Experimental Design and Protocol
Open Label Trials: Fluid therapy first was given in vigorous amounts in attempts to reach optimal Cl, Do2 and Vo2 values without increasing wedge pressures greater than 15 mm Hg; these optimal supranormal values had been determined empirically from a large series of critically ill postoperative survivors. Usually colloids were used because they were found to be more effective than crystalloids in reaching and maintaining the optimal therapeutic goals. If there were an inadequate circulatory response or optimal flow and oxygen transport values were not achieved, PGE, was given as a trial of therapy. flovent inhaler
After one or two baseline control sets of measurements were obtained, an infusion of PGE, (Prostin VR, The Upjohn Company, Kalamazoo, MI) was started at 5 ng/kg-min and progressively increased by doses of 5 ng/kg*min until a dose of 60 ng/kg*min was reached provided there was no appreciable hypotension. Sets of measurements were taken at 20, 40, and 60 ng/kg-min and 2 h after reaching the highest dose; this usually took 3 to 4 h. During this dose titration, no other therapy was started, stopped or altered; no transfusions or other fluid therapy was given except for the continuous infusion of crystalloids needed for water replacement, usually 50 to 80 ml/h. The PGE, infusion was usually continued for two to five days.