A NEW COMBINED SPINAL-EPIDURAL APPARATUS - MEASUREMENT OF THE DISTANCE TO THE EPIDURAL AND SUBARACHNOID SPACES

A new combined spinal-epidural anaesthesia apparatus with a 27G lockab le spinal needle was used in 151 patients. Two groups could be created , based on whether dural perforation was felt or not (group 1: with du ral click; group 2: no dural click). Measurements of the epidural spac e depth and of the protrusion of the spinal needle from the epidural n eedle (tip-to-tip distance) were made. The mean depth of the epidural space was 5.59 cm. Correlations were found with body weight, weight-to -height ratio and body mass index (p < 0.001). The mean tip-to-tip dis tance measured was 7.0 mm in the patients of group 1, whereas in group 2 a distance of 8.9 mm was found. This difference was statistically s ignificant. Correlations were found between the epidural space width a nd the patient's height, weight-to-height ratio and body mass index. F our patients felt paraesthesia during placement of the spinal needle a nd, in another four patients, aspiration was necessary to detect cereb rospinal fluid. Two patients needed epidural top-ups due to insufficie nt level of anaesthesia. The lockable spinal needle provides safe and stable conditions during injection and a high rate of success in reach ing the subarachnoid space.