Popliteal venous access for renal replacement therapy in a critically ill patient with central access failure

A woman in her 80s was admitted to the emergency department with an acute infective exacerbation of chronic obstructive pulmonary disease and type 2 respiratory failure, culminating in cardiac arrest for 2 min. She was successfully resuscitated, connected to a mechanical ventilator and subsequently transferred to the intensive care unit. Later in her hospital stay, the patient underwent a tracheostomy following prolonged intubation. During this period, she developed septic shock with complications, including acute kidney injury, metabolic acidosis and volume overload. As a result, the nephrologist recommended emergency haemodialysis. Initially, a left femoral haemodialysis catheter was established but had to be withdrawn a few days later due to the development of deep vein thrombosis (DVT). A left internal jugular catheter was then inserted but was removed after 5 days due to another DVT. It was subsequently replaced with a central line for vasopressor support. A Doppler scan revealed a large thrombus in the right internal jugular vein, extending to the area just above the superior vena cava. A similar thrombus was detected in the left internal jugular vein, with weak blood flow observed in both the right and left subclavian veins. Although the subclavian vein flows were deemed adequate, there was unsatisfactory blood flow through the catheter after insertion, rendering it unsuitable for haemodialysis. Due to an earlier central line-related infection, the right femoral site exhibited signs of infection and the presence of a pus pocket, making it unsuitable for haemodialysis access. To address this, the right popliteal vein was chosen for catheterisation using a 20-cm, 12 French catheter, the longest available catheter in the country at the time. The patient was placed in a prone position, and the catheter was smoothly inserted with ultrasound guidance, resulting in good flow. Subsequent haemodialysis sessions were carried out regularly.