6: Pre-procedural ultrasonography as an adjunct to landmark technique for identification of epidural space in parturients coming for labour analgesia- a prospective randomised controlled trial.

BACKGROUND AND AIMS: Pregnancy-induced softening of tissues and ligaments, may increase the false-positive rate when identifying the epidural space by the loss of resistance ( LOR ) technique. Ultrasonography (USG), which has now become the EYE of anesthesiologists, can be used as a reliable tool to facilitate epidural needle placement in parturients. The objectives of the study included finding out the correlation between USG guided estimated depth versus actual depth of epidural space in parturients. Number of attempts taken and incidence of dural punctures by landmark technique versus USG guided technique were the secondary objectives METHODS: After the approval from the institutional ethics committee and Clinical Trials Registry of India registration, 62 parturients of American Society of Anesthesiologists(ASA) II requesting labor analgesia were randomised into two groups of 31 each- GROUP-L (conventional landmark technique) and GROUP-U (preprocedural ultrasound scan done before epidural). In group-U, Tuohy needle was introduced through the USG pre-determined insertion point and epidural space was located using LOR technique. RESULTS: Ultrasound increased the success rate of epidural at first attempt from 51.6% in group “L” to 87% in group “U” Fewer needle attempts (P value - 0.001) were required in group “U” as compared to group “L”. No accidental dural punctures in group U, compared to 6 in group-L. Mean depth of epidural space (cm)-UD= 3.89 ± 0.45 cm and ND=4.05±0.37 cm. CONCLUSION: Pre-procedural ultrasonography is a simple, safe and accurate tool to determine the needle insertion site, decrease the incidence of accidental dural punctures and helps to assess epidural space depth in parturients.