Postoperative pain has been shown in prior research to be a major challenge for patients with burns who undergo autologous skin grafting. Burn injuries cause severe pain, with many patients requiring large doses of opioids for pain control and opioid doses tending to escalate during hospitalization as patients develop opioid tolerance. In this setting, patients who undergo autologous skin grafting often struggle with postoperative pain.
Determining the Benefits of Perioperative Multimodal Analgesia
Many anesthesiologists at the University of Wisconsin School of Medicine and Public Health were using non-opioid medications to provide multimodal analgesia in the treatment of patients with burn injuries. However, the practice varied among providers, as few studies exist to guide evidence-based practice for this patient population. Therefore, we performed a retrospective chart review to determine whether the use of perioperative multimodal analgesia was beneficial for patients with burns and published our results in the Journal of Burn Care & Research.
In order to account for the large individual variation in injuries and responses to opioids, we compared total opioid use the day before surgery with opioid use on the day of surgery for each patient. We found that large increases in opioid use after surgery were prevented by a combination of acetaminophen, gabapentin, and ketamine. Patients who received all three non-opioid medications used 47 mg less morphine (or morphine equivalents; 95% confidence interval, -81 to -11) than those who did not receive non-opioid medications for analgesia (Table). Importantly, the combination of medications was more beneficial than the use of any individual medication alone. We interpret our findings as a clinically significant reduction in opioid use after surgery and support for the use of perioperative multimodal analgesia in burn patients.
Our study has important limitations. Foremost, we performed a single-center retrospective study, and there have been many randomized controlled studies on perioperative multimodal analgesia. Some studies question the efficacy of gabapentin, and our findings do not discount their results. Many other studies have reported a modest benefit with the use of acetaminophen or ketamine. It is important to acknowledge that patients with burn injuries are not well-represented in most of these studies. The burn injury itself, prolonged hospital course, and opioid tolerance are not typical of surgical patients, and any of these factors may change the benefits of multimodal analgesia. Of note, two randomized controlled studies found that gabapentinoids did not reduce opioid use in the immediate postburn period. However, neither study specifically addressed perioperative analgesia, and one did report improvements in procedural and evoked pain measures.
Another limitation of our study is that the sample size was relatively small and did not include some non-opioid medications that may be beneficial for patients with burns. In particular, lidocaine and dexmedetomidine infusions were not used in our patient population. NSAIDs were not used in our patients either, due to the potential for renal injury and increased risk of perioperative bleeding. Regional anesthesia was not included in the study but may be beneficial prior to autologous skin grafting. Further, our sample size precluded an analysis of these additional medications and their combinations, as we would have needed to study thousands of patients instead of hundreds.
It may be challenging to perform a large, randomized controlled study to evaluate the efficacy of multimodal analgesia specifically in patients with burn injuries. However, it would be feasible to perform a large, multicenter retrospective study to assess the efficacy of perioperative multimodal analgesia in this patient population. Such a study would inform our current practice and could identify specific multimodal regimens to assess in targeted prospective studies. In the meantime, our findings support the use of combination acetaminophen, gabapentin, and ketamine for perioperative multimodal analgesia in patients with burns.