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Portal Vein Thrombosis 814.e3

IM prn, or fentanyl constant-rate infusion Recommended Monitoring Prevention
[CRI] 2-5 mcg/kg/h). • If receiving antiplatelet drugs: evidence of Consider prophylactic anticoagulant and/or
VetBooks.ir ○ Proton pump inhibitors, such as panto- • If receiving heparin: evidence of bleeding. to increase risk of thrombosis. Diseases and Disorders
bleeding (petechiae, ecchymoses, hematuria,
antiplatelet medications with conditions known
• GI medications
hematochezia, hematemesis)
prazole 0.7-1 mg/kg IV q 12h
Technician Tips
○ Antiemetics, such as maropitant 1 mg/kg
IV or SQ q 24h Monitor aPTT (target: 1.5 times upper • Frequent cardiovascular monitoring (heart
reference limit) with unfractionated heparin.
○ Prokinetics: metoclopramide CRI 1-4 mg/ Anti-Xa levels may be considered and is rate, respiratory rate, and blood pressure)
kg/day or 0.3 mg/kg SQ q 8h encouraged but not required if using low- with acute PVT patients
• Anticoagulation may be started if PVT is molecular-weight heparin. • Monitor for acute deterioration (tachycardia,
definitively diagnosed or highly suspected • If receiving warfarin: evidence of bleed- increasing abdominal pain, hemorrhagic diar-
with or without visualization of other ing. Requires frequent monitoring of PT rhea) that may suggest thrombus propagation
thrombi (e.g., splenic vein thrombus). or international normalized ratio (INR). and intestinal ischemia.
○ Unfractionated heparin 100 IU/kg IV Regulation can be difficult. • Monitor for signs of bleeding (petechiae,
loading dose followed by 12.5-37.5 IU/ • Recheck abdominal ultrasound to monitor ecchymoses, hematuria, hematochezia,
kg/h IV CRI (requires monitoring of for clot resolution may be considered. melena) in patients receiving anticoagulant
aPTT) or antiplatelet medications.
○ Low-molecular-weight heparin (e.g., PROGNOSIS & OUTCOME
enoxaparin 1 mg/kg SQ q 6-8h, dalteparin SUGGESTED READING
150 IU/kg SQ q 8h) • Chronic PVT is associated with a lower Respess MJ, et al: Portal vein thrombosis in 33 dogs:
mortality than acute PVT. 1998-2011. J Vet Intern Med 26:230-237, 2012.
Chronic Treatment • Dogs with acute PVT that have > 75% portal
• Treat underlying condition(s). vein occlusion and other concurrent thrombi ADDITIONAL SUGGESTED
• Long-term anticoagulant medications are have increased mortality. READINGS
indicated for all chronic PVT cases and if • Thrombocytopenia may indicate a worse Laurenson MP, et al: Concurrent diseases and condi-
underlying disease persists or until resolved. outcome in dogs. tions in dogs with splenic vein thrombosis. J Vet
Consider either/or • Mesenteric infarction that does not resolve Intern Med 24:1298-1304, 2010.
○ Inhibition of coagulation: heparin, dalte- with initial stabilization is associated with Ness SL, et al: Hyperammonemic encephalopathy
parin, enoxaparin, rivaroxaban, warfarin higher morbidity and mortality. associated with portal vein thrombosis in a thor-
○ Platelet inhibitors: clopidogrel 1-5 mg/ • Long-term prognosis highly depends on the oughbred foal. J Vet Intern Med 27:382-386, 2013.
kg PO q 24h (dog); 18.75 mg/CAT PO underlying condition. Rogers CL, et al: Portal vein thrombosis in cats: 6
q 24h • Increased survival has been associated with cases (2001-2006). J Vet Intern Med 22:282-287,
• Abdominal fluid drainage may be needed if anticoagulant therapy in human medicine 2008.
ascites impairs respiration. and may be true in dogs (unproven).
RELATED CLIENT EDUCATION
Nutrition/Diet PEARLS & CONSIDERATIONS SHEETS
Dietary recommendations as necessary for
underlying disorders, as well as to promote Comments Consent to Perform Abdominal Ultrasound
GI health in the acute critical PVT patient • Diagnosis by abdominal ultrasound may Consent to Perform Abdominocentesis
be limited by lack of clinical suspicion, Consent to Perform Computed Tomography
Behavior/Exercise ultrasonographer experience, machine quality, (CT Scan)
Caution with patients receiving anticoagulants patient conformation, pain, and/or presence AUTHORS: Meghan J. Respess, DVM, DACVECC;
or antiplatelet medications of ascites. Therapeutic abdominocentesis, Cynthia R. L. Webster, DVM, DACVIM
analgesia, or serial ultrasound exams may EDITOR: Keith P. Richter, DVM, MSEL, DACVIM
Drug Interactions be necessary.
Many if patient is receiving warfarin • Prolonged PT and aPTT can occur with
acute PVT, and despite this coagulopathy,
Possible Complications anticoagulation is indicated when PVT is
• Intestinal/mesenteric infarction diagnosed.
• DIC

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