LAUSR

To the Editor, I read with great interest the original research “Estimating the Lumbar Puncture Needle Depth in Children” by Dr. Derbys Celik in the journal (J Invest Surg. 2019:1–7). I will absolutely support author’s research that it is necessary to estimate the correct depth of the needle insertion based on age weight or height when we do lumbar puncture in children. And clinically useful formulae must be simple even, such formulae would never be 100% accurate as author mentioned in the article. Epidural anesthesia is also an essential technique in pediatric anesthesia, and we also reported formula for determining the distance from the skin to the lumbar epidural space in infants and children in 1992 [1]. Our formula for determining the depth of epidural needle insertion at L3 is D 1⁄4 (Wþ 10) x 0.8, where D is the depth in mm and W is the weight in kg [1,2]. There are several reports that evaluated the distance from the skin to the epidural space and subarachnoid space from different parts of the world [3–6]. And one of them evaluated the precision of several formulae using the mean absolute deviation and the newly estimated formulae using MRI for the distance from the skin to the epidural space were compared with each of the B€ osenberg, Uemura, and Hasan formulae [4]. Our formula made less deviation from the formula using MRI that is not simple like ours and difficult to calculate. When we perform epidural anesthesia or spinal anesthesia, especially in infants and children, estimating the distance from the skin to the epidural space or subarachnoid space is special importance because of the great differences in size of the patients. The body habitus is not the same in all over the world, so those formulae based on anthropometric measures have to be calculate in each area where they practice [2]. Also, in recent tendency, pediatric population are overweight and we need up to date the formula to keep up to with the times.