Comparing Three Different Modified Sitting Positions for Ease of Spinal Needle Insertion in Patients Undergoing Spinal Anesthesia.

Background: The most important point for performing a neuroaxial block in a sitting position is reducing lumbar lordosis, resulting in easier access to interspinous space and dura mater. There are a few studies comparing 2 different sitting positions including a traditional sitting position (TSP) versus forward bending or hamstring stretch position (HSP) as well as TSP versus squatting position (SP) for reversing the lumbar lordosis and improving access to intervertebral space for neuroaxial block.

Objectives: We compared 3 different sitting positions including traditional sitting position vs. hamstring stretch position vs. squatting position and hypothesized that squatting position reverses the lumbar lordosis and reduces the number of spinal needle bone contacts more than TSP and HSP.

Methods: A total of Thirty hundred and sixty ASA class I or II patients aged 18 to 60 years were scheduled for elective surgeries under spinal anesthesia were randomized into 3 groups. Our primary endpoint was the number of spinal needle-bone contacts and our secondary endpoint was ease of needle insertion or space identification.

Results: Demographic data were statistically different between the study groups. There was no statistical difference between the study groups regarding the number of needle bone contacts and the ease of finding intervertebral space (P = 0.63, P = 0.56, respectively).

Conclusions: There was no statistical difference between the TSP, HSP, and SP regarding the number of needle bone contacts and the ease of finding of intervertebral space. In this regard, each of these 3 positions can be used as an alternative sitting position for administration of spinal anesthesia.