Perioperative Opioid Consumption and Clinical Outcomes in Surgical Patients with a Pre-existing Opioid-Based Intrathecal Drug Delivery System

BACKGROUND: Intrathecal drug delivery systems (IDDS) have been utilized for over 3 decades for management of chronic pain and spasticity. Patients with IDDS may present for surgical procedures unrelated to the IDDS device, although data are limited regarding perioperative outcomes. METHODS: This is a historical matched cohort study conducted between January 1, 2007 and December 31, 2016 of patients with an opioid-based IDDS versus matched control patients undergoing surgery excluding interventional pain procedures. Patients in the IDDS group were matched with up to 2 patients without an IDDS. Multivariable regression analyses were utilized to assess differences in the primary outcome of cumulative perioperative opioid consumption (ie, intraoperative and postanesthesia care unit [PACU] opioid consumption), and opioid consumption during the first 24 and 72 postoperative hours. Postoperative clinical outcomes were also assessed including escalating oxygen requirements, naloxone administration, pain-sedation mismatch, and perioperative pain service consultation. RESULTS: A total of 321 surgeries were included, 112 with IDDS and 209 controls, with median (interquartile range [IQR]) age of 57 (49-64) years. Compared to matched controls, patients with an IDDS had greater perioperative opioid consumption (median [IQR] oral morphine milligram equivalents [OME] of 110 [60-163] vs 93 [IQR, 53-142]; adjusted multiplicative increase 1.28 [95% confidence interval {CI}, 1.03-1.59]; P =.026). IDDS patients also had greater opioid consumption in the first 24 and 72 postoperative hours (multiplicative increases of 2.23 [95% CI, 1.36-3.63], P =.001, and 2.46 [95% CI, 1.41-4.32], P =.002, respectively). There were no significant differences in postoperative oxygen requirements, naloxone administration, or pain-sedation mismatch. Inpatient pain medicine consultation was more frequent in IDDS patients compared to controls (51.8% vs 6.2%; P <.001). CONCLUSIONS: Patients with opioid-based IDDS received more perioperative opioids and were more likely to receive postoperative pain service consultation compared to matched controls. There were no significant differences in clinical safety outcomes, suggesting tolerance for higher opioid doses. Further research is warranted to optimize perioperative outcomes in those with IDDS.