SHOCK
Shock is a condition in which the blood supply (which carries oxygen and nutrients) to various organs of the body is insufficient to meet metabolic demands. The signs and symptoms are restlessness, low blood pressure, weak and rapid (thready) pulse, altered mental status (restlessness, anxiety, confusion), moist and cool (clammy) skin, rapid shallow breathing, inability to control urination and bowel movements, nausea, and profound weakness. It is a life-threatening condition and may follow a large number of inciting events. Causes of shock include severe internal or external bleeding (25% to 30% acute loss of an adult’s total blood volume, equivalent to 1.5 to 2 liters out of 6 liters), overwhelming infection, burns, dehydration, heart attack or disease, hormonal insufficiency, hypoglycemia, hypothermia, hyperthermia, allergic reaction, drug overdose, and spinal cord injury (loss of sympathetic nervous system support allows blood vessels to dilate as they lose tone). If shock is caused by blood loss (hemorrhage), the following rough estimates apply:
1. Blood loss of 750 mL to 1 liter corresponds to heart rate (“pulse”) of up to 100 beats per minute and respiratory rate of approximately 14 to 20 breaths per minute. Blood pressure may remain normal.
2. Blood loss of 1 to 1.5 liters corresponds to heart rate greater than 100 and respiratory rate of 20 to 30. Blood pressure is decreased.
