Dialysis catheter

  1. If a dialysis catheter is inserted into a large vein like the superior vena cava, it obviously will have to travel through a smaller vein first such as the jugulag vein, so when it gets into the larger vein there will be extra space on the sides of the catheter for blood to sneak through? Is there a balloon or whatever that inflates to create a tight seal?
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  2. 16 Comments

  3. by   MunoRN
    Dialysis catheters such as those placed in the IJ aren't intended to seal the vein or occlude flow around the catheter. Dialysis catheters generally range in size from 12-14 French (between 4 and 5 mm), which is still much smaller than the diameter of even the left IJ vein.
  4. by   Pharmahaulic
    So how do they ensure that blood flows into the catheter and more of it doesn't flow around it?
    Last edit by Pharmahaulic on Nov 9
  5. by   MunoRN
    A dialysis catheter doesn't rely on all of the flow through the IJ going into the catheter. Dialysis pulls a portion of the flow in a major vein then returns it downstream.
  6. by   traumaRUs
    A perm-cath is a cuffed catheter - there is indeed material (kinda looks like cotton batting) that is located close to the distal (patient) end of the catheter.permcath-jpg

    You see the cuff on the end (upper part of the pic) - it takes approx 3 weeks for the catheter to adhere to the skin.
  7. by   Pharmahaulic
    Quote from MunoRN
    A dialysis catheter doesn't rely on all of the flow through the IJ going into the catheter. Dialysis pulls a portion of the flow in a major vein then returns it downstream.
    So it sucks the blood up as its flowing by?

    What if it doesn't suck enough of it up?
  8. by   Pharmahaulic
    Quote from traumaRUs
    A perm-cath is a cuffed catheter - there is indeed material (kinda looks like cotton batting) that is located close to the distal (patient) end of the catheter.permcath-jpg

    You see the cuff on the end (upper part of the pic) - it takes approx 3 weeks for the catheter to adhere to the skin.
    And what is this kind of cath used for? Does the cuff prevent all blood from.flowing by?
  9. by   MunoRN
    Quote from Pharmahaulic
    So it sucks the blood up as its flowing by?

    What if it doesn't suck enough of it up?
    Flow into the catheter occurs due to a combination of mild positive pressure in the major veins, and the negative pressure produce by the dialysis machine's pumping action. If it is not getting enough blood, the machine has sensors that will alarm for low flow.
  10. by   MunoRN
    Quote from Pharmahaulic
    And what is this kind of cath used for? Does the cuff prevent all blood from.flowing by?
    The cuff isn't in the vein, it's in the tract under the skin that the catheter goes through to get to the vein, it's purpose is help seal the tract from contamination and encourage the tissues to encase the catheter.
  11. by   chare
    Quote from Pharmahaulic
    And what is this kind of cath used for? Does the cuff prevent all blood from.flowing by?
    This ia a longterm catheter used for dialysis. The cuff does not enter the vein. The cuff remains in the subcutaneos tissues, and eventually the tissue adheres to the cuff, thus helping to secure and stabilize the catheter.
  12. by   Pharmahaulic
    Quote from MunoRN
    Flow into the catheter occurs due to a combination of mild positive pressure in the major veins, and the negative pressure produce by the dialysis machine's pumping action. If it is not getting enough blood, the machine has sensors that will alarm for low flow.
    And when the sensor goes off, it sucks more blood? What if s lot of blood sneaks by?
  13. by   MunoRN
    Quote from Pharmahaulic
    And when the sensor goes off, it sucks more blood? What if s lot of blood sneaks by?
    The machine will alarm, notifying the nurse or dialysis tech running the machine that there is reduced flow who then troubleshoots, it may be that the patient has turned their head too far, the external line is kinked, etc.
  14. by   Pharmahaulic
    Quote from MunoRN
    The machine will alarm, notifying the nurse or dialysis tech running the machine that there is reduced flow who then troubleshoots, it may be that the patient has turned their head too far, the external line is kinked, etc.
    So how do they get more flow in the catheter?

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