Ultrasound - Guided Paramedian Techniques in Spinal Anesthesia

In group P, a portable ultrasound unit was used for initial pre-procedural marking. The interspinous space at which the clearest image of the anterior complex (ligamentum flavum dura complex- LFD) and posterior complex (posterior longitudinal ligament- PLL) was obtained, was selected. At the selected interspace, and with the probe positioned to obtain the clearest ultrasound image, a skin marker was used to mark the midpoint of the long border of the probe and the midpoints of the short borders of the probe . At the same horizontal level as the midpoint of the long border of the probe, the midpoint of the line drawn between the two short border midpoints of the probe was used as paramedian insertion point for the spinal needle.

Spinal anaesthesia was administered based on conventional landmark based midline approach.