Effect of Spinal Needles used by Anesthesia Residents on Procedural Success and the Perception of Click Sensation: A Randomized Prospective Trial

Aim: The type and diameter of the needle used in spinal anesthesia (SA) affect the procedure’s success and the sensation of clicking during a dura puncture. This study aimed to compare the effects of Quincke and pencil-point needles of the same thickness, when used by anesthesia residents new to SA application, on procedural success and the number of trials required to perceive click sensation. Methods: This prospective randomized study included 213 adult patients undergoing elective surgery under SA, divided into six groups based on needle type and diameter: Group I: Quincke (Q)-25 Gauge (G), Group II: Q-26G, Group III: Q-27G, Group IV: Pencil-point (P)-25G, Group V: P-26G, and Group VI: P-27G. The number of interventions for SA (1-3), the attempt (1, 2, or ≥3) during which the stylet was removed and cerebrospinal fluid (CSF) flow occurred, considering that the click sensation was felt during the procedure, and the time taken for CSF appearance (<1.9 s or ≥2 seconds) were recorded. Results: No difference was found between the groups in terms of demographic data, the American Society of Anesthesiologists risk, puncture site, number of click sensation trials, time for CSF appearance, and feasibility of the procedure (p>0.05). The SA success rate in the first trial (p<0.001) was higher when pencil-point needles were used. Conclusion: Although the effects of spinal needles with different tip designs and diameters on the number of trials required to perceive click sensation are similar, due to the high rate of SA success in the first trial, the use of pencil-point needles is recommended for anesthesia residents new to SA application.