Shock is defined as a situation where oxygen transport is inadequate to meet the body's oxygen demand. An understanding of the mechanism(s) of reduced cardiac output, a determinant of oxygen transport, is crucial in order to initiate appropriate therapy to manage shock. Combining the concept of venous return with the ventricular pressure-volume relationship is a useful method to appreciate the complex circulatory physiology of shock. Clues from the patient's history, physical examination, and key laboratory tests, along with the careful inspection of hemodynamic, electrocardiographic and respiratory waveforms can help with the identification of the etiology and mechanism(s) of shock. Following verification of the arterial pressure, general resuscitation can begin, and more specific treatment can be undertaken to manage shock. If the patient is unresponsive to these measures, bedside ultrasound can then be performed to ascertain more detail regarding the mechanism(s) and etiology of shock.
Purpose: To develop an approach to the management of the hemodynamically unstable patient.
Principal finding: Not applicable.
Conclusion: Not applicable.