Accurate prediction of the needle depth required for successful lumbar puncture

Using Body Mass Index to Predict Needle Length in Fluoroscopy-Guided Lumbar Punctures

“…A formula derived from a wider range of patient weights suggests that the formula is potentially more applicable to a larger subset of the general population. We speculate that our formula more accurately predicted the needle length than the formulas of Stocker and Bonsu 12 or Chong et al 13 because children, who constituted their patient population, have shorter skin-to-mid-spinal canal measurements compared with adults and typically require 1.5-, 2.5-, or 3.5-inch needles. Needle-length predictions from our formula are validated for FGLPs at L2-L3 and L3-L4 because 90% of the patients from whom we devised our formula underwent LPs at these levels.…”

“…Our formula would have predicted the correct needle length in 14/15 (93%) female patients and selection of a needle that was too long (5 versus 3.5 inch) in 1 patient; while in men, our formula predicted the correct needle in 25/30 (83%) patients and selection of a needle that was too long (5 versus 3.5 inch) in 5 male patients. There have been studies that have derived formulas to estimate SCD for interspinous approach LPs, including the formulas by Abe et al, 10 Ma et al, 11 Stoker and Bonsu, 12 , and Chong et al, 13 which are often cited in the literature. The SCD that all 4 formulas predicted were significantly different from the actual SCD (all, P Ͻ .001) measured in our cohort of 45 patients.…”

“…9 Formulas to determine proper needle length in non-fluoroscopy-guided interspinous lumbar punctures have been investigated [10][11][12][13] ; however, there is no established method to determine the appropriate needle length for OIA-FGLPs. The purpose of this study is to determine whether BMI could help predict the appropriate needle length in OIA-FGLPs.…”

A prospective observational study of skin to subarachnoid space depth in the Indian population

“…Of these, most focused on SSD in the paediatric population,[45678] considering spinal anaesthesia to be more challenging in children. [9] Studies determining SSD in the adult population are few[101112] and have not evaluated differences, if any, based on gender.…”

“…Our study hypothesis was that there would be significant differences in SSD between males, females and parturients. We conducted this study (1) to determine the SSD in Indian males, females, parturients and in the overall population (2) to derive formulae for predicting SSD and (3) to determine which of the previously suggested formulae (Abe's, Bonadio's, Craig's, Stocker's and Chong's modified formula)[45678] for predicting SSD best suited our population in terms of both accuracy and ease of application.…”