Trigger Point Injection Effective for Myofascial Pain in the ED

Trigger point injections (TPI) with 1% lidocaine may improve myofascial pain in the emergency department (ED) compared with conventional methods, according to study results published in The Journal of Emergency Medicine. TPIs may reduce length of stay in the ED, as well as decrease the number of opioid prescriptions given to patients during discharge.

Myofascial pain, defined as pain arising from muscles or fascia, is becoming more and more common in the ED. While there are multiple treatment options for myofascial pain, there are no widely accepted conventional therapies, and limited data are available on the efficacy of interventions such as TPI.

The goal of the current study was to compare TPI with 1% lidocaine vs. conventional approaches for myofascial back and neck pain in the ED. In addition, differences in length of stay and number of opioid prescriptions on discharge, were determined.

The prospective, randomized, pragmatic trial included patients with clinically diagnosed myofascial neck or back pain treated between November of 2017 and April of 2019 in an ED. Participants were randomized to an experimental group, treated with TPI with 1% lidocaine, or a control group, receiving standard conventional approach.

The primary outcome was a reduction of pain according to the Numeric Rating Scale (NRS) at 20 minutes after the intervention, compared with baseline.

The study cohort included 62 participants, including 27 randomized into the control group and 35 patients randomized into the TPI group. Of these, 52 subjects (19 in the control group and 33 in the TPI group) with available data were included in the data analysis.

The pain score according to NRS at 20 minutes after treatment was lower in the TPO group, compared with the control group (median difference, -3.01; 95% CI, -4.20 to -1.83; P <.001).

The median length of ED visit was 2 hours and 37 minutes in the TPI group and 4 hours and 38 minutes in the control group (P <.001). Significantly more participants in the control group received opioid prescription at discharge (47.4% vs 2.9%, respectively; odds ratio, 28.8; 95% CI, 3.2-255.9; P <.001).

Most participants in the TPI group (88.2%) reported they would undergo the procedure again.

The study had several limitations, including the relatively small sample size, exclusion of 9 patients due to missing data on pain score measurements, potential breach of the original blinding protocol, as well as possible placebo effect as TPI was administered by the physician and the placebo from the nurses.

“Emergency physicians face pressures to reduce length of stay within the department and reduce the amount of opioids prescribed to discharged patients, all while maintaining patient satisfaction and maximizing pain control. The data within this study suggest that TPIs may play a role in accomplishing these goals,” concluded the researchers.

Reference

Yanuck, J, Saadat S, Lee JB, Jen M, Chakravarthy B. Pragmatic randomized controlled pilot trial on trigger point injections with 1% lidocaine versus conventional approaches for myofascial pain in the emergency department. Published online Jul 22, 2020. J Emerg Med. doi:10.1016/j.jemermed.2020.06.015