Effects on arterial blood gases and some clinical parameters of caffeine, atropine sulphate or doxapram hydrochloride in calves with neonatal asphyxia

Abstract

In this study, the effects of treatment with caffeine, atrophine sulphate or doxapram hydrochloride on arterial blood gases, acid-base equilibrium and some clinical parameters in 24 calves with neonatal asphyxia were investigated. These animals were allotted in 3 equal groups according to the received treatment: group 1 - caffeine (0.5 g in toto subcutaneously), group 2 - atropine sulphate (0.02 mg/kg subcutaneously) and group 3 - doxapram hydrochloride (40 mg in toto intravenously). Clinical parameters (rectal temperature, respiratory and heart rates) were assessed before and 10, 20 and 30 minutes after the drug administration whereas arterial pH values, pressure of carbon dioxide (pCO(2)), pressure of oxygen (POD, base excess (BE) and bicarbonate concentrations (HCO(3)(-)) were measured before and 0.5 and 24 hours after. Significant and gradual increases of the clinical parameters according to time evidenced a clinical improvement induced by the 3 drugs. In the same way, the moderate respiratory acidosis observed in 15 calves and the mixed metabolic-respiratory acidosis observed in 9 calves before treatment were greatly corrected; arterial pH values, pO(2), BE and HCO(3)(-) concentrations progressively and significantly increased whereas PCO(2) markedly declined in the same time. Moreover, the doxapram treatment appeared to be the most secure because no mortality was observed in this group contrary to the 2 other groups and the most efficient: changes in clinical parameters at 20 and 30 minutes as well as the acidosis correction at 30 minutes (modifications of pH, pO(2) and PCO(2)) were significantly higher in calves treated with doxapram than in those treated with caffeine or atropine. These results demonstrate the highest therapeutical interest of doxapram compared to caffeine or atropine during neonatal asphyxia in calf.