Transoesophageal echocardiography as a clinical tool to maximise oxygen delivery intraoperatively in major high risk surgery

Intraoperative oxygen delivery should be able to meet the increased oxygen requirements, associated with major surgery and high risk surgery. The main factor which affects oxygen delivery intraoperatively is the stroke volume. This is affected by the volume status, fluid responsiveness, myocardial contractility, and afterload. The only clinical tool available at present, which can assess all these factors, some of the complicating factors, and the response to various measures seems to be intraoperative transoesophageal echocardiography. The views required are a high oesophageal view of the superior vena cava, the long axis view of the aortic valve, and the transgastric view of the left ventricle.