Syncope Due to a Vasovagal Response for Drainage of Perianal Abscess Under Spinal Anesthesia: A Case Report

BACKGROUND Vasovagal syncope is a loss of consciousness caused by decreased arterial pressure and cerebral blood flow. The characteristic features of vasovagal syncope include cardiovascular inhibition caused by neural reflexes, accompanied by vasodilation and bradycardia. To date, there is little literature to report several episodes of syncope under spinal anesthesia during the perioperative period for drainage of an anal abscess. The purpose of this article is to alert clinical practitioners to the early identification of the underlying causes of vasovagal syncope and to facilitate timely and effective management strategies. CASE REPORT We present the case of a 44-year-old man with a perianal abscess who was scheduled for an incision and drainage procedure for the abscess under spinal anesthesia. Preoperative assessment revealed no history of cardiac disease, neurological disorders, or drug allergies. During the perioperative period, the patient experienced 3 episodes of syncope: 1 episode during puncture of spinal anesthesia, and the others at 6.5 h and 8.5 h after the procedure. The patient was discharged 4 days later, and a 30-day postoperative follow-up showed good recovery, without any episodes of syncope. CONCLUSIONS We described a case of 3 episodes of vasovagal syncope occurring in a patient during the perioperative period of drainage of perianal abscess under spinal anesthesia. Pain may have been the main cause of vasovagal syncope in this patient. To avoid vasovagal syncope, it is best for anesthesiologists to choose the lateral position to perform spinal anesthesia and to provide good perioperative pain management for these patients.