In two separate reviews, published respectively in The Journal of Bone and Joint Surgery and in the Journal of Spinal Disorders and Techniques, investigators at the Vanderbilt University Medical Center (Nashville, USA) have shown that increased preoperative opioid use is a significant predictor of worse patient-reported outcomes and increased hospital stay. However, they did not find a link between increased preoperative opioid use and an increased rate of complications.
Dennis Lee (Department of Orthopaedics & Rehabilitation, Vanderbilt University Medical Center, Nashville, USA) and others write in The Journal of Bone and Joint Surgery that although previous studies have shown that preoperative opioid use has a negative impact on spinal surgery outcomes, these studies are limited and “do not account for differences in opioid consumption among patients”. They add that there is also a lack of data for the effect of preoperative opioid use on patient-reported outcomes. The aim of their study was therefore to: “Investigate whether the amount of preoperative opioid use predicted worse postoperative patient-reported outcomes at three and 12 months following spinal surgery.”
Lee et al reviewed data for 583 patients who underwent lumbar, thoracolumbar, or cervical spine surgery at the Vanderbuilt Medical Center between October 2010 and June 2012. In this patient population, the mean age was 57±13.2, 54% were female, and lumbar fusion was the most common surgery performed (35% of patients). The median preoperative daily morphine equivalent amount was 8.75mg (interquartile range 0–36.5mg), with 56% of patients reporting some degree of preoperative opioid use.
All patients, regardless of preoperative opioid use, had significant improvements in the study’s outcome measures—Mann-Whitney U tests, SF-12 physical component summary (PCS), and mental component summary (MCS), Oswestry Disability Index (ODI), Neck Disability Index (NDI), and EQ-5D—at three and 12 months postoperatively. However, multivariate analysis showed that increased preoperative opioid use was a significant predictor of worse SF-12 PCS, SF-12 MCS, ODI, NDI, and EQ-5D scores. Lee et al write that every 10mg increase in morphine equivalent amount taken preoperatively in a 24-hour period predicted a 0.3 decrease in SF-12 PCS and SF-MCS scores, a 0.6 increase and 0.5 increase in the ODI and NDI scores, and a 0.1 decrease in EQ-5D scores at the three and 12 months postoperative follow-up points.
In the study in the Journal of Spinal Disorders and Techniques, Sheyan Armaghani and others (including Dennis Lee) also reviewed data from patient population examined in the first study (Armaghani et al were all co-authors in that study). However, the aim of their study was to assess whether increasing amounts of preoperative opioid use were associated with 30-day and 90-day complications as well as increased hospital stay. They explain that the link between these outcomes and preoperative opioid use have not been previously directly evaluated in patients undergoing spinal surgery.
They found that preoperative opioid use, in a multivariate analysis, was not a significant predictor for an increased rate of complications at 30 days or for an increased rate of complications at 90 days. However, they did find that preoperative opioid use was a significant predictor (p=0.006) of length of stay in hospital. “Based on the β coefficient of preoperative narcotic use in our linear regression analysis of length of stay, we calculated that for every 100 morphine equivalents a patient is taking preoperatively, their stay is extended 1.1 days,” Armaghani et al write. They add that they hypothesise that postoperative pain control in patients on preoperative, or chronic, opioids is more “challenging” to control, which delays “mobilisation and discharge milestones”.
The authors comment that interventions could be used to reduce opioid use prior to surgery and could, therefore, potentially reduce the risk of prolonged hospital stays. Similarly, Lee et al write in The Journal of Bone and Joint Surgery that “Knowledge that increased preoperative opioid use negative predicts outcomes may provide motivation to both patient and surgeon to decrease or to eliminate opioid use prior to surgery.”
Lee told Spinal News International: “Our work highlights the importance of careful preoperative counseling with patients on high doses of preoperative opioids, pointing out the potential impact on long term outcome and working toward opioid reduction prior to undergoing surgery. Consideration of preoperative multimodal pain agents in conjunction with appropriate referral to psychiatric and addiction specialists may help in achieving this goal.”