Intraoperative angioedema induced by angiotensin II receptor blocker: a case report.

Background: Angiotensin II receptor blockers are a class of antihypertensive agent that is developed to exclude the adverse effects of angiotensin converting enzyme inhibitors. However, as angiotensin II receptor blockers have begun to be more widely prescribed, cases of angiotensin II receptor blocker-induced angioedema have been reported. Rare cases of angioedema following surgery in patients using angiotensin converting enzyme inhibitors have been published.

Case presentation: A 38-year-old man with past history of hypertension was admitted for an elective lumbosacral spine surgery. He had been taking Valsartan 160 mg a day for the past 4 years.At the end of the surgical procedure and turning the patient into supine position, we noticed severe swelling in the neck and the face with.an edematous tongue, floor of the mouth, glottis, and supraglottic areas. A diagnosis of drug induced angioedema was made and intravenous dexamethasone, diphenhydramine and ranitidine were given. The patient remained intubated and was transferred to the intensive care unit. The valsartan was suspected to be the precipitating factor for the angioedema and was therefore discontinued.The swelling started to regress after 2 h, and resolved completely by the third day.

Conclusion: The precise mechanism of angiotensin II receptor blocker-induced angioedema is still unknown and should be thoroughly investigated. This report demonstrates a unique case of intraoperative angiotensin II receptor blocker-induced angioedema. Potential differential diagnoses of postoperative facial edema are discussed in detail, including the prolonged prone positioning for posterior spine surgery. Anesthesiologists should be aware of such rare, but potentially dangerous, perioperative adverse reaction that can occur with angiotensin II receptor blockers use.