Thromboelastography in healthy, sick non‐septic and septic neonatal foals

Abstract

Objectives To evaluate citrated recalcified thromboelastography (TEG) in healthy newborn foals, and to determine intra-assay, interindividual and intra-individual (at 12 h, 24 h and 7 days after birth) variations. Additionally, to compare TEG variables, haematological values and conventional coagulation profiles from healthy, sick non-septic, and septic foals.Design Prospective study. MethodsThe study group comprised 18 healthy, 15 sick nonseptic and 17 septic foals. Two citrated (3.2%; 1 : 9 anticoagulant : blood ratio) blood samples were submitted for haemostatic evaluation using a TEG analyser and conventional coagulation profile. TEG values (R time (R), K time (K), angle (a), maximum amplitude (MA) and G value (G)), complete blood count (CBC) and conventional coagulation profile (prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration (Fib) and antithrombin (AT)) were evaluated. Signalment, presenting complaint, sepsis scores, blood culture results and outcome were taken from the medical records of the sick foals.Results Mean values Ϯ SD for TEG variables in healthy neonatal foals were: R = 11.82 Ϯ 5.35 min, K = 3.06 Ϯ 1.34 min, a = 51.19 Ϯ 12.66 degrees, MA = 55.06 Ϯ 6.67 mm and G = 6361 Ϯ 1700 dyn/cm 2 . Mean coefficients of variation for intra-assay/inter-individual/ intra-individual in healthy foals were: R = 3.5/45.2/43.1%; K = 5.3/ 58.7/28.7%; a = 1.5/24.7/11.9%; MA = 0.3/12.1/6.1%; G = 1.6/26.7/ 14.7%. Septic foals had significantly greater a, MA and G values than sick non-septic foals, and significantly greater MA and G than healthy foals, changes that are consistent with hypercoagulability. Weak correlations were detected between TEG variables and haematological or haemostatic values.Conclusions TEG could be used to provide additional information about the haemostatic system in equine neonates. Keywords coagulation; foals; hypercoagulability; sepsis; thromboelastographyAbbreviations aPTT, activated partial thromboplastin time; AT, antithrombin; CBC, complete blood count; CV, coefficient of variation; DIC, disseminated intravascular coagulation; FDP, fibrinogen degradation product; Fib, fibrinogen concentration; IgG, immunoglobulin G; MA, maximum amplitude; PAI, plasminogen activator inhibitor; PCV, packed cell volume; PLT, platelet count; PT, prothrombin time; TEG, thromboelastography; TP, total protein; WBC, white blood cell Aust Vet J 2011;89:500-505 doi: 10.1111/j.1751-0813.2011.00854.x S epsis is a major cause of morbidity and mortality in human and equine neonates. [1][2][3][4][5] During septic shock, the relationships among procoagulant, anticoagulant and fibrinolytic factors that maintain the delicate balance of the haemostatic system are disrupted. 6 Haemostatic abnormalities have been reported in neonatal foals with severe sepsis and these findings are frequently associated with poor outcome.7-9 One recent report evaluating six coagulation parameters showed that foals in septic shock were 12.7-fold more likely to have clinical evidence of bleeding than ...

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