Increased packed cell volume alters point of care viscoelastic clotting parameters in horses.
Abstract: Polycythaemia and coagulopathy are identified risk factors for non-survival in critically ill horses. Assessment of coagulation is recommended for critical care monitoring but may be affected by concurrent polycythaemia. Objective: To evaluate the effects of induced polycythaemia on coagulation parameters as measured by a point-of-care viscoelastic coagulation device (VCM Vet™). Methods: Prospective interventional study. Methods: Healthy adult horses (n = 7) were given 6 mcg/kg of phenylephrine IV over 15 min to induce transient polycythaemia. Samples for packed cell volume (PCV), total solids (TS), complete blood count (CBC), activated partial thromboplastin time (PTT), prothrombin (PT) and VCM Vet™ viscoelastic testing were collected at baseline (T0), 5 min (T1) and 2 h (T2) post-phenylephrine infusion. Splenic volume was measured by transabdominal ultrasonography. VCM Vet™ and plasma-based coagulation parameters, splenic volume and haematologic values were compared within and between time points. Results: Splenic volume decreased from T0 (11.5 ± 4.8 L) to T1 (6.1 ± 2 L, p = 0.04) and returned to baseline volume by T2 (12.1 ± 3.9 L, p = 0.8), consistent with phenylephrine-induced splenic contraction. PCV increased from T0 (37% ± 4%) to T1 (56.3% ± 5.3%; p < 0.001) and returned to baseline at T2 (41.6% ± 3.6%; p = 0.1). A10 and A20 (amplitude at 10 and 20 min, VCM units) were decreased from T0 (12.6 ± 1.6, 18.9 ± 5) to T1 (5.4 ± 1.9, 7.6 ± 2.4; both p < 0.001) and remained lower than baseline at T2 (9.3 ± 2.1, 12.7 ± 3; both p = 0.01). PT and PTT remained within reference ranges with no significant difference over time (p = 0.5 and 0.09, respectively). PCV was negatively correlated with CFT (R = -0.61, p = 0.003), A10 (R = -0.9, p < 0.001) and A20 (R = -0.87, p < 0.001). Conclusions: Small sample size, limited to healthy mares. Conclusions: Phenylephrine-induced polycythaemia was associated with hypocoagulable viscoelastic traces using the VCM Vet™ device without effect on plasma-based coagulation assessments or platelet number. Further investigation of viscoelastic testing is needed in horses with increased PCV due to clinical illness. Unassigned: Polyzythämie und Koagulopathie sind bekannte Risikofaktoren für Nicht‐Überleben bei schwererkrankten Pferden. Die Beurteilung der Blutgerinnung wird für die Überwachung auf der Intensivstation empfohlen, kann aber durch gleichzeitige Polyzythämie beeinträchtigt werden. ZIEL: Bewertung der Auswirkungen einer induzierten Polyzythämie auf die Gerinnungsparameter, die mit einem viskoelastischen Point‐of‐Care‐ (“Patientennahe Sofortdiagnostik”)‐Koagulationsgerät (VCM Vet™) gemessen warden. Methods: Prospektive Interventionsstudie. Methods: Gesunden erwachsenen Pferden (n = 7) wurden 6 mcg/kg Phenylephrin intravenös über 15 Minuten verabreicht, um eine vorübergehende Polyzythämie auszulösen. Proben für PCV, Gesamtfeststoffe (TS), vollständiges Blutbild (CBC), aktivierte partielle Thromboplastinzeit (PTT), Prothrombin (PT) und VCM Vet™ viskoelastische Tests wurden zu Beginn (T0), 5 Minuten (T1) und 2 Stunden (T2) nach der Phenylephrin‐Infusion entnommen. Das Milzvolumen wurde mittels transabdominaler Ultraschalluntersuchung gemessen. VCM Vet™ und plasmabasierte Gerinnungsparameter, Milzvolumen und hämatologische Werte wurden innerhalb und zwischen den Zeitpunkten verglichen. Unassigned: Das Milzvolumen verringerte sich von T0 (11,5 ± 4,8 L) auf T1 (6,1 ± 2 L, p = 0,04) und kehrte bis T2 (12,1 ± 3,9 L, p = 0,8) zum Ausgangsvolumen zurück, was mit der durch Phenylephrin induzierten Milzkontraktion übereinstimmt. Das PCV stieg von T0 (37 ± 4%) auf T1 (56,3 ± 5,3%; p < 0,001) und kehrte bei T2 zum Ausgangswert zurück (41,6 ± 3,6%; p = 0,1). A10 und A20 (Amplitude nach 10 und 20 Minuten, VCM‐Einheiten) waren von T0 (12,6 ± 1,6, 18,9 ± 5) zu T1 (5,4 ± 1,9, 7,6 ± 2,4; beide p < 0,001) verringert und blieben bei T2 (9,3 ± 2,1, 12,7 ± 3; beide p = 0,01) niedriger als der Ausgangswert. PT und PTT blieben innerhalb der Referenzbereiche und wiesen im Laufe der Zeit keine signifikanten Unterschiede auf (p = 0,5 bzw. 0,09). PCV war negativ korreliert mit CFT (R = ‐0,61, p = 0,003), A10 (R = ‐0,9, p < 0,001) und A20 (R = ‐0,87, p < 0,001). Unassigned: Kleine Stichprobengröße, beschränkt auf gesunde Stuten. Unassigned: Phenylephrin‐induzierte Polyzythämie war mit hypokoagulierbaren viskoelastischen Spuren unter Verwendung des VCM Vet™‐Geräts verbunden, ohne Auswirkungen auf plasmabasierte Gerinnungsmessungen oder die Thrombozytenzahl. Weitere Untersuchungen von viskoelastischen Tests sind bei Pferden mit erhöhtem PCV aufgrund einer klinischen Erkrankung erforderlich.
