Background and Aims Continuous peripheral nerve blocks (cPNB) are widely used and have potential benefits for providing pain relief for several days. Successful insertion of cPNBs and avoidance of their dislocation can represent a challenge.
Dislocation of cPNBs can result in failure of the block and is poorly described in the literature. The rate of catheter dislocation is probably underestimated.
We designed an cadaveric anatomical study to assess the rate of catheter displacement after a simulated program of intensive physiotherapy. The aim was to compare the location of the catheter tip just after placement and after physiotherapy.
Methods Eight ultrasound guided continuous suprascapular nerve blocks were performed. The catheter tip localization was confirmed by tomodensitometry. We then simulated a physiotherapy session by performing a series of standardized movements on anatomical specimen. After marking with methylene blue, an anatomical dissection followed to localize the position of the catheter tip.
Results There was radiological evidence of correct placement in the vicinity of the suprascapular notch for all catheters.
Dissections demonstrated that in six specimens (75%), catheters remained in the correct place after physiotherapy.
Two catheters came out and escaped through supraspinatus muscle and trapezius.
Conclusions From an anatomical point of view, catheter dislocation of continuous suprascapular nerve blocks after an intense program of physiotherapy of shoulder mobilization, occurs in 25% of cases.