Anaesthesia for open heart surgery in the calf

Light and Electronmicroscopic Examination of Calf Lung Tissue after Left Ventricular Assisted Circulation with the Spindle Pump

The influence of the spindle pump, a nonpulsatile blood pump, used as LVAD on calf lung tissue was examined by means of the actual 16th protoype, which was applied in 3 “acute ” tests up to 13 hours of pumping duration and 8 prolonged experiments with pumping periods up to 63 hours. Samples were taken during the operation and after exitus of the test animal and investigated by light and electronmicroscopy. Histological findings of tissue changes could be ascribed to mechanical manipulations and shock-like influences. Regardless of the time of nonpulsatile perfusion this tissue damage remained within an acceptable range, indicating the absence of a deleterious effect of nonpulsatile flow.

Gas exchange during xylazine-ketamine anesthesia in neonatal calves

Ten neonatal calves were anesthetized with xylazine and ketamine intramuscularly and breathed air spontaneously. Drug injection was repeated after 45 minutes. Each injection resulted in a rapid and sustained increase in respiratory rate, but arterial carbon dioxide tension (PaCO2) increased, indicating hypoventilation. Arterial hypoxemia, primarily caused by hypoventilation, developed within 15 minutes of each injection, but gradually disappeared. Acidemia was primarily respiratory in origin. Heart rate and arterial blood pressure decreased for the duration of anesthesia (90 minutes). This form of anesthesia is a satisfactory alternative to inhalation anesthesia of neonatal calves.