Predictors for Acute Postsurgical Pain Identified Using New Model

A clinically applicable model can predict acute postsurgical pain and pain for 3 months after surgery, according to results of a prospective observational study published in Scientific Reports.

Patients (N=2258) undergoing a variety of surgical procedures were enrolled in the current study at the Radboud University Medical Center in the Netherlands. Patients were asked to complete a prospective questionnaire. Preoperative predictors were combined with pain trajectories to predict acute postsurgical pain (APSP) at 3 months. Pain intensity was assessed using an 11-point (0-10) numerical rating scale.

A total of 52.0% of study participants were women, with a median age of 58.8 years; BMI was 25.6. The most common surgical procedures that patients underwent were general (20.0%), urologic (17.3%), orthopedic (16.1%), and otolaryngologic (10.5%), and 69.4% of patients were admitted to the hospital for their procedure.

Following surgery, movement-evoked pain was 0 to 3 in 67% of patients, which increased to 88% by month 3. A total of 12% of individuals with the highest level of pain after surgery decreased to 2% at month 3. At 3 months, 1049 patients had APSP.

Meaningful predictors for APSP in at least 1 of the pain models included sex, hospital admittance, medical specialty, movement evoked pain, pain trajectories, unknown wound size, wound size of greater than 10 cm, younger age, and higher anxiety score, functional disability score, Janssen classification of expected pain score, pain catastrophizing score, and preoperative pain. Pain trajectories alone were able to predict APSP at 3 months (P <.001).

In a model that did not include pain trajectories, increased preoperative movement-evoked pain and functional disability scores remained significant predictors.

The best-fit model included preoperative predictors and pain data during the first week after surgery (root mean square error [RMSE], 1.37; R²=0.501).

The study was limited by a large amount of missing data, which caused the imputation of unknown variables.

Overall, the researchers found that risk for APSP was best predicted by preoperative pain and functional disability as well as pain trajectories based on the first 7 days of postoperative pain scores.

Researchers concluded, “Our models can be used to identify patients at risk preoperatively, as well as in the direct postoperative period. Further studies need to focus on clinical application of the models.”

Reference

Van Boekel RLM, Bronkhorst EM, Vloet L, Steegers MAM, Vissers KCP. Identification of preoperative predictors for acute postsurgical pain and for pain at three months after surgery: a prospective observational study. Sci Rep. 2021;11(1):16459. doi:10.1038/s41598-021-95963-y