Factors associated with vasovagal reactions in whole blood donors: A case-control study

Vasovagal reactions to blood donation though generally mild and account for about 1% of donations, causes embarrassment/injury to the donors, lower likely return rates for future donations etc. The workforce hours devoted to attending to those who reacted can also affect the efficiency of the blood centre. There are various factors, both modifiable and nonmodifiable, involved in the causation of such reactions.

This study sought to identify the factors associated with vasovagal donor reactions in a case-control study.

This was a descriptive comparative study between donors who had VVRs (cases) and those who did not (controls) during or after blood donation from a single center in southern India. All the biophysical and demographic variables were collected from the donor records. In addition, a questionnaire was administered to the donors after donation within half an hour, addressing the psychosocial variables. All the data were captured in Microsoft Excel and analyzed using SPSS for Windows version 20.

A total of 178 donors who had donor reactions were included in the study with an equal number of controls who were age and sex-matched. Donors who had VVRs had an odds of 4.1 (95% confidence interval [CI]: 2.4-7.7) of admitted anxiety for blood donation. They also had an odds of 4.4 (95% CI: 2.8-6.9) of disturbed sleep the night before blood donation. Having an accompanying person to the blood center was detrimental, with an odds of 0.32 (95% CI: 0.2-0.6). Donors with local complications such as hematoma, double prick, or delayed collection had an odds of 21.2 (95% CI: 1.8-159.8) of developing VVR.

The psychosocial factors such as fear of the needle, the sight of the blood, state of mind, and quality and duration of sleep seem to have an association, adversely impacting the donors resulting in VVRs after/during blood donation.