Persistent hypoxia: Where is the shunt?

摘要

Case Report:A 57-year-old woman with end-stage renal disease presented with a 4-month history of progressive dyspnea. She had a history of polycystic kidney disease, failed renal transplant, and occluded left arteriovenous fistula. Both subcla-vian veins were thrombosed due to multiple hemodialysis catheter placements. An intrahepat-ic tunneled catheter was being used for dialysis. On admission, she was found to have an oxygen saturation of 80% on room air, with no evidence of pulmonary congestion on chest radiograph or pulmonary embolism on computed tomography (CT). A right-to-left shunt was considered in the differential diagnosis, and a transthoracic echo-cardiogram (Vivid e9, GE Healthcare, Pittsburgh, PA, USA; iE33, Philips Healthcare, Andover, MA, USA) was performed. The left and right ventricular systolic function was normal and no valvular abnormalities were noted. Injection of agitated saline in left upper extremity resulted in immediate, dense opacification of the entire left heart (Fig. 1). However, injection via the intrahepatic catheter demonstrated the bubbles to appear in the right heart (Fig. 2), with no evidence of patent foramen ovale.