[Prevention and treatment of hypotension during spinal anesthesia].

Spinal and epidural anaesthesias alter self-regulation of arterial pressure as they lead to a sympathetic blockade. The extent and the speed of appearance of this blockade conditions the magnitude of the decrease of arterial pressure. So, epidural or spinal anaesthesias may only be performed on hemodynamically stable patients for a non hemorrhagic surgery. The routine fluid preloading is illogical and poorly efficient. Correcting a deep arterial hypotension demands first of all the use of vasoconstricting agents the choice of which depends on the site of the anaesthesia and on the cardiovascular condition of the patient. The occurrence of bradycardia more often indicates a hypovolaemic state.