Factors Predictive of Prolonged Postoperative Pain Resolution and Opioid Use

Researchers have identified separate risk factors for prolonged postsurgical pain and opioid use, according to findings from a study reported in the Journal of Pain Research. These variables may assist in preoperative risk stratification risk to identify which patients may benefit from further personalized interventions.

The study was a post hoc analysis of a randomized, placebo-controlled trial evaluating gabapentin vs an active placebo in 410 patients (median age, 56.8 years) who were undergoing a surgical procedure. Investigators in the study took preoperative assessments of pain, opioid use, substance use, and examined various psychosocial variables.

Following surgical intervention, the patients answered questions on a modified Brief Pain Inventory (BPI) by phone daily for 3 months. The BPI was then administered by phone weekly for 6 months, and then monthly for up to 2 years following surgery.

Patients in the study reported postoperative pain for a median of 79 days, which exceeded the time period of postoperative opioid use for a median of 27 days. The duration of pain following the operation also exceeded opioid use, irrespective of the type of surgery.

Persistent-post surgical pain was reported in 36.1% of patients at 3 months, but this lowered to 19.8% at 6 months and 9.5% at 12 months. Continued opioid use after surgery at 3, 6, and 12 months was reported in 9.5%, 2.4%, and 1.7% of patients, respectively.

Determinants of postoperative pain cessation in the multivariable analysis included preoperative pain at the future surgical site (for every 1-point increase in the Numeric Pain Rating Scale; hazard ratio [HR], 0.93; 95% CI, 0.87–1.00; P =.034), trait anxiety (for every 10-point increase in the Trait Anxiety Inventory; HR, 0.79; 95% CI, 0.68–0.92; P =.002), and a history of delayed recovery following injury (HR, 0.62; 95% CI, 0.40–0.96; P =.034).

Factors associated with delayed opioid cessation following surgery included preoperative opioid use (HR, 0.60; 95% CI, 0.39–0.92; P =.020), elevated depressive symptoms (for every 5-point increase in the BPI-II score; HR, 0.88; 95% CI, 0.80–0.98; P =.017), and preoperative pain outside of the surgical site (HR, 0.94; 95% CI, 0.89–1.00; P =.046).

In contrast, perioperative gabapentin use was associated with postoperative opioid cessation (HR, 1.37; 95% CI, 1.06–1.77; P =.016).

A limitation of this study was the exclusion of patients with moderate to severe preoperative pain outside the surgical site, which limits the generalizability of the findings.

In spite of the study’s limitations, the researchers noted that given “the ongoing opioid crisis, increased attention to postoperative opioid prescribing, and legislation limiting the duration of postoperative opioid prescribing, research is urgently needed to provide” interventions that simultaneously optimize “opioid prescribing and perioperative pain management.”

Reference

Hah JM, Hilmoe H, Schmidt P, et al. Preoperative factors associated with remote postoperative pain resolution and opioid cessation in a mixed surgical cohort: Post hoc analysis of a perioperative gabapentin trial. Published online November 18, 2020. J Pain Res.  doi:10.2147/JPR.S269370