Ultrasound Guidance for Introducing Spinal Anesthesia through Paramedian Approach Versus Landmark Guided Technique During Lower Limb Surgeries, Randomized Controlled Trial

Introduction: Ultrasound imaging skills are appreciated for improving the safety of different puncture techniques supported with the fact that the advances in imaging quality have significantly improved our understanding of neuroaxial Sonoanatomy (1). Today, ultrasound imaging has been used to assist or guide central neuroaxial blocks (2).

Objectives: To identify the value of using the ultrasound guidance in applying spinal anaesthesia when compared with the conventional landmark guided approach, regarding the duration of applying the anaesthetic technique and incidence of associated common complications.

Design: Randomized controlled trial.

Method: 178 patients scheduled to undergo elective lower limb surgeries under spinal anaesthesia in El Kasr Al- Aini Hospital, Cairo University were enrolled in the study. Patients were randomly assigned into landmark guided control group in which 89 patients received landmark guided paramedian spinal anaesthesia and ultrasound group in which 89 patients received real time ultrasound guided paramedian spinal anaesthesia.

Results: The mean numbers of puncture attempts, levels and needle redirections between the control group and ultrasound group were 1.61±0.83 vs. 1.12±0.36 (P value 0.013), 1.15±0.36 vs. 1.06±0.25 (p value 0.018) and 2.68±2.75 vs1.94±1.93 (p value 0.021) respectively. Also the duration recorded during applying the anaesthetic procedure for the control group and ultrasound group were 136.4±83.2 vs. 138.3±63.4 (P value 0.001) correspondingly.

Ultrasound guided group of patients showed significant lower incidence of bloody puncture and paraesthesia after engaging the needle through the dura.

Conclusion: Ultrasound guiding although it took longer duration in application but improved the ease of introducing spinal anesthesia, reduced the number of puncture attempts, number of puncture levels, number of needle redirections, and incidence of complications.