Journal
of Wildlife
Diseases
Vol.
17. No.
1, January,
1981
121
Present
address:
Division
of
Lung
Diseases,
N.I.H.,
Westwood
Bldg.,
Rm.
6ACI3,
5333
Westbard
Avenue,
Bethesda,
Maryland
20205.
CARDIOVASCULAR
DEPRESSION
AND
THERMOREGULATORY
DISRUPTION
CAUSED
BY
PENTOTHAL/HALOTHANE
ANESTHESIA
IN THE
HARBOR
SEAL,
Phoca
vitulina
LU
EVERETT
E. SINNETT,
Physiological
Research
Laboratory,
Scripps
Institution
of Oceanography,
La
Jolla,
California
92093,
USA.
ERIC
A. WAHRENBROCK,
Anesthesia
Research
Laboratory,
School
of Medicine,
University
of California,
San
Diego,
La
Jolla,
California
92093,
USA.
GERALD
L. KOOYMAN,
Physiological
Research
Laboratory,
Scripps
Institution
of Oceanography,
La
Jolla,
California
92093,
USA.
Abstract:
Anesthesia
was
induced
in
the
harbor
seal
(Phoca
vitulina)
with
an
intravenous
injection
of 10mg/kg
thiopental
sodium;
this
was
followed
by halothane
(1%)
anesthesia
for
up
to
9.5
h.
Cardiac
output
was
reduced
to
30%
of
the
pre-
anesthesia
value (from
an
average
of 11.5
1/mm
to 3.5
1/mm)
while
systemic
blood
pressure
fell
from
an average
150/110
to 80/60.
Arterial
oxygen
partial
pressures
were
somewhat
depressed
(58-72
Torr)
during
ventilation
with
air.
Heart
rate
became
stable
at
90-100
beats/mm.
Hypothermia
was
an
occasional
problem
during
the
first
hour
of
anesthesia,
but
this
trend
reversed
and
gave
way
to hyperthermia
during
prolonged
anesthesia.
INTRODUCTION
In
recent
years,
the
use
of halothane
for
general
anesthesia
in marine
mam-
mals
has
become
widely
accepted.
Induc-
tion
of
anesthesia
can
be
accomplished
in
otariid
seals
(sea
lions
and
fur
seals)
by
placing
a cone
over
the
animal’s
head
and
passing
a
halothane
gas
mixture
through
the
cone.’2
This
type
of
induc-
tion
has
been
found
to
be
troublesome
and
somewhat
dangerous
in
the
harp
seal6
(one
of
the
phocid,
or “true”
seals
-
harbor,
grey,
Weddell,
etc.).
Induction
of
anesthesia
in
harp
seals,6
grey
seals,
and
porpoises”
can
be
safely
ac-
complished
with
an
intravenous
(iv.)
injection
of
sodium
pentothal;
after
tracheal
intubation,
an