Acute Abdomen: Additional Diagnostics Flashcards
when should you consider additional diagnostics for an acute abdomen?
- when you need to supplement the basic diagnostics or cannot perform some aspect of your diagnostics to reach a working diagnosis
-ex. mini horse (fractious), rectal exam (butthole too tiny) - to support your working diagnosis
-if the owner wants more
-if you want more
what can and can’t you image with ultrasound?
GI:
-stomach(s), SI, cecum, large and small colon
-location: consistent (duodenum) versus variable (moving intestines)
-characteristics: wall thickness, motility, contents, size
extra-GI:
-peritoneal fluid: amount and echogenicity
-spleen, liver, pancreas, kidney, bladder, +/- uterus/fetus: echogenicity and size
-add on: thorax, transrectal
can’t:
-detail deep to gas: stomach(s), LI contents
-beyond depth of probe: LA issue (want low frequency curvilinear probe for max depth)
–low frequency: 30 cm
–different areas to rectal: ultrasound = complimentary to rectal exam
describe ultrasound targeted exam in horses
left side:
-stomach
-spleen/kidney
-colon
-small intestine
ventral:
-colon
-small intestine
-peritoneal fluid
right:
-duodenum: between liver and dorsal colon, distension could cause concern for reflux
-liver
-colon
-kidney
-cecum
cranioventral thorax:
-R and L
-pleural fluid
tips and tricks:
-get good contact
-do a systematic exam
-know your machine
-know normal and variations of normal
–ex. normal amounts of motility for intestines versus effects from drugs or disease
group ultrasound exam findings with LA colic types for non-strangulating obstructions
small intestine:
-wall thickness normal
-contents: fluid
-distension: mod-severe
-motility: hypo/amotile
large intestine:
-wall thickness: normal
-contents: gas
group ultrasound exam findings with LA colic types for strangulating obstructions
small intestine:
-wall thickness: ++increased
-contents: fluid
-distension: mod-severe
-motility: often amotile
large intestine:
-wall thickness: ++increased (LCV)
-contents: gas
group ultrasound exam findings with LA colic types for inflammatory lesions
small intestine:
-wall thickness: + increased
-contents: fluid
-distension: moderate
-motility: hypo to amotile
large intestine:
-wall thickness: +++increased
-contents: fluid
relate the ultrasound exam to the specific disease findings possible from this diagnostic in horses
non strangulating obstruction:
-small intestine: ascarid impaction
-large intestine: rule out LDDLC
strangulating:
-small intestine: intussusception, inguinal hernia
-large intestine: intussusception
NONE for inflammatory
other: hemoabdomen, cholelith, nephrolith
describe ultrasound findings/diagnosable diseases in other large animals
looking for similar abnormalities as in horses
- peritoneal fluid changes
- SI distension, motility, contents, wall thickness
-strangulating lesions
-intussusceptions - LI contents, wall thickness: intussusceptions
- stomach(s)
-omental: abomasal ulcers
-reticular abscess: hardware disease - liver: abscesses
describe radiographs in large animals with acute abdomen
- limited availability/use in adult horses and cows
- adult horse:
-sand
-enterolith - adult cattle:
-hardware disease
-standing or dorsal recumbency - smaller LA:
-plain films: to eval for intestinal distension, meconeum impaction in foals
-contrast: barium swallow/tube for gastric emptying disorders, barium enema for atresia coli
describe normal abdominocentesis values of large animals
horse:
-straw, clear
-TPP: <2.0 g/dl
-WBCC: <5000, 40-80% PMN, 20-60% mononuclear
-lactate: <2mmol/L (or less than 2x peripheral)
in other species = harder to obtain a representative sample bc have a tendency to wall things off
cow:
-straw, clear
-TPP: <3.0
-WBCC: <10,000
-lactate: unknown
small ruminant:
-straw, clear
-TPP: 1.0-5.0
WBCC: <10,000
-lactate: unknown
camelid:
-straw, clear
-TP: <2.5 but variable
-WBCC: <3000 but variable
-lactate: unknown
describe abdominocentesis locations in large animals
horse:
-one hand right of midline
-ventral most or midline behind xiphoid
cow:
-just caudal to xiphoid between midline and right milk vein (for abomasal ulcers)
-above udder on right side inside of flank fold
small ruminant:
-most ventral aspect of abdomen just right of midline (for uroabdomen)
-four sites: left and right sides of locations used in cattle to increase chances of finding local peritonitis
camelid:
-right paracostal: several cm dorsal and caudal to costochondral junction
ultrasound guided:
-ID fluid pocket
-avoid spleen
-even if don’t see any can still get fluid
-avoid enterocentesis (esp if ddx is rupture)
-helpful in ruminants and camelids!
