Ultrasound Compared With Nerve Stimulation Guidance for Peripheral Nerve Catheter Placement
Survey of Anesthesiology
Editor's key points † An area of topical discussion is the role of ultrasound (US) in regional block. † This systematic review and meta-analysis used Cochrane methodology to explore for possible differences between regional techniques. † There was little difference between US-guided regional blocks and nerve stimulator-placed blocks. † Further work is needed to clarify what a 'successful' block is before doing larger scale studies. Background. The aim of this meta-analysis was to compare the
... icacy and safety of ultrasound (US) vs nerve stimulation (NS) guidance for peripheral nerve catheter placement. Methods. This meta-analysis was performed according to the PRISMA statement and the recommendations of the Cochrane Collaboration. For dichotomous outcomes relative risks [RRs; 95% confidence intervals (CIs)] were calculated, while for continuous outcomes, mean differences (MDs; 95% CI) were calculated. All statistical analyses were performed using the Revmanw statistical software (Version 5.1). Results . Fifteen randomized controlled trials including 977 patients satisfied the inclusion criteria. Peripheral nerve catheters placed under US guidance showed a higher RR of 1.14 (95% CI: 1.02-1.27; P¼0.02) for an overall successful block in comparison with NS. However, postoperative pain scales at movement (numeric rating scale: 0-10) were comparable between US-vs NS-guided peripheral nerve catheters 24 (MD: 0.08; 95% CI: 20.77 to 0.94; P¼0.85) and 48 (MD: 1.0; 95% CI: 20.3 to 2.3; P¼0.13) h after surgery. Patients receiving a US-guided peripheral nerve catheter had a lower RR of 0.13 (95% CI: 0.04 -0.38; P¼0.0002) for an accidental vascular puncture. Conclusions. There is evidence that US-guided peripheral nerve catheters show a higher success rate and a lower risk for an accidental vascular puncture compared with NS guidance. However, this difference resulted only in marginally lower postoperative pain scores at rest. Nevertheless, these results were influenced by heterogeneity and should be interpreted with caution. The perioperative use of ultrasound (US) as the primary guiding technique for regional anaesthesia has significantly increased during the past two decades and might have replaced the former 'gold standard' nerve stimulation (NS). 1 2 Two recent meta-analyses demonstrated numerous advantages of US-guided peripheral nerve blocks in comparison with NS, including higher success rates, lower need of local anaesthetics, reduced performance, and onset time and also reduced complication rates. 3 -8 However, as mentioned in a recent editorial by Ilfeld and colleagues, 9 data focusing specifically on UScompared with NS-guided peripheral nerve catheter placement are currently lacking in the literature. Therefore, the aim of the present meta-analysis was to compare the success rates, performance times, postoperative pain outcomes, and rates of neurological complications of USvs NS-guided peripheral nerve catheters for postoperative pain therapy. Methods This systematic review of randomized controlled trials was performed according to the criteria of the PRISMA statement 10 and the current recommendations of the Cochrane Collaboration. † Both authors contributed equally.