Predictors for Failure to Respond to Erector Spinae Plane Block Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

Study Design. Retrospective review of prospectively collected data. Objective. To identify the risk factors associated with failure to respond to erector spinae plane (ESP) block following minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Summary of Background Data. ESP block is an emerging opioid-sparing regional anesthetic that has been shown to reduce immediate postoperative pain and opioid demand following MI-TLIF—however, not all patients who receive ESP blocks perioperatively experience a reduction in immediate postoperative pain. Methods. This was a retrospective review of consecutive patients undergoing one-level MI-TLIF who received ESP blocks by a single anesthesiologist perioperatively at a single institution. ESP blocks were administered in the OR following induction. Failure to respond to ESP block was defined as patients with a first numerical rating scale (NRS) score postsurgery of >5.7 (mean immediate postoperative NRS score of control cohort undergoing MI TLIF without ESP block). Multivariable logistic regressions were performed to identify predictors for failure to respond to ESP block. Results. A total of 134 patients were included (mean age 60.6 yr, 43.3% females). The median and interquartile range (IQR) first pain score postsurgery was 2.5 (0.0–7.5). Forty-nine (36.6%) patients failed to respond to ESP block. In the multivariable regression analysis, several independent predictors for failure to respond to ESP block following MI TLIF were identified: female sex (OR 2.33, 95% CI 1.04-5.98, P =0.040), preoperative opioid use (OR 2.75, 95% CI 1.03-7.30, P =0.043), anxiety requiring medication (OR 3.83, 95% CI 1.27-11.49, P =0.017), and hyperlipidemia (OR 3.15, 95% CI 1.31-7.55, P =0.010). Conclusions. Our study identified several predictors for failure to respond to ESP block following MI TLIF, including female gender, preoperative opioid pain medication use, anxiety, and hyperlipidemia. These findings may help inform the approach to counseling patients on perioperative outcomes and pain expectations following MI-TLIF with ESP block. Level of Evidence. 3