409: METHYLENE BLUE DOSE RESPONSE FOR VASOPLEGIC SYNDROME IN ADULT CARDIOTHORACIC SURGERY

Vasoplegic syndrome is a rising problem affecting morbidity and mortality in patients undergoing cardiac surgery. Vasoplegia is a vasodilatory, shocklike syndrome characterized by decreased systemic vascular resistance, normal to high cardiac index, and hypotension refractory to fluid resuscitation and vasopressors. This review describes the presentation, physiology, risk factors, treatments, and implications of vasoplegia after cardiac surgery. No standardized methods for diagnosing and treating vasoplegia are available. Vasoplegia is caused by surgical trauma, systemic inflammation, and vascular dysregulation. Patients with comorbidities and those undergoing complex surgical procedures are at increased risk for vasoplegia. The use of β-blockers is protective. Vasoplegia is potentially reversible. Vasopressin is likely the most effective first-line vasopressor, and the use of methylene blue and/or hydroxocobalamin may restore vascular tone. Alternative therapies such as methylene blue and hydroxocobalamin show promise, but additional research and education are needed.

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Serotonin Syndrome Following Methylene Blue Administration During Cardiothoracic Surgery

Journal of Pharmacy Practice ◽

10.1177/0897190014568389 ◽

2015 ◽

Vol 28 (2) ◽

pp. 207-211 ◽

Cited By ~ 18

Author(s):

Christina J. Smith ◽

Dorothy Wang ◽

Anna Sgambelluri ◽

Robert S. Kramer ◽

David J. Gagnon

Keyword(s):

Methylene Blue ◽

Serotonin Syndrome ◽

Artery Bypass ◽

Concomitant Administration ◽

Cardiothoracic Surgery ◽

Monoamine Oxidase A ◽

Toxic Encephalopathy ◽

Spontaneous Movements ◽

Surgery Patient ◽

Favorable Safety

Introduction: Despite its favorable safety profile, there have been reports of methylene blue-induced encephalopathy and serotonin syndrome in patients undergoing parathyroidectomy. We report a case of serotonin syndrome following methylene blue administration in a cardiothoracic surgery patient. Case Report: A 59-year-old woman taking preoperative venlafaxine and trazodone was given a single dose of 2 mg/kg methylene blue (167 mg) during a planned coronary artery bypass and mitral valve repair. Postoperatively, she was febrile to 38.7°C and developed full-body tremors, rhythmic twitching of the perioral muscles, slow conjugate roving eye movements, and spontaneous movements of the upper extremities. Electroencephalography revealed generalized diffuse slowing consistent with toxic encephalopathy, and a computed tomography scan showed no acute process. The patient’s symptoms were most consistent with a methylene blue-induced serotonin syndrome. Her motor symptoms resolved within 48 hours and she was eventually discharged home. Discussion: Only 2 cases of methylene blue-induced serotonin syndrome during cardiothoracic surgery have been described in the literature, with this report representing the third case. Methylene blue and its metabolite, azure B, are potent, reversible inhibitors of monoamine oxidase A which is responsible for serotonin metabolism. Concomitant administration of methylene blue with serotonin-modulating agents may precipitate serotonin syndrome.

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