of PA orientation Signs encouraging performance of PA radiographs Doctors Signs requesting ED doctors to specify PA CXR and patient ability to stand safely on CXR request forms Performance re-audited on 73 patients.

9 Bar chart comparing % proportions of each radiograph orientation (95% CI), with NS radiographs corrected PA AP NS Audit Re-audit

10 Mean age of PA radiographs in first and second cycles was 54.6 and 53.1 respectively, with AP being 71 and 70.8 respectively

11 Discussion: Communication is key! Mean age for AP films was similar likely inappropriate AP films being performed Anecdotal reports found uncertainty of patients being able to stand was a major factor Improving communication between the doctors and radiographers via the CXR request form, specifying the need for a PA film and if the patient could stand, can lead to more PA films being performed This may improve dissection detection rate in low/intermediate risk cases

12 References 1. Pape LA, Awais M, Woznicki EM, Suzuki T, Trimarchi S, Evangelista A, et al. Presentation, Diagnosis, and Outcomes of Acute Aortic Dissection: 17-Year Trends From the International Registry of Acute Aortic Dissection. J Am Coll Cardiol Jul 28;66(4): Members WG, Hiratzka LF, Bakris GL, Beckman JA, Bersin RM, Carr VF, et al ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons, and Society for Vascular Medicine. Circulation Apr 6;121(13):e Puddy E, Hill C. Interpretation of the chest radiograph. Contin Educ Anaesth Crit Care Pain Jun 1;7(3): Pape LA, Awais M, Woznicki EM, Suzuki T, Trimarchi S, Evangelista A, et al. Presentation, Diagnosis, and Outcomes of Acute Aortic Dissection: 17-Year Trends From the International Registry of Acute Aortic Dissection. J Am Coll Cardiol Jul 28;66(4): Hagan PG, Nienaber CA, Isselbacher EM, Bruckman D, Karavite DJ, Russman PL, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA Feb 16;283(7): Lai V, Kan Tsang W, Chi Chan W, Wai Yeung T. Diagnostic accuracy of mediastinal width measurement on posteroanterior and anteroposterior chest radiographs in the depiction of acute nontraumatic thoracic aortic dissection. Emerg Radiol Mar 14;19:309 15

13 Results Increased proportion of PA radiographs being performed Proportion increased from 50±10.96% to 83.6±8.50% (to 95% confidence intervals) A two tailed Z-test showed significance: Z= , p < The proportion of AP CXRs reduced from 50±10.96% to 13.7±7.89% Mean age of PA radiographs in first and second cycles was 54.6 and 53.1 respectively, with AP being 71 and 70.8 respectively

14 Pie charts of numbers of chest radiographs performed in first and second cycles of audit PA = posteroanterior, AP = anteroposterior, NS = non-specified

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