Acute Post-Hemorrhagic Anemia

What is Acute Post-Hemorrhagic Anemia?

Acute post-hemorrhagic anemia is understood as anemia that has developed as a result of the rapid loss of a significant amount of blood.

In the mechanism of development of the main symptoms of acute blood loss, the leading role is played by a rapid decrease in the total volume of blood, especially its plasma. Reducing the volume of red blood cells leads to acute hypoxia, which is clinically manifested by the appearance of shortness of breath, palpitations.

Collapse (fainting) or hypotension (lowering blood pressure) are mainly caused by plasma loss. During and immediately after bleeding, adrenal glands of catechol amines are released, causing peripheral vasospasm. Reducing the volume of the vascular bed helps to compensate for the decrease in circulating blood volume. However, a long spasm of peripheral vessels adversely affects the microcirculation and can lead to the development of shock. One of the main mechanisms of self-regulation of the body is the restoration of blood volume by mobilizing its own interstitial fluid and its release into the bloodstream. This process is called autohemo modulation. If autohemiodiuosis is not sufficiently expressed or depleted, then decompensation occurs, and without treatment the patient dies. As a result of hypoxia associated with blood loss, the content of erythropoietin increases, resulting in an increased formation of cells sensitive to it and the release of reticulocytes.

Symptoms of Acute Post-Hemorrhagic Anemia

Acute post-hemorrhagic anemia causes primarily symptoms of collapse. The patient has severe weakness, dizziness, pallor, dry mouth, cold sweat, vomiting. Arterial and venous pressure decreases, cardiac output of blood decreases, pulse sharply increases. The filling of the pulse becomes weak.

The clinical picture is determined by the amount of blood lost, the speed of its expiration, and to some extent depends on the source of blood loss. There is evidence of unequal compensation depending on the source of bleeding.

To assess blood loss, it is recommended to use the formula:

P = K + 44lgIIIU,

Where P is the percentage loss of blood;

K is a coefficient equal to 27 for gastrointestinal blood loss, 33 for abdominal hemorrhages, 24 for injured limbs, and 22 for lesions of the chest;

SHI – shock index equal to the ratio of heart rate to systolic pressure.

In the first hours with a large blood loss, there may be a slight decrease in the level of hemoglobin and red blood cells, respectively, the hematocrit is not reduced (part of the blood volume falling on the shaped elements), and only a study of the volume of circulating red blood cells can reveal its significant decrease.

If the bleeding was stopped, then after 2-3 days there is a decrease in the level of hemoglobin and red blood cells due to the penetration of tissue fluid into the blood, so the first time after blood loss anemia has a normochromic character. The content of platelets in the period of bleeding may be reduced due to their consumption in the process of thrombus formation.

Clinical manifestations, supported by some laboratory data (samples of Gregersen, Weber, increased levels of residual nitrogen in case of bleeding from the upper digestive tract), are the basis for the diagnosis of latent massive bleeding.

Treatment of Acute Post-Hemorrhagic Anemia

Treatment of acute post-hemorrhagic anemia begins with stopping bleeding and carrying out anti-shock measures. Indications for blood transfusion in acute blood loss are: prolonged bleeding, a significant drop in the numbers of systolic blood pressure to 90 mm Hg. Art. and lower, increased heart rate compared with the norm by 20 beats per minute or more. Blood loss within 10-15% of the initial volume of circulating blood (BCC) does not require blood circulation, and the loss of even 25% of BCC requires only a small correction. Blood transfusions are transfused in patients with more than 25% blood loss. For replacement therapy use polyglukin in the amount of up to 2 l / day. In order to improve microcirculation, intravenous administration of reopolyglucin, gelatinol or albumin is used. Erythrocyte mass in the amount of 30–40% of blood loss should be used only after the restoration of blood circulation by filling the BCC with the above solutions. To improve the rheological properties of blood, the erythrocyte mass is diluted with reopolyglucine or 5% albumin solution in a 1: 1 ratio.

With massive blood loss, the rate of transfusion is important. Usually, the venous pressure is sharply reduced, the ulnar veins are collapsed, therefore, we should resort to the puncture of the subclavian veins or venosecals with the subsequent jet injection of solutions into 2-3 veins. It is necessary to emphasize the inadmissibility of replenishing all blood loss with blood in order to avoid the “massive transfusion syndrome”. It is also necessary to remember about the correction of plasma proteins, for which they use albumin or protein. In order to correct the water balance of the body, intravenous infusions of 0.9% sodium chloride solution, 5% glucose solution, Ringer’s solution – Locke are produced. Lactasol is used to normalize the blood pH.

Transfusion of whole blood, as a rule, is inexpedient.