Hemorrhages - First Aid

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First aid

First aid

hemorrhage

What are they What to do Nasal haemorrhage (epistaxis) Cough haemorrhage (hemoptysis) Vomiting haemorrhage (hematemesis) Vaginal haemorrhage (menometrorrhagia) Intestinal haemorrhage (enterorrhage)
  • What are they
    • Signs and symptoms
  • What to do
  • Nasal bleeding (epistaxis)
  • Cough bleeding (hemoptysis)
  • Vomiting bleeding (hematemesis)
  • Vaginal bleeding (menometrorrhagia)
  • Intestinal bleeding (enterorrhage)

What are they

Hemorrhage is a leak of blood from the cardiovascular system. In order for bleeding to occur, a full-wall injury to a vessel (arterial or venous) or heart must occur. Furthermore, it is necessary that, in correspondence with the lesion, the pressure of the circulating blood exceeds the pressure of the environment, so that it can pour out. This clarification may appear superfluous if referred to the bleeding that occurs on the surface of the body (external bleeding), since the blood pressure, in any artery or vein, is generally higher than atmospheric. However, it should be considered that bleeding also occurs within the body (internal bleeding), where the pressure of the tissues can be higher than atmospheric and can therefore limit the leakage of blood from the injured vessels. For example, in large muscle masses, which are highly stressed during exertion, injuries of small vessels often occur, without however appreciable bleeding being observed. The blood, in this case, has difficulty making its way into the muscular interstice, compressed by sheaths, ligaments and tendons. For the same reason, we are able to stop external bleeding when we apply pressure on the bleeding skin lesion that is higher than the pressure with which the blood is "pushed" out. But, exactly, with what pressure is the blood "pushed out" of a vessel? The average blood pressure flowing in the venules is 10 mmHg higher than atmospheric (from now on, for simplicity, we will simply say that it is "10 mmHg"), while in the arterioles it is 90 mmHg during cardiac systole and 70 mmHg during diastole. It is therefore clear how much easier it is to stop a hemorrhage that comes from a venous vessel (venous hemorrhage) than an arterial hemorrhage: the external pressure to be applied to offset the blood flow is in fact much lower. It is also clear why venous hemorrhages appear as slow superficial blood spills, while in arterial hemorrhages the blood spurts out of the wound with intermittent sprays that can even reach several centimeters in height, perfectly synchronized with the heartbeats. This characteristic means that, for the same size of the vascular lesion, the loss of blood in a given period of time is much higher in arterial bleeding than in venous bleeding.

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Signs and symptoms

External bleeding is evident from the leakage of blood from a skin lesion. Internal bleeding, even serious, can remain hidden even for hours, dangerously delaying therapeutic interventions. If internal bleeding occurs in a cavity communicating with the outside (e.g. the digestive tract, bladder, uterus, bronchi) the lost blood can become visible if it is expelled, for example from the stomach with vomiting (hematemesis), from the intestine with feces (hematochezia, melena), from the bladder with urine (hematuria), from the bronchi with cough (hemophtoe, hemoptysis), or from the vagina (metrorrhagia). On the contrary, in bleeding in closed cavities, such as the abdomen (hemoperitoneum), the pleura (hemothorax), the pericardium (hemopericardium), the cranial cavity (cerebral hemorrhage), the blood remains hidden inside the body and its escape it can only be suspected because it occupies spaces normally destined for other organs, disturbing their functioning. For example, hemothorax compresses the lung, causing breathing difficulties; Cerebral hemorrhages compress the brain resulting in neurological disorders. Moreover, if the blood collection compartment is very large and contains organs that can at least partially give up the space they occupy (as in the abdominal cavity, in which the intestine can be compressed and moved without any damage), the bleeding can remain asymptomatic (or almost), at least until it reaches a certain entity. In fact, regardless of where they occur, large bleeding always causes general symptoms, due to the progressive decrease in the volume of circulating blood (hypovolemia). Blood losses of less than 15% of the total blood mass cause few disturbances; however, if the loss reaches 15% -30% an increase in heart rate and respiratory rate is observed, the skin becomes pale, especially at the extremities, and diuresis contracts (oliguria). These manifestations can be interpreted as attempts by the body to "make the best use of the little blood left": the heart and breath accelerate, to guarantee acceptable nourishment and oxygenation to the tissues; the cutaneous and muscular vessels narrow (vasoconstriction) to divert their blood to more critical organs for survival; the kidneys retain as much water as possible, in order to increase the volume of circulating blood. An even higher loss, between 30% and 40%, leads to marked tachycardia and tachypnea, cold sweating, drop in blood pressure, weakening of the wrists, anxiety and mental confusion, due to the poor blood supply of the brain. If more than 40% of the circulating blood is lost, hypovolemia becomes critical for survival (hypovolemic hemorrhagic shock): the wrists disappear, the patient becomes lethargic or comatose, the kidneys stop producing urine and death can occur.

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