Improving Accuracy of Landmarks for Neuraxial Blocks in Pregnancy: The Sacral Anatomical Interspace Landmark (SAIL) Technique

"Researcher will use the classic technique to estimate the L4-L5 interspace. The classic technique begins by palpating both the right and left posterior iliac crests and following the imaginary line that intersects each (intercristal line) with the non-dominant hand to the spine where it is estimated to intersect the L4 spinous process or L4-L5 interspace. A marker pen will mark an X lateral to the estimation, opposite side from the estimation of the other technique."

"Researcher will use the novel technique to estimate the L4-L5 interspace. The SAIL technique begins by palpating the sacrum and the researcher sliding the non-dominant hand up the dorsal surface of the sacrum to the first interspace (L5-S1) and then up one more interspace to estimate the L4-L5 interspace. A marker pen will mark an X lateral to the estimation, opposite side from the estimation of the other technique."