Serotonin syndrome triggered by postoperative administration of serotonin noradrenaline reuptake inhibitor (SNRI).

BACKGROUND: Serotonin syndrome is a rare but potentially severe disease, which is caused by hyperstimulation of serotonin receptors in the central nervous system. Several antidepressants exert their effect by modulating intrasynaptic serotonin concentration and anesthetics may affect the metabolism of serotonin, implicating to induce serotonin syndrome in patients taking those antidepressants. We present a case which provoked serotonin syndrome immediately after taking serotonin noradrenaline reuptake inhibitor (SNRI) in the postoperative period. CASE PRESENTATION: A 31-year-old female underwent laparoscopic ovarian cystectomy under general anesthesia with propofol, fentanyl, and remifentanil. She has been taking duloxetine, a SNRI for depression. She developed myoclonus seizure with an increase of blood pressure and heart rate after taking duloxetine on the day after the surgery, which was subsided by a non-selective serotonin receptor antagonist. CONCLUSIONS: Anesthesiologists should be aware of the risk of perioperative serotonin syndrome in patients taking antidepressants affecting serotonin metabolism.

Alteration of fatal 1:1 conducted atrial flutter to less conducted ratio by landiolol infusion.

An 84-year-old male patient with a past history of atrial-flutter-fibrillation and dementia underwent an urgent femoral neck fracture surgery. Preoperative electrocardiography demonstrated atrial flutter (AFL) with ventricular conduction at a ratio of 2:1-4:1, and transthoracic echocardiography showed severe left ventricular dysfunction with Ejection Fraction of 14.6 %. Femoral nerve block and Lateral femoral cutaneous nerve block with sedation was planned for the surgery. Upon entry to the operating room, ECG showed 2:1 conducted AFL at the rate of 128 beats min(-1). Due to the stimulation of urethral catheter insertion, it has altered to 1:1 conducted AFL. Loading dose of landiolol hydrochloride 7.5 mg followed by 1.5-3 µg/kg/min continuous administration was given, which had decreased the conduction ratio to 2:1 without causing hypotension. A further episode of 1:1 conducted AFL occurred when the pin was inserted to the thighbone, which caused circulatory collapse. Additional bolus dose of landiolol immediately altered it to 2:1 before operating cardioversion and stabilized the hemodynamics. He maintained AFL with 2:1 conduction thereafter, and 1:1 conduction was never seen postoperatively even after discontinuation of landiolol.

[Emergent operation for a patient of duodenal bleeding accompanied with fulminant myocarditis].

A 53-year-old woman developed general fatigue following an upper airway infection, which abruptly progressed to cardiogenic shock showing systolic blood pressure of 60 mmHg. An echocardiography revealed an ejection fraction of 0.11, diffuse severe hypokinesis and left ventricular thrombosis. Fulminant myocarditis was suspected, and intensive care including mechanical ventilation, intraaortic balloon pumping (IABP), catecholamine support and anticoagulation therapy was initiated immediately. Although the cardiac function gradually recovered, she developed a duodenal bleeding on the third therapeutic day. Factors such as low output syndrome, heparinization, steroid pulse therapy and platelet dysfunction due to IABP can enhance the hemorrhagic tendency. Since it was difficult to control bleeding by the endoscopy, blood transfusion was performed, and the operation was planned on the 13rd day when the cardiac function seemed to have recovered enough. The patient was anesthetized with ketamine, propofol and fentanyl. To maintain stable circulation, circulatory parameters such as blood pressure, central venous pressure, and cardiac output were monitored. After a preoperative consultation with the surgeon, the surgical technique had been preoperatively decided to reduce the surgical stress, and then partial duodenosectomy and gastro-jejunum anastomosis was performed. She was discharged on the 38th post operative day without complications. In cases of hemorrhagic disease accompanied by an acute phase of fulminant myocarditis, consultation among surgeons, cardiologists and anesthegiologists should be mandatory to determine the timing of the operation and to decide the degree of surgical invasion.