- The perioperative TOE guide is a pocket-sized manual designed to provide a compact portable reference and tool for the perioperative echocardiographer and the critical care physician The perioperative TOE guide is a pocket-sized manual designed to provide a compact portable reference tool for the perioperative echocardiographer and the critical care physician. The guide is created in response to a need for a practical synopsis of the cardiovascular pathology in a dynamic environment like the operating room and the intensive care unit. All chapters are written by clinical experts in the field of transoesophageal echocardiography. This guide is endorsed by the European Association of Cardiovascular and Thoracic Anaesthesiologists EACTA.