Ultrasound Guided Paramedian versus Landmark Guided Midline Technique for Spinal Anaesthesia- A Randomised Clinical Trial

Abstract

Introduction: Spinal anaesthesia has been traditionally performed using landmark guided technique. Ultrasound helps in identifying the insertion point, depth, as well as angle of the needle advancement by visualisation of the neuraxial structures, thus, increasing the probability of successful dural puncture. Aim: To compare the success rates of dural puncture at first attempt between Preprocedural Ultrasound (PUS) guided paramedian and landmark guided midline approach in spinal anaesthesia. Materials and Methods: This was a randomised clinical study, conducted at a Tertiary Care Hospital during May 2017-December 2018. Patients (n=110) undergoing lower limb orthopaedic surgery were randomly allocated into group US (PUS guided with paramedian approach) and group LM (landmark guided with midline approach), with 55 patients each. Number of attempts and passes, procedure time, any complication, periprocedural pain and patient satisfaction were noted. The correlation between quality of ultrasound view and success rate was also analysed using Fisher’s-exact test. Results: The success rate of dural puncture at first attempt was 89.09% in US group versus 76.36% in LM group, p>0.05. Total number of needle insertion attempts (1.31±0.63 in group LM, 1.11±0.31 in group US, p>0.05) were comparable. Total procedure time was higher (11.96±1.55 minutes) in US group as compared to LM group (3.26±0.68 minutes), p<0.001. Periprocedural pain score was significantly lower in US group with p<0.01. The patient satisfaction score was comparable in the two groups, p>0.05. Correlation between the quality of parasagittal oblique view and success rate of dural puncture was good, p<0.01. Conclusion: PUS guided paramedian approach does not significantly increase the success rate at first attempt as compared to midline landmark guided approach.