LAUSR

© BMJ Publishing Group Limited 2021. No commercial reuse. See rights and permissions. Published by BMJ. DESCRIPTION A woman in her 50s presented for surveillance bronchoscopy 3 months after bilateral lung transplantation for alpha-1 antitrypsin deficiency. She was asymptomatic and her physical examination was unremarkable. While performing a prebronchoscopy pleural ultrasound examination to assess for lung sliding, a large mobile thrombus was incidentally found in the proximal right axillary vein below the clavicle. The thrombus was adhered to a venous valve and wavered with each venous pulsation (figure 1A, video 1). Further evaluation of the right upper extremity veins revealed complete thrombosis of the basilic vein where a peripherally inserted central venous catheter (PICC) had been previously placed. The lung transplantation team initiated subcutaneous enoxaparin and bridged her to warfarin as an outpatient. She returned for her next surveillance bronchoscopy 4 weeks later, and the same team performed a repeat ultrasound examination over the same venous valve, which showed complete resolution of the thrombus (figure 1B, video 2). Upper extremity deep venous thrombosis (UEDVT) accounts for 5%–10% of all deep venous thromboses (DVTs). 2 The incidence of venous thromboembolism (VTE) is high among lung transplant patients, with a reported incidence of 6%–9% in retrospective studies. 4 Postmortem examination of lung and heartlung transplant patients found 27% had evidence of pulmonary embolism. VTE among lung transplant patients is associated with increased length of stay, costs of hospitalisation and inhospital mortality. Approximately 50% of UEDVTs are caused by central venous catheters (CVCs), 2 and 30% of patients with indwelling venous catheters can have asymptomatic UEDVTs. PICC has a 2.6fold increased risk of thrombosis compared with CVC. Other important risk factors for UEDVT include malignancy, recent surgery or trauma, pregnancy, hormone therapy and thrombophilic disorders. UEDVT occurs most frequently in the subclavian, axillary, jugular, brachial and brachiocephalic veins but can involve more distal veins. Pointofcare ultrasound (POCUS) is a wellvalidated tool for detection of lower extremity DVTs, with a sensitivity of 86%–96% and a specificity >96%. 9 Conversely, data on the ability of POCUS to detect UEDVT are limited. One study comparing POCUS versus radiologyperformed ultrasound examinations found no discordance for