Plasma lactate as a predictor of colonic viability and survival after 360 degrees volvulus of the ascending colon in horses.

OBJECTIVES

To determine the relationship between plasma lactate concentration and colonic viability and survival in horses with >or=360 degrees volvulus of the ascending colon.

STUDY

DESIGN

Retrospective study.

ANIMALS: Horses (n=73) with >or=360 degrees volvulus of the ascending colon.

METHODS

Medical records (January 2000-November 2005) of all horses examined for colic at Michigan State University Veterinary Teaching Hospital were reviewed. Horses were included only if plasma lactate concentration was measured preoperatively and a diagnosis of >or=360 degrees volvulus of the ascending colon was confirmed by surgery or necropsy. Non-survivors were only included if the ascending colon was evaluated histopathologically. Logistic regression analysis was used to model the relationship between lactate, colonic viability, and survival.

RESULTS

Of 73 horses, 61 were discharged. Mean (+/-SD) plasma lactate concentration was significantly lower in survivors (2.98+/-2.53 mmol/L) compared with non-survivors (9.48+/-5.22 mmol/L; odds ratio [OR]=1.628, 95% confidence limit [CI]=1.259-2.105). Plasma lactate concentration was significantly lower in horses with a viable colon (3.30+/-2.85 mmol/L) compared with horses with a non-viable colon (9.1+/-6.09 mmol/L; OR=1.472, 95% CI=1.173-1.846). Plasma lactate concentration <6.0 mmol/L had a sensitivity of 84% and a specificity 83% for predicting horse survival.

CONCLUSIONS

Our results demonstrate a strong association between plasma lactate concentration at the time of hospital admission and outcome in horses with >or=360 degrees volvulus of the ascending colon.

CLINICAL RELEVANCE: Plasma lactate concentration may help predict colonic viability and horse survival after ascending colon volvulus in horses.