Abstract
Background
Peripheral nerve catheters remain underutilised due to their procedural complexity, prolonged placement time, and secondary catheter displacement. We developed a novel integrated system enabling push-button one-handed catheter deployment under continuous ultrasound guidance and tested the hypothesis that it is non-inferior to single-shot nerve blocks regarding time on task.
Methods
In a prospective, randomised, crossover study at two centres, 22 anaesthesiologists each performed a single-shot nerve block and a catheter placement on a standardised bovine phantom model. Non-inferiority was assessed using the paired mean difference with a 95% confidence interval (CI); the pre-specified non-inferiority margin was 30 s. Secondary outcomes included needle tip accuracy, catheter deployment precision, number of needle redirections and ease of use.
Results
Mean time on task was 27.8 (SD 12.0) s for single-shot and 28.8 (SD 13.2) s for the catheter technique (mean difference −1.0 s, 95% CI −5.6 to 3.7 s); the upper CI bound (3.7 s) was below the 30 s non-inferiority margin. Needle tip accuracy was similar for both methods (median 1.0 mm [IQR 0.8–1.5 mm] vs 1.3 mm [IQR 0.8–1.8 mm]; P=0.852). The median deployment-induced tip displacement was 0.6 [IQR 0.0–1.5] mm (range −1.2 to +5.7 mm); four of 21 deployments exceeded 2 mm, with no correlation between needle and catheter tip positions (Spearman r=0.05, P=0.828). Redirections (P=0.152) and ease of use (P=0.655) were similar.
Conclusions
The novel integrated push-button catheter system is non-inferior to single-shot nerve block in time on task and achieves comparable needle tip precision after a brief demonstration.