[Critical study of the hemodynamic status during anesthesia]

Physicians must choose the anaesthetics for their patients and select the methods to cheek their haemodynamic status. Experimental works do not always bring sufficient information to help them in their daily practice. Circulatory reaction to a pharmacodynamic agent is diffuse and non-specific. Some examples drawn from theoretical considerations and practical situations support this view. The difficulty of assessing the actual damage caused by one apparent variation still remains. On the other hand, haemodynamic indices such as PA, CVP, dP/dt are composed of elementary data that are interdependent; so indices are interdependent, too. A puzzling fact is that depressing anaesthetics can initiate severe haemodynamic crisis, generally badly tolerated by tissues, but better tolerated by myocardium which is not definietely altered if the anoxia inflicted is accompanied by a real decrease in cardiac work. This explains the often slight effect of short anesthetic overdosage. Previous haemodynamic variations to be countered relative to anaesthesia are not really known. Biochemistry of the venous coronary blood does not yet bring striking features in this field.