Haemorrhage is the escape of blood from the vascular system due to damaged blood vessels. When an artery, vein, or capillary wall is compromised, blood flows out into either the body cavities, hollow organs, or externally through a break in the skin. Maintaining vascular integrity is vital for tissue perfusion and cellular oxygenation throughout the human body.
Haemorrhage is classified based on the anatomical source of bleeding and the visibility of blood loss.
When significant blood loss occurs, arterial blood pressure drops, triggering baroreceptors in the carotid sinus and aortic arch. The autonomic nervous system responds by increasing sympathetic output. Heart rate and myocardial contractility rise to maintain cardiac output, while selective vasoconstriction shunts blood away from the skin, gut, and kidneys to prioritize vital organs like the brain and heart. Renin-angiotensin-aldosterone activation further retains sodium and water to preserve intravascular volume.
Haemorrhage stems from numerous traumatic and medical origins.
Assessing blood loss requires careful monitoring of vital signs, level of consciousness, and skin perfusion. Nurses categorize haemorrhage into classes based on the percentage of total blood volume lost. Early signs include tachycardia, mild anxiety, and cool, pale skin. As blood loss advances past thirty percent, systolic blood pressure plummets, urine output ceases, and confusion or lethargy sets in, signaling impending shock.
Immediate nursing care focuses on stopping the bleeding and restoring tissue perfusion. Direct pressure must be applied immediately to external bleeding sites, accompanied by elevation of the affected limb if appropriate. Nurses secure large-bore intravenous access to facilitate rapid fluid resuscitation and blood product administration. High-flow oxygen is administered to maximize oxygen delivery to ischemic tissues, while continuous monitoring of vital signs tracks the patient's stability.
When first-aid measures fail, definitive medical and surgical interventions become necessary. Transfusions of packed red blood cells, platelets, and fresh frozen plasma correct anemia and coagulopathies. Surgical exploration, vessel ligation, or cauterization directly seals bleeding sites within the operating theatre. Pharmacological agents such as tranexamic acid are often administered to inhibit fibrinolysis and stabilize newly formed blood clots.
Uncontrolled blood loss leads to severe systemic complications. Hypovolemic shock develops when tissue perfusion falls below critical levels, resulting in cellular hypoxia and multiple organ dysfunction syndrome. Prolonged ischemia damages the kidneys, causing acute kidney injury, while severe brain deprivation leads to irreversible neurological deficits. Additionally, massive transfusions can induce hypothermia, acid-base imbalances, and dilutional coagulopathy.