Objective—To evaluate cardiopulmonary effects of anesthetic induction with diazepam and ketamine or xylazine and ketamine, with subsequent maintenance of anesthesia with isoflurane, in foals undergoing abdominal surgery.
Animals—17 pony foals.
Procedures—Foals underwent laparotomy at 7 to 15 days of age and laparoscopy 7 to 10 days later. Foals were randomly assigned to receive diazepam, ketamine, and isoflurane (D/K/Iso; n = 8) or xylazine, ketamine, and isoflurane (X/K/Iso; 9) for both procedures.
Results—During anesthesia for laparotomy, cardiac index, and mean arterial blood pressure ranged from 110 to 180 mL/kg/min and 57 to 81 mm Hg, respectively, in the D/K/Iso group and 98 to 171 mL/kg/min and 50 to 66 mm Hg, respectively, in the X/K/Iso group. Cardiac index, heart rate, and arterial blood pressures were significantly higher in the D/K/Iso group, compared with the X/K/Iso group. During anesthesia for laparoscopy, cardiac index and mean arterial blood pressure ranged from 85 to 165 mL/kg/min and 67 to 83 mm Hg, respectively, in the D/K/Iso group, and 98 to 171 mL/kg/min and 48 to 67 mm Hg, respectively, in the X/K/Iso group. Heart rates and arterial blood pressures were significantly higher in the D/K/Iso group, compared with the X/K/Iso group. There were no significant differences between groups during either experimental period for percentage end-tidal isoflurane, arterial blood gas partial pressures, or pH values.
Conclusions and Clinical Relevance—Anesthesia of foals for abdominal surgery with D/K/Iso was associated with less hemodynamic depression than with X/K/Iso.
Objective—To compare laparoscopic dissection withlaparoscopic
dissection combined with abdominal
instillation of ferric hyaluronate gel for the treatment
of experimentally induced adhesions in pony foals.
Animals—12 healthy pony foals.
Procedure—A serosal abrasion method was used to
create adhesions at 4 sites on the jejunum (day 0). At
day 7, laparoscopy was performed and the adhesions
observed in each foal were recorded. In group-1 foals
(n = 6), the adhesions were separated laparoscopically
(treatment 1). In group-2 foals (n = 6), 300 mL of
0.5% ferric hyaluronate gel was infused into the
abdomen after the adhesions were separated laparoscopically
(treatment 2). At day 24, terminal
laparoscopy was performed and the adhesions
observed were recorded. Total number of adhesions
within each group was compared between day 7 and
24. Data were analyzed to determine whether an
association existed between the number of adhesions
on day 24 and treatment type.
Results—At day 24, the number of adhesions was
significantly decreased within each group, compared
with the number of adhesions at day 7 (group-1 foals,
10 vs 22 adhesions; group-2 foals, 3 vs 20 adhesions).
Treatment 1 was associated with a significantly higher
number of adhesions at day 24, compared with
treatment 2 (odds ratio, 4.54; 95% confidence interval,
1.03 to 23.02).
Conclusions and Clinical Relevance—Abdominal
instillation of 0.5% ferric hyaluronate gel after laparoscopic
dissection was a more effective technique
than laparoscopic dissection alone to treat experimentally
induced adhesions in pony foals.
Laparoscopic adhesiolysis following abdominal
surgery in foals is a safe and effective technique. ( Am J Vet Res 2004;65:681–686)
Objective—To describe and compare the distribution
of technetium Tc 99m (99mTc) pertechnate following
intraosseous or IV injection (with or without use of a
tourniquet) in the distal portion of the forelimb in
Procedure—Each horse received 4 forelimb treatments
in random sequence: intraosseous infusion
with tourniquet application (IOT), intraosseous infusion
without tourniquet application, IV infusion with
tourniquet application (IVT), and IV infusion without
tourniquet application. Dynamic nuclear scintigraphic
imaging of the third metacarpal bone, proximal and
middle phalanges, and distal phalanx was performed
from the start of each treatment until 1 hour after infusion
was completed. Radionuclide activity was compared
within and between treatment groups.
Results—Tourniquet application was necessary to
maintain high levels of radionuclide activity in the distal
portion of the forelimb after intraosseous or IV
infusion with 99mTc pertechnate; IVT and IOT treatments
resulted in similar radionuclide activity in the
proximal and middle phalanges and distal phalanx. Of
the 4 treatments, there was significantly higher
radionuclide activity in the distal aspect of the third
metacarpal bone after the IOT treatment.
Conclusions and Clinical Relevance—By use of a
tourniquet, radionuclide administration via the
intraosseous or IV routes resulted in effective perfusion
of the distal portion of the forelimb and similar
distribution of the agent in the phalanges of horses.
Further studies are required to ascertain whether
these findings apply to delivery of therapeutic agents
in infected tissues via IOT or IVT. (Am J Vet Res
Objective—To determine the relationship between
epidural cranial migration and injectate volume of an
isotonic solution containing dye in laterally recumbent
foal cadavers and evaluate the cranial migration and
dermatome analgesia of an epidural dye solution during
conditions of laparoscopy in foals.
Animals—19 foal cadavers and 8 pony foals.
Procedure—Foal cadavers received an epidural
injection of dye solution (0.05, 0.1, 0.15, or 0.2 mL/kg)
containing 1.2 mg of new methylene blue (NMB)/mL
of saline (0.9% NaCl) solution. Length of the dye column
and number of intervertebral spaces cranial and
caudal to the injection site were measured.
