Real-time ultrasound-guided spinal anaesthesia vs pre- procedural ultrasound-guided spinal anaesthesia in obese patients

Background and Aims: Spinal anaesthesia is conventionally performed using a landmark-guided midline approach. These surface landmarks may be absent, indistinct or distorted in the presence of obesity, previous spinal surgeries, deformities, or degenerative changes associated with ageing. In the present study, we compared the efficacy of real-time ultrasound (RUS)-guided paramedian approach, and pre-procedure ultrasound (PUS) landmark-guided paramedian approach in obese patients. Methods: Eighty patients with body mass index (BMI) >30 kg/m2 were included in the study. The participants were randomly assigned to two intervention groups, i.e., RUS and PUS approach. The primary end point was to attain a successful lumbar puncture. Variables like the number of attempts, the number of passes, the time taken for identifying landmark(s), and time for a successful lumbar puncture(s) were secondary end points and were recorded in both the groups. Results: The median number of attempts were 4 (IQR 2-4) and 2 (IQR 1-2), respectively, in the PUS and RUS group (P-value < 0.001). The median number of passes, the median time for identifying space, and the time for successful lumbar puncture was statistically significantly less in the RUS group, than the PUS group. Conclusion: The time taken for the identification of the space, the number of attempts, number of passes, and the time taken for successful lumbar puncture was more in the PUS group as compared to the RUS group.