Perioperative Nerve Injury After Peripheral Nerve Block in Patients With Previous Systemic Chemotherapy

Background and Objectives: There are multiple risk factors for developing perioperative nerve injury (PNI). Perioperative nerve injury after peripheral nerve blockade (PNB) is rare. Exposure to systemic chemotherapy may cause peripheral neuropathy, but its role as a risk factor for PNI after PNB is unknown. The objective of this retrospective study was to determine the incidence of PNI in patients undergoing PNB as part of extremity surgery after prior exposure to systemic chemotherapy. Methods: All patients aged 18 years or older who received systemic chemotherapy and subsequently underwent PNB were identified. The primary outcome was defined as the presence of new or worsened PNI documented within 3 months of the procedural date. Cases of PNI were independently reviewed by 3 investigators, and the etiology of all PNI cases were categorized as possibly or unlikely related to the PNB. Results: A total of 216 PNB (165 lower extremity blocks, 51 upper extremity blocks) were performed in 186 patients previously exposed to chemotherapy; 4 cases met criteria for PNI (2.2%; 95% confidence interval, 0.8%-5.4%). One case of PNI was possibly related to PNB (0.5%; 95% confidence interval, 0.1%-3.0%) and 3 cases were unlikely related to PNB. Complete recovery occurred in 3 cases, with partial recovery occurring in 1. Conclusions: The overall incidence of PNI in this cohort (2.2%) was not different than baseline risk established in large cohort studies. Perioperative nerve injury was possibly attributable to the PNB in 0.5% of patients. However, in the absence of a control group of surgical patients who previously received systemic chemotherapy without regional anesthesia, we cannot determine whether the higher incidence of neurologic injury is secondary to the surgical procedure, the anesthetic technique, the natural progression of chemotherapy-induced peripheral neuropathy, or a combination of factors and the relative contribution of each.