Lecture 4: Abdominal Anesthesia and Surgeries (Wronski) Flashcards
3 borders of paralumbar fossa
1) cranial: last rib
2) dorsal: lateral border of large spinal muscles between last rib and tuber coxae
3) caudoventral: junction of tendinous and muscular parts of transversus abdominis m. between last rib and tuber coxae
nerve supply to paralumbar fossa
dorsolateral branch of spinal nerve
3 methods of desensitizing paralumbar fossa
1) epidural
2) paravertebral
3) inverted L (simplest method)
describe use of epidural to desenthesize paralumbar fossa
anesthetic agent is deposited in epidural space of vertebral canal
describe paravertebral method of desensitizing paralumbar fossa
anesthetic agent is deposited at cranial tips of lumbar transverse processes
describe inverted L method of desenstitizing paralumbar fossa
SQ injection of anesthetic agent cranial and dorsal to the site of incision
where is CSF located?
subarachnoid space
where is epidural space located?
in fat cells between bone and dura mater in the vertebral canal
3 nerves you want to block to paralyze paralumbar fossa **
T13, L1, L2
Rumenotomy =
surgical entry into the rumen
Entry into the rumen via paralumbar fossa would enter which sac of the rumen?
dorsal sac
Where is interarcuate space? Why is it important?
Space between L1 and L2. Where anesthesia should be deposited to anesthetize paralumbar fossa. (It will diffuse and anesthetize T13, L1, and L2).
If too much anesthetic is given during epidural, and it diffuses too far caudally, what happens?
Can anesthetize area of L4/L5, which contains roots of the femoral n., which is motor to the extensor mm. of stifle joint. Stifle will collapse.
Describe 3 injections given in paravertebral method of anesthesia to paralumbar fossa.
1) injection to cranial tip of transverse process of L1 to block T13
2) L2 to block L1
3) L4 to block L2
direction of external abdominal oblique fibers?
caudoventral
direction of internal abdominal oblique fibers?
cranioventral
What is a line block?
Same as inverted L block, but extends line further cranially instead of dorsoventrally
High vs. lumbosacral vs. low epidurals
High: b/w L1 and L2 to paralyze paralumbar fossa
lumbosacral: at L/S junction. Blocks femoral, sciatic, and obturator nn. and results in loss of motor and sensory fx
Low: at 1st intercoccygeal space. Blocks pudendal n. (sensory to perineal region). Used in parturition
Structures you have to go through before getting into abdominal cavity ***
1) skin
2) superficial fascia
3) cutaneous trunci
4) abdominal tunic
5) external abdominal oblique
6) internal abdominal oblique
7) transversus abdominis
8) retroperitoneal fat
9) parietal peritoneum
Grid technique
method used during sx in which abdominal muscles are cut along their natural fiber orientation
structures visualized on R lateral view of cow
omasum abomasum liver descending duodenum greater omentum (hides the other organs) R lobe of pancreas
LDA
left displacement of abomasum. Abomasum displaces between the L body wall and rumen
what does “volvulus” mean?
twisting
2 methods to maintain abomasum in its proper anatomical position
1) abomasopexy (suture abomasal wall to parietal peritoneum)
2) omentopexy (suture greater omentum to muscles of abdominal wall near R paralumbar fossa)
structures visualized on R lateral view of horse
R dorsal colon R ventral colon cecum liver R kidney descending duodenum
What structures are seen in R paralumbar fossa of cow?
descending duodenum, R lobe of pancreas
What structures are seen in L paralumbar fossa of horse?
L descending colon
where does apex of cecum lie in situ in horse?
along ventral midline. It is the first abdominal organ visualized during a ventral midline incision during Sx
common site of impaction in horse
pelvic flexure
what artery supplies the dorsal colon?
R colic a.
what artery supplies the ventral colon?
colic branch of ileocolic a.
nephrosplenic entrapment (LDDLC)
L dorsal displacement of large colon above nephrosplenic ligament. Spleen enlarges due to occlusion of blood supply, which traps colon even more firmly in place
Treatment for LDDLC
phenylephrine (vasoconstrictor) and trot the horse
Proper sites for liver biopsies in horses
R 12th intercostal space or L 8th intercostal space
Know bands/sacculations and organs that can/can’t be rectally palpated pg. 7/8 of clinical correlates
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