2 The Practice of Transfusion Medicine in Bovines

Transcript

Greetings

My dear veterinarians, in the last class we saw about how to evaluate Anemia. Now once anemia is confirmed then our the next point is we need to go for a treatment options in the therapeutic drugs. Sometimes if it is a mild anemia your drug therapy will help. Now if it is a severe one you need to go for Transfusion.

How to do transfusion in the large animal practice? So that is what this class will be describing about. Now basically, why we need transfusions? Whenever there is acute disease acute hemolysis, acute hemorrhage there will be volumes of volumes of blood that will be lost. So, in such cases we need to have transfusion and whenever there is a chronic anemia then there is a best way is to go for a blood transfusion. Animals with hemostatic disorders which may not often get responded to regular drug therapy so, they require blood transfusion and whenever there is a critical care acute care is needed many of the patients will be requiring blood transfusion.

Now what are the indications for the acute hemorrhage because acute hemorrhage is the one wherein, we need to go for a blood transfusion. Do acute hemorrhage could be caused by the rupture of the vessels during caesarian section, whenever there is any complications or umbilical muscle damage in case of calfs, some sort of trauma, or accident and then some surgical procedures where unexpectedly some bleeding happens or the vessel get cut we are unable to control. So, these are the ones that causes acute hemorrhages. When the ulcer in the abomination is severe enough that may also cause acute hemorrhages. Similarly, Tick born protozoa diseases. Sometimes massive anemia can come even with the Tick born diseases. Then whatever pathologies that causes acute destruction of the erythrocytes all of these are the causes for the acute hemorrhage.

Similarly, chronic hemorrhage basically Parasites are the one that causes the chronic hemorrhage the best example is the Haemonchus then Strongyles species that causes a typical white mucous membrane, there is not even a small sign of pink. Similarly, hemolysis this is caused by blood parasites – Theileria, plasma everything. The other important thing especially in case of buffalos Post-Parturian Hemoglobin- uria. This also produces the anemia. Then Bacillary Hemoglobinuria.

Now all these cases in bovine practice the most commonest thing is whole blood transition. In small level practice we go with blood component therapy like a separate RBC, separate platelet, separate plasma this can be used. For largen your practice because high volume of blood is needed many of the time it is the whole blood transfusion that is happening. So, this is the blood bags available for large animals. In some of the countries larger blood bags are also marketed in India too we have large animal thing, okay. Now the advantage is that it gives some amount of relief and oxygen carrying capacity supports the oxygen carrying capacity. Sometimes, if we need only RBC we can do that. So, when to use RBC transfusion? The decision to transfuse RBCs is always determined by the clinical science and not by any pre[1]selected or predetermined PCV levels. The acute anemia cases will show weakness, tachycardia, tachypnea even at a higher PCV than animals with the chronic anemia. So, the amount of RBCs is required to alleviate clinical sign will generally increase the PCV above 20 percent.

Sometimes we can even go with the platelet and plasma transfusion. Platelet numbers will rise rapidly after hemorrage so many of the times platelet may not totally be required because they somehow manage and increase their count. Plasma that helps to equilibrate the interstitial space unless there is a massive hemorrhage plasma is not generally required and where the plasma is most useful those with coagulation disorders that will be benefited by your plasma therapy especially those with von Willebrand factor deficiency whereas the plasma therapy will be most useful. The other component therapies use of platelets or platelet-rich plasma. In case of thrombocytopenia this will be of use, in case if it is immune mediated you cannot expect much relief from that.

Now, what is the basic Blood Volume? Domestic animals will have about seven to nine percent of their body weight i.e., the Blood Volume. So by determining the recipient’s Blood Volume and knowing the animals PCV the requested replacement of RBC can be calculated and always never collect more than 20 percent of a donor’s blood so, that is the most important thing. Whenever you are collecting never collect more than 20 percent of the donors Blood Volume. Some of the facts which you need to keep in mind for your Clinical practice is the normal blood volume is eight percent of the body weight and, the adult bovine PCV is like 24 to 43 percent and Haemorrhagic shock may happen when there is 30 to 40 percent of the total blood volume. Blood Volume is lost many times a cow with a PCV of 10 percent would have lost almost two thirds of the circulating red cells. still the animal may be standing. So, these are sometimes misguiding us. Now if we are using one liter of blood this may raise PCV sometimes by 75 percent, it depends on the case varies from case to case. The clinical difference between a cow with a PCV of 8 percent and another cow with 14 percent is always highly remarkable and the red cell turnover happens probably once in two to three days. But what is the most important thing is whenever you are using a repeated transfusion, second transfusion that may end up in the transfusion reactions. And the most important thing is red cell survival happens only for few hours so, within which it has to improve.

So, with this in this presentation we saw about basics of the Blood Transfusion for a large annual practice. So, what are the basic Clinical Facts you need to know before moving into the actual transfusion practice and there are reading materials available you can refer them if you have any query kindly contact us.

Thank You