Ultra-high pre-membrane lung oxygen saturation in a patient on veno-arterial extracorporeal membrane oxygenation

A 55-year-old man who suffered from acute myocardial infarction complicated with cardiogenic shock was administered veno-arterial extracorporeal membrane oxygenation. Ultra-high pre-membrane lung oxygen saturation of 93% was observed. Transthoracic echocardiography revealed the presence of patent foramen ovale. The four-chamber view showed that the tip of the cannula was located in the patent foramen ovale, which resulted in a left-to-right shunt. Without adjusting the position of the drainage cannula, the patient was weaned from extracorporeal membrane oxygenation at 136 hours after initiation and survived to hospital discharge.