384 
SURGERY AND TRANSPLANTATION 
In order to insure that only calves in good 
health were utilized, the physical status of all 
animals was evaluated preoperatively. Those 
with poor appetities, diarrhea or rectal temper- 
atures above 102° F were eliminated from the 
study.-'' The chests were auscultated for evidence 
of pneumonia, a common disease in commer- 
cially obtained young calves,"* and white blood 
cell counts and differentials were determined. 
(Normal range: 6,000-12,000/mm^) 
Despite these measures, however, several of 
the animals undergoing thoracotomy showed 
gross evidence of acute pneumonia and almost 
all showed evidence of chronic pulmonary fi- 
brosis, mainly involving the lower lobes and 
lingula. Accordingly, antibiotic treatment with 
Ampicillin (Wyeth Laboratories, Inc., Philadel- 
phia, Pa.) (1 gm/day). The effectiveness of 
such treatment, however, is questionable, since 
pulmonary consolidation persists long after 
acute infection subsides.^ 
Bacteriological examination of exudate from 
calves that developed empyema postoperatively 
showed the presence of Pasteurella multocida, 
a small, non-spore-forming, gram-negative ba- 
cillus, particularly common in the respiratory 
tracts of animals.^ ' The strain in our laboratory 
is sensitive to ampicillin, penicillin, tetracycline 
and erythromycin, but resistant to lincomycin, 
streptomycin and nafcillin. 
Profuse salivary and tracheobronchial secre- 
tions are characteristic of ruminants.^ These 
were partially controlled by intramuscular in- 
jection of 0.4-0.8 mg of atropine sulphate (Eli 
Lily and Company, Indianapolis, Indiana) 
prior to induction of anesthesia. Although 
scopolamine has also been used effectively,^ it 
was not used in these experiments since idio- 
syncratic reactions to therapeutic doses in hu- 
mans are more common than with atropine. The 
same doses that normally produce drowsiness 
may instead cause excitement and delirium.^ 
Food is withheld the day before operation but 
free access to water is allowed since the stom- 
achs of ruminants cannot be emptied by with- 
holding water for 12 hours. 
Anesthesia was induced by intravenous in- 
jection of 40-50 cc of 2.5% sodium thiamylal 
(Surital®, Parke-Davis, Detroit, Michigan) via 
a large intracath inserted in the left saphenous 
vein. This was administered slowly until the | 
corneal reflex could no longer be elicited. Al- | 
though others have reported that calves are ! 
extremely sensitive to even the ultrashort-act- 
ing barbiturates and induce anesthesia by ' 
inhalation, ^•"•^^■^^•^^ our experience with intra- | 
venous sodium triamylal for induction has been | 
satisfactory. This might be due to the very \ 
light plane of anesthesia induced. In addition, ] 
the use of an intravenous barbiturate to produce 
loss of consciousness prior to initiation of in- 
halation anesthesia may offer the advantage of 
avoiding the undesirable stage of excitement 
more regularly seen with inhalation anesthet- 
ics.^'^ Thiopental 2 and methohexital ^ have 
also been used for induction of anesthesia with 
apparent success. 
The calves were intubated with 20 mm cuffed 
endotracheal tubes, 50 cm long (Rusch, West 
Germany) with manual abduction of the man- 
dible and maxilla and a standard adult laryn- 
goscope blade (The Foregger Co., Long Island, 
New York) extended 15 cm by attachment of a 
flat metal bar to a total length of 34 cm. Al- 
though muscle relaxants have been used for in- 
tubation,^'^ they were not employed in this study 
to avoid paralysis of the respiratory muscles 
and irreversible hypoxia before assisted ventila- 
tion could be begun. However, prior to thoracot- 
omy each animal received 80-100 mg of gal- 
lamine triethiodide (Flaxedil®, Davis and Geek, 
Danbury, Connecticut) intravenously for mus- 
cular relaxation. This compound has less sym- 
pathetic ganglionic blocking action than most 
neuromuscular blocking agents, but in effective 
doses does block parasympathetics.^ These ac- 
tions are not undesii'able since they may help 
to avoid the potential bradycardia and hypo- 
tension caused by Halothane. 
Anesthesia was maintained with 0.5-1.0% 
Halothane (Ayerst Laboratories, New York, 
New York) (2-bromo-2-chloro-l :1 :l-trifluoro- 
ethane) delivered by a Fluotec vaporizer 
(Fraser Sweatman, Inc., Buffalo, New York). 
Halothane is the anesthetic agent most com- 
monly employed for cardiovascular surgery in 
calves 1.2,5,10,12.14.15 although ether ^ and methoxy- 
flurane ^ have also been used, but the former is 
flammable and precludes the use of electro- 
cautery, while animals anesthetised with the 
