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

Abstract

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 25 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 μg kg⁻¹min⁻¹) and propofol (target plasma concentration 2–4 μg 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 (€1.10, range 0–22) compared with the GA group (€30, range €0–176) (P = 0.0005). There were no differences in total costs: PNB group €158 (range €105–194) versus GA group €160 (range €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.