Digital blood flow and plasma endothelin concentration in clinically endotoxemic horses.
OBJECTIVE
To measure plasma endothelin-1 (ET-1) concentrations and digital blood flow in clinically endotoxemic horses.


METHODS
36 adult horses that underwent emergency celiotomy for primary gastrointestinal tract disease.


METHODS
On days 2 and 5 following surgery, Doppler ultrasonographic digital arterial blood flow measurements were obtained. Hematologic and biochemical analyses were performed, and plasma concentrations of ET-1 and endotoxin (lipopolysaccharide) were determined. A scoring system based on 9 clinical variables was used to assign horses to group B (quartile with greatest cumulative score) or group A (remaining 3 quartiles). Follow-up at 2.5 years was obtained by telephone questionnaire.


RESULTS
For all horses on day 2, median (interquartile values) plasma ET-1 concentrations were 1.4 (0.8, 1.7) pg/mL, whereas on day 5, plasma ET-1 concentrations were 1.0 (0.5, 1.6) pg/mL. On day 2, digital blood flow was 0.057 (0.02, 0.07) mL/min in group A horses and 0.035 (0.02, 0.03) mL/min in group B horses. On day 5, plasma ET-1 concentration was significantly (73%) higher in group B horses, compared with group A horses. Thirty of 36 horses were alive at 2.5 years; group A horses were more likely to have survived (odds ratio, 25; 95% confidence interval, 2.4 to 262). Significant associations were found between an increase in digital pulses, hoof wall temperatures, or both and increased digital blood flow (0.14 vs 0.04 mL/min) on day 2 and increased digital arterial diameter (0.32 vs 0.23 cm) on day 5.


CONCLUSIONS
Horses with more severe endotoxemia had decreased digital blood flow, increased plasma ET-1 concentrations, and decreased long-term survival.
Menzies-Gow
Nicola J
NJ
Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire AL9 7TA, United Kingdom.
Bailey
Simon R
SR
Stevens
Kim
K
Katz
Lisa
L
Elliott
Jonathan
J
Marr
Celia M
CM
D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D013505:Digestive System Surgical Procedures / Q000009:adverse effects / Q000662:veterinary; D019332:Endothelin-1 / Q000097:blood*; D019446:Endotoxemia / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000662:veterinary*; D005260:Female; D005500:Follow-Up Studies; D005528:Foot / Q000098:blood supply* / Q000000981:diagnostic imaging; D005767:Gastrointestinal Diseases / Q000150:complications / Q000601:surgery / Q000662:veterinary; D006339:Heart Rate / Q000502:physiology; D006734:Horse Diseases / Q000097:blood* / Q000503:physiopathology; D006736:Horses; D007958:Leukocyte Count / Q000662:veterinary; D008070:Lipopolysaccharides / Q000097:blood; D008297:Male; D012119:Respiration; D011795:Surveys and Questionnaires; D014463:Ultrasonography
D019332:Endothelin-1; D008070:Lipopolysaccharides