Haemodynamic, metabolic and physical responses to a neuroleptanalgesic-glyceryl guaiacolate combination in the horse.

This research inspects the reactions of four horses to a medical mix made of a neuroleptanalgesic compound with glyceryl guaiacolate. The results revealed severe tachycardia, increased muscular tension, hypoxemia, hypercapnia, metabolic acidosis, and hyperglycemia in the horses; thus suggesting this combination might not be a safe anesthetic procedure for equines.

Experiment and Findings

• The paper discusses a study in which a commercial neuroleptanalgesic compound known as acepromazine-etorphine was injected into four horses. The effect of this injection led to a considerable increase in the heart rate (a condition known as severe tachycardia), increase in muscular tone, and other metabolic changes.
• Some of the changes noted in the horses included hypoxaemia, a condition where the oxygen level in the blood is below normal range, hypercapnia (increased level of carbon dioxide in the blood), metabolic acidosis which is a condition that occurs when the body produces excessive quantity of acid, and hyperglycaemia, which implies very high blood sugar level.
• The researchers did not observe any changes in the electrolyte levels of the horses during this experimental phase. However, the administration of another drug, diprenorphine, a reversal agent for etorphine, led to long-lasting decreases in calcium and phosphorus serum concentrations, as well as decreases in the packed cell volume and total protein serum concentration.

Second Experiment and Findings

• In a second phase of the experiment, the researchers administered glyceryl guaiacolate (a type of expectorant that helps loosen mucus (phlegm) and thin bronchial secretions) to the horses once they were anesthetized with the acepromazine-etorphine combination.
• The administration of glyceryl guaiacolate caused the previous muscular rigidity observed in the horses to disappear and also caused the tachycardia to be less noticeable. This second experiment also led to a more pronounced hypoxaemia, but the changes observed in other parameters were similar to those found in the first experiment.

Conclusion

• The study concluded that the combination of neuroleptanalgesic and glyceryl guaiacolate is not a safe anesthetic procedure in horses due to the severe reactions it caused.