Perioperative echocardiography is an essential tool in the anesthetic management of the cardiac surgical patient. Moreover, echocardiographic skills and knowledge can be applied to patients irrespective of the nature of surgical procedure. Consequently, this text begins with a discussion about transesophageal echocardiography (TEE) and other echocardiographic modalities. Throughout this book, TEE will be employed to illustrate various cardiac pathologies and the anesthetic manipulations required to manage patients with a variety of cardiac conditions. TEE imagery will be integrated into the discussion and explanations of perioperative management much in the way that echocardiographic images are employed in routine, daily anesthetic practice. Although it is not the authors’ intention to write a definitive text of perioperative echocardiography, it is hoped that the reader will become sufficiently familiar with this valuable tool to appreciate how echocardiographic imagery can be mated with clinical knowledge and clinical experience to effectively manage the cardiac surgery patient.
WHAT CAN BE LEARNED FROM PERIOPERATIVE TRANSESOPHAGEAL ECHOCARDIOGRAPHY (TEE)?
Perioperatively, TEE is employed to help anesthesiologists, surgeons, and cardiologists answer questions about the heart’s structure and function. TEE guides diagnosis and therapy in a number of ways including:
Identification of the source of hemodynamic instability: TEE can detect myocardial ischemia, poor ventricular function, hypovolemia, and pericardial tamponade.
Determination of hemodynamic parameters: TEE can be used to determine stroke volume (SV) and cardiac output (CO) and can also be used to assess pulmonary arterial and intraventricular pressures.
Examination and confirmation of structural diagnoses: TEE helps to detect new pathology perhaps missed on previous examinations including patent foramen ovale, atheromatous aorta, or undiagnosed valvular heart disease. More likely, however, perioperative TEE will confirm the previous cardiac diagnoses.
Guidance and confirmation of the adequacy of surgical interventions: TEE is used to ascertain the success of valvular repair/replacement and to detect any unexpected surgical complications.
Diagnosis of postoperative hemodynamic instability: Echocardiography will readily reveal causes of postoperative hemodynamic instability secondary to pericardial tamponade; left, right, or biventricular failure; pulmonary embolism; aortic dissection; and other catastrophic perioperative events.
Throughout this text, echocardiography will be integrally linked to perioperative anesthetic management and its use in each of the ways described above will be illustrated. Moreover, just as in the operating room or intensive care unit, echocardiography will inform and illustrate appropriate medical decision making.
WHAT ECHOCARDIOGRAPHIC MODALITIES ARE EMPLOYED AND HOW CAN THEY BE USED?
TEE was introduced to operating rooms in the mid- to late 1980s. By the mid-1990s it had increasingly become a “routine” part of perioperative management.1 The National Board of Echocardiography (NBE) was subsequently established to credential and “certify” individuals in perioperative TEE. TEE is the echocardiographic modality most commonly associated with cardiac anesthesiologists. Anesthesiologists have subsequently expanded the use of TEE in noncardiac surgical suites and in the intensive care unit (ICU) (Figures Intro–1 and Intro–2 and Video Intro–1).