SPINAL-ANESTHESIA IN OUTPATIENT KNEE SURGERY - 22-GAUGE VERSUS 25-GAUGE SPROTTE NEEDLE

Spinal anesthesia in day-care surgery is still controversial because o f the possibility of postdural puncture headache (PDPH). The use of th e Sprotte needle with a conical tip that spreads the dural fibers may reduce the incidence of PDPH. The aim of this study was to compare the 22-gauge and 25-gauge Sprotte needles with respect to PDPH and postop erative complaints in outpatients undergoing arthroscopy. The rate of spinal anesthesia failure and the feasibility of unilateral spinal ane sthesia when using a low dose of anesthesia was also verified. For thi s randomized, prospective study, 234 patients undergoing elective arth roscopy were chosen. Patients were allocated randomly to have spinal a nesthesia with either a 22-gauge or 25-gauge Sprotte needle. Dural pun cture was performed with the patient in a lateral flexed decubitus pos ition. After the injection of anesthetic solution (0.5-1.2 mL of 1% bu pivacaine in 8% glucose) patients remained in the lateral decubitus po sition for 30 min. The time to regression of analgesia, time of mictur ition, and all postoperative complaints were recorded. The most freque nt side effect was backache (10.2%) with a more frequent incidence in the group using the 22-gauge needle (14.5% and 5.9%, respectively). PD PH was recorded in only one patient (0.8%) in the group using the 22-g auge needle. The failure rate was 0.8%. Unilateral anesthesia was achi eved in 88% of 213 patients. Our data indicate that the use of spinal block is a suitable technique in the ambulatory setting, with a low ra te of unplanned hospital admission. The use of a Sprotte needle does n ot solve the PDPH problem; however, we confirm that the extremely low incidence and mild character of PDPH when Sprotte needles are used fav ors spinal anesthesia for outpatient surgery.