Accuracy Level of Inter-vertebral Space Estimation by Palpation:The Ultrasonic Revelation

Ideal space for spinal anethesia is below connus medullaris to avaoid trauma to the cord. The intercristal line or tuffier’s line is the line joining the superior iliac crests which crosses the L4 vertebra or L4-L5 space. Adult conus medullaris ends at lower border of L1 bur it is variable. So selecting lower most space is crucial for safe neuraxial anesthesia. The most common method for selecting IVS is palpation based on Tuffier’s line , but its accuracy is less. USG is a less tome consuming , simple, non invasive and easy to learn technology , which can accurately identify the IVS.. Hence in this study ultrasound is used to evaluate the accuracy of palpation method to estimate the level of IVS. In addition the effect of demographic parameters , patient positioning and anersthesiologist experience in determining the accuracy will also be assessed.