Prediction of Packed Cell Volume after Whole Blood Transfusion in Small Ruminants and South American Camelids: 80 Cases (2006–2016)

Abstract

BackgroundCalculation of desired whole blood transfusion volume relies on an estimate of an animal's circulating blood volume, generally accepted to be 0.08 L/kg or 8% of the animal's body weight in kilograms.ObjectiveTo use packed cell volume before and after whole blood transfusion to evaluate the accuracy of a commonly used equation to predict packed cell volume after transfusion in small ruminants and South American camelids; to determine the nature and frequency of adverse transfusion reactions in small ruminants and camelids after whole blood transfusion.AnimalsFifty‐eight small ruminants and 22 alpacas that received whole blood transfusions for anemia.MethodsRetrospective case series; medical record review for small ruminants and camelids that received whole blood transfusions during hospitalization.ResultsMean volume of distribution of blood as a fraction of body weight in sheep (0.075 L/kg, 7.5% BW) and goats (0.076 L/kg, 7.6% BW) differed significantly (P < 0.01) from alpacas (0.103 L/kg, 10.3% BW). Mild transfusion reactions were noted in 16% of transfusions.Conclusions and Clinical RelevanceThe generally accepted value of 8% for circulating blood volume (volume of distribution of blood) is adequate for calculation of transfusion volumes; however, use of the species‐specific circulating blood volume can improve calculation of transfusion volume to predict and achieve desired packed cell volume. The incidence of transfusion reactions in small ruminants and camelids is low.

Crossmatching Maternal and Fetal Blood in Sheep

“…Outside of a research setting, intensive care of individual sheep, including the administration of blood transfusions, is not common. One recent retrospective study in sheep underemphasizes the incidence of transfusion reactions, 6 whereas another prospective study considers the risk of a reaction to be clinically important 16 despite reporting a similar incidence of incompatibility (16% to 17%). 1 These differences of opinion, in combination with our current results, reflect the need for comprehensive and detailed knowledge in this field.…”

“…4 In a clinical environment, crossmatching of donor and recipient blood in sheep is not considered necessary if the animal has not been transfused previously. 6 This practice is justified on the basis that crossmatching is time-and cost-prohibitive and that the incidence of transfusion reactions in small ruminants is low (16%). 6 One retrospective study reported that the administration of non crossmatched blood to small ruminants represents minimal risk for the recipient.…”

“…6 This practice is justified on the basis that crossmatching is time-and cost-prohibitive and that the incidence of transfusion reactions in small ruminants is low (16%). 6 One retrospective study reported that the administration of non crossmatched blood to small ruminants represents minimal risk for the recipient. 6 Other investigators emphasize the importance of pretransfusion compatibility testing in sheep, given the documentation of 17% incompatibility in a prospective study using saline and albumin agglutination methods.…”

“…6 One retrospective study reported that the administration of non crossmatched blood to small ruminants represents minimal risk for the recipient. 6 Other investigators emphasize the importance of pretransfusion compatibility testing in sheep, given the documentation of 17% incompatibility in a prospective study using saline and albumin agglutination methods. 16 To our knowledge, preterm and neonatal offspring of small ruminants that have received single or multiple blood transfusions have not been reported previously in the literature.…”

Anaemia in a llama (Lama glama): treatment, regeneration and differential diagnoses

“…In a retrospective study of 22 alpacas, the PCV before blood transfusion had a median of 8 per cent after transfusing blood (median: 28.1 ml/kg, median PCV of the donors: 30 per cent) and the median PCV was 16 per cent 44. In the present llama, the PCV increased from 6 to 10 per cent after transfusing 450‐ml blood, equivalent to 8.7 ml/kg, and after a second transfusion to 12 per cent (total amount of transfused blood from the first and second transfusion: 850‐ml blood, equivalent to 16.5 ml/kg).…”