Studies of Hemodynamic Changes in Humans Following Induction of Low and High Spinal Anesthesia

After a lapse of some years, surgeons and anesthesiologists alike are re-exploring the use of high spinal anesthesia, which is designed to produce a "useful" hypotension coupled with maximal relaxation. In the present study the hemodynamic changes induced by low and high spinal anesthesia, the latter arbitrarily defined as ablation of sympathetic, sensory and somatic nerves fibers above the fourth dermatomic segment, have been investigated in a series of waking patients not undergoing surgery.