Dv. Wilson et al., Perioperative management of calves undergoing implantation of a left ventricular assist device, VET SURGERY, 29(1), 2000, pp. 106-118
Objective-To describe perioperative management of calves that underwent lef
t lateral thoracotomy, aortic cross-clamping, partial left heart bypass and
implantation of a left ventricular assist device.
Sample Population-A total of 43 healthy castrated male calves, weighing 121
+/- 24 kg.
Results-Diazepam (mean +/- SD, 0.26 +/- 0.07 mg/kg), ketamine (5.9 +/- 2.17
mg/kg) and isoflurane were used in the anesthetic management of calves und
ergoing implantation of a left ventricular assist device in the descending
thoracic aorta. Other adjunctive agents administered were fentanyl (11 +/-
5.4 mu g/kg), lidocaine (4.9 +/- 3.19 mg/kg), bupivacaine (0.75%) and butor
phanol (0.49 +/- 0.13 mg/kg). None of the calves regurgitated at induction
or during intubation. A tube was used to drain the rumen and prevent bloat
during the procedure,
Partial left heart bypass was used to perfuse the caudal half of the body d
uring the period of aortic cross clamp and device implantation. Initial mea
n systemic blood pressure was 96 +/- 25 mm Hg, and pressures measured in th
e auricular artery increased during aortic cross-clamping and bypass. Vasoc
onstrictor therapy was required to treat caudal arterial hypotension during
the procedure in 9 calves. Mean systemic arterial pressures returned to ba
seline values by the end of the anesthetic period. Initial mean pulmonary a
rterial pressures (PAP) were 22 +/- 3 mm Hg. A significant but transient in
crease in pulmonary arterial pressure occurred after both heparin and prota
mine administration.
Conclusions-The described anesthetic protocol was effective for thoracotomy
and implantation of an intra-aortic left ventricular assist device in norm
al calves. Partial left ventricular bypass was a useful adjunct during the
period of aortic cross clamp. The doses of heparin and protamine administer
ed were effective. Responsibility to monitor oxygenation of the cranial hal
f of the animal continues during the bypass period as hypoxemia due to pulm
onary dysfunction will not be detected by the perfusionist. (C)Copyright 20
00 by The American College of Veterinary Surgeons.