EVALUATION OF CLOSED LOOP CONTROL OF ARTERIAL PRESSURE DURING HYPOTENSIVE ANAESTHESIA FOR LOCAL RESECTION OF INTRAOCULAR MELANOMA

We have studied 20 patients undergoing local resection of intraocular melanoma during hypo-tensive anaesthesia, allocated randomly to receive either manual control by an experienced anaesthetist or closed-loop computer control of an infusion of a 5:1 mixture of trimetaphan camsylate (TMP) and sodium nitroprusside (SNP). There were no significant differences in the smallest systolic and diastolic arterial pressures obtained, heart rate or infusion requirements between the two groups, but the duration of both the infusion and the operation were significantly longer in the computer-controlled group (P