Letter to the Editor: Preoperative Peripheral Nerve Blocks in Orthopaedic Trauma Surgery: A Guide to Diagnosis-Based Treatment

Abstract

T o the Editor: Thank you for publishing this interesting work from Kandemir and Cogan. We have a few comments that we think merit additional discussion. In the section entitled Approach for Perioperative Peripheral Nerve Blocks (PNB), the authors suggested that a standardized approach to considering PNBs is important because "it also helps prevent complications associated with the inappropriate use of PNB for certain injuries," but they provided no references to support the assertion that there are injuries where the use of PNBs is inappropriate. 1 Throughout their article, there are unwritten assumptions that PNBs increase the risk of acute compartment syndrome (ACS) or missed ACS but nowhere are there any data or references to support these assumptions. Furthermore, ACS causes ischemic pain, which has been demonstrated to be carried on afferent sympathetic fibers, which run separately from peripheral nerves 2 ; thus, PNBs cannot block ischemic pain. 3,4 Although there is literature linking regional anesthesia with delayed diagnosis of ACS, the cases involved used epidural anesthesia. [5][6][7] Using these examples as justification to avoid PNBs is inappropriate because PNBs, unlike epidurals, do not provide afferent sympathetic blockade. Consequently, a large number of orthopaedic trauma patients are being denied effective analgesia and subjected instead to opioids and their associated risks based on unfounded fears. Furthermore, intravenous opioid patient-controlled analgesia is no less likely to interfere with the diagnosis of ACS. 8 In contradistinction to the framework presented by Kandemir and Cogan, our experience at the University of Florida suggests that broad application of continuous PNBs to orthopaedic trauma patients can be achieved with great safety when a culture of mutual trust and respect exists between the surgeons and the anesthesiologists. Ten years of electronic health record data from the University of Florida reveal over 8,300 patients with long bone fractures who were at high risk for ACS and fell into either the yellow or red groups described in the study by Kandemir and Cogan, all of whom were treated with PNBs. Of these, only two required fasciotomy and there were zero cases of missed ACS. These data are currently being analyzed for publication.We state with confidence that there is no convincing evidence to support the idea that PNBs mask or delay diagnosis of ACS. On the contrary, there is evidence that diagnosis of ACS is unaffected by the presence of PNBs. Breakthrough pain in the presence of PNBs is very concerning for ACS. 9-14 When ACS has been diagnosed in the presence of PNBs, it is preceded by severe, escalating pain. 15 Currently, there are no definitive guidelines on how to manage the analgesic needs of orthopaedic trauma patients. The article of Kandemir and Cogan laid out some of the advantages that PNBs have to offer, but they were also quick to