The definition of the word "shock" is much different in the medical community than what the general public usually thinks when hearing the term. Typically, people use the word to describe a surprisingly intense emotional or psychological reaction to information or an occurrence. In the medical community, the word shock refers to a physical imbalance between the oxygen needed and the oxygen actually supplied to cells in addition to a lack of nutrients being delivered. This can cause cellular dysfunction, organ failure, and can eventually lead to death. There are four stages of shock:
Stage 1: Initial Stage of Shock
The first of the stages of shock is reversible, but there aren't any signs to indicate shock at this stage. Cells begin to change due to issues with perfusion and oxygenation. Perfusion is the method used by arteries to deliver blood to capillary beds in body tissues. Without this nutritive blood and an adequate oxygen supply, the cells switch to anaerobic metabolism, producing pyruvic and lactic acid.
Stage 2: Compensatory Stage of Shock
During the compensatory stage of shock, the body tries to reverse the results of the initial stage. Physiological, neural, hormonal, and biochemical reactions are employed to correct the imbalances. Hyperventilation is one such mechanism. This causes an increased rate of breathing which, in turn, may help to get more oxygen flowing to the cells and neutralize the newly acidic conditions.
Another mechanism is the catecholamine response. Hypotension, or low blood pressure, due to the reduced volume of blood flow triggers this response. Catecholamines are hormones released by the adrenal glands. These hormones increase heart rate and attempt to increase blood pressure.
A third mechanism used in the compensatory stage of shock is the renin-angiotensin response. During this response, a hormone called vasopressin is released into the bloodstream. Vasopressin helps to retain fluid and triggers vasoconstriction.
Stage 3: Progressive Stage of Shock
If the stages of shock progress to the third stage before the initial cause is corrected, damages become more severe and can be irreversible. Cellular function continues to deteriorate, anaerobic metabolism leads to increased metabolic acidosis, and the compensatory mechanisms can no longer maintain the balance required to protect the organs.
Stage 4: Refractory Stage of Shock
The stages of shock will eventually lead to the refractory stage if the cause of shock cannot be fixed. At this stage, the organs completely fail and lead to death. It is important to understand the stages of shock in order to recognize and prevent the progression to this final stage.