Venous Thrombo Embolism (VTE) = (DVT + PE) Flashcards
What is hemostasis?
Arrest of bleeding; the1st step of wound healing.
What are the 4 Steps of hemostasis?
Vessel injury Vascular spasm Platelet plug Primary hemostasis Coagulation Secondary hemostasis
Describe the main features of Thrombocytes (Platelets)?
Small fragments of megakaryocytes
Formation is regulated by thrombopoietin
Platelets contain granules that are secreted in response to “activation”
Important in preventing blood loss
Platelet plugs
Promoting formation and contraction of clots
What are normal and abnormal thrombocyte count levels?
Normal: 150 to 400 x 10^3/mm3
What are therapy considerations for thrombocytopenia between 50,000 and 140,000?
low intensity progressive resistive exercise (PRE) and aerobic exercise (none to minimal elevations/ resistance)
What are therapy considerations for thrombocytopenia betweeen 30, 000 – 50, 000?
(typically not associated with spontaneous bleeding.) AROM exercise, walking ad lib
What are therapy considerations for thrombocytopenia between < 10, 000 – 20, 000?
Risk of spontaneous bleeding, petechia, ecchymosis and prolonged bleeding time.
Therapy may be contraindicated/ minimal AROM
No brushing of teeth
What are therapy considerations for Thrombocytosis ?
(elevated values) Thrombocytosis: > 400 x 103/ mm3. No distinct recommendation; note paradoxical increased risk of bleeding.
What is Venous Thromboembolism (VTE)?
disease that includes both deep vein thrombosis (DVT) and pulmonary embolism (PE)
3rd most common cardiovascular illness
acute coronary syndrome (ACS) & CVA ; ~ 2/3 associated with hospitalization
what is the prevalence of VTE?
PE remains the most common preventable cause of hospital death, accounting for up to 10% of hospital mortality1
DVT/PE is much more common in the hospitalized patient (surgical and medical2) compared to those living in the community
Why should outpatient PTs be concerned about VTE?
Because there is a growing number of cases of VTE in patients who were recently hospitalized, and who she outpatient PTs.
What is Virchow’s Triad?
1858, RudolphVirchowfamously proposed that the alteration of one of the three characteristics of venous circulation may precipitate a thromboembolic event.
3 characteristics:
(1) venous stasis
(2) activation of blood coagulation, and
(3) vein damage
What are the statistics for inpatients and risk factors for VTE?
almost all have 1 RF, 40% have 3 or more RFs.
What are the Primary VTE Risks in Hospitalized Patients?
Increasing age,Cancer, Pregnancy 60/100,000 women, Immobility, Surgery, Hormone replacement therapy / OCP’s
10-30 / 100,000 users vs 4-8/100,000 non-users
Thrombophilic disorders
What is now recommended beyond risks from the Well’s criteria?
1st thing done is a D-dimer test, which looks for fibrin –> clotting factor –> very sensitive for a blood clot somewhere in the body. Also look for Dyspnea, pleuritic pain, tachypnea, dyspnea and chest pain.
What is Homan’s sign, and what does it say about VTE?
palpate calf and dorsiflex. Found to not be sensitive.
What are mechanical prophylaxes for VTE?
Graduated compression stockings (GCS)
Intermittent pneumatic compression (IPC)
What are some medical prophylaxes for VTE?
Unfractionated Heparin (UfH) Low Molecular Weight Heparin (LMWH) Warfarin (Coumadin©) Aspirin Fondaparinux (Arixtra©)
Why do mechanical prophylaxes for VTE?
Multiple studies have shown benefit to reduce risk of DVT
less effective than medical prophylaxis (adjunct)
Must be worn continuously
May reduce tissue oxygenation (risk in PVD population)
Need to be sized and fitted properly
No bleeding risk
What are contraindications for putting pts on anticoagulation ?
Active bleeding or high bleeding risk
History of heparin-induced thrombocytopenia
Platelet count <100,000
Already receiving oral anticoagulants or platelet inhibitors
Abnormal creatinine clearance rate
what is one histological mechanism behind mechanical compression?
If reduce size of vein, you increase venous pressure, and may actually improve valve function. Pressure causes release of protein called tissue factor inhibitor. So kind of cool mechanism.
What is measured when pt is on Heparin?
PTT: Partial Thromboplastin Time.
Normal: 21-35 seconds
Therapeutic endpoint: 1.5-2.5 times control
Goal: 46-70 seconds
What is measured when pt is on Coumadin (Warfarin)?
PT: Prothrombin Time INR: International Normalized Ratio Normal: PT: 11 -13 sec; INR 1 Therapeutic endpoint: 2-3 times control Goal may be higher if recurrent VTE or mechanical valve (2.5-3.5)
What is the American Heart Association recommendation for the INR to prevent risk of Ischemic or hemorrhagic stroke?
between 2 and 3.
