In-depth course


This In-depth Course is designed as part of the continuous Educational Programme. In this part we will go through the following:

  • Background
  • Risk Factors
  • Education and awareness
  • Risk assessment tool
  • Managing the risk of VND
  • Take home messages
  • References


The level of risk is based upon a combination of the frequency of an incident occurring and the severity of the incident.


There are varying figures for the frequency of VND events and the real frequency is not well known.

A blame-free and transparent culture is lacking. There needs to be a willingness to report all incidents of VND as presently many estimates of VND frequency will under-estimate the true problem.

In summary – VND incidents are relatively infrequent

  • Most healthcare professionals will have to deal with one or more incidents in their career.
  • The perception that VND is infrequent can breed complacency and increase risk.


VND can and does kill:

  • 10-33% mortality rate (Sandroni, 08)

Complications include:

  • Hospitalisation
  • Need for blood transfusion
  • Death

Indirect consequences include:

  • Psychological suffering
  • Reluctance to undertake home haemodialysis/nocturnal haemodialysis/other potentially isolated treatments

In summary – The consequences of VND incidents are extremely serious.

Risk factors

There are a number of modifiable risk factors for VND events. These can be divided in patient-related risk factors and unit-dependent risk factors.

Risk factors: patient-related

  • Covering up of access site
  • Patients who get cold
  • Cultural reasons
  • Patients who lack ability to notice a VND
  • Patients who sleep
  • Patients who are confused or have cognitive impairment
  • Patients who sweat or have small bleeds at the access site
  • Home haemodialysis patients who may be alone
  • Patients prone to erratic or restless behaviour, including cramping and intradialytic hypotension

Risk factors: unit-dependent

  • Low staff: patient ratios
  • Poor fixation of needles
  • Inappropriate venous pressure alarm window
  • Alarm fatigue
  • Poor lighting or room design, obstructing patient monitoring

Education and awareness

Education and awareness is possibly the most powerful tool in managing the risk of VND.

Education should be provided across the range of healthcare professionals who interact with patients and also be provided to patients, relatives and carers.

Education should be refreshed periodically.

Awareness can be heightened by use of posters, checklists and continuous education.

Risk assessment tool

A formal risk assessment tool has been developed to help healthcare staff decide the individual risk level for a particular patient.

Do your own test, find it under Risk Management.

Step 1 – Securing needle site

Dialysis units should have a consistent procedure for taping needles and bloodlines.

The butterfly or chevron technique is advocated.

Bloodlines should be looped loosely to allow patient movement.

If it is necessary to move a needle, all taping should be replaced.

Van Waeleghem, 2008

Step 2 – Venous pressure alarms

Venous pressure alarms are not sufficient on their own to detect a VND and should not be relied upon.

Upon a VND, venous pressure will drop by the fistula pressure, which is on average around 30 mmHg, but often below 20 mmHg.

  • If the alarm limit is more than 20 mmHg below the venous pressure it will often fail to detect a VND.
  • If the alarm limit is too high it will cause false alarms.

Ribitsch, 2014

Step 3 – Blood loss detection devices

Patients who are deemed to be at particularly high risk may benefit from a blood loss detection device.

These devices can be placed on or near to the site of the vascular access and an alarm raised when they come into contact with blood.

Take home messages

VND is a real and severe complication of haemodialysis treatments.

Reporting incidents and creating a blame-free culture will allow a better understanding of VND and facilitate research in this field.

Education and awareness are key to minimising the risk of VND.

Risk assessment can highlight patients most at need of extra staff monitoring or use of a blood loss detection device.


  • Van Waeleghem JP, Chamney M, Lindley EJ, Pancírová J. Venous needle dislodgement: how to minimise the risks. J Ren Care.
    2008 Dec;34(4):163-8
  • Ribitsch W, Schilcher G, Hafner-Giessauf H, Krisper P, Horina JH, Rosenkranz AR, Schneditz D. Prevalence of detectable venous pressure drops expected with venous needle dislodgement. Semin Dial. 2014 Sep-Oct;27(5):507-11
  • Sandroni, S., Sherockman, T., & Hayes-Light, K. Catastrophic hemorrhage from venous needle dislodgement during hemodialysis: Continued risk of avoidable death and progress toward a solution. JASN. 2008 19 (Abstract issue), 891A