2022 FSA Podium and Poster Abstracts

P044: UNEXPECTED VAGAL EPISODE DURING NON-OBSTETRIC, NON-LAPAROSCOPIC ROUTINE PROCEDURE
Brian Cheung, MD; James Bolduc, DO; Emily Chung, DO; Nicholas Nedeff, MD; Kendall Regional Medical Center

Introduction: A 36-year-old male with no significant past medical history presents for an incision and drainage of a perirectal abscess. The only medication he was taking at home was Augmentin for his infection. He denied any history of smoking or alcohol/drug abuse. Denied any history of known drug allergies.

Methods: In the operating room, ASA standard monitors were placed the patient induced with fentanyl, lidocaine, and propofol. An LMA Classic size 5 was placed with an appropriate seal confirmed with end-tidal capnography and bilateral breath sounds. Return of spontaneous respirations occurred shortly after and the patient was placed on pressure support ventilation with an EtCO2 goal of 36-40. An upper b-air hugger was placed and the patient put into lithotomy position. Anesthesia was maintained with 1 MAC of sevoflurane at 2.1%. Upon surgical incision, there was a precipitous drop in blood pressure followed by elevations in peak airway pressures along with mild bradycardia. Bilateral breathe sounds revealed wheezing. Ephedrine and albuterol were administered with little effect. Surgical stimulation was stopped. Intraoperative pudendal nerve block was performed. Almost immediately after, vitals and airway pressures normalized. Surgery continued unremarkably. 

Results: He was transported to the post-anesthesia care unit and went on to make an uneventful recovery, discharged home the same day.

Discussion: This case describes an intraoperative vagal episode under general anesthesia as a response to extreme surgical pain. Under general anesthesia it may be difficult to make this diagnosis. The sympathetic response to pain is typically tachycardia and hypertension which is quickly resolved with boluses of fentanyl. 

Another differential to consider is an anaphylactic reaction, but given this diagnosis you would expect tachycardia with possible dermal/cutaneous findings.  

One could attempt to temporize the problem by administering an anti-cholinergic, such as atropine. The definitive treatment would be to stop all surgical insult until you get control of the underlying pain.