The choice of which catheter to use depends on what you plan to use the catheter for and which insertion sites are available to you. Large bore percutaneous sheaths are useful as conduits for subsequent insertion of, for example, Pulmonary Artery Catheters and temporary pacing wires. They are also useful in situations requiring rapid administration of large volumes of fluid. Multiple lumen catheters are useful in situations requiring multiple infusions of fluid or drugs in addition to measurement of the pressure in the central veins. Specialised large bore double lumen catheters (eg. vascaths) are required to perform renal replacement therapy such as haemofiltration.