Subarachnoid anaesthesia produced by hyperbaric lignocaine in elderly patients. Prolongation of effect with...

The effects of adrenaline on the duration of spinal anaesthesia induced with hyperbaric lignocaine were investigated in 60 elderly patients in a double-blind study. Each patient received 5% lignocaine 2 ml in 7.5% dextrose to which was added physiological saline 1 ml, 1:1000 adrenaline 0.2 ml (0.2 mg) plus normal saline 0.8 ml, or adrenaline 0.4 ml with normal saline 0.6 ml. The duration of sensory block (measured by two- and four-segment regression times, and times to regression to T12 and L2 dermatomes) was prolonged significantly by both doses of adrenaline. The addition of adrenaline also produced a significant increase in the duration of complete motor block.