Use of blood and blood products

It is sometimes necessary for the practitioner to transfuse the ruminant with whole blood or plasma. These techniques are often difficult to perform in practice and are time-consuming, expensive, and stressful to the animal. Acute loss of 20-25% of the blood volume will result in marked clinical signs of anemia, including tachycardia and maniacal behavior. The PCV is only a useful tool with which to monitor acute blood loss after intravascular equilibration with other fluid compartments has occurred. An acutely developing PCV of 15% or less may require transfusion. Chronic anemia with PCV of 7-12% can be tolerated without transfusion if the animal is not stressed and no further decline in erythrocyte mass occurs. Seventy-five per cent of transfused bovine erythrocytes are destroyed within 48 hours of transfusion. A transfusion rate of 10-20 ml/kg, recipient weight, is necessary to result in any appreciable increase in PCV. A nonpregnant donor can contribute 10-15 ml of blood/kg body weight at 2-4 week intervals. Sodium citrate is an effective anticoagulant, but acid citrate dextrose should be used if blood is to be stored for more than a few hours. Blood should not be stored more than 2 weeks prior to administration. Heparin is an unsuitable anticoagulant because the quantity of heparin required for clot-free blood collection will lead to coagulation defects in the recipient. Blood crossmatching is only rarely performed in the ruminant. In field situations, it is advisable to inject 200 ml of donor blood into the adult recipient and wait 10 minutes. If no reaction occurs, the rest of the blood can probably be safely administered as long as volume overload problems do not develop. Adverse reactions are most commonly seen in very young animals or pregnant cattle. Signs of blood or plasma transfusion reaction include hiccoughing, tachycardia, tachypnea, sweating, muscle tremors, pruritus, salivation, cough, dyspnea, fever, lacrimation, hematuria, hemoglobinuria, collapse, apnea, and opisthotonos. Intravenous epinephrine HCl 1:1000 can be administered (0.2 to 0.5 ml) intravenously or (4 to 5 ml) intramuscularly if clinical signs are severe. Pretreatment with antipyretics and slowing the administration rate may decrease the febrile response. Blood or plasma administered too rapidly will also result in signs of cardiovascular overload, acute heart failure, and pulmonary hypertension and edema. Furosemide and slower administration of blood or plasma should alleviate this problem.(ABSTRACT TRUNCATED AT 400 WORDS)     

Red blood cell transfusions in cats: 126 cases (1999)

OBJECTIVE: To determine the number of and reasons for RBC transfusions, incidence of acute transfusion reactions, prevalence of blood types, volume of blood administered, change in PCV, and clinical outcome in cats. DESIGN: Retrospective study. ANIMALS: 126 cats that received RBC transfusions. PROCEDURE: Medical records of cats that received whole blood or packed RBC transfusions were reviewed for signalment, blood type, pre- and post-transfusion PCV, volume of blood product administered, clinical diagnosis and cause of anemia, clinical signs of acute transfusion reactions, and clinical outcome. RESULTS: Mean volume of whole blood administered i.v. was 172 mL/kg (7.8 mL/lb) versus 9.3 mL/kg (4.2 mL/lb) for packed RBCs. Ninety-four percent of cats had blood type A. Mean increase in PCV among all cats was 6%. Fifty-two percent of cats had anemia attributed to blood loss, 10% had anemia attributed to hemolysis, and 38% had anemia attributed to erythropoietic failure. Acute transfusion reactions occurred in 11 cats. Sixty percent of cats survived until discharge. CONCLUSIONS AND CLINICAL RELEVANCE: RBC transfusions resulted in an increase in PCV in cats with all causes of anemia in this study. The rate of death was greater than in cats that did not receive transfusions, but seriousness of the underlying disease in the 2 groups may not be comparable. Death rate of cats that received transfusions was not attributable to a high rate of transfusion reactions. Results confirm that pretransfusion blood typing or crossmatching is required to minimize the risk of adverse reactions.     

Effects of a polymerized ultrapurified bovine hemoglobin blood substitute administered to ponies with normovolemic anemia

The development of ultrapurified hemoglobin-based oxygen carriers has eliminated many problems associated with whole-blood transfusions in other species. We hypothesized that the administration of polymerized ultrapurified bovine hemoglobin (PUBH) would result in improved hemodynamic parameters in ponies with normovolemic anemia without adverse effects on renal function or coagulation times. Normovolemic anemia was induced in 6 healthy adult ponies. Over a 3-day period, at least 45 mL/kg of whole blood was withdrawn from each pony until a target PCV of <12% was attained. Plasma was separated from the red blood cells via centrifugation and readministered to the ponies on each day. After the final plasma transfusion, 15 mL/kg of hetastarch (control, n = 6) or 15 mL/kg of PUBH (treatment, n = 6) was administered at 10 mL/kg/h IV. Administration of PUBH at a rate of 10 mL/kg/h was not associated with any adverse effects in 5 of the 6 ponies. One pony experienced an anaphylactoid reaction during infusion of PUBH. The reaction, characterized by intense pruritus, tachycardia, and tachypnea resolved shortly after stopping the infusion. Ponies receiving PUBH had significantly lower cardiac indices (P = .03) and heart rates (P = .002) than control animals. A significantly greater increase in central venous pressure was observed in the PUBH group compared to the hetastarch group (P = .02). No adverse renal or coagulation effects were observed with PUBH infusion. These results suggest that PUBH improves hemodynamics and oxygen transport parameters in horses experiencing normovolemic anemia. Patients should be monitored closely during infusion for any adverse reactions.     

Evaluation of an 18-micron filter for use in reptile blood transfusions using blood from American alligators (Alligator mississippiensis)

Blood transfusions are a common therapeutic procedure in small animal medicine and have been investigated in some exotic species but little information is available about their safety and efficacy in reptiles. In human pediatrics and small animal practice, the Hemo-Nate18-micro filter is used to prevent embolic clots and particulate waste from entering the recipient during a transfusion. The goal of this study was to determine the hemolytic effect of an 18-micro Hemo-Nate filter for whole blood cell transfusions in reptiles using the American alligator (Alligator mississippiensis) as a reptilian model. Results revealed no significant difference in free plasma hemoglobin between the unfiltered and filtered samples (P = 0.21). There was no difference in the prefiltration and postfiltration packed cell volume (PCV) (P = 0.41). Results suggest that an 18-micro Hemo-Nate filter does not cause hemolysis or decrease the PCV of small quantities of alligator blood.     

Hematology, blood typing, and immunology of the neonatal foal

Hematologic parameters change during the first 10 days of life. Erythrocytes increase in number but decrease in size and hemoglobin concentration. The PCV, hemoglobin, and platelet count also decrease. Total blood and plasma volume and, to lesser extent, erythrocyte volume decrease. Normal neonatal foals may have immature neutrophils (up to 5 per cent bands), and their early rapid rise in neutrophil numbers may be accompanied by a lymphopenia. Monocytes, eosinophils, and basophils are all absent or low initially. Infectious processes can cause rapid and variable changes in the leukogram. However, elevation of fibrinogen levels may lag behind the development of an inflammatory process, and this parameter should not be relied on for early evidence of infection. After 12 hours of life, there is generally a decrease in serum concentrations of Na, Cl, iron, creatinine, BUN, plasma protein, and possibly calcium. LDH, SAP, P, bilirubin, and glucose concentrations are all higher in foals than in mature horses. Creatinine may actually be elevated during the first 12 hours of life and then decreases. If azotemia, hypochloremia, hyponatremia, and hyperkalemia are found, ruptured bladder with uroperitoneum should be suspected. The creatinine concentration is preferable to BUN determination for diagnosis of this condition. Blood typing is useful for diagnosis of NI, determination of blood compatability between donor and transfusion recipient, and for verification of parentage for breed registries. Several techniques are available. Several tests are available for evaluation of the foal's immunoglobulin levels and confirmation of passive antibody transfer. Because foals suffering from FPT are more predisposed to infections, their immunoglobulin status should be determined as early as possible so that additional colostrum or plasma can be administered as needed. Neonatal isoerythrolysis is uncommon but is an important immunologic syndrome that often results in a fatal hemolytic crisis. If one suspects the condition may be likely, the optimal time for testing the mare is during the last 2 weeks of gestation. If the foal's dam is shown to have alloantibodies against a panel of known erythrocyte alloantigens, prevention is possible by feeding colostrum from another mare. If a foal develops NI, further colostrum ingestion from the dam must be prevented. Good nursing care, minimizing stress, and adequate frequent feedings are essential; prophylactic antibiotics should be used, and transfusion may be necessary.     

A newly recognized blood group in domestic shorthair cats: the Mik red cell antigen

BACKGROUND: Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions. HYPOTHESIS: Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen. METHODS: Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used. RESULTS: Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar. CONCLUSIONS AND CLINICAL IMPORTANCE: The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion.     

Effects of blood collection for transfusion on arterial blood pressure, heart rate, and PCV in cats

BACKGROUND: Collection of 50 mL of blood (standard unit) in cats is a common procedure. There are several studies on the health status of donors, but to our knowledge there are no reports on the effects of blood collection on the feline donor. HYPOTHESIS: Collection of a standard unit of blood from cats does not significantly change arterial blood pressure (BP), mean arterial pressure (MAP), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), PCV, and heart rate (HR) in healthy blood donor cats. ANIMALS: Twenty-six healthy blood donor cats (6 spayed females and 20 castrated males). METHODS: An oscillometric method was used to measure MAP, SAP, DAP, and to quantify HR before and after blood collection; PCV was obtained before and immediately after blood collection. RESULTS: Despite a significant decrease (P < .05) in all variables (ie, BP, PCV, HR) after blood collection, no adverse events were observed. CONCLUSIONS AND CLINICAL IMPORTANCE: The collection of a unit of blood for transfusion from healthy donor cats weighing more than 5 kg appears to be safe, but this procedure leads to a decrease in arterial BP, PCV, and HR.     

The association of lung function and plasma volume expansion in neonatal alpaca crias following plasma transfusion for failure of passive transfer

Objective– Failure of passive transfer in neonatal alpacas is often corrected by IV administration of commercial camelid plasma. The goal of this study was to characterize changes in pulmonary function, gas exchange, and cardiovascular parameters associated with IV plasma transfusion. Design– Prospective clinical study. Setting– A university‐based referral hospital. Animals– Eleven clinically healthy alpaca crias (age: 1–18 days) with failure of passive transfer (IgG<8 g/L [800 mg/dL]). Interventions– Thirty milliliters per kilogram of commercial camelid plasma was administered IV over 90 minutes. Before and after the transfusion, the following cardiopulmonary measurements were obtained: arterial blood gas analysis, pulmonary functional residual capacity (FRC), PCV, total plasma protein and echocardiographic M‐mode measures. Additionally, central venous pressure and indirect arterial blood pressure were monitored throughout the plasma transfusion. Measurements and Main Results– The IV plasma transfusion resulted in significantly reduced PCV (−5.4±5.1%), increased total plasma protein (+4±4 g/L [0.4±0.4 g/dL]), elevated central venous pressure and changes in left and right ventricular M‐mode indices, consistent with plasma volume expansion. Transfusion was further associated with a significant increase in arterial oxygen pressure (PaO₂) (+11.2±15 mm Hg) and decrease in FRC (−5.6±8.3 mL/kg). Conclusions– IV administration of 30 mL/kg camelid plasma to neonatal crias resulted in measurable plasma volume expansion and a concurrent reduction in FRC. Administration of this quantity of plasma appeared to be safe in healthy neonatal crias. However, changes in lung volume associated with plasma administration may create risks for crias with underlying cardiopulmonary or systemic disease.     

The effect of a single intravenous fluid bolus on packed cell volume and plasma total solids concentration in Red-collared Lorikeets (Trichoglossus haematodus rubritorquis)

OBJECTIVE: To determine the effect of a single intravenous (IV) fluid bolus on the hydration of an avian patient, using packed cell volume (PCV) and plasma total solids (TS) to estimate hydration. PROCEDURE: Ten birds were allocated randomly to one of three groups, and administered 30 mL/kg or 50 mL/kg intravenous fluid, or were part of a control group and did not receive IV fluid. Blood was collected before the IV fluid bolus was administered, and at 1 minute, 3 hours and 6 hours after administration of the fluid. Samples were used to determine PCV and TS and results were compared between groups and between the different time points. RESULTS: Administration of 30 mL/kg or 50 mL/kg compound sodium lactate solution caused a statistically significant decrease in PCV. Within 3 hours, the PCV was not significantly different to the initial value or to the PCV of control birds. Administration of 30 mL/kg compound sodium lactate solution did not result in a significant decrease in TS. However, administration of 50 mL/kg produced a significant decrease in TS, which was still significantly less than controls 6 hours after the fluid was administered. CONCLUSION: These findings suggest that an intravenous bolus of fluid may be safely administered to an anaemic bird, since PCV is significantly decreased for less than 3 hours. Up to 50 mL/kg of fluid may be administered as an intravenous bolus to a bird, to produce significant haemodilution that persists for up to 6 hours.     

Results of blood transfusion in anemia of dairy cattle with references to serological tolerance

Therapeutic use of blood transfusion as a life-saving step in cases of dairy cattle anaemia cannot be recommended unless serological tolerance is taken into due consideration. The results obtainable from cross-testing and biological testing are useless in avoiding transfusion problems caused by blood groups in situations of first transfusion. Suitable donors can be identified only by haemolysis and haemolysis inhibition tests. Preliminary selection of donors in advance is permissible for first transfusions. The most important antigens, which may correspond with normal agglutinins, must not be present in the blood patterns of selected donors. Blood transfusion without knowledge of serological tolerance and compatibility between donor and recipient may be justified in emergency situations, yet, together with desensitisation.     

Prevalence of feline blood groups in the Montreal area of Quebec,Canada

The feline AB blood group system has clinical significance because type B cats have natural alloimmune anti-A antibodies which can cause isoerythrolysis of the newborn and life-threatening transfusion reactions. In the United States, the prevalence of type B blood is estimated to be 1% to 2%. This study determined the prevalence of feline AB blood groups among 207 potential blood donor cats that included 178 domestic cats, in the Montreal area of Quebec, Canada. Blood typing was performed using a standardized tube technique. Blood types AB and B were confirmed using a backtyping technique. The frequency of blood types among the studied population was as follows: 95.2% type A, 4.4% type B, and 0.48% type AB. Among domestic cats, the frequency was 94.4% for type A, 5% for type B, and 0.6% for type AB. The frequency of type B was higher than expected, which reinforces the recommendation to ensure blood compatibility of the recipient and donor before transfusion through typing and possibly cross-matching as well.     

Clinical and clinicopathologic variables in adult horses receiving blood transfusions: 31 cases (1999-2005)

OBJECTIVE: To determine clinical and clinicopathologic abnormalities in horses administered a blood transfusion and evaluate effects of blood transfusion on these variables. DESIGN: Retrospective case series. ANIMALS: 31 adult horses that received > or = 1 blood transfusion. Procedures-Medical records of horses receiving a blood transfusion were reviewed to obtain clinical findings, laboratory test results before and after transfusion, adjunctive treatments, transfusion type and volume, response to transfusion, results of donor-recipient compatibility testing, adverse reactions, and outcome. RESULTS: 31 horses received 44 transfusions for hemorrhagic anemia (HG; n = 18 horses), hemolytic anemia (HL; 8), or anemia attributable to erythropoietic failure (EF; 5). Tachycardia and tachypnea were detected in 31 of 31 (100%) and 22 of 31 (71%) horses, respectively, before transfusion. The PCV and hemoglobin concentration were less than the reference range in 11 of 18 horses with HG, 8 of 8 horses with HL, and 5 of 5 horses with EF. Hyperlactatemia was detected in 16 of 17 recorded values before transfusion. Heart rate, respiratory rate, and PCV improved after transfusion, with differences among the types of anemia. Seventeen (54%) horses were discharged, 9 (29%) were euthanized, and 5 (16%) died of natural causes. Adverse reactions were evident during 7 of 44 (16%) transfusions, varying from urticarial reactions to anaphylactic shock. CONCLUSIONS AND CLINICAL RELEVANCE: Abnormalities in clinical and clinicopathologic variables differed depending on the type of anemia. Colic, cold extremities, signs of depression, lethargy, tachycardia, tachypnea, low PCV, low hemoglobin concentration, and hyperlactatemia were commonly detected before transfusion and resolved after transfusion.     

Effect of specimen collection and storage on blood glucose and lactate concentrations in healthy,hyperthyroid and diabetic cats

Abstract: The objective of this study was to compare and investigate differences in glucose and lactate concentrations in sodium fluoride/potassium oxalate (NaF/Ox) plasma and serum in healthy cats and cats with metabolic disease. Glucose and lactate concentrations were determined in routinely processed serum and NaF/Ox plasma obtained from healthy (n = 30), hyperthyroid (n = 27) and diabetic (n = 30) cats, and in samples from 6 healthy cats stored at 25°C or 4°C for 0,1, 2, 4, or 8 hours. The packed cell volume (PCV) of blood collected in NaF/Ox was compared with that of blood collected in EDTA. Mean glucose concentration was significantly (P < .05) lower in NaF/Ox plasma than in serum in all groups of cats, by 0.7–2.5 mmol/L (11–45 mg/dL); the difference was greater in cats with hyperglycemia. Mean lactate concentration was significantly higher in serum than in NaF/Ox plasma in all groups of cats, by 0.4–1.2 mmol/L (3.6–10.8 mg/dL); the difference was greater in hyperthyroid and diabetic cats. In vitro, only serum stored on the clot for ≥ 1hour at 25°C had significantly lower glucose and higher lactate concentrations. The PCV of NaF/Ox-anticoagulated blood was lower than that of EDTA-anticoagulated blood, by 7.0%± 1.4% (P<.01). In conclusion, collection of feline blood in NaF/Ox was necessary to prevent in vitro increases in lactate concentration; however, NaF/Ox artifactually decreased plasma glucose concentration because of RBC shrinkage. The PCV should not be determined on blood collected in NaF/Ox.     

Comparison of whole blood and plasma potassium concentrations in dogs using the Reflovet system

Background: The Reflovet system is designed for chemical analysis of whole blood. However, plasma or serum is recommended for potassium analysis because of possible interference from RBC potassium. Because RBC potassium concentration is low in most canine erythrocytes, however, there should be little or no interference.
Objective: The objective of this study was to compare potassium results obtained in whole blood and in plasma from dogs using the Reflovet system.
Methods: Blood samples were collected from 104 dogs into lithium-heparin tubes. The potassium concentration was measured in whole blood, and subsequently the PCV was measured. Samples were centrifuged and the potassium concentration was measured in plasma. Comparisons were made using Deming's regression and Bland-Altman difference plots.
Results: There was very good correlation between results of potassium measurements in whole blood and plasma ( r = 0.93). Potassium values were moderately lower in whole blood: Potassium_blood= 0.912 × Potassium _plasma+ 0.119. Hemolysis had a negligible effect on the results, but the difference increased with the PCV value. In more than 90% of samples, the difference between the 2 measurements was ≤ 0.3 mmol/L.
Conclusion: There is only a negligible difference in most cases between potassium values in canine plasma and whole blood using the Reflovet system.     

In vitro lysis and acute transfusion reactions with hemolysis caused by inappropriate storage of canine red blood cell products

Background: Transfusion of red blood cell (RBC) products carries considerable risk for adverse reactions, including life‐threatening hemolytic reactions. Objective: To report the occurrence and investigation of life‐threatening acute transfusion reactions with hemolysis in dogs likely related to inappropriate blood product storage. Animals: Four dogs with acute transfusion reactions and other recipients of blood products. Methods: Medical records were reviewed from 4 dogs with suspected acute hemolytic transfusion reactions after receiving RBC products at a veterinary clinic over a 1‐month period. Medical records of other animals receiving blood products in the same time period also were reviewed. Blood compatibility and product quality were assessed, subsequent transfusions were closely monitored, and products were diligently audited. Results: During or immediately after RBC product transfusion, 4 dogs developed hemolysis, hemoglobinuria, or both. Two dogs died and 1 was euthanized because of progressive clinical signs compatible with an acute hemolytic transfusion reaction. Blood type and blood compatibility were confirmed. RBC units from 2 blood banks were found to be hemolyzed after storage in the clinic's refrigerator; no bacterial contamination was identified. After obtaining a new refrigerator dedicated to blood product storage, the problem of hemolyzed units and acute transfusion reactions with hemolysis completely resolved. Conclusions: Acute life‐threatening transfusion reactions can be caused by inappropriate storage of RBC products. In addition to infectious disease screening and ensuring blood‐type compatibility, quality assessment of blood products, appropriate collection, processing, and storage techniques as well as recipient monitoring are critical to provide safe, effective transfusions.     

Autologous blood collection and transfusion in cats undergoing partial craniectomy

OBJECTIVE: To describe the procedure for autologous blood donation and associated complications in cats undergoing partial craniectomy for mass removal. DESIGN: Prospective case series. ANIMALS: 15 cats with intracranial mass confirmed by computed tomographic scan, no evidence of renal failure, and PCV > or = 22%. PROCEDURE: One unit (60 ml) of blood was collected and stored 7 to 17 days before surgery and transfused during the perioperative period if needed. The PCV was measured before donation, before surgery, during surgery, and after surgery to assess effect of donation on PCV before surgery and effect of transfusion on PCV after surgery. Cats were evaluated for donation complications, iatrogenic anemia, and adverse reactions associated with administration of autologous blood. RESULTS: Complications associated with phlebotomy were not detected. Fifteen cats underwent partial craniectomy 7 to 17 days after blood donation; all had histologic confirmation of meningioma by examination of tissue obtained at surgery. Eleven cats received autologous blood transfusions. None of the cats received allogeneic blood transfusions. Transfusion reactions were not observed. Subclinical iatrogenic anemia was detected in 3 cats. Two cats were considered to have received excessive transfusion, and 3 cats received inadequate transfusion. All cats undergoing partial craniectomy were discharged from the hospital and were alive > 6 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Autologous blood donation before surgery was considered safe for cats undergoing partial craniectomy for resection of meningioma. The only complication observed was iatrogenic anemia. The procedure contributed to blood conservation in our hospital.     

Whole blood transfusions in 91 cats: a clinical evaluation

This survey assessed the feline transfusion practices at the University of Berlin from 1998 to 2001 in regard to patient population, indications, efficacy, and transfusion reactions. Blood was obtained from seven healthy in-house donors and 127 mostly indoor client-owned pet cats. Over a 3-year period 91 cats were transfused with blood type compatible blood. The blood was fresh (within 8 h of collection) or stored no longer than 15 days. Transfusions were required because of blood loss anaemia (n=40), haemolytic anaemia (n=13), ineffective erythropoiesis (n=35), hypoproteinaemia (n=2) or coagulopathy (n=2). The anaemic cats had a pretransfusion haematocrit of 5-20% (m [median]=13), and received one to six transfusions (m=1). The survival rates of the anaemic cats at 1 and 10 days after transfusion were 84 and 64%, respectively. None of the deaths appeared to be related to transfusion reactions. The major crossmatch, undertaken before 117 transfusions, was incompatible for eight cats. All except for one had previously been transfused. Lysis of transfused cells in six cases resulted in a less than expected haematocrit rise and an increase in serum bilirubin. Transient mild transfusion reactions were only noted in two cats during the second or third transfusion. In conclusion, with proper donor selection and appropriate compatibility screening, blood transfusions are well tolerated, appear effective, and may increase chances of survival.     

Artifactual changes in PCV, hemoglobin concentration, and cell counts in bovine, caprine, and porcine blood stored at room and refrigerator temperatures

BACKGROUND: Blood samples collected from farm animals for hematology testing may not reach the laboratory or be examined immediately upon collection, and in some cases may need to be transported for hours before reaching a laboratory. OBJECTIVE: The objective of this study was to investigate the artifactual changes that may occur in PCV, hemoglobin (Hgb) concentration, and cell counts in bovine, caprine, and porcine blood samples stored at room (30 degrees C) or refrigerator (5 degrees C) temperature. METHODS: Baseline values for PCV, Hgb concentration, and RBC and WBC counts were determined immediately after blood collection from 36 cattle, 32 goats, and 48 pigs using manual techniques. Blood samples were split into 2 aliquots and stored at 30 degrees C or 5 degrees C. Hematologic analyses were carried out at specified intervals during 120 hours of storage. Results were analyzed by repeated measure ANOVA; results at different temperatures were compared by paired t-tests. RESULTS: Compared to baseline values, there were no significant changes in Hgb concentration, RBC count, or WBC count in samples from cattle; in Hgb concentration and RBC count in samples from goats; and in Hgb concentration and WBC count in samples from pigs throughout the 120 hours of storage at both 30 degrees C and 5 degrees C. Significant changes (P <.05) from baseline occurred in PCV after 14 hours of storage at 30 degrees C and after 19 hours of storage at 5 degrees C in cattle and goats; and after 10 hours of storage at 30 degrees C and 14 hours of storage at 5 degrees C in pigs. Significant changes also were observed in Hgb concentration at 96 hours at 30 degrees C and 5 degrees C, and in RBC counts at 48 hours at 30 degrees C and 96 hours at 5 degrees C in porcine samples; and in total WBC counts at 120 hours at 30 degrees C and 5 degrees C in caprine samples. Artifactual changes were more pronounced in the samples stored at 30 degrees C. CONCLUSIONS: At both 30 degrees C and 5 degrees C, blood samples from cattle and goats can be stored for up to 12 hours, while blood samples from pigs can be stored for up to 8 hours without any significant changes in PCV. Blood samples from all 3 species can be stored for more than 24 hours without significant changes in Hgb concentration, RBC count, and total WBC count.     

Transfusion issues in the cancer patient

Blood transfusions are a lifesaving but transient therapy used to correct deficiencies of blood cells and coagulation factors that occur in cancer patients. Anemia can occur in cancer patients as a result of hemolysis, blood loss, or bone marrow failure. The blood component most commonly recommended for the treatment of anemia is packed red blood cells. Coagulation disorders are common with hemangiosarcoma and diffuse hepatic tumors. Fresh frozen plasma is used as a source for replacement coagulation factors for the treatment of disseminated intravascular coagulation or other cancer-associated coagulopathies. Although thrombocytopenia and neutropenia can be the result of bone-marrow failure from tumor infiltration, chemotherapy, or radiation therapy, these platelets and neutrophils are rarely transfused to veterinary cancer patients. Pretransufsion testing consists of blood typing in cats, and cross matching in dogs and cats if the dog has previously been transfused. Cancer patients receiving transfusions should be monitored on a continual basis during and immediately following the transfusion to enable early identification of an adverse event, allowing the transfusion to be discontinued.     

Use of a prestorage leukoreduction filter effectively removes leukocytes from canine whole blood while preserving red blood cell viability

Leukoreduction of blood products is a technique used to prevent leukocyte-induced transfusion reactions. Filters currently used for human blood products achieve at least a 99.9% reduction in leukocyte numbers per unit (450 mL) of blood. Goals of this study were to determine if a prestorage leukoreduction filter could effectively achieve leukoreduction of canine blood and to determine if viability of the leukoreduced red blood cell (RBC) product could be maintained after 35 days of storage. Blood collected from each dog was filtered through a leukoreduction filter at either room temperature or after cooling (4 degrees C) for 4 hours. Filtration efficacy was determined by measurement of pre- and postfiltration leukocyte counts. In vitro viability of RBCs was determined by comparing RBC adenosine triphosphate concentration and percent hemolysis before and after the storage period. In vivo viability of stored cells was determined using a biotin-streptavidin-phycoerythrin labeling technique and flow cytometry. Blood filtered within 30 minutes of collection versus blood filtered after cooling had mean reductions in leukocyte numbers of 88.90 and 99.99%, respectively. The mean ATP and hemoglobin concentrations from the in vitro analysis were comparable to those obtained in previously for canine RBC adequately stored for 35 days. The mean in vivo 24-hour survival of the stored RBC was 84.7%. The leukoreduction filter used did not adversely affect in vitro or in vivo viability of canine RBCs. The filter effectively removed leukocytes from blood, with maximal efficiency of filtration achieved with use of cooled blood.