Evaluation of plasma catecholamine and serum cortisol concentrations in horses with colic.
OBJECTIVE
To evaluate plasma epinephrine and norepinephrine concentrations and serum cortisol concentration in horses with colic and assess the relationship of these variables with clinical signs, routinely measured clinicopathologic variables, and outcome in affected horses.


METHODS
Prospective observational study.


METHODS
35 horses with colic.


METHODS
Blood samples were collected within 30 minutes of arrival at the veterinary hospital from horses referred because of colic. Plasma and serum samples were analyzed for cortisol, epinephrine, norepinephrine, lactate, and electrolyte concentrations and acid-base variables. Heart rate at admission and outcome (survival or nonsurvival) were recorded. Univariate logistic regression was used to calculate crude (unadjusted) odds ratios and 95% confidence intervals.


RESULTS
Of the 35 horses with colic, 26 survived. Higher plasma epinephrine, plasma lactate, and serum cortisol concentrations were significantly associated with increased risk of nonsurvival, but plasma norepinephrine concentration was not associated with outcome. Plasma epinephrine concentration was significantly correlated with heart rate (r = 0.68), plasma lactate concentration (r = 0.87), blood pH (r = -0.83), anion gap (r = 0.74), and base excess (r = -0.81).


CONCLUSIONS
The risk of death appears to be greater in colic-affected horses with high circulating concentrations of epinephrine and cortisol. The correlation of epinephrine with other biochemical markers of illness severity and with heart rate indicates that the degree of sympathetic activation in horses with colic can be inferred from routinely measured variables.
Hinchcliff
Kenneth W
KW
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210-1089, USA.
Rush
Bonnie R
BR
Farris
James W
JW
D000136:Acid-Base Equilibrium; D000818:Animals; D002395:Catecholamines / Q000097:blood*; D003085:Colic / Q000097:blood / Q000401:mortality / Q000662:veterinary*; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate; D006734:Horse Diseases / Q000097:blood* / Q000401:mortality; D006736:Horses; D006854:Hydrocortisone / Q000097:blood*; D007773:Lactates / Q000097:blood; D008297:Male; D009638:Norepinephrine / Q000097:blood; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012720:Severity of Illness Index; D016019:Survival Analysis
D002395:Catecholamines; D007773:Lactates; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine