SESSION TYPE: Miscellaneous Student/Resident Case Report Posters
PRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PM
INTRODUCTION: Compression ultrasonography (CUS) is the gold standard for the routine diagnosis of deep venous thrombosis, DVT. A free-floating thrombus (FFT) is often considered a risk factor for pulmonary embolism. Few cases in which CUS may have dislodged a blood clot and caused a pulmonary embolism have been reported.
CASE PRESENTATION: A 85 year old man presented with 4-day history of dyspnea and bilateral lower limb edema. He also had cough productive of purulent sputum and hemoptysis. Clinical examination revealed a heart rate of 80/min, respiratory rate 22/min and SpO2 96% on a Fi02 of50%. Bilateral pitting edema was present and lung auscultation revealed widespread crepitations. Chest X-Ray showed bilateral alveolar infiltrates. ECG and cardiac enzymes were unremarkable. Hemoglobin 11g/dl, White cell counts 15.7x10(9)/l, Platelet 41x10(9)/l, Serum Creatinine 174umol/L, Urinary Protein Creatinine ratio 10.52. The patient improved with Frusemide and Moxifloxacin. On his 4th day of hospitalization, his right lower limb was noted to be bigger than the left. Anticoagulation was not started as the patient had hemopytsis and thrombocytopenia. CUS of the right lower limb was performed 6 hours later. Unfortunately, the patient collapsed suddenly while talking to his relatives 1 hour after the scan. Despite aggressive cardiopulmonary resuscitation, he remained in asystole. The scan reported thrombosis of the entire right common femoral vein and floating thrombus (extending proximally).
DISCUSSION: The risk factors for DVT in this case include immobilization in an elderly person due to acute illness, diuersis and nephrotic range proteinuria. The discrepancy in size of his lower limbs was noted only after treatment with diuretics. Unfortunately the patient had an acute cardiorespiratory arrest within an hour of the CUS. Dynamic tests such as compression of muscles upstream from the probe and assessment of vein compressibility accelerate venous flow and may have contributed to fragmentation of the FFT. Although a post-mortem was not done, the temporal relation of the collapse to the recent CUS seemed consistent with a fatal pulmonary embolism secondary to dislodgement of a FFT in the common femoral vein.
CONCLUSIONS: 1. High index of suspicion with meticulous clinical measurement is required to detect lower limb DVT in a patient with bilateral limb edema due to fluid overload state. 2. Earlier diagnosis, avoidance of excessive pressure of the ultrasound probe, and more importantly the omission of dynamic test when a FFT is detected on CUS together with emergent surgical or endovascular intervention could have prevented this fatal outcome. 3. CUS is not absolutely safe.
1) G Pacouret, D Alison, J Pottier et al. Free-Floating Thrombus and Embolic Risk in Patients With Angiographically Confirmed Proximal Deep Venous Thrombosis. A Prospective Study Arch Intern Med. 1997;157(3):305-308.
DISCLOSURE: The following authors have nothing to disclose: Annthea Lee, James Li, Anne Hsu
No Product/Research Disclosure InformationYong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore