ABSTRACT. Objective. Echocardiography can be a rapid, noninvasive, objective tool in the assessment of ventricular function and preload during resuscitation of a critically ill or injured child. We sought to determine the accuracy of bedside limited echocardiography by the emergency physician (BLEEP) in estimation of (1) left ventricular function (LVF) and (2) inferior vena cava (IVC) volume, as an indirect measure of preload.Methods. We conducted a prospective observational study of a convenience sample of patients who were admitted to our intensive care unit. All patients underwent BLEEP followed by an independent formal echocardiogram by an experienced pediatric echocardiography provider (PEP). H ypotension is observed in late decompensated shock. It occurs when compensatory mechanisms that maintain end-organ perfusion fail. Although shock can be broadly categorized into hypovolemic, cardiogenic, septic, or distributive, there is considerable overlap in clinical presentation and underlying pathophysiology. 1,2 Varying degrees of relative or absolute hypovolemia and myocardial dysfunction may exist in each category, particularly in sepsis. 3 Similarly, although hemorrhagic (hypovolemic) shock is most common in the severely traumatized patient, neurogenic shock (secondary to severe craniospinal injury), obstructive shock (from pericardial tamponade), or cardiogenic shock (secondary to myocardial contusion) may coexist in polytrauma.Critically ill or injured patients are being cared for in the emergency department (ED) with increasing frequency. Furthermore, there has been a 152% increase in the number of patients with ED length of stay of Ͼ6 hours from 1988 to 1997. 4,5 This reality necessitates provision of critical care in the pediatric ED. In a recent study of management of pediatric-neonatal septic shock referred from community hospitals to a referral urban pediatric center, 91 patients were identified during a 9-year period. 6 In a database of severely injured children who presented to the ED at a level 1 pediatric trauma center, using initial base deficit as a marker of tissue hypoperfusion and shock, 117 patients were identified during a 6-year period. 7 We are also an urban, tertiary-level regional pediatric referral center with an annual ED census of 80 000 visits. Most initial encounters of hemodynamically unstable patients mandate prompt goal-directed resuscitation. The exact cause and underlying pathophysiology of shock are not immediately evident in most clinical situations. We speculate that bedside limited echocardiography by the emergency physician (BLEEP) would be useful in 2 to