The effect of pre-donation hypotension on whole blood donor adverse reactions: a systematic review.

Blood services are reliant upon healthy blood donors to provide a safe and adequate supply of blood products. Inappropriate variables contained within blood donor exclusion criteria can defer potentially appropriate donors. The aim of this systematic review was to examine the effect of low pre-donation blood pressure, as compared with normal blood pressure, on adverse events in allogeneic whole blood donors. A systematic review was performed using highly sensitive search strategies within five databases (Cochrane Central Register of Controlled Trials, CINAHL, Embase, MEDLINE, and Web of Science) from inception date until April 12, 2013. Out of 8305 records, 10 observational studies were identified that addressed the question. Five of these studies (with a combined total of 1,482,020 donations and 2903 donors) included either a statistical analysis or an appropriate study design that controlled for possible confounding factors. Based on the currently available evidence, hypotension has not been shown to be an independent predictive factor for donor complications. However, the overall quality of evidence was rather limited and rated 'low,' using the GRADE approach. In conclusion there is currently no evidence that hypotensive blood donors have a greater risk for donor adverse events compared with their normotensive counterparts.