The Incidence of Peripheral Nerve Injury After Multimodal Perineural Anesthesia/Analgesia Does Not Appear to Differ from That Following Single-Drug Nerve Blocks (2011-2014).

Abstract

Recently, we reported on the in vitro [1] and in vivo [2] animal safety (rat) of four-drug nerve block (multimodal perineural anesthesia-analgesia, or MMPNA) combinations involving bupivacaine (BPV [2]), ropivacaine (RPV [1]), or midazolam (MDZ [1,2]) with the following three preservative-free injectable drugs: clonidine, buprenorphine, and dexamethasone [1,2] (hereafter abbreviated as CBD). In addition, we provided clinical benchmark data for patients having received nerve blocks with combined BPV-CBD [3] and MDZ-CBD [4]). The chronological time frame for these previous clinical benchmark reports [3,4] was July 2011 through March 2014. The current report covers intermediate and long-term peripheral nerve injury (PNI) outcomes for n = 1830 patient-block encounters dating from July 2011 through December 2014. We define a “patient-block encounter” as a uniquely identified patient encounter receiving one or more nerve blocks on a specific day for pre- and intra-operative anesthesia/analgesia, immediate postoperative analgesia, or rescue postoperative analgesia on a day after surgery, typically during the same hospital stay. The blocks used for these 1830 patient-block encounters were composed primarily of BPV-CBD (n = 1726; 94.3%), or MDZ-CBD (n = 104; 5.7%). Patients who were having surgery related to a current or previous surgical site infection typically did not have blocks that included perineural dexamethasone (n = 109/1830, or 6%). The objective of this report is to present complication-related quality improvement (QI) data from our institution in the epidemiologic context of such data published elsewhere regarding the risk of PNI complications related to surgery itself (without specific nerve block considerations) or specifically related to nerve blocks typically using local anesthetics only (in the absence of multiple or any perineural adjuvants). In our institution (Veterans Affairs Pittsburgh Healthcare System, VAPHS), the lead author was charged with …