Allergy to Ringer's Lactate - Uncommon Cause of Anaphylaxis during Intraoperative Period: A Case Report.

Perioperative anaphylaxis is a rare but potentially fatal event, with an incidence ranging from 1:300 to 1:20,000 surgeries and a mortality rate of 3-9%. Its intraoperative occurrence is diagnostically challenging due to patient sedation and overlapping drug effects. Crystalloids like Ringer's Lactate are rarely implicated. A 27-year-old American Society of Anesthesiologists grade I female undergoing mastoidectomy developed intraoperative hypotension, tachycardia, and generalized erythema after induction with standard anesthetics and Ringer's Lactate infusion. Anaphylaxis was suspected, and Ringer'Lactate was discontinued. The patient improved rapidly upon switching to normal saline. A subcutaneous challenge postoperatively confirmed Ringer's Lactate as the trigger. This case highlights an uncommon but serious hypersensitivity to Ringer's Lactate. Clinicians must maintain high suspicion for all agents, including crystalloids, during Perioperative anaphylaxis. Prompt recognition, discontinuation of the offending agent, and supportive treatment are crucial. Given the widespread use of Ringer's Lactate, awareness of this rare reaction is essential to prevent misdiagnosis and ensure patient safety.