RESUMO
BACKGROUND AND OBJECTIVES: Blood establishments strive to ensure the safety and comfort of blood donors while minimizing adverse events. This review aims to assess the efficacy and effectiveness of eating and/or drinking interventions before, during and/or after blood donation in reducing vasovagal reactions (VVRs). MATERIALS AND METHODS: We analysed randomized and non-randomized controlled trials comparing eating and/or drinking interventions to no intervention, placebo or usual practice on (pre-)syncopal VVRs and related symptoms. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach was used to assess the risk of bias and overall certainty of the evidence. RESULTS: Pre-donation water ingestion likely results in reduced on-site VVRs, compared to no water (2 fewer per 100 donors, moderate-certainty evidence). A pre-donation isotonic drink likely results in reduced VVRs, compared to usual practice (2 fewer per 100 donors, moderate-certainty evidence). Pre-donation salt-loaded sweetened lemon water may result in fewer off-site VVRs, compared to sweetened lemon water only (1 fewer per 100 donors, low-certainty evidence). Pre-donation water and a gel cap containing sucrose with 250 mg caffeine may result in fewer blood donor reaction ratings, compared to pre-donation water only (low-certainty evidence). CONCLUSIONS: Pre-donation plain water ingestion or isotonic drink probably results in a large reduction in on-site and off-site VVRs. Pre-donation water ingestion with caffeine consumption or salt supplementation may result in a VVR reduction, compared to water ingestion only. Future large trials are required to increase the certainty of the effect of these and other interventions in the prevention of VVRs.
RESUMO
BACKGROUND AND OBJECTIVES: Most research studies on the effects of repeated plasma donation are observational with different study limitations, resulting in high uncertainty on the link between repeated plasma donation and health consequences. Here, we prospectively investigated the safety of intensive or less intensive plasma donation protocols. MATERIALS AND METHODS: Sixty-three male subjects participated in this randomized controlled trial and were divided into low-frequency (LF, once/month, n = 16), high-frequency (HF, three times/month, n = 16), very high-frequency (VHF, two times/week, n = 16) and a placebo (P, once/month, n = 15) groups. Biochemical, haematological, clinical, physiological and exercise-related data were collected before (D0), after 1½ months (D42) and after 3 months (D84) of donation. RESULTS: In VHF, red blood cells, haemoglobin and haematocrit levels decreased while reticulocyte levels increased from D0 to D84. In both HF and VHF, plasma ferritin levels were lower at D42 and D84 compared to D0. In VHF, plasma levels of albumin, immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM) dropped from D0 to D42 and remained lower at D84 than at D0. In HF, plasma IgG, IgA and IgM were lower at D42, and IgG and IgM were lower at D84, compared to D0. Few adverse events were reported in HF and VHF. Repeated plasma donation had no effect on blood pressure, body composition or exercise performance. CONCLUSION: VHF plasmapheresis may result in a large reduction in ferritin and IgG levels. HF and VHF plasmapheresis may result in little to no difference in other biochemical, haematological, clinical, physiological and exercise-related parameters.