Anemia, also referred to as low hemoglobin level, is a common finding in critically ill patients. Red blood cell (RBC) transfusion is used to increase patients’ hemoglobin level. Approximately 26 -... Show moreAnemia, also referred to as low hemoglobin level, is a common finding in critically ill patients. Red blood cell (RBC) transfusion is used to increase patients’ hemoglobin level. Approximately 26 - 40% of critically ill patients receive RBC transfusions during their stay in the Intensive Care Unit (ICU), making transfusion a substantial element of critical care practice. Current available evidence supports utilising a restrictive transfusion trigger of 7 g/dL in non-bleeding ICU patients. A burning question is whether 7 g/dL is the optimal trigger for all non-bleeding ICU patients. This research focused on increasing our understanding of clinicians’ red cell transfusion decisions, of possible consequences of red cell transfusion in individual non-bleeding critically ill patients, and on the methodology to achieve the latter goal.We showed that there is considerable variation in transfusion decisions amongst critical care physicians, suggesting that clinicians have varying ideas about benefits of transfusion. We identified clinical determinants of transfusion decisions, because these determinants might be associated with observed effects of RBC transfusion. The data were derived from the electronic medical health records of ICU patients. Our results confirmed that besides hemoglobin concentration, inherently the most important predictor of RBC transfusion, a number of other clinical parameters were associated with transfusion decisions. Using the same data, we developed a model for the prediction of the effect of RBC transfusion on subsequent organ functioning in non-bleeding critically ill patients. Show less
Knowledge of physiological changes in renal function, EPO and haemoglobin level and their impact at old age are essential for clinicians especially those working with older patients. The results of... Show moreKnowledge of physiological changes in renal function, EPO and haemoglobin level and their impact at old age are essential for clinicians especially those working with older patients. The results of the studies presented in this thesis provide more insight in the physiological aspects of age related decline in renal function and the relation with erythropoietin production and the maintenance of haemoglobin levels at old age. Furthermore, these results allow us to speculate about the predictive value of renal function, EPO and haemoglobin as markers of mortality in a clinical population of oldest old patients. Proper knowledge of these markers could contribute to increased attention of clinicians for the increased mortality risk of their oldest old patients. Furthermore, knowledge of these markers could be helpful in tailor made medicine, individual prognostication and decision making procedures, in the oldest old patients. Show less
In this thesis, several studies on neonatal red cell alloimmune hemolytic disease are presented, including various management options, associated complications and co-morbidities and the short-term... Show moreIn this thesis, several studies on neonatal red cell alloimmune hemolytic disease are presented, including various management options, associated complications and co-morbidities and the short-term and long-term outcome of children with Rhesus hemolytic disease. Show less
Red blood cells (RBCs) are probably the most frequently used drug given to very preterm infants; more than 90% of infants with a birth weight <1000 grams receive one or more RBC transfusions.... Show moreRed blood cells (RBCs) are probably the most frequently used drug given to very preterm infants; more than 90% of infants with a birth weight <1000 grams receive one or more RBC transfusions. Except for reduction of the amount of blood drawn for laboratory tests and use of a single donor program, no measures have been shown to be an irrefutable safe way to reduce donor exposure. Preventative measures for anemia should be used to reduce the number of RBC transfusions needed. Alternatives for allogenic RBC transfusions, such as autologous RBC cord blood transfusion, should be further explored and implemented. A restrictive transfusion strategy does not seem harmful for the children in short term or long term outcome. Thrombocytopenia is also a frequently encountered problem in neonatal medicine with an increased risk for hemorrhage. Thrombocytopenia, irrespective of the severity, increases the incidence of intraventricular hemorrhage. A more restrictive platelet transfusion policy significantly reduces the number of infants receiving a platelet transfusion without a difference in occurrence of (severe) hemorrhage. We state that both for red blood cell and platelet transfusions in (premature) newborn infants, safe thresholds are still not established. Transfusions may have (late) detrimental effects. Safe thresholds for both erythrocytes and platelets need to be found by large prospective randomized trials focusing not only on the direct effects but also on the long-term effects. Show less
The aim of this thesis was to study the impact and etiology of anemia in the oldest old in the general population, in order to support the development of evidence-based diagnostic and treatment... Show moreThe aim of this thesis was to study the impact and etiology of anemia in the oldest old in the general population, in order to support the development of evidence-based diagnostic and treatment recommendations for anemia in the oldest old. All studies presented in this thesis were embedded in the Leiden 85-plus Study and the Newcastle 85-plus Study. First, the impact of anemia was investigated. Anemia in old age appeared to be associated with an increased risk of death, independent of comorbidity, but the associated functional decline appeared to be attributed mainly to comorbidity. In various chapters, the etiology of anemia in old age was studied. An important finding was that, while folate deficiency at age 85 years was associated with the development of anemia during follow-up, vitamin B12 deficiency was not. In addition, low ferritin was associated with lower hemoglobin levels, but this association was more pronounced in participants with inflammation than in participants without inflammation. In the general discussion, a description of the possible clinical implications of this thesis and recommendations for further studies are provided. Show less
In this thesis fetal fluid and protein dynamics are investigated to gain insight in fetal (patho-)physiology. Studies were performed in fetuses with severe anemia and/or hydrops fetalis.... Show moreIn this thesis fetal fluid and protein dynamics are investigated to gain insight in fetal (patho-)physiology. Studies were performed in fetuses with severe anemia and/or hydrops fetalis. Measurements were performed in fetal blood or amniotic fluid, obtained before or during intrauterine transfusion. The severity of anemia can be predicted by measurement of bilirubin in amniotic fluid. We showed that this concentration is based on bilirubin in fetal blood and on albumin concentrations. Albumin in amniotic fluid is most probably not of fetal however of membrane or maternal origin. Thus, bilirubin seems to exchange between albumin in fetal blood and amniotic fluid over the intramembraneous pathway. Low albumin concentration in fetal blood seems to be a secondary effect of hydrops fetalis. Fetuses with severe anemia were found to maintain their total blood volume. Thus, the decrease in red cell volume is compensated by an increase in plasma volume. This could explain the decrease in albumin concentration. During intrauterine transfusion, part of the plasma volume leaves the circulation. It is expected that this process continues after transfusion, thus further increasing the hematocrit. Acquired insights and differences between fetuses and neonates are discussed. Finally, implications for current practice and future research are described. Show less
