[Unexpected atrial fibrillation when monitoring in operating room. Case of the trimester].

A real case reported to the SENSAR database of incidents is presented. In a patient scheduled for nose fracture repair surgery an unexpected atrial fibrillation was found when monitored in the operating room. The operation was not delayed. After induction of general anaesthesia heart rate suddenly increased and hemodinamic situation was impaired. Cardioversion was required. Two electric countershocks were given but sinus rhythm was not restored. Heart rate was controlled with amiodarone infusion. Optimal defibrillation characteristics are described in these cases. Increased risk of thromboembolism (1-2%) following cardioversion is present even if atrial thrombi are ruled out. The mainstay therapies of are rhythm and rate control and prevention of thromboembolic complications. We describe recommendations on the management of these critical situations with emphasis in learning through the creation of protocols and training practice in simulation.