© 2024 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
Publication Date: 2024-09-03 PubMed ID: 39228098DOI: 10.1111/evj.14413Google Scholar: Lookup
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Summary
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The research article examines the effects of induced polycythaemia (an increase in the number of red blood cells) on the coagulation parameters of horses, using the point-of-care viscoelastic coagulation device, VCM Vet™. The study suggests that polycythaemia results in hypocoagulable readings without affecting plasma-based coagulation assessments or platelet number.
Objective of the Study
- The primary goal of the study was to understand the influence of induced polycythaemia on the coagulation parameters of horses. This assessment was conducted using a point-of-care viscoelastic coagulation monitoring device named VCM Vet™.
Methods Used in The Study
- This study was carried out using healthy adult horses, all of which were given Phenylephrine intravenously to induce temporary polycythaemia.
- Several parameters were measured at different times, starting from the induction of polycythaemia (T0) to 5 minutes (T1) and 2 hours (T2) post-phenylephrine infusion. These parameters include packed cell volume (PCV), total solids (TS), complete blood count (CBC), activated partial thromboplastin time (PTT), prothrombin (PT) and VCM Vet™ viscoelastic testing.
- The splenic volume of the horses was also assessed using transabdominal ultrasonography. This provided information about the impact of polycythaemia and the infusion of Phenylephrine on the spleen of the horses.
Results of the Study
- Findings from the study indicated that splenic volume decreased at T1 but returned to its normal level by T2. This reduction and subsequent increase can be linked to the infusion of Phenylephrine, which contributes to splenic contraction.
- The PCV increased dramatically at T1 but returned to baseline levels by T2. This was an expected result as Phenylephrine is known to induce polycythaemia.
- The A10 and A20 values reduced significantly at T1 and remained lower than the baseline values at T2. The reduction in these values indicates an effect on the coagulation parameters of the horses.
- No significant anomalies were found in the PT and PTT values, suggesting that polycythaemia has no effect on plasma-based coagulation assessment or the number of platelets.
Conclusion of the Study
- Though the sample size was small and restricted to healthy mares, it was concluded that polycythaemia (induced by Phenylephrine) was associated with hypocoagulable readings using the VCM Vet™ device, without effect on plasma-based coagulation assessments or platelet count.
- The research recommends further investigation of viscoelastic testing in horses with increased PCV due to clinical illness. This is important for understanding the implications of polycythaemia in disease conditions.
Cite This Article
APA
Bishop RC, Jonk KM, Migliorisi A, Austin SM, Mullins EC, Wilkins PA.
(2024).
Increased packed cell volume alters point of care viscoelastic clotting parameters in horses.
Equine Vet J.
https://doi.org/10.1111/evj.14413 Publication
Researcher Affiliations
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
- Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
Grant Funding
- VM622 / University of Illinois College of Veterinary Medicine Student Research Course
References
This article includes 22 references
- McMichael MA, Smith SA. Viscoelastic coagulation testing: technology, applications, and limitations.. Vet Clin Pathol 2011;40:140–153.
- deLaforcade A, Goggs R, Wiinberg B. Systematic evaluation of evidence on veterinary viscoelastic testing part 3: assay activation and test protocol.. J Vet Emerg Crit Care 2014;24:37–46.
