Acta anaesthesiologica Belgica
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Acta Anaesthesiol Belg · Jan 2004
Coronary sinus venoarterial CO2 difference in different hemodynamic states.
Myocardial metabolic rate and coronary flow are closely related limiting thus the diagnostic value of coronary sinus saturation monitoring as an indicator of flow. Regional venoarterial CO2 gradient was found elevated during low flow in various clinical and experimental conditions, in animals and humans. This study was undertaken to examine the impact of the variations of cardiac mechanical work on veno-arterial CO2 content and partial pressure difference (deltaPCO2) of the coronary sinus blood. ⋯ Heart's little extraction reserve is faced with coronary flow reserve. In the physiologic range and under the conditions of anesthesia, elevated CO2 production is accompanied with increased coronary flow. Under these circumstances, deltaP(cs-a)CO2 appears stable and is not suitable for clinical decisions concerning heart's coronary flow.
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Acta Anaesthesiol Belg · Jan 2003
ReviewShould we reconsider triggers for red blood cell transfusion?
Very few randomized controlled trials on the benefits of red blood cell (RBC) transfusions in humans have been published. Consequently, most clinical practice guidelines remain based on expert opinion, animal studies and the limited human trials available. In the absence of definitive outcome studies, numerous theoretical arguments have been put forward either to support or to condone the classic transfusion threshold of 10 g/dL. ⋯ All RBC transfusions must be tailored to the patient's needs, at the moment the need arises. In conclusion most published recommendations are appropriate but their conclusions are limited, as they are commensurate with existing knowledge. Reliable monitors to guide transfusion therapy and well conducted trials to determine optimal transfusion strategies are required.