Hypovolemia Definition and Meaning
According to abbreviationfinder, the term hypovolaemia describes a lack of volume in the circulatory system. This means that the amount of blood circulating is reduced. Hypovolaemia can result in life-threatening hypovolemic shock.
What is hypovolemia?
In hypovolemia, the amount of blood in the bloodstream is reduced. Hypovolaemia is the opposite of hypervolaemia. The amount of blood in the human body normally corresponds to seven to eight percent of body weight. A person weighing 70 kilograms has around five liters of blood. The loss of about 750 milliliters of blood is not in the critical range. The first symptoms appear from a loss of 1.5 liters. Loss of more than two liters of blood can be life-threatening.
The most common cause of hypovolemia is bleeding. A distinction can be made between internal and external bleeding. External bleeding bleeds out of the body, internal bleeding bleeds into the body. Severe bleeding can result from vascular injuries. Cut injuries to large arteries or the rupture of an aortic aneurysm can lead to hypovolemia within a very short time.
Bleeding in the gastrointestinal tract, for example due to ruptured ulcers or tumors, can also be so massive that hypovolemia occurs. Fractures of well-perfused bones also result in heavy blood loss. The amount of blood circulating is also reduced by the loss of plasma or fluids. Fluid losses occur with severe and persistent diarrhea or with profuse sweating. Plasma losses, on the other hand, are found in severe inflammation or extensive burns.
Symptoms, Ailments & Signs
In hypovolemia, the amount of blood in the bloodstream is reduced. Hypovolaemia is the opposite of hypervolaemia. The amount of blood in the human body normally corresponds to seven to eight percent of body weight.
Since there is not as much blood circulating in the blood vessels, the blood pressure drops. The blood pressure amplitude is small. The blood pressure amplitude is the difference between the systolic and diastolic blood pressure values. The normal blood pressure amplitude is around 40 mmHg. To compensate for the low blood pressure, the body increases the pulse rate. Nevertheless, there is usually insufficient blood flow to the periphery. The central venous pressure is reduced, the urinary excretion decreased.
If no liquid or no blood is substituted, sooner or later hypovolemic shock will occur. Hypovolaemia and volume depletion shock can be roughly divided into three stages. In the early stages, blood pressure is normal. The skin appears pale and is cool and clammy. Other signs of decompensation are not yet visible. In the second stage, tachycardia occurs . This means that the pulse rate is accelerated. The pulse is weak and therefore difficult to feel.
The systolic blood pressure falls below 100 mmHg. The urination decreases and the patients complain of severe thirst. The veins in the neck are no longer visible because they have collapsed due to the lack of fluid. In the third stage, massive signs of decompensation appear. The systolic blood pressure is below 60 mmHG, the pulse can no longer be felt. Breathing slows and gets faster. There is a loss of kidney function with anuria and disturbances of consciousness.
Diagnosis & course of disease
Symptoms of the cause provide the first indications of hypovolaemia. Open wounds may be visible, patients report diarrhoea, burns are visible or the pain indicates internal bleeding. A careful anamnesis is therefore obligatory. Symptoms such as cold sweats, sunken veins or a barely palpable pulse also indicate hypovolemia.
The so-called shock index is suitable for estimating the extent of hypovolemia. The heart rate is divided by the systolic blood pressure value. Values less than one are physiological. A shock threatens around the value one. All values greater than one can be taken as an indication of an overt shock.
In the worst case, hypovolemia can lead to death. The patient’s resilience is significantly reduced by the disease and there is a severe reduction in quality of life and limitations in everyday life. The low blood pressure can also lead to a loss of consciousness, in which case the patient can be injured by a fall or an accident.
Urine excretion is also reduced in the patient. The affected person often appears pale and exhausted and suffers from a general feeling of illness. Furthermore, there is a revered thirst. If left untreated, the kidneys can become damaged, resulting in kidney failure. The patient is dependent on dialysis or a donor organ. Disturbances of consciousness and coordination disturbances also occur.
The treatment is carried out with the help of infusions. Furthermore, the volume in the patient is increased again in order to avoid consequential damage. With early treatment, there are no complications. However, these can occur if the hypovolemia is not treated quickly enough. In the process, organs are irreversibly damaged, which in the worst case can lead to the death of the patient.
When should you go to the doctor?
