The term hypovolemia refers to a lack of volume in the circulatory system. This means that the amount of blood circulating is decreased. As a result of hypovolemia, life-threatening hypovolemic shock can occur.
What is hypovolemia?
In hypovolemia, the amount of blood that is in the bloodstream is decreased. Hypovolemia is the opposite of hypervolemia. The amount of blood in the human body is normally equivalent to seven to eight percent of body weight. Thus, a 70-kilogram person has about five liters of blood. The loss of about 750 milliliters of blood is not in the critical range. The first symptoms appear at a loss of 1.5 liters. Losses of more than two liters of blood can be life-threatening.
Causes
Bleeding is the most common cause of hypovolemia. A distinction can be made between internal and external bleeding. External hemorrhages leak outward from the body, while internal hemorrhages bleed into the body. Drastic bleeding can result from injuries to vessels. For example, cuts to large arteries or rupture of an aortic aneurysm can cause hypovolemia within a very short time. Bleeding in the gastrointestinal tract, for example from ruptured ulcers or tumors, can also be massive enough to cause hypovolemia. Fractures of well-vascularized bones also result in severe blood loss. Loss of plasma or fluids also reduces the amount of circulating blood. Fluid losses occur with violent and prolonged diarrhea or profuse sweating. Plasma loss, on the other hand, is found in severe inflammation or extensive burns.
Symptoms, complaints, and signs
Because there is not as much blood circulating in the blood vessels, blood pressure drops. Blood pressure amplitude is small. Blood pressure amplitude is the difference between the systolic and diastolic blood pressure values. The normal blood pressure amplitude is about 40 mmHg. To compensate for low blood pressure, the body increases the pulse rate. Despite this, there is usually insufficient blood flow to the periphery. Central venous pressure is reduced, and urine output is decreased. If no fluid or blood is substituted, hypovolemic shock will occur sooner or later. Hypovolemia and volume deficiency shock can be roughly divided into three stages. In the initial stage, blood pressure is normal. The skin appears pale and is cool and moist. Other signs of decompensation are not yet evident. In the second stage, tachycardia occurs. This means that the pulse rate is accelerated. The pulse is weak and therefore poorly palpable. The systolic blood pressure drops to values below 100 mmHg. Urinary output decreases and patients complain of severe thirst. The jugular veins are no longer visible because they have collapsed due to the lack of fluid. In the third stage, massive signs of decompensation appear. Systolic blood pressure is below 60 mmHG, and the pulse is no longer palpable. Respiration flattens and becomes more rapid. There is failure of renal function with anuria and impaired consciousness.
Diagnosis and course of the disease
Initial clues to hypovolemia are provided by symptoms of the cause. Open wounds may be evident, patients may report diarrhea, burns may be visible, or pain may indicate internal bleeding. A careful history is therefore mandatory. 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. Here, the pulse rate is divided by the systolic blood pressure value. Values less than one are physiological. Around the value of one, shock is imminent. All values greater than one can be interpreted as an indication of manifest shock.
Complications
Hypovolemia can cause death in the worst case scenario. The patient’s ability to cope with stress is significantly reduced by the disease, and there is a severe reduction in quality of life and limitations in daily living. The low blood pressure can also lead to a loss of consciousness, during which the patient can injure himself through a fall or an accident. The patient’s urine output is also reduced. The patient often appears pale and listless and suffers from a general feeling of illness.Furthermore, there is a revered thirst. Without treatment, the kidneys can be damaged, resulting in renal insufficiency. In this case, the affected person is dependent on dialysis or a donor organ. Disturbances in consciousness and coordination also occur. Treatment is carried out with the help of infusions. Furthermore, the volume is also increased again in the patient 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 this case, 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, tiredness, and low blood pressure may indicate hypovolemia. If these symptoms persist for more than two to three days and increase in intensity as they progress, medical advice is needed. Severe thirst and impaired consciousness that cannot be attributed to any other cause must also be clarified by a physician. This applies in particular if the complaints occur in connection with an injury in which the affected person has lost a lot of blood. If there is a concomitant drop in blood pressure, a doctor must be consulted immediately. Otherwise, serious complications may arise. At the first signs of hypovolemic shock, the emergency physician must be called. In any case, the affected person must be examined and treated in a hospital, although 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 and therapy
The goal of treating hypovolemia is to normalize circulating blood volume. This is usually achieved with administration of isotonic crystalloid or colloid infusion solutions. Hyperosmolar infusion solutions are also available for particularly rapid volume substitution. Of course, it is not only the hypovolemia itself that must be treated, but also the cause of the volume deficiency. In cases of blood loss, bleeding must be stopped as soon as possible. Bleeding wounds should be covered with a dressing if possible. In the case of more severe bleeding, a pressure dressing 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, bicarbonate buffer solutions are used to prevent hyperacidity of the body. Due to the reduction in renal and pulmonary blood flow, hypovolemia can result in shock kidney or shock lung. Shock kidney refers to renal failure in the setting of shock. Any reduction in urine volume during shock should be considered shock kidney. Shock lung is also called acute lung injury syndrome. A few days after the actual shock, there is pulmonary edema with respiratory distress. Blue discoloration of the skin, agitation and confusion may also occur.
Prevention
To prevent hypovolemic shock, care should always be taken to maintain a balanced fluid intake. In cases of severe diarrhea or prolonged vomiting, adequate fluid should always be substituted. Electrolyte solutions from the pharmacy are particularly suitable for this purpose. In addition, a doctor should always be consulted in the event of persistent diarrhea and especially diarrhea in children. The same applies to symptoms such as severe stomach or intestinal pain. An ulcer may be hidden behind these pains. If this ruptures, it can lead to severe internal bleeding. This can be prevented by early diagnosis and appropriate therapy.
Follow-up care
There is no causative cure for hypotrichosis with juvenile macular dystrophy, but as part of follow-up care, affected individuals can make their lives more comfortable. Prevention of the physical damage is important. Frequently, vision is impaired in children with the disease. An early therapeutic approach can slow down the deterioration or blindness and perhaps even prevent it. The treating physician often involves the patients in active therapy and aftercare. Through the doctor’s recommendations, the children feel motivated to consistently keep their treatment appointments.In order to accept the limitations in everyday life, psychotherapeutic support is advisable. This type of aftercare plays a relevant role especially for patients with malformed limbs. The long-term support of psychological caregivers is just as helpful as targeted physiotherapy. Physiotherapy exercises help patients maintain their mobility. Comprehensive measures in connection with follow-up treatment 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.
Here’s what you can do yourself
When hypovolemia occurs, the cause of the volume deficiency must first be treated. If blood is lost, the bleeding must be stopped immediately and the wound covered with a dressing if possible. More severe bleeding should be stopped with the aid of a pressure dressing. In severe cases, it is necessary to tie off the blood vessels. If hypovolemic shock has already occurred, the injured person must be placed in the shock position. Elevating the legs allows blood to flow from the legs into the body, thereby regulating the volume of blood in the upper body. First responders should call an emergency physician to accompany this. Medical treatment of hypovolemia can be supported by some hygiene measures and a change in lifestyle. In the first days after surgery, the wound must be carefully cared for and well observed. If signs of infection or other complications become apparent, the patient should inform the physician. The diet should be composed in such a way that any deficiencies as a result of the blood loss can be compensated for quickly. Although infusions are usually started while the patient is still in the hospital, a supplemental diet is still useful.
