(A) VOLUME EXPANDERS:-
Because normal human blood has significant excess oxygen transport capability that is only used in cases of great physical exertion, patients can safely tolerate very low hemoglobin levels (about one-third in normal healthy patients). As such, a volume expander can be used to provide volume during surgical blood loss and can help prevent shock which is a alternative to blood transfusion; the remaining red blood cells can still oxygenate body tissue. Crystalloids and colloids are the two main types of volume expanders. These solutions are put right into the bloodstream through a vein. They boost fluid volume and help with circulation, but don’t carry oxygen or raise the number of blood cells.
(B) GROWTH FACTORS:-
Hematopoietic growth factors stimulate the bone marrow to make more blood cells. In patients with low blood counts, these agents can help increase the red blood cell, white blood cell, or platelet counts. Growth may help patients who would otherwise need transfusions.
But they have some drawbacks that may limit their use in some cases:-
(A) Unlike transfusions, growth factors can take many days or weeks to boost blood counts, thus they may be ineffective in patients who require their blood cell levels to be raised fast, such as those who are actively bleeding.
(B) People with severe bone marrow illness may not respond to growth factors because their bone marrow does not contain enough blood-producing cells.
(C) Certain growth factors may induce certain cancer cells (such as lymphocytic leukemia, multiple myeloma, head and neck cancer, breast cancer, cervical cancer, and some types of lung cancer cells) to grow quickly.
(D) Growth factors are typically far more expensive than transfusions.
Because of these drawbacks, some growth factors are not utilized in people whose treatment is expected to cure their cancer. And when they are used, they are given for as short a time as possible.
(C) INTRA-OPERATIVE OR POST-OPERATIVE BLOOD SALVAGE:-
Patients undergoing surgery may require transfusions to replenish blood lost during or after the procedure. This lost blood can sometimes be “salvaged” or preserved by collecting it with a special machine and re-injecting it into the patient.
It is a major form of autotransfusion. This alternative to blood transfusion eliminates the need and associated risk of giving a patient blood collected through blood donation of an unknown person. Autologous blood salvage is frequently used in cardiothoracic and vascular surgery, or in other surgeries in which blood loss is anticipated to be high. Autologous blood salvage is frequently used in cardiothoracic and vascular surgery, or in other surgeries in which blood loss is anticipated to be high.
It is a useful method in patients whose religious belief prohibits them from receiving an allogeneic blood transfusion. However, some studies have discovered tumor cells in blood salvaged during cancer operations, and this cannot be done for all patients. It is generally restricted to clean surgical fields and non oncologic procedures because of the risk of reinfusing bacteria or tumor cells into the patients. Several medical devices have been developed to assist in salvaging the patient’s own blood in the perioperative setting.
(D) BLOOD SUBSTITUTES:-
There is currently no real replacement for human blood. However, researchers are attempting to create a liquid that can carry oxygen and replace blood in some conditions, at least for a short time.
Some products being tested can perform some of the tasks of red blood cells, such as transporting oxygen to tissues, but they cannot replace the many other functions of human blood.