Hypotension

Abstract

Determining the cause of hypotension in the critically ill patient is essential for a rapid and appropriate therapeutic response. The relative contributions of left ventricular systolic dysfunction, excessive afterload, and inadequate preload are often unclear in these patients, even when invasive hemodynamic monitoring is utilized. Moreover, structural abnormalities amenable to surgical intervention may be undiagnosed. Recently, echocardiography has been shown to provide valuable information in the critical care setting with regard to volume status, contractility, and valvular function. Transthoracic echocardiography, although portable and inexpensive, often provides limited information in critically ill patients because of technical difficulties. Frequently, patients are mechanically ventilated with a limited acoustic window, or they cannot be positioned optimally for transthoracic imaging. In particular, although depressed left ventricular function is noted with both transthoracic and transesophageal echocardiography, significant right ventricular dysfunction is noticed only on transesophageal echocardiography in several patients. Transesophageal echocardiography should be strongly considered in the evaluation of the critically ill patient with unexplained hypotension.