Quantitative assessment of left ventricular volume and function by transthoracic and transesophageal echocardiography, ultrasound velocity dilution, and gated magnetic resonance imaging in healthy foals.

OBJECTIVE: To compare measurements of left ventricular volume and function derived from 2-D transthoracic echocardiography (2DE), transesophageal echocardiography (TEE), and the ultrasound velocity dilution cardiac output method (UDCO) with those derived from cardiac MRI (cMRI) in healthy neonatal foals. ANIMALS: 6 healthy 1-week-old Standardbred foals. PROCEDURES: Foals were anesthetized and underwent 2DE, TEE, and cMRI; UDCO was performed simultaneously with 2DE. Images acquired by 2DE included the right parasternal 4-chamber (R4CH), left apical 4- and 2-chamber (biplane), and right parasternal short-axis M-mode (M-mode) views. The longitudinal 4-chamber view was obtained by TEE. Measurements assessed included left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), ejection fraction, stroke volume (LVSV), cardiac output (CO), and cardiac index (CI). Bland-Altman analyses were used to compare measurements derived from biplane, R4CH, and M-mode images and UDCO with cMRI-derived measurements. Repeatability of measurements calculated by 3 independent reviewers was assessed by the intraclass correlation coefficient. RESULTS: Compared with cMRI, all 2DE and TEE modalities underestimated LVEDV and LVESV and overestimated ejection fraction, CO, and CI. The LVSV was underestimated by the biplane, R4CH, and TEE modalities and overestimated by UDCO and M-mode methods. However, the R4CH-derived LVSV, CO, and CI were clinically comparable to cMRI-derived measures. Repeatability was good to excellent for measures derived from the biplane, R4CH, M-mode, UDCO, and cMRI methods and poor for TEE-derived measures. CONCLUSIONS AND CLINICAL RELEVANCE: All assessed modalities yielded clinically acceptable measurements of LVEDV, LVESV, and function, but those measurements should not be used interchangeably when monitoring patient progress.

Assessment of agreement among diplomates of the American College of Veterinary Anesthesia and Analgesia for scoring the recovery of horses from anesthesia by use of subjective grading scales and development of a system for evaluation of the recovery of horses from anesthesia by use of accelerometry.

OBJECTIVE To evaluate agreement among diplomates of the American College of Veterinary Anesthesia and Analgesia for scores determined by use of a simple descriptive scale (SDS) or a composite grading scale (CGS) for quality of recovery of horses from anesthesia and to investigate use of 3-axis accelerometry (3AA) for objective evaluation of recovery. ANIMALS 12 healthy adult horses. PROCEDURES Horses were fitted with a 3AA device and then were anesthetized. Eight diplomates evaluated recovery by use of an SDS, and 7 other diplomates evaluated recovery by use of a CGS. Agreement was tested with κ and AC1 statistics for the SDS and an ANOVA for the CGS. A library of mathematical models was used to map 3AA data against CGS scores. RESULTS Agreement among diplomates using the SDS was slight (κ = 0.19; AC1 = 0.22). The CGS scores differed significantly among diplomates. Best fit of 3AA data against CGS scores yielded the following equation: RS = 9.998 × SG0.633 × ∑UG0.174, where RS is a horse's recovery score determined with 3AA, SG is acceleration of the successful attempt to stand, and ∑UG is the sum of accelerations of unsuccessful attempts to stand. CONCLUSIONS AND CLINICAL RELEVANCE Subjective scoring of recovery of horses from anesthesia resulted in poor agreement among diplomates. Subjective scoring may lead to differences in conclusions about recovery quality; thus, there is a need for an objective scoring method. The 3AA system removed subjective bias in evaluations of recovery of horses and warrants further study.

Assessment of acute moderate hyperglycemia on traditional and thromboelastometry coagulation parameters in healthy adult horses.

OBJECTIVE: To determine whether experimentally induced acute moderate hyperglycemia is associated with coagulation activation in healthy adult horses. DESIGN: Prospective experimental study. SETTING: University veterinary teaching hospital. ANIMALS: Six healthy adult horses. INTERVENTIONS: Hyperglycemia (10.0-13.3 mmol/L [180-240 mg/dL]) was induced and maintained for 6 hours using a hyperglycemic clamp technique. Blood glucose concentrations were assessed using a point of care (POC) glucometer at 10- and 20-minute intervals throughout the hyperglycemic clamp procedure. Platelet count, fibrinogen concentration, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin antithrombin complex level (TAT), and thromboelastometry (TEM) were determined before and after jugular catheter placement, prior to glucose administration, and at 3 and 6 hours of sustained hyperglycemia. Data were analyzed by repeated measures analysis of variance with significance defined as P < 0.05. MEASUREMENTS AND MAIN RESULTS: All horses maintained blood glucose concentration >10.0 mmol/L (>180 mg/dL) throughout the duration of the hyperglycemic clamp with a mean concentration of 11.9 ± 0.3 mmol/L [216 ± 6 mg/dL] as measured by the POC glucometer. No significant difference was found for any evaluated parameter associated with sustained hyperglycemia. Intravenous catheter placement resulted in a significant increase in mean TAT (0.8 ± 0.3 µg/L pre-catheter, 2.3 ± 0.8 µg/L post-catheter; P = 0.008). CONCLUSIONS: Acute, moderate hyperglycemia in healthy adult horses does not have a detectable effect on coagulation based on evaluated parameters. Jugular catheter placement results in a transient increase in thrombin generation as determined by increased TAT concentrations.