Normally, you can feel a patient s radial and carotid pulses. If the patient is unconscious or suffering from shock or both, it may be impossible for you to feel a radial pulse. If the patient appears to be in shock or is unconscious, attempt to locate the carotid pulse first. You should be able to locate the carotid pulse within three seconds of touching a person s larynx. Shock is defined as failure of the circulatory system.
Circulatory failure has many possible causes.
The three primary causes of shock are pump failure, pipe failure and fluid loss. Pump failure can result if the heart has been weakened by a heart attack. This causes blood to pool in the capillaries instead of circulating throughout the system. When blood pools in the capillaries, there is less circulating blood for the rest of the body. The heart and other vital organs are deprived of blood.