Incidental finding of persistent left superior vena cava after 'bubble study' verification of central venous catheter.

We report a case of a patient with septic shock who underwent central venous catheter placement in the left internal jugular vein, and a bedside ultrasound 'bubble study' revealed venous cannulation. A chest X-ray postprocedure revealed concern for arterial system catheterisation. However, the possibility of a persistent left superior vena cava was discussed and confirmed with a formal transthoracic echocardiogram and CT. This case demonstrates the importance of ultrasound-guided visualisation of anatomical structures in real time during central venous catheterisation. Other similar cases from the literature are briefly described.