Predonation hydration and applied muscle tension combine to reduce presyncopal reactions to blood donation.
BACKGROUND
A randomized controlled trial was conducted to test the effects of hydration and applied muscle tensing on presyncopal reactions to blood donation. Both interventions are designed to prevent the decreases in blood pressure that can contribute to such reactions, but due to the distinct physiologic mechanisms underlying their pressor responses it was hypothesized that a combined intervention would yield the greatest benefit.


METHODS
Before blood donation, first- and second-time blood donors (mean age, 20.2 years; SD, 4.9) were randomly assigned to 1) standard donation, 2) placebo (leg exercise before venipuncture), 3) predonation water, or 4) predonation water and leg exercise during donation.


RESULTS
Main effects of group were observed for phlebotomist classification of vasovagal reactions (chi(2)(3) = 8.38, p < 0.05) and donor reports of presyncopal reactions (chi(2)(3) = 13.16, p < 0.01). Follow-up analyses of phlebotomist classifications revealed fewer reactions in the predonation water and predonation water and leg exercise groups relative to placebo but not standard donation. Follow-up analyses of self-reported reactions revealed that women, but not men, had lower scores in both the predonation water and the predonation water and leg exercise groups relative to both placebo and standard donation.


CONCLUSIONS
Predonation hydration and a combination of hydration and leg exercise may help attenuate presyncopal reactions in relatively novice donors, although future studies with larger samples are required to confirm this effect.
France
Christopher R
CR
Ohio University, Athens, Ohio 45701, USA. france@ohio.edu
Ditto
Blaine
B
Wissel
Mary Ellen
ME
France
Janis L
JL
Dickert
Tara
T
Rader
Aaron
A
Sinclair
Kadian
K
McGlone
Sarah
S
Trost
Zina
Z
Matson
Erin
E
D000328:Adult; D001782:Blood Donors; D001794:Blood Pressure; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D012737:Sex Factors; D013575:Syncope / Q000209:etiology / Q000517:prevention & control*; D014867:Water / Q000008:administration & dosage*
D014867:Water