SESSION TITLE: Critical Care Student/Resident Case Report Posters I
SESSION TYPE: Medical Student/Resident Case Report
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: Aortic Aneurysm (AA) is a life threatening condition and if not detected early, can lead to deadly outcomes. Clinical suspicion is critical to avoid a delay in diagnosis. Ours is a case where a false positive ventilation perfusion (V/Q) scan resulted in treatment for pulmonary embolism (PE) instead of the real diagnosis of AA. False positive V/Q scans can also be found in cases of surgically corrected congenital heart disease, compression of pulmonary vasculature with a mass lesion or adenopathy. There are but a few reported cases of false positive V/Q scans which caused a misdiagnosis of an acute dissecting aortic aneurysm. Our case is one of such fatal cases.
CASE PRESENTATION: A 67 year old female, arrives via EMS after falling complaining of chest and back pain. Physical exam and vital signs were normal. She was found to have a positive troponin and D-Dimer, with no EKG changes. Differentials were non ST elevation MI versus (PE). The patient was allergic to iodinated dye and thus a V/Q scan was performed and was high probability for a PE, demonstrating almost complete absence of perfusion to the right lung. Following treatment with heparin, on day 4 after admission, the patient was found to be bradycardic, with upper back pain, became hypotensive, and lost consciousness. Physical exam revealed discordant blood pressures and irregular pulses. Repeat chest x-ray showed widening of the mediastinum. Preparation for allergy to dye was given and an emergent CT of the chest and abdomen revealed a rupture of the proximal aortic arch, and a mediastinal hematoma completely compressing and occluding the right main pulmonary artery. She was taken to emergent cardiac surgery which revealed a ruptured saccular aneurysm, repair was completed and the patient later died post operatively.
DISCUSSION: There are a rare number of cases (6 in our review) of complete pulmonary artery occlusion from an AA with absence of perfusion to one lung on V/Q scan. The majority of these cases were initially thought to be PE, clouded the actual diagnosis, and initiation of heparin resulted in fatal complications. A strong clinical suspicion is paramount in establishing an accurate diagnosis.
CONCLUSIONS: Diagnostically, a unilateral loss of perfusion on V/Q scan to the lung should merit investigation of AA and remain within the differential diagnosis until proven otherwise.
Reference #1: Neri E, Toscano T, Civeli L, Capannini G, Tucci E, Sassi C: Acute dissecting aneurysm of the ascending thoracic aorta causing obstruction and thrombosis of the right pulmonary artery. Tex Heart Inst J 2001, 28:149-151.
DISCLOSURE: The following authors have nothing to disclose: Annuradha Bhandari, Alaa Abu Sayf
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