Effect of tranexamic acid on intra- and postoperative haemorrhage in dogs with surgically treated hemoperitoneum

Tranexamic acid (TXA) is an antifibrinolytic drug that is used for uncontrolled bleeding of various origin. This retrospective study investigated the effect of tranexamic acid administration on bleeding tendency in dogs with surgically managed hemoperitoneum. Thirty dogs were treated with (TXA group) and 25 dogs without (CTR group) tranexamic acid prior to surgery. Various parameters (decrease in haematocrit, number of transfusions, shock index and changes in abdominal fluid accumulation) were used for characterization of bleeding tendency and compared between groups. Groups were similar at presentation and prior to surgery. None of the dogs undergoing rotational thromboelastography analysis showed hyperfibrinolysis prior to surgery. Overall transfusion and erythrocyte transfusion requirements as well as bleeding tendency, hospitalisation time and hospital discharge rate were similar between groups. Dogs of the TXA group received significantly more intraoperative plasma transfusions (P=0.013) and showed a higher systolic and mean arterial blood pressure (P=0.002 and 0.050) and lower shock index (P=0.028) with less dogs being in shock (P=0.012) at 24h. In summary, in this study population of dogs with surgically managed spontaneous hemoperitoneum dogs treated with tranexamic acid received more plasma transfusions intraoperatively and showed a lower shock index 24h after presentation. In dogs with surgically treated hemoabdomen tranexamic acid administration prior to surgery does not reduce red blood cell transfusion requirements or postoperative bleeding tendency

Evaluation of the Effect of Storage Time on ROTEM S® Parameters in Healthy and Ill Dogs.

Viscoelastic testing as a bedside test to assess global haemostasis has gained popularity in the past decade, with rotational thromboelastometry (ROTEM) and thromboelastography (TEG) being the two commonly used devices. TEG studies suggest analysis 30 min after blood sampling. However, the reproducibility of results over time for ROTEM analysis using lyophilized samples in dogs has not been established. In this study, we investigated the influence of time on viscoelastic testing, using 33 healthy staff-/client-owned dogs for blood sampling and repeated measurements of ROTEM tracings at three different time points after blood collection. Additionally, a group of 21 hospitalized patients with suspected coagulation disorders were included to investigate whether stability over time was comparable between healthy and ill dogs. We demonstrated a significant difference of ROTEM tracings over time, with a tendency towards hypocoagulability over time. These changes do have a clinical relevance as they exceed reference intervals and could therefore lead to erroneous conclusions about a patient's coagulation status. Therefore, time-specific reference intervals are proposed and presented in this publication

Comparison of Jugular vs. Saphenous Blood Samples, Intrarater and In-Between Device Reliability of Clinically Used ROTEM S Parameters in Dogs

Rotational Thromboelastometry (ROTEM) allows for the global assessment of hemostasis in whole blood samples. Preanalytical and analytical factors may influence test results, and data about the reliability and reproducibility of lyophilized ROTEM tests are scarce. Therefore, the objective of this study was to evaluate the influence of blood collection site on ROTEM S parameters and to assess intrarater and in-between device variability. A total of thirty, healthy, staff-owned dogs were included. Blood collection and ROTEM analysis were performed by trained staff according to a standardized protocol. Extrinsically activated (tissue factor; Ex-TEM S), with the addition of cytochalasin for platelet inhibition (Fib-TEM S), and intrinsically activated (In-TEM) analyses were performed. Analysis of our data showed significant variability for various Ex-TEM S and Fib-TEM S parameters from different collection sites and intrarater and in-between device measurements. We conclude that serial monitoring with ROTEM should be performed on the same device, with blood always taken from the same collection site using a standardized blood sampling technique. While In-TEM S, apart from maximum lysis, showed very stable and reliable results, we suggest interpreting especially clotting and clot formation parameters from Ex-TEM S and Fib-TEM S tests with caution and using duplicate measurements to detect outliers and to prevent initiation of incorrect therapies

Evaluation of the Effect of Storage Time on ROTEM S® Parameters in Healthy and Ill Dogs

Viscoelastic testing as a bedside test to assess global haemostasis has gained popularity in the past decade, with rotational thromboelastometry (ROTEM) and thromboelastography (TEG) being the two commonly used devices. TEG studies suggest analysis 30 min after blood sampling. However, the reproducibility of results over time for ROTEM analysis using lyophilized samples in dogs has not been established. In this study, we investigated the influence of time on viscoelastic testing, using 33 healthy staff-/client-owned dogs for blood sampling and repeated measurements of ROTEM tracings at three different time points after blood collection. Additionally, a group of 21 hospitalized patients with suspected coagulation disorders were included to investigate whether stability over time was comparable between healthy and ill dogs. We demonstrated a significant difference of ROTEM tracings over time, with a tendency towards hypocoagulability over time. These changes do have a clinical relevance as they exceed reference intervals and could therefore lead to erroneous conclusions about a patient’s coagulation status. Therefore, time-specific reference intervals are proposed and presented in this publication

Comparison of Jugular vs. Saphenous Blood Samples, Intrarater and In-Between Device Reliability of Clinically Used ROTEM S Parameters in Dogs.

