Shock exists when the circulatory system fails to provide sufficient circulation to parts of the body.
Organs and tissues that do not receive sufficient fluids (blood and plasma) fail to perform due to inadequate cellular perfusion. There are several types of shock. Any significant injury causes some degree of shock. It may be slight and unnoticed, lasting only a moment, or it may be severe enough to cause death.
a. Hypovolemic Shock.
Hypovolemic shock results when there is a decrease in the volume of circulating fluids in the body. Hypovolemic shock is usually caused by severe bleeding (hemorrhaging) or severe loss of body fluids (dehydration) due to heat injury, severe burns (second- and third-degree burns on 20 percent or more of the body surface area), vomiting, diarrhea, or excessive sweating.
b. Other Types of Shock.
The following are types of shock that also result in inadequate cellular profusion.
(1) Metabolic shock. Metabolic shock is caused by a severe fluid loss due to an illness.
(2) Neurogenic shock. Neurogenic shock is caused by dilation of the blood vessels due to loss of nervous control over the vascular system. There is not enough blood and plasma in the circulatory system to fill the vessels even though no circulatory fluids have been lost.
(3) Psychogenic shock. Psychogenic shock (fainting) is caused by a temporary dilation of the blood vessels which results in a decreased blood supply to the brain.
(4) Cardiogenic shock. Cardiogenic shock is caused by a failure of the heart to pump sufficient blood.
(5) Septic shock. Septic shock is caused by a severe infection that attacks the blood vessels and causes them to loose circulating fluid.
(6) Respiratory shock. Respiratory shock is due to an insufficient amount of oxygen in the blood.
(7) Anaphylactic shock. Anaphylactic shock is caused by an allergic reaction to an insect sting, food, drugs, or other substance. In anaphylactic shock, the casualty’s skin may be flush, warm, itch, or break out. The face and tongue may swell and the lips turn bluish (cyanosis). The casualty may have difficulty in breathing, cough, or have pain in the chest. The blood pressure drops and pulse becomes weak, which results in faintness or coma.