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

Objectives To evaluate citrated recalcified thromboelastography (TEG) in healthy newborn foals, and to determine intra-assay, inter-individual 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. Methods The study group comprised 18 healthy, 15 sick non-septic 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 (alpha), 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 +/- SD for TEG variables in healthy neonatal foals were: R = 11.82 +/- 5.35 min, K = 3.06 +/- 1.34 min, alpha = 51.19 +/- 12.66degrees, MA = 55.06 +/- 6.67 mm and G = 6361 +/- 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%; alpha = 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 alpha, 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.