HEMODYNAMIC-EFFECTS OF UNILATERAL SEGMENTAL LUMBAR EPIDURAL ANALGESIA IN CATTLE

  • 1 January 1979
    • journal article
    • research article
    • Vol. 40  (5) , 645-650
Abstract
Hemodynamic measurements, arterial and mixed venous blood gas tensions, and pH were determined in 12 adult cows (mean wt 538 kg) following the injection of 8 ml of 5% procaine between the 1st and the 2nd lumbar vertebra into the epidural space. Comparison of base-line data with data obtained during unilateral segmental lumbar analgesia between T13 [13th thoracic vertebra] and L3 [3rd lumbar vertebra] segments indicated significant decreases (P < 0.05) in total peripheral resistance and diastolic and mean arterial blood pressures, and significant increases (P < 0.05) in heart rate and cardiac output. Arterial and mixed venous blood gas tensions and pH, O2-uptake, stroke volume, left ventricular stroke work, left ventricular minute work and hematocrit did not change significantly (P > 0.05). Cardiovascular and respiratory values in 2 cows (mean wt 700 kg) given xylazine (50 mg, i.m.) were depressed from base-line data, but did not change significantly (P > 0.05) during unilateral segmental epidural analgesia of segments T13 to L3. The nonsedated healthy cow tolerates sympathetic vasomotor blockade between T13 and L3 segments well and is able to mobilize circulatory mechanisms effectively.