Single perineural catheter for hybrid technique of combined peripheral nerve stimulation and regional local anesthetic nerve block to manage phantom limb pain: time to jump on the neuromodulation bandwagon?

Role of neuromodulation in acute pain settings

Peripheral nerve stimulation (PNS), a type of neuromodulatory technique, is increasingly used to treat chronic pain syndromes. PNS has also recently gained popularity as a viable adjunct analgesic modality in acute pain settings, where the practice primarily relies on using boluses or infusion of local anesthetics for nerve blockade, followed by stimulation to extend the analgesia. There is some early promise in PNS for perioperative analgesic control, but considerable obstacles must be addressed before it can be implemented into standard practice. In this daring discourse, we explore the possibilities and constraints of using the PNS paradigm in acute pain.

Neuromodulation using a hybrid technique of combined perineural local anesthetic and nerve stimulation in six challenging clinical scenarios

PURPOSE

Postamputation pain is challenging because of complex mechanisms involving a multitude of pain pathways and psychological factors. This patient population also tends to have extensive comorbidities with or without a background of chronic pain. Electrical neuromodulation such as peripheral nerve stimulation has gained traction in the realm of chronic pain. Recently, the off-label use of hybrid perineural nerve stimulation in combination with locoregional block via the stimulating nerve block catheter has been described in single-center case reports.

CLINICAL FEATURES

Herein, we present a case series of six patients from two different Canadian hospitals using such a hybrid technique in three different clinical scenarios. These scenarios were (1) local anesthetic dose minimization in the presence of multiple nerve block catheters, (2) analgesia augmentation when local anesthetic alone is insufficient, and (3) provision of an analgesic adjunct as part of a multimodal regimen. A stimulating sciatic nerve block catheter was inserted under ultrasound and nerve stimulation guidance for these cases. Patients tended to experience pain on the subsequent postoperative days whereby the off-label use of nerve stimulation successfully reduced their pain score and stabilized or decreased their opioid consumption or minimized the need to increase the local anesthetic dose when doing so could have precipitated local anesthetic toxicity.

CONCLUSION

Our case series supports the feasibility of using a combination of low-frequency perineural stimulation and local anesthetic infusion via a single perineural nerve block catheter to manage challenging postamputation pain.

Peripheral nerve stimulation through a 'dry' peripheral nerve catheter for shoulder analgesia: a case report

Revision shoulder surgery can pose significant analgesic challenges as locoregional blocks are often avoided to enable early recognition of iatrogenic nerve injuries. Our case describes the utilisation of pre-operative and intra-operative low-frequency percutaneous peripheral nerve stimulation via a 'dry' interscalene catheter, inserted pre-operatively for a patient presenting for revision total shoulder arthroplasty who was experiencing significant shoulder joint pain despite a prior total shoulder arthroplasty. The clinical considerations and safety aspects are discussed further.