2025 FSA Podium and Poster Abstracts

Serotonin syndrome is a life-threatening condition resulting from excessive serotonergic activity, typically due to the use of multiple serotonergic agents. This report presents a case of perioperative serotonin syndrome in a patient on multiple psychotropic medications undergoing elective surgery. The case highlights the diagnostic challenges, clinical manifestations, anesthetic implications, and management strategies. Increased awareness among anesthesia providers is critical to preventing, recognizing, and managing serotonin syndrome in the perioperative setting.

Introduction: Serotonin syndrome (SS) is a potentially fatal condition caused by excessive serotonergic activity in the central nervous system, often due to interactions between serotonergic medications. It is characterized by a triad of autonomic dysfunction, neuromuscular excitation, and altered mental status. In the perioperative setting, the risk of SS increases with the administration of certain anesthetic drugs, opioids, and antiemetics that modulate serotonin levels. This case highlights a perioperative presentation of SS and underscores the need for vigilance in patients taking multiple psychotropic medications.

Case Presentation: A 51-year-old female with a history of major depressive disorder, bipolar disorder, history of substance abuse, chronic back pain, and ADHD presented for elective hysterectomy. Her medication regimen included escitalopram, tramadol, Adderall, lithium, and occasional ondansetron and clonazepam. Preoperative evaluation revealed no acute concerns aside from a history of postoperative nausea following a laparoscopic cholecystectomy several years ago. Lab values were within normal limits, and preoperative ECG showed mild QTc prolongation but was otherwise normal.

A scopolamine patch was administered preoperatively, and 4 mg IV midazolam was given. Standard induction with propofol, fentanyl, succinylcholine, and lidocaine was performed without issues. Intubation was uneventful.

Intraoperatively, the patient developed tachycardia and hypertension, which were managed with opioids and deepening the sedation. Her temperature remained between 36 to 37°C, and end-tidal CO2 was normal throughout the case. Before emerging from anesthesia, she was noted to have rigid lower extremities with limited passive range of motion. She met extubation criteria and was extubated successfully.

In PACU, the patient reported significant nausea, which was treated with ondansetron and metoclopramide. Shortly thereafter, she exhibited additional signs and symptoms concerning for serotonin syndrome, including autonomic instability, neuromuscular hyperactivity, and altered mental status. She was admitted overnight for observation and supportive management.

Discussion: This case highlights the importance of recognizing serotonin syndrome in the perioperative setting, particularly in patients on multiple serotonergic medications. Factors contributing to SS include drug interactions (e.g., escitalopram, tramadol, ondansetron, and metoclopramide), intraoperative medication administration, and patient-specific vulnerabilities. Anesthesia providers must be aware of serotonin syndrome's clinical presentation and manage it promptly by discontinuing serotonergic agents, providing supportive care, and considering serotonin antagonists.

Conclusion: Serotonin syndrome should be considered in perioperative patients presenting with autonomic instability, neuromuscular hyperactivity, and altered mental status. Preoperative medication review and anesthetic planning are essential in preventing SS. A high index of suspicion and prompt intervention can prevent severe complications and improve patient outcomes.