Respiration and Applied Tension Strategies to Reduce Vasovagal Reactions to Blood Donation

For a number of years, researchers have examined the effects of the muscle-tensing technique, Applied Tension (AT), on blood donation-related vasovagal symptoms and donor retention. AT was developed originally to reduce symptoms and avoidance behaviour in people with strong fears of blood and needles (phobics). It was based on the idea that exercise-related increases in blood pressure might be able to counteract the effects of stimuli that lead to a decrease in delivery of blood to the brain. AT was adapted for non-phobic blood donors and significant reductions in self-reported vasovagal symptoms and the need for nurse-initiated treatment as well as increases in donor retention were observed in some groups. That said, individual response to AT is quite variable. This is probably related to recent research indicating that exercise-related maintenance of heart rate and blood pressure plays only a minor role in reducing vasovagal symptoms. Rather, AT appears to be working at least in part by regulating breathing and reducing the possibility of hyperventilation. Pilot results suggest that a novel intervention aimed specifically at breathing may be more effective and reliable than traditional AT. To evaluate this idea, 408 blood donors at mobile clinics in colleges and universities will be assigned randomly to four conditions. In brief, 5-minute preparation sessions using a notebook computer, donors will either learn a respiration control technique to avoid hyperventilation, AT, both, or neither. As a manipulation check and also a means of examining mechanisms of the interventions, e.g., the possibility that AT may work by regulating breathing and CO2, participants will wear non-invasive portable capnometers while they are giving blood. Outcome will also be assessed by self-report of vasovagal symptoms, observational data, and number of return visits to a blood clinic in the following year verified by the provincial blood collection agency, Héma-Québec. As a secondary aim, the research will examine possible moderating effects of pre-donation anxiety and sex. The development of simple, effective approaches to reduce vasovagal symptoms during blood donation has the potential to improve the blood donation experience and blood donor retention as well as encourage people who have never given blood to consider the procedure. It will also improve medical and dental care more generally given the use of needles in so many procedures.

The primary goal is to examine the role of hyperventilation in blood donation-related vasovagal reactions and whether breathing is influenced by two treatments (alone and in combination) for reactions. The study will examine the clinical impact of these treatments but this is not the primary goal of the project.

Volunteer blood donors complete assessment materials, including assessment of respiratory activity, but otherwise undergo the typical blood donation procedure.

Participants are taught a simple muscle tensing technique with a brief video presented on a notebook computer before giving blood. They are asked to engage in repeated gentle 5-sec on, 5-sec off cycles of whole body isometric muscle tension before and while giving blood.

Participants are taught a simple respiration control technique with a brief video presented on a notebook computer before giving blood. They are asked to breathe in a gentle shallow but regular fashion aimed at reducing risk for hyperventilation before and while giving blood.

Participants are asked to practice both Applied Tension and Respiration Control before and while giving blood.

change in mean value during the pre-donation waiting period (registration to going to chair, approximately 30 minutes) to the mean value in the donation chair (approximately 15 minutes)

change in mean value during the pre-donation waiting period (registration to going to chair, approximately 30 minutes) to the mean value in the donation chair (approximately 15 minutes)

participant anxiety, fainting, whether or not treatment for a vasovagal response required, etc., noted by a research assistant

completed just after registering at the clinic and also in the recovery area, approximately 15 minutes after blood donation, to assess change in anxiety

measured just after registering at the clinic and also in the recovery area, approximately 15 minutes after blood donation, to assess change in blood pressure

measured just after registering at the clinic and also in the recovery area, approximately 15 minutes after blood donation, to assess change in blood pressure

measured just after registering at the clinic and also in the recovery area, approximately 15 minutes after blood donation, to assess change in heart rate

number of times the donor returns to give blood again in a one-year time frame as reported by Hema-Quebec