Improving donor safety by using applied muscle tension: a randomised controlled trial
What was the question?
Some donors react to the sight of blood or a needle by feeling dizzy, faint or nauseous. This is known as a vasovagal reaction, and the symptoms are caused by a sudden drop in blood pressure and heart rate. International studies have suggested that applied muscle tension can reduce these symptoms.
A donor is asked to cross their legs, tense their inner thigh and abdominal muscles for five seconds, and then relax for five seconds. These simple exercises increase a donor’s blood pressure within two to three seconds, and prevent the occurrence of vasovagal symptoms.
We wanted to find out if applied muscle tension is effective in reducing donor risk of vasovagal reactions in the Australian donation setting and how to best implement the exercises into routine blood collection practice.
Why is it important?
Vasovagal reactions (VVR) have a negative impact on donor safety - as it increases the risk of sustaining an injury - and the donation experience - as donors often feel embarrassed or anxious. VVRs disrupt the flow within a donor centre, reduce the number of completed blood collections and can prolong donor wait times.
It is important to reduce donors’ risk of experiencing a VVR by developing evidence-based interventions that can be used in our donor centres.
What did we do?
Seven hundred and thirty-six blood donors participated in this multicentre randomised controlled trial. After registering at reception, donors were asked to complete a short pre-donation survey and were randomised into one of three groups:
- Group 1 received instructions to use AMT fromneedle in until they left the donation couch
- Group 2 received instructions to use AMT before the needle was inserted or removed, and before leaving the donation couch (VVR high risk time points)
- Group 3 was a “business as usual” control group.
We asked them to complete a survey after their donation in refreshments to capture how they felt during their donation and what they thought of the exercises.
What did we find out?
Donors who practised AMT at high risk time points had the lowest number phlebotomist-registered vasovagal reactions of all groups tested. Donors who practiced AMT were happy with their donation experience and there was no effect of AMT on reported blood flow issues.
Donors reported a high likelihood of continuing to use AMT in their future donations. Of the more than 200 donors using AMT at key time points, only two mild reactions were recorded. This compares with 6 mild, 6 moderate and 3 severe reactions in the control group-representing a reduction of over 83% in the incidence of vasovagal reactions.
What are the next steps?
The materials developed for this study will be rolled out nationally to increase the use of AMT across all donor centres in Australia. The instruction card will be given to all donors attending a blood appointment and the staff training materials will be distributed to all donor centre staff.
If you would like more information please contact Amanda Thijsen.
We would like to thank the Donor Services staff involved in recruiting the donors and collecting the data in centre (Ruth Webster, Betty Torma, Joanna Blair, Wendy Ryder, and Kim Kovac). We are also thankful for the donor centres involved in allowing us to conduct the study and for all the donors who have participated.