WHY REDSENSEall about redsense blood loss detection

Venous Needle Dislodgement - A safety problem

Venous needle dislodgement posses a threat to every hemodialysis patient during every treatment. Massive blood loss may occur before the notoriously unreliable venous pressure alarms detect changes of pressure within the dialysis machine. An average size patient can lose up to 50% of their total blood volume within 5 minutes of a venous needle dislodgement.

 redsense bloodloss article


Study results

  • 1 in 720 hemodialysis treatments is affected by VND1
  • >Most incidents are never reported2
  • Globally, approximately 1200 patients die every year due to VND3
  • 1 in 62 500 treatments result in serious bleeding or dead4
  • Following a VND, the patient has a higher risk of dying due to infection5


  1. Renal Physicians Association, US, patient survey 2007
  2. Ny teknik, nummer 33, 15 Augusti 2007
  3. Sandroni S. Catastrophic Hemorrhage from Venous needle dislodgement during hemodialysis. Journal of the American Society of Nephrology, volume 19, November 2008 adjusted for market increase
  4. Patients Safety Advisory; Veteran Health Administration Warning System; Published by VA Central Office; October 21, 2008
  5. Gambro, France


Globally this would mean that:

redsense 21 21


EDTNA/ERCA questionnaire recordings of 283 VND incidents indicate that 23% of VND's are serious and severe needing resuscitation to save patients lives and 5% either died or suffer from long term sequelae.


Hemodialysis 15 hours per week

During Hemodialysis blood is cleared from waste products when our kidneys fail to do so. A typical dialysis session lasts 4-5 hours and is completed 3 times weekly. Throughout the world 2.5 million patients receive hemodialysis.


Blood access

During each dialysis session the blood access site is punctured with two needles. The blood is pumped through an artificial kidney where the blood is cleared from waste products before being returned to the patient in a loop.


A serious complication

Venous needle dislodgement, VND, is when the needle slips out and the returning blood is pumped onto the bed or chair instead of back to the patient's bloodstream. As much as 400-500 ml of blood is lost every minute and if not detected immediately the consequences may be catastrophic and in some cases fatal.


Equipment limitation

The hemodialysis equipment used today are not equipped to detect VND reliably. The method of detection is limited to pressure measurements. When the venous needle is dislodged the pressure drop is often too small to activate the system.


Measures for detection

VND can happen to anyone. Every attempt should be made to minimize the risk, and protection such as Redsense can be used to detect blood loss.

The video above shows a controlled test of a venous needle dislodgement. The blood pump in the dialysis machine was turned off during the test, so the blood flow is substantially stronger during actual incidents. Please note that the Redsense system used here is of an older model.


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