Studies on Intravenous Regional Analgesia of the Hind Limb in the Bovine

Abstract

Twenty-five buffalo calves (age: 14 +/- 1.9 months; body weight: 102 +/- 9.4 kg) were subjected to intravenous regional analgesia (IRA) of the hind limb with 2% lignocaine HCl (4 mg/kg b.w.), infused through the dorsal digital vein. In control animals 15 ml of normal saline was infused. The effect of tourniquet release after 35 (8 calves) and 65 min (7 calves) on EEG, ECG, arterial and venous pressures, blood gases and pH, respiration and temperature were studied. A detectable concentration of lignocaine occurred before the release of tourniquet. The lignocaine concentration recorded in the systemic circulation did not produce any significant nervous or cardiovascular changes before or after release of tourniquet. Transient EEG and ECG changes were seen in six (tourniquet release after 35 min) and three (tourniquet release after 65 min) IRA animals, respectively. No significant changes were seen in heart rate, respiratory rate and rectal temperature, systolic, diastolic, mean arterial and central venous pressures. Arterial blood pH, PCO2 and HCO3- concentration showed no significant differences. Animals receiving IRA did not show hypoxaemia typical to postural changes.