Review the pathophysiology of shock in trauma.
Discuss the diagnosis and treatment of shock in the trauma patient.
Shock is a systemic disease caused by inadequate tissue oxygen delivery. Shock consists of both primary cellular injury due to hypoperfusion and the secondary inflammatory response that follows. Shock is a complication of many traumatic conditions and is the cause of up to half of all deaths from trauma: 40 percent due to acute hemorrhage and up to 10 percent due to multiple organ system failure long after the initial cause of shock has been controlled . This chapter describes the mechanisms of injury that lead to shock, the pathophysiologic progression of shock, the way in which shock is diagnosed and monitored, and the ways in which shock is treated. The chapter concludes with specific recommendations for resuscitation today, and a brief survey of therapies that will be important in years to come.
Shock may result from any traumatic or nontraumatic process that impairs the systemic delivery of oxygen, or that prevents its normal uptake and utilization. Table 3.1 lists the causes of shock in trauma patients, and although hemorrhage is the most common of these, it is by no means the only one. It is not unusual for shock to result from the combination of multiple triggers. Hemorrhage, tension pneumothorax, and cardiac contusion can all coexist in the patient with chest trauma, for example, with each contributing to systemic hypoperfusion.