Background

Equine whole blood collection and storage methods have been evaluated to assess red blood cell viability; however, platelet (PLT) viability has not been comprehensively assessed.

Objectives

The purpose of the study was to compare viability of PLTs collected in whole blood into 2 different anticoagulants.

Methods

Whole blood from 6 healthy adult Thoroughbred horses was collected into citrate-phosphate-dextrose-adenine (CPDA) or acid-citrate-dextrose (ACD). Platelet count, pH, and concentrations of glucose, lactate, carbon dioxide, oxygen, bicarbonate, sodium, potassium, and chloride were measured within 10 minutes of collection and then again one hour later at which time PLT aggregometry was performed to assess PLT function.

Results

Aggregometry mean amplitudes were significantly higher in CPDA compared to ACD. Blood glucose, pH, bicarbonate, sodium, and lactate concentrations were significantly higher in CPDA compared to ACD. Lactate concentration was higher following one hour in either anticoagulant. Potassium, oxygen, and carbon dioxide concentrations were significantly higher in ACD compared to CPDA at collection.

Conclusions

Platelet aggregometry results suggest that CPDA is superior to ACD for maintaining PLT viability following whole blood collection. This may be associated with the higher, more neutral pH as well as an increase in glucose available for metabolism. Although lactate was increased in the CPDA samples it was not high enough to decrease pH and therefore may not have been high enough to cause morphologic lesions and loss of PLT viability.

Background

Development of equine platelet concentrate (PC) would aid management of cases requiring transfused platelets (PLTs), where adminstration of whole-blood or platelet-rich plasma (PRP) might be contraindicated.

Objectives

To test and validate a method for production of an equine PRP-PC product.

Animals

Six healthy Thoroughbred geldings from a research herd.

Methods

In this prospective experimental study, whole blood was collected and processed through multiple centrifugation steps to yield 120 mL of PC. The PC was stored at 22°C and gently and continuously agitated. Measurements of PLT count, pH, and concentrations of glucose, lactate, electrolytes, lactate dehydrogenase (LDH), and aspartate aminotransferase (AST), as well as partial pressures of oxygen and carbon dioxide were performed on days 0, 1, 2, 3, 5, and 7. Platelet aggregometry and bacterial culture were also performed.

Results

The PC always had a PLT count of ≥550 × 10³ cells/μL. Aggregometry graph amplitude (P < .0001) and area under the curve (P < .05) significantly decreased over time. Sodium, chloride, lactate (P < .0001), and oxygen (P < .01) concentrations significantly increased over time. pH (P < .001), glucose and bicarbonate concentrations (P < .0001) significantly decreased over time. There was no significant difference in potassium concentration, PLT count, LDH and AST activities and no bacterial growth from culture.

Conclusions and clinical importance

The described technique yielded a PC that meets the standards of the American Association of Blood Banks for human PC.

Background

Viscoelastic analysis provides information on the dynamics and strength of clot formation as well as clot stability. A novel point-of-care viscoelastic test (Viscoelastic Coagulation Monitor Vet, VCM Vet) could be more cost-effective, simpler to use, and more portable than thromboelastography (TEG).

Objectives

The primary aim of this study was to establish a feline reference interval (RI) for the VCM Vet. A secondary aim was to compare VCM Vet analysis with TEG in healthy cats.

Methods

Fifty-six healthy cats were enrolled in this study. Linear regression was completed to determine whether age and CBC parameters were associated with the VCM Vet parameters and if TEG parameters were correlated with VCM Vet data. Statistical significance was set at P < .05.

Results

Fifty-three VCM Vet tracings were used to determine RIs for healthy cats. The determined RIs were: clot time (CT) 104-438 seconds; clot formation time (CFT) 104.5-488 seconds; alpha angle (AA) 30.5°-70°; a10 13.8-32.7 VCM units; a20 19.2-40.1 VCM units; maximum clot formation (MCF) 22.5-44.8 VCM units; Lysis Index 30 (Li30) 92.9%-100.9%; and Lysis Index 45 (Li45) 92%-100%. Linear regression identified a strong positive correlation between the CT and R-time measured using the VCM Vet and TEG methods, respectively; no other parameters were correlated.

Conclusions

The use of VCM Vet is feasible in cats, and we determined the first described feline RIs for this test. In general, the VCM Vet data did not correlate with TEG in healthy cats.

Objective

To measure and compare viscoelastic coagulation in 2 canine blood donor populations using a novel, point-of-care device (VCM Vet Analyzer, VCM).

Design

Cohort study.

Setting

Academic and commercial veterinary blood banks.

Animals

Non-Greyhounds from community-based blood donor program and Greyhounds from a blood bank colony.

Intervention

Blood was collected from all dogs via direct venipuncture for a complete hemogram, biochemistry, and point-of-care viscoelastic coagulation.

Measurement and main results

All biochemical measurements for all dogs in Group NG (n = 38, non-Greyhounds) and Group G (n = 53, Greyhounds) were within local reference intervals. Hematology data showed significant statistical differences between groups in hemoglobin, RBC, platelet, and WBC concentrations. Group G demonstrated lower maximum clot firmness (MCF) with 17 VCM units (26 VCM units in Group NG), increased lysis with 30 VCM units at 30 minutes (LI30) and 27 VCM units at 45 minutes (LI45) (86 VCM units LI30 and 85 VCM units LI45 in Group NG), and decreased amplitude of 13 VCM units 10 minutes (A10) after clot time (CT) and 6 VCM units 20 minutes after CT (A20) (18 VCM units [A10] and 22 VCM units [A20] in Group NG).

Conclusion

This study found differences between healthy Greyhound and non-Greyhound blood donors in measures of clot strength and fibrinolysis as measured by the VCM. Whereas Greyhound have unique hematologic and hemostatic profiles, these measured viscoelastic differences are important to note prior to and following surgical intervention to aid in clinical decision-making if bleeding complications develop.