Page 460 - Problem-Based Feline Medicine

452 PART 7 SICK CAT WITH SPECIFIC SIGNS

– If a large volume of fluid is known to be present, the catheter more difficult to advance and
a regular needle, butterfly needle, intravenous more prone to kinking or breakage) or peri-
catheter or peritoneal lavage catheter attached to toneal dialysis/lavage catheter (preferred) is
a syringe ± three-way stopcock may be used to inserted caudally, or right laterally, to the
remove the desired volume. Following surgical umbilicus (dissection may be used), and
preparation of the skin, the needle or catheter is directed caudally and towards the right.
inserted along the ventral midline caudal to the – 20 ml/kg warm saline is infused by gravity or
umbilicus. injected over 2–5 minutes. The cat is gently
– If the procedure is being used to diagnose the rolled from side-to-side (catheter in place),
presence of a small volume of fluid, a 1-inch, 22-G and then after 2–5 minutes a diagnostic sam-
needle should be inserted along the ventral mid- ple is retrieved by gravity or by aspiration (it
line caudal to the umbilicus, and the fluid is neither necessary nor possible to retrieve all
allowed to drip out by gravity. Samples should the infused fluid). The catheter is removed
be collected into an EDTA (purple top) tube and and the skin incision sutured.
into a clot tube (red top). If no fluid appears, the – Complications from presence of a large
needle should be gently twisted, and, if this is volume of ascites may necessitate large-volume
unsuccessful, a syringe may be attached and abdominocentesis. This is normally a safe proce-
gentle suction applied. If midline abdominocen- dure, however:
tesis is negative, the abdomen may be “divided” – The fluid may rapidly re-accumulate, espe-
into four quadrants with the umbilicus as the cially if intra-abdominal pressure from the
center point, and the procedure repeated in each fluid (tamponade) was in equilibrium with the
quadrant, stopping when a sample is obtained. forces promoting fluid accumulation. Very
– Minimal analysis of the fluid consists of visual rapid re-accumulation could lead to acute
inspection, specific gravity, packed cell volume hypovolemia. This is most likely to occur
and total protein (measured by refractometer or with hypoproteinemia and right-sided heart
urine dipstick), and cytologic examination using failure.
a routine hematology stain. Fluids with high cel- – Repetitive large-volume abdominocentesis
lularity may be examined using a smear similar will promote hypoproteinemia because of
to a blood smear or using a squash smear. Fluids repetitive loss of protein in the ascitic fluid.
with low cellularity should be centrifuged prior – For these reasons it is recommended to
to examination and/or examined using a line- remove enough fluid to resolve secondary
smear technique, a technique similar to a blood problems, but not to try to empty the
smear, but where the spreader slide is rapidly abdomen.
drawn back several millimeters before the end of
The prognosis for cats with peritoneal effusion is
the sample slide, thus concentrating the cells in a
generally poor, especially if accompanied by pleural
line. More extensive evaluation may include cell
effusion.
counts, bilirubin, urea, creatinine, potassium,
glucose, bibarbonate, lactate, pH, albumin, glob-
ulin, cholesterol, triglyceride, amylase and DISEASES CAUSING ABDOMINAL
lipase levels, RT-PCR for feline coronavirus, DISTENTION OR ABDOMINAL FLUID
Gram-stain and microbial culture.
– If abdominocentesis is unsuccessful, diagnostic
peritoneal lavage may be performed. OBESITY***
– The bladder is emptied and the cat is
restrained in dorsal or left lateral recumbency. Classical signs
– The skin is surgically prepared. An intra- ● Disproportionately large abdomen
venous catheter (which may be fenestrated compared to head, thorax and distal limbs.
with a scalpel blade, although this may make