Intraoperative Injection Significantly Reduces Postoperative Pain in Trauma Patients Too: Commentary on an article by Daniel Koehler, MD, et al.
Efficient and adequate pain control after fracture fixation is an important aspect of optimal treatment from the perspectives of both the patient and the providers. Narcotics, parenteral and oral, have been the traditional mainstay of postoperative pain control in trauma patients. There are a variety of problems with relying exclusively upon narcotics, including unwanted side effects, dependency, and variable pain control efficacy. There are also problems with alternative solutions like nerve blocks, including unwanted prolonged paralysis, rebound pain, and potential for nerve injury. Injection of local anesthetics into the surgical site has previously been shown to be effective in arthroplasty and other orthopaedic procedures, but this is one of the first reports of its use in trauma. The improved pain control in these patients appears to be clinically important as well as significant, as the median visual analog scale score was reduced to 1 to 3.5 in the injection group compared with 5 in the control group with standard postoperative pain control. In my opinion, the fact that postoperative pain was very low but not zero is desirable because these patients were not deprived of the value of caution provided by some degree of pain1, which may be absent in nerve blocks. Furthermore, there was neither motor deficit (temporary paralysis) nor rebound pain (pain levels at 12 to 48 hours were reported and equivalent). There was no comparison with other modes of injection like lysosomal compounds, which are purported to increase the duration of activity of analgesics2.
Practicing orthopaedists may be able to immediately incorporate this technique into their practice. They should note that Koehler et al. used 100 mL of a cocktail of 400 mg of 0.75% ropivacaine (53.33 mL), 0.6 mg of 1-mg/mL epinephrine (0.6 mL), 5 mg of 0.5-mg/mL morphine sulfate (10 mL), and 36.07 mL of 0.9% sodium chloride solution. The typical duration of action of ropivacaine is 6 hours, which is extended by the addition of epinephrine. The duration of observed postoperative pain control is consistent with the expected duration of action of the injected medication. Koehler et al. infiltrated the surgical field (deep and superficial) but avoided injections around articular cartilage. Special care was taken (such as side port injection needles) to avoid injection in or around neurovascular structures. This series was limited to patients with femoral fractures, in which there is an extensive soft-tissue envelope, and the noted absence of soft-tissue healing problems reported in this study may not be transferable to other locations like distal tibial fractures in which the soft tissue may not be as tolerant of the mechanical impact of this amount and type of fluid injection. The injection was part of a multimodal analgesic approach that included patient-controlled analgesia and oral analgesics. The injections reduced but did not eliminate the use of postoperative narcotics.