describe abdominocentesis diagnoses in all species
- septic peritonitis:
-rupture: ddx enterocentesis, will see intracellular bacteria
-idiopathic - hemoabdomen:
-ddx: splenic tap, contamination
-does NOT CLOT
-contamination low in the PCV - other:
-bile peritonitis
-uroabdomen
-chyloabdomen
describe abdominocentesis process
- safety is sexy:
-restraint, stand next to front leg and watch your head - clip, prepare, +/- block
- blunt tip catheter:
-stab incision
-firm grip 2-3” from tip
-advance until you hear 1-3 pops or until a horse tenses at the peritoneum - needles:
-near tip, use to pop through skin
-slowly advance - collect fluid:
-multiple tubes! EDTA and serum
describe abdominocentesis clinical applications in large animals for non strangulating lesions
small intestine:
clear, straw
TP: normal to slight increase
lactate: normal to slight increase
WBCC: normal to slight increase
large intestine: expect near normal
describe abdominocentesis clinical applications in large animals for strangulating lesions
small intestine:
serosanguinous, cloudy
TP: moderate to severe increase
lactate: increased (>2x peripheral blood)
-WBCC: moderate to severe increase
large intestine:
-similar to small intestine but may be delayed or less severe
describe abdominocentesis clinical applications in large animals for inflammatory lesions
small intestine:
-straw or cloudy
-TP: hella increased
-lactate: normal to slight increase
-WBCC: moderate increase
large intestine:
-similar to small intestine but may be delayed or less severe
describe ultrasound targeted exam in small animals
- AFAST: abdominal focused assessment with sonography for trauma
-looking for free fluid, score out of 4 for fluid in each of the 4 regions (little anechoic triangles) - right or left lateral recumbency
-transducer centered at one of the locations
-use longitudinal view first, then transverse if questionable - views:
-diaphragmatic-hepatic/subxiphoid: hepato-diaphragmatic interface, gallbladder region, pericardial sac and pleural spaces
-splenorenal: splenorenal interface, left kidney, areas between spleen and body wall
-cysto-colic: apex of bladder
-hepatorenal: hepatorenal interface, right kidney
-then just scan around to look in the areas between intestinal loops
describe ultrasound interpretation in small animals
- anechoic triangles = free fluid
- gallbladder halo: supports anaphylaxis diagnosis
- gallbladder mucocele ID
- pyometra: fluid filled uterus
-looks like multiple bladders on cysto-colic view
-due to dilated uterine horns with pus on either side of bladder - fluid filled stomach or SI loops
-can see dilation
describe radiographs for acute abdomen in SA
- helpful when GI is prioritized over extra-GI causes of acute abdomen
- mechanical versus functional distension
-stomach
-small intestine - contrast between soft tissue and fat s essential for ID organs!
-ascites
-thin body condition - IMPERATIVE to take 3 orthogonal views!!
-choose one anatomical site and get the entire site in the series
describe radiographic interpretation for SA with acute abdomen
- ensure thorough eval of intra-abdominal and extra-abdominal structures
- eval all organs for change in size, shape, and location
-pancreas is NOT visible on radiographs - small amounts of fluid may be difficult to appreciate
-streaking or haziness - free gas is ALWAYS abnormal
-usually indicative of ruptured GI tract
-or due to recent surgery (only normal cause of free gas), ruptured GI tract, pneumomediastinum that progressed to pneumoretroperitonum - contrast:
-positive: administer barium orally
-negative: pneumocolonogram
-weigh the pros and cons of admin oral contrast!
-wanting to highlight an obstruction
describe abdominocentesis technique in small animals
- lateral recumbency is usually easier: sternal, dorsal, or standing will work too
-can be US guided or blind
-NO amount of fluid in small animal abdomen in normal - method:
-clip and sterile prep
-advance through skin and SQ
-apply negative pressure
-advance until pop through peritoneum
-should lose negative pressure as syringe fills with fluid
describe abdominal fluid analysis in small animals
pure transudate:
-clear
-TP <2.5
-TCC: <500; nondegenerative nuetrophils or reactive mesothelial cells
modified transudate:
-serous to serosanguinous
-TP: 2.5-5.0
-TCC: 300-5500; RBCs, nondegen neuts, mesothelial cells, macrophages, lymphocytes
exudate:
-cloudy
-TP: >3.0
-TCC: >5000-7000; neuts predominate but depends on etiology of exudate
describe clinical applications of abdominocentesis in small animals
- septic abdomen: fluid glucose
- >20mg/dL difference with blood glucose - septic abdomen: fluid lactate
- >2.0mmol/L difference with blood glucose - uroabdomen:
-fluid: blood K ratio
-dogs: 1.4:1
-cats: 1.9:1 - uroabdomen:
-fluid: blood creatinine ratio
-dogs and cats: 2:1 - bile peritonitis
-fluid: blood bilirubin
- >2:1
always pair with an in-house cytology!!!!!
what bloodwork do you perform for acute abdomen and when?
- PCV/TS:
-when dehydrated, both will go up
-if SIRS or leaking colon, PCV will go up but TP will go down - lactate:
-indicates anaerobic metabolism
-shock versus strangulating dz or both - electrolytes:
-anorexia: decreased K and Ca
-reflux/vomiting/internal vomiting: lose Cl
-diarrhea: lose Na and Cl (+/- HCO3-_ - WBCC:
-leukopenia with SIRS, especially colitis - leukocytosis:
-stress
-inflammation
group PCV/TS with types of obstructions in colic
non-strangulating:
-small and large intestine: can increase with time if dehydration
strangulating:
small intestine: can increase with time if dehydration
large intestine: abnormals variable due to dehydration, SIRS, protein loss
inflammatory:
-small intestine: increase due to fluid loss from dehydration
-large intestine: abnormals variable due to dehydration, SIRS, protein loss
group blood lactate by type of obstruction with colic
NSO:
-small and large: often normal
SO:
-small and large: usually slight to severe increase
inflammatory:
-small and large: usually increased
group electrolytes by types of obstruction in colic
NSO:
small and large: depend on degree of anorexia
SO:
-small: depends on degree of anorexia/reflux
-large:
-often normal
inflammatory:
-small and large: often abnormal
group WBCC by types of obstruction in colic
NSO:
small and large: normal or stress luekogram
SO:
-small: normal or stress leukogram
-large: often leukopenia
inflammatory:
-small: leukocytosis or leukopenia
-large: often leukopenia