Symptoms such as fatigue, exhaustion and low blood pressure can indicate hypovolemia. If these symptoms persist for more than two to three days and increase in intensity over time, medical advice is required. Severe thirst and disturbances of consciousness that cannot be attributed to any other cause must also be clarified by a doctor. This is especially true if the symptoms occur in connection with an injury in which the person concerned has lost a lot of blood.
If the blood pressure drops at the same time, a doctor must be consulted immediately. Otherwise, serious complications may arise. At the first sign of hypovolemic shock, an ambulance must be called. In any case, the affected person must be examined and treated in a hospital, whereby hypovolemia can usually be treated well. The prerequisite for this is that the lack of blood in the body is recognized and clarified at an early stage. In addition to the family doctor, a specialist in internal medicine can be consulted.
Treatment & Therapy
The aim of treating hypovolemia is to normalize the circulating blood volume. This is usually achieved by administering isotonic crystalline or colloidal infusion solutions. Hyperosmolar infusion solutions are also available for particularly rapid volume substitution.
Of course, not only the hypovolemia itself but also the cause of the volume deficiency must be treated. In the event of blood loss, the bleeding must be stopped as soon as possible. Bleeding wounds should be covered with a wound dressing if possible. In the case of heavy bleeding, a pressure bandage is usually applied first. If this does not stop the bleeding, it may be necessary to tie off blood vessels. After this initial treatment, severe bleeding is usually treated surgically. In addition to these therapies, over-acidification of the body is prevented by means of bicarbonate buffer solutions.
Due to the reduced blood flow in the kidneys and lungs, hypovolemia can result in shock kidneys or shock lungs. The shock kidney refers to kidney failure in the context of the shock event. Any reduction in urine volume during shock should consider a shock kidney.
Shock lung is also known as acute lung injury syndrome. A few days after the actual shock, pulmonary edema occurs with shortness of breath. Blue discoloration of the skin, restlessness and confusion can also occur.
In order to prevent hypovolemic shock, a balanced fluid balance should always be ensured. In the case of severe diarrhea or prolonged vomiting, sufficient liquid should always be substituted. Electrolyte solutions from the pharmacy are particularly suitable for this. In addition, a doctor should always be consulted in the event of persistent diarrhea, especially diarrhea in children.
The same applies to symptoms such as severe stomach or intestinal pain. An ulcer may be hiding behind this pain. If this ruptures, severe internal bleeding can occur. This can be prevented by early diagnosis and appropriate therapy.
There is no causal cure for hypotrichosis with juvenile macular dystrophy, but those affected can make their lives more comfortable with follow-up care. It is important to prevent physical injuries. The eyesight of the sick children is often impaired. Early treatment can slow down and perhaps even prevent the deterioration or blindness.
The attending physician often involves the patient in the active therapy and aftercare. The children feel motivated by the doctor’s recommendations to consistently keep to the treatment appointments. In order to accept the restrictions in everyday life, psychotherapeutic support is advisable.
This type of aftercare is particularly important for patients with deformed limbs. Long-term support from psychological caregivers is just as helpful as targeted physiotherapy. Physiotherapy exercises maintain the patient’s mobility.
Comprehensive measures related to aftercare also help to participate in social life. This is an important point for the affected children as well as for the whole family. Self-help groups and special care facilities provide the necessary support and offer patients good opportunities to lead a relatively independent life.
You can do that yourself
In the case of hypovolemia, the cause of the volume deficiency must first be treated. In the event of blood loss, the bleeding must be stopped immediately and the wound must be covered with a wound dressing if possible. Heavier bleeding should be stopped with a pressure bandage. In severe cases it is necessary to tie off the blood vessels.
If hypovolemic shock has already occurred, the casualty must be placed in the shock position. Elevating the legs allows blood to flow from the legs into the body and thereby regulates the blood volume in the upper body. The first responders should also call an ambulance.
The medical treatment of hypovolemia can be supported by a few hygiene measures and a change in lifestyle. In the first few days after the operation, the wound must be carefully tended to and closely monitored. If signs of infection or other complications become apparent, the person concerned should inform the doctor. The diet should be put together in such a way that any deficiency symptoms as a result of blood loss can be quickly compensated. Although infusions are usually given in the hospital, a supplementary diet is still useful.