Critically ill patients need urgent diagnostic evaluation and expedient, appropriate intervention to improve the course of disease and chance of survival. Often their clinical condition and medical environment (e.g., respirator, multiple intravenous lines, cardiac monitoring) limit diagnostic options, because transport involves major effort and risk. Therefore, echocardiography has become extremely popular because of (1) bedside mobility, (2) high-quality imaging, (3) noninvasive nature, (4) immediate on-line image analysis, and (5) extensive yield of data, including structural, functional, and hemodynamic information. In addition, transesophageal echocardiography (TEE) has increased the quality of studies in patients on respirators, with chest injuries requiring chest tubes, or surgical wounds of the chest, all of which limit the transthoracic windows.
How important is an echocardiography study in a critically ill patient?
The bedside echocardiography study gives immediate data to direct management strategies. The extensive differential diagnosis of hemodynamic instability includes critical valve disease, intracardiac shunt, cardiomyopathy, and tamponade, all of which are easily diagnosed with echocardiography and require different management despite similar clinical presentations. Therefore, emergent echocardiography is important to help to eliminate several of the possible etiologies and either to make the diagnosis or to establish a foundation for initial management.
Are different risks or procedural problems involved in the use of TEE in critically ill patients?
TEE is semiinvasive. Passing the probe into the stomach of critically ill patients requires more experience and manual guidance. The patient may be agitated, unable to cooperate and confined to the supine position. Adequate sedation and prophylaxis for endocarditis in patients with prosthetic valves are necessary before passage of the probe. Problems with hemodynamically unstable and critically ill patients are uncommon, except in the presence of extensive neck and facial trauma. A laryngoscope is often helpful if the procedure proves difficult. Although patients are often hemodynamically unstable, clinically significant complications are rare. TEE should be performed by a cardiologist ready to manage hemodynamic deterioration, fully trained in endoscopic intubation procedures, and experienced in TEE interpretation.