Real-time ultrasonic observation of combined spinal-epidural anaesthesia

The quality of combined spinal-epidural anaesthesia mainly depends on accurate identification of the epidural space. The real-time ultrasound control of the procedure for puncture was therefore evaluated.

Thirty parturients scheduled for Caesarean section were randomized to three equal groups. Ten control patients received conventional combined spinal-epidural anaesthesia. Ten of the remaining patients received ultrasonic scans by an offline scan technique, and 10 received online imaging of the lumbar region during epidural puncture. The epidural space was identified and needle advancement was surveyed through the interspinal and flaval ligaments. The number of attempts to advance the needle to achieve a successful puncture was measured and compared, as well as the number of vertebral interspaces punctured before successful entry into the epidural space.

There was no difference between patient characteristics in the three groups. The visualization of the epidural structures and of the needle manipulations was very effective. In the ultrasound group, the reduction in the number of attempts at puncture was significant (P < 0.036). The number of interspaces necessary for puncture was reduced (P < 0.036) in the ultrasound online group compared with controls. The number of spinal needle manipulations was significantly reduced (P < 0.036).

Real-time ultrasonic scanning of the lumbar spine is an easy procedure. It provides an accurate reading of the location of the needle tip and facilitates the performance of combined spinal-epidural anaesthesia.