Hemodynamic response during standing test after blood donation can predict the late phase vasovagal reaction.

A major complication of blood donation is vasovagal reaction (VVR) with or without syncope. VVR occurs not only in the early phase, but also in the late phase after blood donation. We previously reported the hemodynamic characteristics of blood donors susceptible to early phase VVR. In the present study, we investigated the hemodynamic characteristics of those who developed late VVR. Ninety-six healthy volunteers donating 400 ml of whole blood were studied. After asking about their physical condition or routine questions for blood donation, blood pressure (BP) and heart rate (HR) were recorded while the donors were kept standing up for 3 min before and after blood collection. Questionnaires were distributed to all donors for reporting late VVR symptoms within 24 h. Those with younger age and lower diastolic blood pressure were more susceptible to late VVR (both p < 0.05). Furthermore, we identified the increase in HR during the standing test after blood collection as a good predictor of late VVR (odds ratio 1.063, 95 % CI 1.005-1.124; p = 0.031). Also, analysis of questions asked before donation revealed that significantly more donors considered themselves as sensitive to pain in the late VVR group (Odds ratio 0.070, 95 % CI 0.008-0.586; p = 0.014). Excessive HR response to standing after blood collection and subjective sensitivity to pain as well as younger age and lower diastolic BP may be useful to detect donors at high risk for late VVR.