SPINAL ANAESTHESIA WITH HYPERBARIC BUPIVACAINE: Effects of Age on Neural Blockade and Pharmacokinetics

Effects of ageing were studied on the neural blockade and thepharmacokinetics after subarachnoid administration of 0.5% bupi-vacaine3 ml in 8% glucose in two groups of 15 male patients, between20 and 55 yr and older than 55 yr, respectively. The blockadewas performed with the patient in the sitting position. Twominutes after the injection the patient was placed in the supineposition. The time to maximum cephalad spread and the upperlevel of analgesia increased with advancing age, whereas thetime to onset of motor blockade decreased with advancing age.Effects of age on the total duration of analgesia and motorblockade could not be demonstrated. Age had no effect on thepeak plasma concentration of bupivacaine. The time to peak concentrationand the terminal half-life increased, whereas the total plasmaclearance decreased with advancing age.