Der Anaesthesist
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Meta Analysis
[The menstruation cycle in the postoperative phase. Its effect of the incidence of nausea and vomiting].
Several studies suggest that the menstrual cycle has an impact on postoperative nausea and vomiting (PONV). However, many studies report inconsistent results. Thus, in this systematic review the results of all available studies are compared and statistically synthesised. ⋯ Studies investigating the influence of the menstrual cycle on the incidence of PONV show inconsistent results. Summarising the data of these studies suggests that the phase of the menstrual cycle has no impact on the occurrence of PONV.
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The separation of whole blood into components is the state-of-the-art in transfusion of allogeneic blood. The main reasons are the negative effects of the buffy coat and the need for FFP. Nevertheless, especially in Germany whole blood is being rejected more and more even as autologous blood. However, most of the negative effects of the buffy coat do not apply to autologous blood. Additionally, these patients usually do not develop coagulation disorders and therefore do not need plasma as a hemostatic component. On the other hand, separation into components of autologous blood leads to an increase of costs and to logistic problems that restrict autologous blood predeposit to a few institutions. Therefore, we have reviewed the literature in order to find a scientific basis for this. ⋯ Whole blood (resuspended in CPDA-1) and red cell units (stabilized in CPDA-1 or additive solutions) with a different buffy coat or leucocyte content have comparable pH values and red cell 2,3-DPG and ATP concentrations at the end of the approved storage time. The potassium load of a whole blood unit appears to be higher than red cell concentrates, but this is to some extent caused by the higher plasma content of whole blood and is not thought to be a clinically relevant problem for patients receiving only a few units. A number of studies demonstrate that dependent upon the leucocyte content of a red cell unit, leucocyte metabolites and enzymes are released and accumulate during storage. A detrimental influence on the integrity of the red cell membrane was found in several in vitro studies. Nevertheless, a significant improvement in red cell survival by leucocyte reduction was detected by only one group. Undoubtedly, nonhemolytic febrile transfusion reactions (NHFTR) are generally caused by an antibody-antigen interaction due to the transfusion of allogeneic buffy coat. On the other hand, there is some evidence that non-specific immunological mechanisms such as the release of histamine or cytokines are also capable of causing NHFTR. Thus, these reactions are expected to occur in autologous blood transfusion. However, so far, there are no data about the frequency and severity of these reactions and whether they are more likely to emerge after transfusion of blood units with a particular preparation. Blood transfusions can cause septic complications due to bacterial contamination of the transfused units. These fatal but rare complications may be reduced by pre-storage filtration of blood, but there is no indication that buffy coat reduction is effective. Three cases with septic complications have been reported after autologous transfusion, in two of which red cell concentrates (at least one was free of buffy coat) had been used. Thus, there is no justification for the conclusion that the risk of septic complications is increased by transfusion of whole blood. After all, whole blood and red cell concentrates exhibit only minor differences in relevant in vitro parameters. Hence, a higher incidence of adverse effects following the transfusion of autologous whole blood compared to autologous red cell concentrations is unlikely. Therefore, the 24 h in vivo recovery is considered to be the most valid criterion to assess the quality of red cell preparations.(ABSTRACT TRUNCATED)