[Monitoring in hemodilution].
Normovolaemic haemodilution is an established part within the 'Concept of Autologous Transfusion'. According to the mechanisms to compensate for the dilution-induced anaemia, monitoring of haemodilution has to consider (1) maintenance of normovolaemia; (2) stability of the cardio-vascular system and of a normal pulmonary function; (3) an adequate myocardial oxygen supply. (1) Normovolaemia: Under routine clinical conditions normovolaemia is controlled by close monitoring of fluid balance (considering surgical blood loss, diuresis, and insensible perspiration). If the expected blood loss is > 2.0 litres, additional monitoring of the central venous pressure appears to be reasonable. It is not a single value of the central venous pressure (CVP) but rather its time-course that allows conclusions on changes of intravascular volume. (2) Cardio-vascular and pulmonary function: Pulmonary function is easily controlled by intermittent arterial blood gas analysis. Non-invasive and discontinuous or invasive and continuous blood pressure recording, respectively, are routinely used for monitoring of cardiovascular function. Heart rate together with the time-course of the CVP give additional information on the cardio-vascular system. Central-venous oxygen saturation is only a minor substitute for mixed venous oxygen saturation; however, its changes with time make it possible to draw conclusions on global haemodynamics and total body oxygen supply. However, in situations of extreme haemodilution--as in Jehova's witnesses--a pulmonary artery catheter has to be used for monitoring the cardio-vascular system as well as bulk oxygen parameters. (3) Myocardial oxygen supply: Monitoring for myocardial ischaemia is routinely performed by ECG. It is both the number and the kinds of leads chosen that give adequate information.(ABSTRACT TRUNCATED AT 250 WORDS)
Singbartl
G
G
Abteilung Anästhesiologie, Intensiv- und Transfusionsmedizin, Endo-Klinik, Hamburg, BRD.
Schleinzer
W
W
D016063:Blood Loss, Surgical / Q000503:physiopathology*; D001804:Blood Transfusion, Autologous; D001810:Blood Volume / Q000502:physiology*; D004562:Electrocardiography; D006438:Hemodilution / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D016343:Monitoring, Intraoperative; D017202:Myocardial Ischemia / Q000503:physiopathology / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology