真空采血在兽医临床血液分析上的应用

动物机体的外周血可用于疾病的诊断、科研实验及抗血清的制备。普通的采血方法通常易交叉污染、溶血或凝血等，而真空采血避免上述情况，特别是采血管内含有负压对于采血十分有利，适合于宠物血液化验、中等大小试验动物血液分析。     

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)     

Effects of blood donation on arterial blood pressure in retired racing Greyhounds

The purpose of this study was to evaluate changes in systolic arterial blood pressure (SABP) immediately after collection of blood for transfusion in retired racing Greyhounds. We prospectively evaluated 19 blood donor Greyhounds before and after the collection of a unit (450 mL) of blood. The SABP was measured with Doppler in the right forearm after the dogs had been in the blood collection room for a few minutes (PRE-FLOOR) and again 5-10 minutes after the dogs were placed on the table where they would be bled (PRE-TABLE). A total of 3-5 minutes after completing the blood collection, the SABP was measured again while the dogs were still in lateral recumbency on the table (POST-TABLE) and once more 60-90 minutes later, when the dogs were on the floor after completing the donation (POST-FLOOR). All dogs were monitored for clinical signs of hypotension, including depression, weakness, collapse, and pallor, for a minimum of 2 hours after donation. There was a significant difference in SABP for the group between PRE-FLOOR and POST-TABLE (P = .02) and between PRE-TABLE and POST-TABLE determinations (P = .01). There were no significant differences for any of the other time points; there were no adverse events. Therefore, we conclude that the collection of 450 mL of blood from normal Greyhounds results in a short-lived yet significant decrease in SABP, but the likelihood of adverse events is negligible.     

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, are time-consuming, expensive, and stressful to the animal. Acute loss of 20% to 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% to 12% can be tolerated without transfusion if the animal is not stressed and no further decline in erythrocyte mass occurs. Seventy-five percent of transfused bovine erythrocytes are destroyed within 48 hours of transfusion. A transfusion rate of 10 to 20 mL/kg recipient weight is necessary to result in any appreciable increase in PCV. A nonpregnant donor can contribute 10 to 15 mL of blood/kg body weight at 2- to 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 cross-matching 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 (preferable) 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. Administration rates have been suggested starting from 10 mL/kg/hr; faster rates may be necessary in peracute hemorrhage. Plasma should be administered when failure of absorption of passive maternal antibody has occurred or when protein-loosing enteropathy or nephropathy results in a total protein of less than 3 g/dL or less than 1.5 g albumin/dL. Plasma can be stored at household freezer temperatures (-15 to -20 degrees C) for a year; coagulation factors will be destroyed after 2 to 4 months when stored in this manner. To maintain viability of coagulation factors, plasma must be stored at -80 degrees C for less than 12 months. When administering plasma, a blood donor set with a built-in filter should always be used. When bovine plasma is thawed, precipitants form in the plasma and infusion of these microaggregates may result in fatal reactions in the recipient.     

The use of vascular access ports for blood collection in feline blood donors

We investigated vascular access ports for feline blood donation. Eight cats were anesthetized for conventional blood collection by jugular venipuncture at the beginning and end of the study. In-between conventional collections, vascular access ports were used for collection with or without sedation every 6 to 8 wk for 6 mo. Ports remained functional except for one catheter breakage, but intermittent occlusions occurred. Systolic blood pressure was lower during conventional collection. Behavioral abnormalities occurred during 3 port collections. Packed red cells prepared from collected blood were stored at 4°C for 25 d and assessed for quality pre- and post-storage. With both collection methods, pH and glucose level declined, and potassium level, lactate dehydrogenase activity and osmotic fragility increased. There were no differences between methods in pre-storage albumin and HCO(3)(-) levels, and pre and post-storage hematocrit, lactate dehydrogenase activity, and glucose and potassium levels. Pre-storage pH and pCO(2) were higher with conventional collection, and pre- and post-storage osmotic fragility were greater with port collection. One port became infected, but all cultures of packed red cells were negative. Tissue inflammation was evident at port removal. In a second study of conventional collection in 6 cats, use of acepromazine in premedication did not exacerbate hypotension. The use of vascular access ports for feline blood donation is feasible, is associated with less hypotension, and may simplify donation, but red cell quality may decrease, and effects on donors must be considered.     

Comparison of spray-dried blood meal and blood cells in diets for nursery pigs

We used a total of 680 pigs to compare spray-dried blood meal and blood cells in nursery diets. In Exp. 1, 350 barrows (17 +/- 2 d of age at weaning) were used to compare three levels of spray-dried blood meal or blood cells (2.5, 5.0, and 7.5%) in the diet fed from d 5 to 19 postweaning (6.6 to 9.9 kg). Inclusion of either blood product improved ADG (P < 0.005) and G:F (P < 0.001) compared to pigs fed the control diet without added blood products. However, pigs fed spray-dried blood meal had greater ADG (P < 0.001), ADFI (P < 0.04), and G:F (P < 0.001) from d 0 to 7 compared to those fed blood cells. The greatest differences observed between the two blood products occurred at the 5 and 7.5% inclusion levels. No differences (P > 0.05) in growth performance were detected between the two blood products from d 7 to 14. In Exp. 2, 380 barrows (initial BW of 10.7 kg and 41 +/- 2 d of age) were used to determine lysine bioavailability of spray-dried blood meal and blood cells via the slope ratio procedure. With G:F ratio as the response criterion, blood meal and blood cells had similar lysine bioavailability relative to crystalline lysine. These experiments indicate that both blood products had similar lysine bioavailability, and that pigs fed spray-dried blood meal had greater performance during the initial 7 d (d 5 to 12 after weaning). However, as the pigs became heavier, there were no differences observed in performance of pigs fed either blood meal or blood cells.     

Changes in blood gas and acid-base values of bovine venous blood during storage

The stability of blood gas and acid-base values in bovine venous blood samples (n = 22) stored on ice for 3, 6, 9, or 24 hours was studied. Values studied include pH, PO2 and PCO2 tensions, base excess, standard base excess, bicarbonate concentration, standard bicarbonate concentration, total carbon dioxide content, oxygen saturation, and hemoglobin. The results indicate that, except for PCO2, changes in blood gas and acid-base values during 24 hours of storage and differences between cattle of differing ages, rectal temperatures, and acid-base status were too small to be of clinical significance. Therefore, bovine venous blood samples stored up to 24 hours on ice are of diagnostic utility.     

Changes in central venous pressure and blood lactate concentration in response to acute blood loss in horses

OBJECTIVE: To evaluate selected hemodynamic, blood gas, and biochemical responses to mild to moderate acute blood loss in standing, awake horses. DESIGN: Prospective study. ANIMALS: 7 healthy mares. PROCEDURES: Each horse was restrained in standing stocks, and its head was maintained in a neutral position; sedatives and tranquilizers were not administered. During a 1-hour period, blood was collected into collection bags by use of a suction pump. The rate of blood collection was approximately 16 mL/kg/h (7.3 mL/lb/h). Thirty minutes after blood collection, the blood was readministered at the same rate. Central venous pressure (CVP), central venous blood gas, blood lactate concentration, and heart rate were measured at baseline (after placement of catheters), after removal of blood, and after readministration of blood. RESULTS: In response to blood loss, CVP decreased and blood lactate concentration increased significantly, compared with baseline values; heart rate and results of central venous blood gas analysis did not change significantly. After readministration of blood, CVP returned to baseline value and blood lactate concentration approached baseline value. CONCLUSIONS AND CLINICAL RELEVANCE: Changes in CVP and blood lactate concentration appear to be early indicators of hypovolemia in horses, which may represent acute blood loss in trauma patients; these variables should be monitored to assess the potential need for blood transfusions. These variables can be used to monitor responses of horses to blood transfusions when whole blood is administered as the replacement fluid.     

Pulmonary blood vessels in goats]

The blood vessels in the lung of the goat, which until now have received little attention, are described in detail for the first time. With regard to the segments of the lung, blood vessels are bronchovascular units in the lobi craniales, lobus medius and lobus accessorius, but bronchoartery units in the lobi caudales. We investigated the types of branches of the Aa. pulmonales dextra et sinistra, the inter- and intraspecific principles of the outlet of the pulmonary veins and the importance of bronchopulmonary segmentation of the lungs.