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Central Lines



Confirming Venous Placement

  • Flashback - the flashback from a needle in a vein should be dark red with slow flow. Bright red blood that pulsates indicates arterial catheterisation; the needle should be removed and pressure placed for at least five minutes.
  • Ultrasound - place the sterile probe over the insertion site and examine the vein both parallel and perpendicular to the direction of insertion, looking for presence of the needle / guidewire in the vein (a non-pulsatile, compressible vessel)
  • Manometry - attach the needle to a transducer system to determine intraluminal pressure.
  • Blood gas - send a blood sample for analysis. Compare this with the patient's arterial sample or look at indicators of oxygenation in the result.
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