Anesthetized foals received an epidural injection of
dye solution (0.2 mL/kg) containing saline solution or
2% mepivacaine. Foals were placed in a 10o headdown
position, and pneumoperitoneum was induced.
Dermatome analgesia was determined by use of a
described electrical stimulus technique. Foals were
euthanatized, and length of the dye column was measured.
Results—Epidural cranial migration of dye solution in
foal cadavers increased with increasing volume injected.
No significant difference was found in epidural
cranial migration of a dye solution (0.2 mL/kg)
between anesthetized foals undergoing conditions of
laparoscopy and foal cadavers in lateral recumbency.
Further craniad migration of the dye column occurred
than indicated by dermatome analgesia.
Conclusions and Clinical Relevance—Epidural cranial
migration increases with volume of injectate. On
the basis of dermatome analgesia, an epidural injection
of 2% mepivacaine (0.2 mL/kg) alone provides
analgesia up to at least the caudal thoracic dermatome
and could permit caudal laparoscopic surgical
procedures in foals. ( Am J Vet Res 2005; 66:1324–1329)
Objective—To use magnetic resonance (MR) imaging
to describe and compare the anatomic distribution of
a lipid contrast medium injected via the retrobulbar
and Peterson nerve block techniques in heads of
Sample—5 grossly normal heads obtained from cattle
Procedure—Standardized techniques for the modified
retrobulbar and Peterson nerve blocks were
established. Each cadaver had 1 treatment performed
on a randomly selected side of the head; the second
treatment was performed on the alternate side of the
head. Injections were performed with canola oil,
which is an MR-positive contrast medium. Images of
heads in the transverse and dorsal planes were
obtained with a 3.0 Tesla short-bore MR system.
Results—The retrobulbar technique was characterized
by widespread distribution of the contrast medium
around the periorbital structures; further distribution
of the medium was detected along the optic
nerve and in the ethmoid turbinates and nasopharynx.
After the Peterson nerve block technique, contrast
medium was repeatedly located in the pterygopalatine
fossa, but distribution to surrounding structures
Conclusions and Clinical Relevance—Results indicate
that the retrobulbar injection technique results in
a greater distribution of contrast medium to the target
nerves and surrounding structures, compared with
that achieved via the Peterson nerve block technique.
This may explain the previously reported clinical
impression that the retrobulbar block is more reliable
than the Peterson nerve block but is associated with
a greater risk of complications. (J Am Vet Med Assoc
Objective—To determine reasons for epidural catheter
placement among horses examined at a veterinary
teaching hospital, efficacy of epidural administration of
analgesics, duration of catheter placement, reasons for
catheter removal, and complications encountered.
Procedure—Medical records were reviewed.
Results—A total of 50 epidural catheters were placed
in the 43 horses. Underlying conditions included fractures,
lacerations, septic arthritis, myositis, perineal
injuries, and cellulitis. Horses ranged from 2 to 21 years
old and weighed between 365 and 795 kg (803 and
1,749 lb). Median duration of catheter placement was
96 hours (range, 1.5 to 480 hours). The response to
epidural drug administration was reported as positive in
34 horses and negative in 4. There was no apparent
response in 2 horses, and response could not be determined
in 3. Three temporary patient-related complications
associated with epidural catheter administration
were observed. Technical problems associated with
the epidural catheters included dislodgement of the
catheter itself (7 catheters) or of the adapter or filter (5),
obstruction (5), and leakage (5). Twenty-two catheters
were removed because of resolution of the underlying
condition, and 10 were removed because of complications.
For 6 catheters, the reason for catheter removal
was not recorded. The remaining 12 catheters were in
place when the horses were euthanatized .
Conclusions and Clinical Relevance—Results suggest
that epidural catheterization can be used successfully
for repeated epidural delivery of analgesics and
anesthetics in horses with various clinical conditions.
Complications associated with epidural catheters or
epidural drug administration were infrequent and transient.
(J Am Vet Med Assoc 2003;222:1394–1398)
Objective—To assess the efficacy of laparoscopic
adhesiolysis in the treatment of experimentally
induced adhesions in foals.
Animals—8 healthy pony foals.
Procedure—Celiotomy was performed and adhesions
created at the jejunoileal junction and at sites
0.5 and 1 m proximal to this junction, using a serosal
abrasion method. Ten days after celiotomy, exploratory
laparoscopy was performed. Laparoscopic adhesiolysis
was performed in the treatment group only (4
foals, randomly selected). Thirty days after the
exploratory laparoscopy, a final laparoscopic examination
was performed, and the foals were euthanatized.
The number and characteristics of abdominal adhesions
were recorded during laparoscopy 10 and 30
days after celiotomy and during necropsy.
Results—At 30 days after celiotomy, the number of
adhesions in the control group was significantly higher
than the number in the treatment group. In the
control group, all adhesions observed during the
exploratory laparoscopy were still evident at the final
laparoscopy and necropsy. In the treatment group,
adhesions did not form again after separation. During
final laparoscopy and necropsy, a focal adhesion
between the omentum and site of the initial laparoscope
portal was observed in 5 of 8 foals.
Conclusions and Clinical Relevance—The serosal
abrasion model is useful for studying abdominal adhesions
in foals. Laparoscopic adhesiolysis was an
effective technique to break down experimentally
induced adhesions in the early maturation stage of
formation in pony foals. Studies are required to investigate
prevention of de novo adhesions at the laparoscope
portal sites. (Am J Vet Res 2002;63:289–294)