Stimulating or conventional perineural catheters after hallux valgus repair: a double-blind, pharmaco-economic evaluation.

Background: We prospectively evaluated direct analgesia-related costs of continuous sciatic nerve block using either a stimulating or conventional catheter after hallux valgus repair. Methods: The perineural catheter was inserted through a stimulating introducer either blindly (group Conventional, n= 38) or while stimulating via the catheter (group Stimulating, n= 38). Nerve block was induced with 25 ml of mepivacaine 15 mg/ml, and was followed 3 h later by a patient-controlled infusion of ropivacaine 2 mg/ml (basal infusion: 3 ml/h; incremental dose: 5 ml; lock-out time: 30 min). Rescue tramadol [100 mg intravenous (i.v.)] was given if required. Local anesthetic consumption, need for rescue tramadol and post-operative nausea and vomiting (PONV) treatment, and patient’s satisfaction were recorded during first 24-h infusion. Cost calculations were based on the acquisition cost of drugs and devices. Results: Both techniques were similarly effective, but local anesthetic consumption and need for rescue analgesics were lower in the Stimulating group [respectively, 120 vs. 153 ml ( P= 0.004) and 21% vs. 60% ( P= 0.001)]. The analgesia-related costs for 24 h were similar when 100-ml bags of ropivacaine 2 mg/ml were used (66 € vs. 67 €; P= 0.26). When 200-ml bags of ropivacaine were used, the analgesia-related costs were higher in the Stimulating group than the Conventional group (75 € vs. 55 €; P= 0.0005). Conclusions: Direct costs of continuous sciatic nerve block ranged from 55 to 75 €. Stimulating catheters reduced local anesthetic consumption and need for rescue analgesics. This was only cost effective when 100-ml bags of 2 mg/ml ropivacaine were used, while the cheapest combination was the use of conventional catheters and 200-ml bags of ropivacaine. [ABSTRACT FROM AUTHOR]