AGEING AND EPIDURAL DOSE REQUIREMENTS: Segmental spread and predictability of epidural analgesia in youth and extreme age

Abstract

SUMMARYThe segmental spread of epidural analgesia was measured in twenty-five surgical patients aged between 4 and 20 years, and in ten patients between 80 and 102 years. Regression equations for epidural dose requirements in terms of age were calculated for the two age groups. These results were combined with data from 166 patients in a previous series, and computer techniques were applied to finding the best relationship betweeen dose requirements and age in the full range between 4 and 102 years. Dose requirements increased in a linear manner from 4 years, and reached a maximum at 18½ years, and then declined in a linear manner to the limit of observations at 102 years. The relative slopes of the regression lines associated with growth and senescence was +6: –1. The predictability of epidural dose was found to be clinically acceptable between 10 and 80 years, but predictions of dose requirements from age became progressively less reliable beyond this range.