Randomized comparison of remifentanil-propofol with a sciatic-femoral nerve block for out-patient knee arthroscopy

Background and objective: To evaluate preparation and discharge times as well as the anaesthesia-related costs of out-patient knee arthroscopy performed with a combined sciatic-femoral nerve block, or a propofol-remifentanil general anaesthetic. Methods: With Ethics Committee approval and written informed consent, 40 healthy patients were premedicated with intravenous midazolam (0.05 mg kg(-1)) and. ketoprofen (50 mg). They were then randomly allocated to receive either a combined sciatic-femoral nerve block with 2 5 mL mepivacaine 2% (15 mL for the femoral nerve, 10 mL for the sciatic nerve) (PNB group, n = 20), or a general anaesthetic with a continuous intravenous infusion of remifentanil (0.1-0.3 mug kg(-1) min(-1)) and propofol (target plasma concentration 2-4 mug mL(-1)) with a laryngeal mask airway (GA group, n = 20). Results: The median (range) preparation time was 16 (10-28) min in the PNB group and 13 (8-22) min in the GA group (P = 0.015). Ten PNB patients were directly discharged to the day-surgery unit after the procedure as compared with one GA patient (P = 0.003). Discharge from the postanaesthesia care unit (PACU) required 5 (5-20) min in the PNB group and 23 (7-95)min in the GA group (P = 0.001). Home discharge criteria were fulfilled after 277 (150-485) min in the PNB group and 170 (100-400) min in the GA group (P = 0.005). Costs related to the time spent in the PACU were lower for the PNB group ((sic)1.10, range (sic)0-22) compared with the GA group ((sic)30, range (sic)0-176) (P = 0.0005). There were no differences in total costs: PNB group (sic)158 (range (sic)105-194) versus GA group (sic)160 (range (sic)101-238) (P = 0.61). Conclusions: In patients undergoing out-patient knee arthroscopy, the length of stay in the PACU can be shorter after a sciatic-femoral nerve block with a small volume of mepivacaine 2% compared with a propofol-remifentanil anaesthetic, and there is an increased likelihood that they will bypass the first phase of the postoperative recovery.