Peripheral nerve blocks and incidence of post-operative neurogenic complaints and pain scores.

Background: Peripheral nerve blocks (PNB) are a common adjuvant for anesthesia. There is little orthopedic literature regarding the incidence of neurogenic complaints and quality of pain control.

Methods: We instituted a questionnaire to post-operative patients who would have potentially received a PNB at a single institution between 2008 and 2009 and asked them to rate their pain on a standardized pain scale at several points in the post-operative period. The survey queried whether patients experienced severe pain, went to the ER, or experienced neurogenic complaints. comparative data was also collected on patients who did not receive a PNB. We instituted a follow up survey several months later to investigate the persistence of these complaints.

Results: 268 patients completed the survey, 215 patients with PNb and 53 control patients. There was a 38.14% incidence of neurogenic complaints in patients who received PNB as compared to 9.43% incidence in patients who did not receive a PNB, p <0.001. There was 27.9% (PNB) versus 15.1% (control) incidence of severe pain (p 0.05). 24 patients that received PNB versus five control patients visited the ER or called the house officer (p = 0.71). Patients who received PNB had significantly better pain control immediately after surgery (p = 0.02) and improved pain control the same night (p = 0.04), but there was no difference in pain control the morning after surgery, 24 hours after surgery and at the one week post-operative period (p values 0.77, 0.28 and 0.69). At the several month follow-up, we found that 41 of the 80 (51%) patients had persistent complaints.

Conclusions: Patients who receive PNBs have more neurogenic complaints and severe pain. They have improved initial pain control, but the profile shows no difference after less than 24 hours. If patients experience initial neurogenic complaints, a significant percentage of these patients have persistent complaints several months after surgery. the relative benefit of PNBs must be weighed against the possibility of persistent neurogenic complaints.

Level Of Evidence: Cohort study type III.