- Rosati T, Jandrey KE, Burges JW, Kent MS. Establishment of a reference interval for a novel viscoelastic coagulometer and comparison with thromboelastography in healthy cats.. Vet Clin Pathol 2020;49:660–664.
- McMichael M, Goggs R, Smith S, Wagg C, Warman S, Wiinberg B. Systematic evaluation of evidence on veterinary viscoelastic testing part 1: system comparability.. J Vet Emerg Crit Care 2014;24:23–29.
- Bishop RC, Kemper AM, Burges JW, Jandrey KE, Wilkins PA. Preliminary evaluation of reference intervals for a point‐of‐care viscoelastic coagulation monitor (VCM Vet) in healthy adult horses.. J Vet Emerg Crit Care 2023;33:540–548.
- Migliorisi A, Kemper AM, Parsley A, Austin SM, Bishop RC, Wilkins PA. In vitro coagulation parameters in healthy and sick foals using the point‐of‐care (POC) viscoelastic coagulation monitor vet‐VCM.. J Vet Emerg Crit Care 2020;30:S1–S34.
- McMichael M, Smith SA, McConachie EL, Lascola K, Wilkins PA. In‐vitro hypocoagulability on whole blood thromboelastometry associated with in‐vivo expansion of red cell mass in an equine model.. Blood Coagul Fibrinolysis 2011;22:424–430.
- Olascoaga A, Vilar‐Compte D, Poitevin‐Chacon A, Contreras‐Ruiz J. Wound healing in radiated skin: pathophysiology and treatment options.. Int Wound J 2008;5:246–257.
- McMichael MA, Smith SA, Galligan A, Swanson KS. In vitro hypercoagulability on whole blood thromboelastometry associated with in vivo reduction of circulating red cell mass in dogs.. Vet Clin Pathol 2014;43:154–163.
- Hardy J, Bednarski RM, Biller DS. Effect of phenylephrine on hemodynamics and splenic dimensions in horses.. Am J Vet Res 1994;55:1570–1578.
- Dallap BL, Dolente B, Boston R. Coagulation profiles in 27 horses with large colon volvulus.. J Vet Emerg Crit Care 2003;13:215–225.
- Epstein KL, Brainard BM, Gomez‐Ibanez SE, Lopes MAF, Barton MH, Moore JN. Thrombelastography in horses with acute gastrointestinal disease.. J Vet Intern Med 2011;25:307–314.
- Mendez‐Angulo JL, Mudge MC, Vilar‐Saavedra P, Stingle N, Couto CG. Thromboelastography in healthy horses and horses with inflammatory gastrointestinal disorders and suspected coagulopathies.. J Vet Emerg Crit Care 2010;20:488–493.
- Wilson ME, Holz CL, Kopec AK, Dau JJ, Luyendyk JP, Soboll Hussey G. Coagulation parameters following equine herpesvirus type 1 infection in horses.. Equine Vet J 2019;51:102–107.
- Navas de Solis C, Foreman JH, Byron CR, Carpenter RE. Ultrasonographic measurement of spleen volume in horses.. Comp Exerc Physiol 2012;8:19–25.
- R Core Team. R: a language and environment for statistical computing.. R Foundation for Statistical Computing 2023.
- Kassambara A. ggpubr: ‘ggplot2’ based publication ready plots, R package version 0.4.0.. 2020.
- Ng KF. Changes in thrombelastograph variables associated with aging.. Anesth Analg 2004;99:449–454.
- Shibata J, Hasegawa J, Siemens HJ, Wolber E, Dibbelt L, Dechun L. Hemostasis and coagulation at a hematocrit level of 0.85: functional consequences of erythrocytosis.. Blood 2003;101:4416–4422.
- Smith SA, McMichael MA, Gilor S, Galligan AJ, Hoh CM. Correlation of hematocrit, platelet concentration, and plasma coagulation factors with results of thromboelastometry in canine whole blood samples.. Am J Vet Res 2012;73:789–798.
- Deniau V, Depecker M, Bizon‐Mercier C, Couroucé‐Malblanc A. Influence of detomidine and xylazine on spleen dimensions and on splenic response to epinephrine infusion in healthy adult horses.. Vet Anaesth Analg 2013;40:375–381.
- Roeloffzen WW, Kluin‐Nelemans HC, Mulder AB, Veeger NJGM, Bosman L, de Wolf JTM. In normal controls, both age and gender affect coagulability as measured by thrombelastography.. Anesth Analg 2010;110:987–994.
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