Are there risk factors for musculoskeletal procedural pain? A national prospective multicentre study of procedural instantaneous pain and its recall after knee and spine injections.

BACKGROUND

Little is known about the risk factors for procedural pain during spinal and joint injections.

METHODS

In this prospective national multicentre study, procedural pain was investigated by rheumatologists who visited four consecutive patients undergoing synovial aspiration and infiltrations of the knee (K), and four consecutive patients undergoing spinal (S) injections. Pain assessments were carried out just before, during, and 48 hours after the procedure.

RESULTS

The 249 rheumatologists enrolled 1350 patients (720 K and 630 S; 64 ± 14 years, 64.6% female). Instantaneous procedure-induced pain was reported in 76.1% of cases, was generally mild (mean 2.6 ± 2.5 on 10) and not different between the two sites. The frequency of procedure-induced pain increased significantly with pain related to the underlying disease and level of anxiety before the procedure. Procedure-induced pain was recalled after 48 hours later by 66.2% of the patients, with an intensity of 2.4 ± 2.6. The recall of procedure-induced pain increased with pain due to the underlying condition, with the intensity of instantaneous procedure-induced pain, with the level of anxiety, but was less frequent if the patient underwent the procedure for the first time. Patients' and physicians' estimates of procedural pain were poorly concordant (kappa coefficient 0.45), physicians tended to overestimate the frequency of pain but to underestimate its intensity.

CONCLUSION

Procedural pain is common, but mild, in patients undergoing musculoskeletal injections. Instantaneous procedural pain and its recall 48 hours later depend principally on the level of underlying pain and anxiety, regardless of the injection site and the analgesic procedure performed.