According to the 2015 National Survey on Drug Use and Health, marijuana continues to be the most common illicit recreational drug used in the US. Cannabis is associated with systemic reactions that potentially affect perioperative outcomes. We have reviewed the most important pharmacological aspects and pathophysiological effects that should be considered during the perioperative management of chronic cannabis/cannabinoids users. The synthetic analogues provide higher potency with increased risk for complications. High cannabinoid liposolubility favors rapid accumulation in fatty tissue which prolongs its elimination up to several days after exposure. The multi-systemic effects of cannabinoids and their pharmacological interactions with anesthetic agents may lead to serious consequences. Low doses of cannabinoids have been associated with increased sympathetic response (tachycardia, hypertension and increased contractility) with high levels of norepinephrine detected 30 min after use. High doses enhance parasympathetic tone leading to dose-dependent bradycardia and hypotension. Severe vascular complications associated with cannabis exposure may include malignant arrhythmias, coronary spasm, sudden death, cerebral hypoperfusion and stroke. Bronchial hyperreactivity and upper airway obstruction are commonly reported in cannabis users. Postoperative hypothermia, shivering and increased platelet aggregation have been also documented.

Peripheral nerve stimulation (PNS) is rapidly increasing in use. This interventional pain treatment modality involves modulating peripheral nerves for a variety of chronic pain conditions. This review evaluated its use specifically in the context of chronic lower extremity pain. Studies continue to elucidate the utility of PNS and better define indications, contraindications, as well as short- and long-term benefits of the procedure for the lower extremity. While large, prospective evidence is still lacking, the best available evidence suggests that improvements may be seen in pain scores, functionality, and opioid consumption. Overall, evidence synthesis suggests that PNS for the lower extremities may be a viable option for patients with chronic lower extremity pain.

Headaches are one of the most common medical complaints worldwide, and treatment is often made difficult because of misclassification. Peripheral nerve stimulation has emerged as a novel treatment for the treatment of intractable headaches in recent years. While high-quality evidence does exist regarding its use, efficacy is generally limited to specific nerves and headache types. While much research remains to bring this technology to the mainstream, clinicians are increasingly able to provide safe yet efficacious pain control.

While denervation can occur with aging, peripheral nerve injuries are debilitating and often leads to a loss of function and neuropathic pain. Although injured peripheral nerves can regenerate and reinnervate their targets, this process is slow and directionless. There is some evidence supporting the use of neuromodulation to enhance the regeneration of peripheral nerves. This systematic review reported on the underlying mechanisms that allow neuromodulation to aid peripheral nerve regeneration and highlighted important in vivo studies that demonstrate its efficacy. Studies were identified from PubMed (inception through September 2022) and the results were synthesized qualitatively. Included studies were required to contain content related to peripheral nerve regeneration and some form of neuromodulation. Studies reporting in vivo highlights were subject to a risk of bias assessment using the Cochrane Risk of Bias tool. The results of 52 studies indicate that neuromodulation enhances natural peripheral nerve regeneration processes, but still requires other interventions (e.g., conduits) to control the direction of reinnervation. Additional human studies are warranted to verify the applicability of animal studies and to determine how neuromodulation can be optimized for the greatest functional restoration.

Introduction While spinal cord stimulator implant is an increasingly safe procedure, one of the most feared complications is spinal cord injury. Still, literature regarding its incidence remains highly variable. This retrospective analysis aims to evaluate the incidence of spinal cord injury after spinal cord stimulator implant using a large-scale claims database. Methods The PearlDiver-Mariner database of national all payer claims was used to identify patients who underwent spinal cord stimulator implant (percutaneous or paddle) and developed subsequent spinal cord injury within 45 days. The primary outcome was to determine the overall incidence of spinal cord injury after spinal cord stimulator implant. Secondary outcomes included an evaluation of potential factors associated with developing spinal cord injury using univariable and multivariable regression analysis. Results A total of 71,172 patients who underwent a spinal cord stimulator implant were included in the analysis, of which 52,070 underwent percutaneous and 19,102 underwent paddle spinal cord stimulator lead implant. The overall incidence of spinal cord injury after spinal cord stimulator implant (any lead type) was found to be 0.42% (302 patients). The incidence of spinal cord injury after percutaneous and paddle lead implants did not differ at 0.45% (233 patients) and 0.36% (69 patients)(p=0.12), respectively. Overall, variables associated with a significantly increased OR (95% confidence interval) of developing spinal cord injury included male gender by 1.31 times (1.04 to 1.65)(p=0.02); having a claim for low molecular weight heparin within 30 days by 3.99 times (1.47 to 10.82)(p<0.01); a diagnosis for osteoporosis within 1 year by 1.75 times (1.15 to 2.66)(p<0.01); and a diagnosis of cervical or thoracic spinal canal stenosis within 1 year by 1.99 (1.37 to 2.90)(p<0.001) and 4.00 (2.63 to 6.09)(p<0.0001) times, respectively. Conclusions Overall, our results support the notion that spinal cord stimulator implant continues to be a safe procedure for chronic pain patients. However, risk factor mitigation strategies for the prevention of spinal cord injury after spinal cord stimulator implant should be undertaken prior to performing the procedure.