Role of Predonation Hydration in the Prevention of Postdonation Vasovagal Reactions in First Time Blood Donors: A Randomised Controlled Trial

Introduction: A crucial component of the effort to meet the growing demand for blood is the recruitment and retention of young novice blood donors. Reducing postdonation syncopal reactions could have a beneficial impact on donor convenience, safety, and desire to donate again. Aim: To evaluate the effectiveness of predonation hydration over standard blood donation in the prevention or decrease in severity of postdonation Vasovagal Reactions (VVR) in hydrated blood donors in comparison with the non hydrated group. Materials and Methods: The randomised controlled trial was conducted on 953 first time voluntary blood donors. Donors in the intervention arm drank 250 mL water 30 minutes before blood donation, while those in the control group did not receive any intervention. Blood was collected by standard protocol. Outcome, VVR, if present was graded as mild, moderate, and severe. Analysis of results were done using Statistical Package for the Social Sciences (SPSS) version 16.0. A sensitivity analysis was also done to consider the dropouts from the study. Results: A total of 900 participants were included in the study, of which 443 were controls and 457 were cases. An effect size of 6.1%, a Relative Risk (RR) of 0.54 {95% Confidence Interval (CI)=0.36-0.81} and a risk reduction of 45% was arrived at, pointing to a protective role for predonation hydration in preventing VVR. There was a significant reduction in the severity of VVR in the predonation hydration group compared to the standard blood donation group (p-value=0.002). The protective effect of hydration on decreasing the occurrence and severity of VVR had statistical support in males in the moderate and severe grades (p-value=0.017). A similar statistical significance was not established in females (p-value=0.173). Sensitivity analysis did not reveal a difference in the statistical significance of variables between compared groups. Conclusion: Predonation hydration was found to be effective in preventing and decreasing the severity of VVR in novice blood donors.