ABSTRACT
Spinal anesthesia is considered safe and reliable for most surgical procedures involving the lower part of the body, but its use in the ambulatory setting requires drugs with rapid onset and regression of the motor and sensory block-like prilocaine.The purpose of this study is to retrospectively analyze data from 3291 procedures recorded in our institutional database, to better define the safety profile of spinal prilocaine and the incidence of complications and side effects.All clinical data, prospectively collected from 2011 to 2019 in an Italian tertiary hospital, of patients treated with spinal anesthesia performed with 40 mg of hyperbaric 2% prilocaine, according to our internal protocol of day surgery, were analyzed.Surgical procedures included saphenectomy (28.5%, n = 937), knee arthroscopy (26.8%, n = 882), proctologic surgery (15.16%, n = 499), and inguinal canal surgery (14.9%, n = 491).Anesthesia-related complication was represented by urinary retention (1.09%, n = 36), lipotimia (0.75%, n = 25), and postoperative nausea (0.33%, n = 11); arrhythmic events were uncommon (0.18%, n = 6). One case of persistent hypotension and 2 cases of persistent hypertension were reported.Persistent motor or sensory block (lasting more than 5 h) was experienced by 7 patients. One patient (0.03%), who underwent knee arthroscopy, experienced pelvic pain lasting for 6 h, compatible with a transient neurological symptom.Proctologic surgery was a factor associated with unplanned admission due to anesthesia-related complications (OR = 4.9; 95% CI: 2-14%).The number of complications related to the method was low as well as the need for hospitalization. This drug is valid and safe for the most performed day surgery procedures; however, further trials are needed to investigate the incidence of complications in the days following the procedure.
ABSTRACT
BACKGROUND AND OBJECTIVES: This prospective, randomized, double-blind study compared the effects of the ultrasound-guided popliteal sciatic nerve block performed by either intraneural or subparaneural approach followed by an electrophysiological evaluation. We hypothesized that intraneural injection provides a faster onset with a better success rate compared with the subparaneural approach. METHODS: Eighty-eight patients were enrolled and randomized to receive an ultrasound-guided popliteal sciatic nerve block injecting 15 mL ropivacaine 1% according to an intraneural injection (group INTRA = 44) or a subparaneural injection (group SUBPARA = 44). The primary end point was the onset time of sensory and motor block, whereas secondary end points were successful, duration of the block, and the variation of the electrophysiological assessment after 5 weeks. The study was registered prior to patient enrollment (clinicaltrials.gov identifier NCT01987128). RESULTS: The median onset time for successful sciatic nerve block in the INTRA group was 10 (5-15 [5-30]) minutes versus 25 (15-35 [5-45]) minutes in the SUBPARA group (P < 0.001), with a rate of 41/43 (95.3%) compared with 25/40 (62.5%) in the SUBPARA group (P < 0.001). No difference was found regardless of the duration of the block. Fifty-three patients also performed the electrophysiological assessment at 5 weeks, showing a subclinical, significant reduction in amplitude of the action potentials with no difference between groups. No patients reported any clinical neurological complications after 6 months. CONCLUSIONS: In ultrasound-guided popliteal sciatic nerve block, intraneural injection provided a faster onset and better success rate compared with subparaneural. Both techniques resulted in a similar subclinical reduction in amplitude of the sciatic action potentials at 5 weeks after surgery. These findings should not be extended to other approaches.
