A Study on the Effect of Pre-donation Salt Loading on Vasovagal Reactions in Young College Going Whole Blood Donors.

Abstract

The pathophysiology of vasovagal reactions (VVRs) involves both psychological and physiological components. Strategies which could allay physiological changes include interventions like pre-donation water intake and applied muscle tension have been published, however salt loading has not been tested. Cross sectional study enrolling 1000 young college going whole blood donors with intervention 250ml of salted loaded water or plain water as placebo. The immediate VVRs were recorded with respect to age, gender, donation status, blood volume, blood volume drawn and BMI. VVRs occurred in 25 out of 1000 (2.5%) young college going whole blood donors. Overall there were 18 VVRs in 526 (3.4%) donors in the placebo arm compared to 7 in 474 (1.5%) in salt loaded arm with odds of 2.36 (p=0.049), however the difference in means of VVRs between the study arms could not achieve statistical significance on binary logistic regression. The independent risk factors including age, gender, blood volume, blood volume withdrawn and BMI or the donation status were not found to be effect modifiers on the occurrence of VVRs. Salt loading before blood donation in young college going whole blood donors does decrease the VVRs in the immediate post donation period; however the decrease was limited to a trend and could not attain statistical significance.