COMPARISON OF DOUBLE-HOLE AND SINGLE-HOLE PENCIL-POINT NEEDLES FOR SPINAL-ANESTHESIA WITH HYPERBARIC BUPIVACAINE

Background and Objectives. The use of thin single-hole pencil-point (S HPP) spinal needles may be a reason for subarachnoid maldistribution o f local anesthetic. A new double-hole pencil-point (DHPP) needle may b e preferable because of a theoretic more uniform initial distribution of local anesthetic. Methods. This was a prospective, double-blinded s tudy of 50 patients randomly selected to have spinal anesthesia using either single-hole 27-gauge (B. Braun, Melsungen, Germany) or double-h ole 26-gauge (A.L.B. Medical Inc., U.S.A.) pencil-point needles. The f ormer were inserted with the side port directed caudally and the latte r with openings in both caudal and cranial direction. Two milliliters of hyperbaric 0.5% bupivacaine were injected in 1 minute, and sensory and motor block were studied at regular intervals during spinal anesth esia. All patients were interviewed on the first (personal) and the se venth (mailed questionnaire) postoperative day. Furthermore, microscop ic inspection of the spinal needles was performed. Results. There were no statistically significant differences in sensory or motor block le vels between the two needle types at any time during spinal anesthesia . Likewise, there was no difference in the duration of spinal block. T he postanesthetic side effects (headache, backache, pricking, numbness , weakness) were similar in both groups. Light and electron microscopi c examination showed resistance of the SHPP needles to tip damage. On the other hand, the DHPP needle lips seemed to be distorted guile freq uently, and, even in unused needles, the tip was blunt and asymmetric. Conclusion. There was no difference between the spread of analgesia u sing either SHPP or DHPP spinal needles. The DHPP needles appear to be vulnerable to lip damage from mechanical contact.