Page 203 - Basic Monitoring in Canine and Feline Emergency Patients

If tubes are filled too slowly or are inappropri- have a normal energy level and was eating nor-
ately mixed, the blood sample may clot despite the mally at home despite the cough. The owners had
VetBooks.ir presence of citrate. Samples should be assessed noted that sometimes when he coughed there was a
terminal retch with some bloody sputum. At that
visually or by insertion of wooden applicator sticks
into the sample, for presence of clots prior to analy-
(CIRDC) at the pet store was suspected and he was
sis. Samples containing clots have consumed coagu- time, exposure to canine infectious disease complex
lation factors and fibrinogen that will be removed treated with over-the-counter cough suppressant.
when centrifuged, and so ‘plasma’ from these sam- On day 2, Teddy was re-presented to the hospital
ples (i.e. serum) will lead to a false prolongation of for decreased appetite, lethargy, and intermittent
PT and aPTT. continued cough. During his physical examination
If samples cannot be assessed for secondary hemo- he was extremely lethargic and noted to have very
stasis on whole blood within 1 hour, they should be pale mucous membranes. His respiratory rate was
spun and the plasma separated. Fresh plasma can elevated at 96 breaths/min. A packed cell volume/
be tested within 4 hours or it can be tested after total protein (PCV/TP) was taken which was
freezing. Freezing is most useful when prolonged 12%/5.5 g/dL (normal 40–45%/6–7 g/dL). His CBC
storage or shipping is necessary for advanced testing showed a mildly decreased platelet count of
such as specific factor testing. Delays in sample 100,000/hpf (normal 200,000–500,000/hpf) with
analysis without freezing may lead to factor degrada- normal morphology. A PT/aPTT revealed values too
tion and a false prolongation of clotting times. high to read.
Tests that rely on optical methodologies for sam- Teddy was suspected to have been exposed to
ple analysis (including some PT, aPTT, fibrinogen, anticoagulant rodenticide leading to pulmonary
FDP, d-dimer, and aggregometry techniques) may hemorrhage based on the hemoptysis and severe
give erroneous results if samples contain significant elevations in both his PT and aPTT (see Table 9.2
amounts of other pigments (bilirubin, lipids, free for rationale). Thoracic radiographs were consid-
hemoglobin) as these will affect passage of light ered to corroborate this theory but he was too
through the sample. Tests of secondary hemostasis unstable to undergo radiography. Instead, Teddy
also only detect >90% (ACT) or > 65% (PT, aPTT) was immediately administered 120 mL of whole
loss of coagulation factors. As a result, milder or blood and placed in oxygen. He was given vitamin
early phase disease states may go undetected. When K orally. Two hours after transfusion, his PCV/TP
assessing hypercoagulability, the PT and aPTT are was 22%/6.2 g/dL.
not reliably shortened in hypercoagulable states Teddy continued to have tachypnea and dis-
and cannot be used to assess risk of thrombosis. played respiratory distress when handled for the
Finally, although aPTT testing is used primarily to next 12 hours and he was left in the oxygen cage
screen for secondary hemostatic conditions, it may with minimal handling. Approximately 24 hours
be mildly prolonged in vWF deficiencies as the after admission to the hospital, he was greatly
decreased amount of vWF can also result in less improved. He was acting more normally with a
factor VIII activity. normal respiratory rate and effort even when han-
Multiple preanalytical and analytical factors may dled. He was still anemic (PCV/TP = 26%/6.5 g/
influence viscoelastic testing; for more information dL), which led to a reduced energy level versus a
on this topic, readers are referred to the PROVETS normal puppy. However, his PT/aPTT had normal-
guidelines (see Further Reading section). ized. Radiographs revealed a mild interstitial lung
pattern and a moderately widened mediastinum
(suspected to be secondary to hemorrhage). He was
9.6 Case Studies discharged to his owners on continued vitamin K
therapy and was reportedly clinically normal 48
Case study 1: Intoxication
hours after discharge.
A 3-month-old male intact Golden Retriever named
Teddy was presented to the emergency room for
evaluation of coughing on day one. The owners Case study 2: Post-dental hemorrhage
had taken him to a pet store a few days prior to An approximately 8-year-old female spayed Yorkie
presentation and noted that he had started cough- named Mini was presented for bleeding in the oral
ing subsequent to that visit. On day 1 he seemed to cavity post-dental extractions. She had several

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