All of the following are true about lumbar puncture except:
(A) Level of needle inseion should be L I -L2 veebral junction (B) The bevel end of needle should face up (C) Needle should be inseed in a slightly cephalad direction (D) Legs should be straightened for CSF pressure measurement
(A) Ans: A. Level of needle inseion should be L I -L2 veebral junction(Ref: Harrison 19Ie p443-e2)The spinal cord ends at L3 veebrae in children and L1 in adults.With a safe margin, lumbar puncture should be performed at L3-L4 or L4-L5 interspace.A useful anatomic guide is a line drawn between the posterior superior iliac crests, which corresponds closely to the level of the L3--L4 interspace.The interspace is chosen following gentle palpation to identify the spinous processes at each lumbar level.The LP needle (typically 20- to 22-gauge) is inseed in the midline, midway between two spinous processes, and slowly advanced.The bevel of the needle should be maintained in a horizontal position, parallel to the direction of the dural fibers and with the flat poion of the bevel pointed upward; this minimizes injury to the fibers as the dura is penetrated.