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Biomedical subjects

P Van Der Linden

Publications and source records attributed to P Van Der Linden.

3 recordsLinked to original sources

Transfusion strategy.

As is often the case in medicine, the risk to benefit ratio of blood transfusion requires careful examination. The decision to transfuse a patient cannot be based only on the haemoglobin or the haematocrit concentration. In a given clinical situation, tolerance to anaemia will depend on the ability of the patient to recruit his compensatory mechanisms in accordance with his metabolic demand. Maintenance of circulating volume is of paramount importance. In the absence of a universal transfusion trigger, decision to transfuse a patient with an haemoglobin concentration between 7.0 and 10.0 g dL-1 depends primarily on clinical judgement. With the exception of emergency situations, blood transfusion will be realized on a unit-by-unit basis, and the efficacy of treatment should be evaluated after each transfused unit.

Acute Disease↗

Normovolemic hemodilution improves oxygen extraction capabilities in endotoxic shock.

We studied the effects of normovolemic hemodilution on tissue oxygen extraction capabilities in a canine model of endotoxic shock. Eighteen anesthetized and mechanically ventilated dogs underwent normovolemic hemodilution with 6% hydroxyethyl starch solution to reach hematocrit (Hct) levels around 40, 30, or 20% before the administration of 2 mg/kg of Escherichia coli endotoxin. Cardiac tamponade was then induced by repeated injections of normal saline into the pericardial sac to reduce cardiac output and study whole body oxygen extraction capabilities. Whole body critical oxygen delivery was lower in the Hct 20% and 30% groups (8.4 +/- 0.4 and 10.4 +/- 0.7 ml. kg(-1). min(-1), respectively) than in the Hct 40% group (12.8 +/- 0.8 ml. kg(-1). min(-1)) (both P < 0.005). The whole body critical oxygen extraction ratio was higher in the Hct 30% and 20% groups (49.1 +/- 8.2 and 55.2 +/- 4.6%, respectively) than in the Hct 40% group (37.1 +/- 4.4 %) (both P < 0.05). Liver critical oxygen extraction ratio was also higher in the Hct 30% and 20% groups than in the Hct 40% group. The arterial lactate concentrations and the gradient between ileum mucosal PCO(2) and arterial PCO(2) were lower in the Hct 20% and 30% groups than in the Hct 40% group. We conclude that, during an acute reduction in blood flow during endotoxic shock in dogs, normovolemic hemodilution is associated with improved tissue perfusion and increased oxygen extraction capabilities.

Animals↗