In Reply:-We appreciate the interest in our article expressed by Dr. Youngs. Unfortunately we did not measure in the study the speed of injection.

The cause of transient neurologic symptoms is still unknown. The idea that the maldistribution of local anesthetic can be affected by the injection speed with the use of pencil-point needles cannot be ignored. However, Holman et al., [1]in a recent study in a spinal cord model, concluded that, at clinically relevant rates of injection, needle characteristics minimally affect solution distribution.

Rafael Martinez-Bourio, M.D.

Staff Anesthesiologist; Service of Anesthesiology and Surgical Intensive Care Unit; Hospital de Galdakao; Galdakao (Vizcaya), Spain;;

(Accepted for publication August 14, 1998.)

Holman SJ, Robinson RA, Beardsley D, Stewart SFC, Klein L, Stevens R: Hyperbaric dye solution distribution characteristics after pencil-points needle injection in a spinal cord model. Anesthesiology 1997; 86:966-73