Do Previous Multiple Scorpion Bites Produce Resistance to Local Anesthetics Administered Via Repeated Subarachnoid and Epidural Blocks? A Case Report and Review of Available Evidence

Introduction: Failure to achieve a subarachnoid block, even after a second attempt, and the inability to activate epidural analgesia, despite a properly placed catheter, can be both frustrating and perplexing. This case presents a situation where these incidents occurred, and two well-conducted attempts at a subarachnoid block and a properly placed epidural catheter block were unable to produce surgical anesthesia. Case Presentation: A 55-year-old female, classified as American Society of Anesthesiologists (ASA) grade II, was scheduled for a total abdominal hysterectomy with bilateral salpingo-oophorectomy. After adequate pre-operative preparation, an epidural catheter was inserted on the morning of surgery, followed by a subarachnoid block with all the proper precautions, which completely failed. After waiting for 10 minutes, the epidural block was activated with a local anesthetic mixture. To our surprise, it also did not produce any desirable effect, so the subarachnoid block was repeated, which again failed to produce any clinical block. Consequently, the surgery had to be conducted under balanced general anesthesia. Recalling previous experience and evidence, a history of scorpion bites was elicited. The patient had a history of multiple encounters (five) and was from a geographical area known to be endemic for scorpions. Conclusions: This case represents another instance of developing resistance to the effects of local anesthetics after exposure to scorpion venom. We believe there is a strong correlation between previous scorpion bites, the number of bites, and the duration between the most recent bite and the development of resistance to local anesthetic agents (LAAs). From a detailed search, it was evident that enough clinical evidence has emerged to irrefutably support this proposal.