Prise en charge anesthésique d'un patient ayant un foramen ovale perméable

Patent foramen ovale (PFO) is frequent in patients scheduled for anaesthesia. Under controlled ventilation with positive ventilator pressure, patients are at risk of hypoxaemia due to right to left shunting and paradoxical embolism. In patients scheduled for neurosurgery in sitting position or cervical spine surgery, guidelines recommend to systematically check for PFO. Transthoracic echocardiography with contrast medium injection and Valsalva manoeuvre is the gold standard for PFO diagnosis. Patients with PFO and high risk of pulmonary embolism have to be monitored during surgery with a central venous catheter placed in the right atrial, and monitor of anaesthetic depth. Prevention of gas embolism is based on avoidance of hypovolaemia to maintain venous pressure. Pulmonary embolism is diagnosed on a dramatic decrease in end tidal CO2 values. When FOP is identified preoperatively, its closure has to be discussed, taking into account the risk of embolism related to surgery.