Acute loss of blood associated with surgery and traumatic accident or injury.
Acute blood loss does not cause immediate anemia.
Severe loss of blood amounting to more than 20% of the circulating blood volume reduces total blood volume and produces shock and other cardiovascular problems, along with oxygen impairment.
Severe acute bleeding can result in circulatory collapse.
Severe acute bleeding requires blood volume expansion.
With acute blood loss fluid from the extravascular space enters the circulation diluting red blood cells.
Acute blood loss of 500cc-1000cc associated with a 10-20% blood volume loss with few or no symptoms.
Acute blood loss of 1000cc-1500cc associated with 20-30% blood volume loss and is associated with no symptoms at rest, light-headedness in the upright position, with hypotension and tachycardia.
Acute blood loss of 1500cc-2000cc associated with a 30-40% blood volume loss and is associated with thirst, shortness of breath, impaired sensorium, decreased blood pressure, decreased cardiac output, decreased venous pressure, tachycardia, pallor, cold extremities and claminess.
Acute blood loss of 2000cc-2500cc associated with a 40-50% blood volume loss and is associated lactic acidosis, shock, irreversible shock and death.