Simple standing test predicts and water ingestion prevents vasovagal reaction in the high-risk blood donors

BACKGROUND: One of the serious complications of blood donation is vasovagal reaction (VVR) with syncope. This study was performed to determine if the measurement of hemodynamic responses to standing before blood collection (BC) was useful to identify the high‐risk donors for VVR and also examined the effect of 300 mL of water ingestion in the prevention of VVR. STUDY DESIGN AND METHODS: Blood pressure and heart rate (HR) during 5 minutes of standing were examined before and after BC in 93 donors. Because HR increase of 6 of 7 donors who developed syncopal VVR during standing after BC was 15 beats per minute (bpm) or greater, those with HR increase of 15 bpm or greater were determined as high‐risk donors (n = 31). In another group (n = 117), 45 donors were identified as high risk based on the HR response before BC (≥15 bpm). The effect of 300 mL of water ingestion 15 minutes before BC on hemodynamic responses to standing and the rate of VVR after BC were analyzed. RESULTS: Water ingestion given to the high‐risk donors of the second group reduced HR increase with standing before BC (−6.6 ± 13.6 bpm, p