Rotational Thromboelastometry (ROTEM) allows for the global assessment of hemostasis in whole blood samples. Preanalytical and analytical factors may influence test results, and data about the reliability and reproducibility of lyophilized ROTEM tests are scarce. Therefore, the objective of this study was to evaluate the influence of blood collection site on ROTEM S parameters and to assess intrarater and in-between device variability. A total of thirty, healthy, staff-owned dogs were included. Blood collection and ROTEM analysis were performed by trained staff according to a standardized protocol. Extrinsically activated (tissue factor; Ex-TEM S), with the addition of cytochalasin for platelet inhibition (Fib-TEM S), and intrinsically activated (In-TEM) analyses were performed. Analysis of our data showed significant variability for various Ex-TEM S and Fib-TEM S parameters from different collection sites and intrarater and in-between device measurements. We conclude that serial monitoring with ROTEM should be performed on the same device, with blood always taken from the same collection site using a standardized blood sampling technique. While In-TEM S, apart from maximum lysis, showed very stable and reliable results, we suggest interpreting especially clotting and clot formation parameters from Ex-TEM S and Fib-TEM S tests with caution and using duplicate measurements to detect outliers and to prevent initiation of incorrect therapies

Serial evaluation of haemostasis following acute trauma using rotational thromboelastometry in cats

Objective: The aim of this study was to describe coagulation abnormalities and incidence of acute traumatic coagulopathy (ATC) in traumatized cats over the first 24 hours after admission. Study Design: This was a prospective observational study at the university teaching hospital including 26 cats with acute (<5 hours) trauma. Blood was sampled for rotational thromboelastometry (ROTEM) parameters at presentation and 6 hours/24 hours thereafter. Rotational thromboelastometry tracings were defined as hypo- or hypercoagulable if ≥ 2 of the following parameters were above or below institutional reference intervals: clotting time, clot formation time (CFT), maximum clot firmness, maximum lysis or maximum clot elasticity. Hypocoagulability at presentation was defined as ATC. Injury severity scores, treatment and survival to hospital discharge were retrieved from patient records Results: The incidence of ATC was 15% and the most common ROTEM abnormalities in cats with ATC were clotting time and CFT prolongation in both extrinsic and intrinsic ROTEM profiles. After 24 hours, compared with presentation, significantly more cats were hypercoagulable (p = 0.047) and none of the cats showed hypocoagulopathy. Cats with ATC received significantly more blood transfusions (p = 0.008) Conclusion: The incidence of ATC in cats is higher than previously reported. Clotting time and CFT prolongations seem to be more common than hyperfibrinolysis and 53% of the cats became hypercoagulable within 24 hours. While the clinical relevance of ATC in cats needs to be investigated, cats diagnosed with ATC required significantly more blood transfusions

Determination of reference intervals for single vial rotational thromboelastometry (ROTEM) parameters and correlation with plasmatic coagulation times in 49 clinically healthy dogs.

The objectives of this prospective study were determination of reference intervals (RI) for rotational thromboelastometry (ROTEM) parameters in single use reagents and to evaluate correlations between plasmatic coagulation times and ROTEM parameters. Blood was sampled from a jugular vein in 49 client-owned healthy dogs and ex-tem S, in-tem S, fib-tem S and ap-tem S parameters, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, haematology, blood chemistry and venous blood gas analysis was performed. Determination of RI was performed using Excel add-in Reference Value Advisor and correlations between PT, aPTT and fibrinogen with selected ROTEM parameters were determined by Spearman correlation. Ex-tem S maximum clot firmness (MCF) RI are smaller compared to RI in people and liquid ex-tem in dogs while maximum lysis was comparable to those in people but smaller than previously reported in dogs. A strong correlation was found between fibrinogen measured by Clauss and fib-tem S and in-tem S MCF (r = 0.541, P < .001 and r = 0.610, P < .001, respectively). PT showed a significant but moderate correlation with ex-tem S CT (r = 0.340, P = .030), in-tem S CFT (r = 0.433, P = .003), fib-tem S CT (r = 0.426, P = .009) and ap-tem S CT (r = 0.354, P = .015) while aPTT was not significantly correlated with any of the evaluated parameters. In conclusion, this study provides single use reagent ROTEM parameter RIs that are different from RI determined with liquid reagents. Significant correlations between fibrinogen concentrations measured by Clauss and clot firmness of fib-tem S and in-tem S profiles and between PT and clotting times of all reagents were identified

Respiratory and cardiovascular effects of doxapram and theophylline for the treatment of asphyxia in neonatal calves

Respiratory stimulants are widely used in asphyxic neonatal calves despite a lack of data about their effectiveness and indications of possible side effects. The effect of doxapram and theophylline on respiratory, cardiovascular, and acid-base variables was investigated in 10 healthy neonatal calves (Bos Taurus). A venous, a peripheral arterial, and a pulmonary arterial catheter were placed, and central venous, pulmonary, and systemic blood pressures and cardiac output were measured using thermodilution technique. Doxapram, but not theophylline, led to an immediate increase in respiratory rate (P </= 0.01). The arterial pCO(2) decreased to 27.1+/-4.7mm Hg within 30sec after doxapram administration and to 46.3+/-5.8mm Hg within 120min after theophylline administration (P<0.0001). The systolic pulmonary pressure increased from 70+/-8mm Hg (mean+/-SD) to 93+/-19mm Hg within 30sec after doxapram, but decreased after theophylline. The pulmonary vascular resistance also increased after doxapram and decreased after theophylline (P<0.01). Doxapram had a more pronounced and faster effect on respiratory rate and elimination of CO(2) than theophylline. Doxapram, but not theophylline, is indicated for treatment of postnatal asphyxia in calves, but there are potential cardiovascular side effects. Copyright © 2009 Elsevier Inc. All rights reserved