Patient and Procedural Determinants of Postoperative Pain Trajectories

Abstract

Background: The primary goal of this study was to evaluate patterns in acute postoperative pain in a mixed surgical patient cohort with the hypothesis that there would be heterogeneity in these patterns.

Methods: This study included 360 patients from a mixed surgical cohort whose pain was measured across postoperative days 1 through 7. Pain was characterized using the Brief Pain Inventory. Primary analysis used group-based trajectory modeling to estimate trajectories/patterns of postoperative pain. Secondary analysis examined associations between sociodemographic, clinical, and behavioral patient factors and pain trajectories.

Results: Five distinct postoperative pain trajectories were identified. Many patients (167 of 360, 46%) were in the moderate-to-high pain group, followed by the moderate-to-low (88 of 360, 24%), high (58 of 360, 17%), low (25 of 360, 7%), and decreasing (21 of 360, 6%) pain groups. Lower age (odds ratio, 0.94; 95% CI, 0.91 to 0.99), female sex (odds ratio, 6.5; 95% CI, 1.49 to 15.6), higher anxiety (odds ratio, 1.08; 95% CI, 1.01 to 1.14), and more pain behaviors (odds ratio, 1.10; 95% CI, 1.02 to 1.18) were related to increased likelihood of being in the high pain trajectory in multivariable analysis. Preoperative and intraoperative opioids were not associated with postoperative pain trajectories. Pain trajectory group was, however, associated with postoperative opioid use (P < 0.001), with the high pain group (249.5 oral morphine milligram equivalents) requiring four times more opioids than the low pain group (60.0 oral morphine milligram equivalents).

Conclusions: There are multiple distinct acute postoperative pain intensity trajectories, with 63% of patients reporting stable and sustained high or moderate-to-high pain over the first 7 days after surgery. These postoperative pain trajectories were predominantly defined by patient factors and not surgical factors.

Fig. 1.

Study flow diagram for analytical sample.

Fig. 2.

Average daily pain across first 7 days following surgery, with overall trajectory for entire sample. Error bars indicate 95%CIs.

Fig. 3.

Group-based pain trajectories for first 7 days following surgery. Error bars indicate 95%CIs.

Fig. 4.

Spaghetti plots for individual trajectories within each pain trajectory group.

Fig. 5.

Mosaic plot for surgical service and pain trajectory groups, numbers in each cell are number of patients in that group. Vascular service (n = 1) was not included in this analysis.

Fig. 6.

Mean score for Patient-Reported Outcomes Measurement Information System Anxiety (A), Depression (B), and Pain Behavior Scales (C), and Mean Pain Catastrophizing Scale score (D) across pain trajectory groups. Error bars indicate 95%CIs.