Coagulopathies and Thrombosis 2022 PDF

Disorders of Hemostasis JOHN D. GONZALEZ DNP, APRN, ACNP-BC, ANP-C Hypercoagulable States Venous Thromboembolism (VTE)  VTE is used as term which includes DVT and PE  Epidemiology  Most medical patients admitted to the hospital have an increased risk of developing a VTE by 130 times, when compare...

Disorders of Hemostasis JOHN D. GONZALEZ DNP, APRN, ACNP-BC, ANP-C Hypercoagulable States Venous Thromboembolism (VTE)  VTE is used as term which includes DVT and PE  Epidemiology  Most medical patients admitted to the hospital have an increased risk of developing a VTE by 130 times, when compared to the community population.  60% of VTEs occur in patients admitted to the hospital, recently discharged or in nursing home patients.  45% of VTEs occur within 3 months following hospitalization  All patients admitted to the ICU have an increase risk of developing a VTE, even with prophylactic therapy.  VTE is more common as we age Venous Thromboembolism (VTE)  Epidemiology  Men are at a greater risk for VTE than women  VTE is the most common preventable cause of hospital related death. Medicare has made the prevention of VTE a pay per performance measure  Pregnant women have a higher risk of VTE than nonpregnant women and the risk is higher post C-section than vaginal delivery. The incidence is highest in the post-partum period. Venous Thromboembolism (VTE)  Epidemiology  DVT risk following general surgery procedures is 15-40%  DVT risk following hip and knee replacement surgery is 4088%  Without prophylaxis fatal PE occurs Elective general surgery 0.1%-0.8%  Elective hip replacement 2%-3%  Surgery for hip fracture 4-7%  VTE Risk Factors Age > 50-65 Previous VTE Prolonged immobility-limited ambulation for > 48 hours Inheritable Hypercoagulable States Paralysis, Obesity, Pregnancy Hospitalization –within the last 3 months ICU admission Stroke COPD and Heart failure Exacerbations Nursing Home Surgery with general anesthesia > 45 minutes Surgery that last longer than 2 hours Surgery within the last 3 months Estrogen therapy and other drugs Testosterone Therapy Tamoxifen, Glucocorticoids Emergency Surgery, Post Operative Malignancy, Cirrhosis, Inflammatory Immobility, Thoracic & Abdominal Surgery Bowel Disease Hip and Knee Surgeries Major Trauma Infection, Renal Disease, Heart Failure Central Venous Catheterization Virchow Triad Venous Stasis Vessel Damage Hypercoagulable States Types of Deep Vein Thrombosis  Proximal DVT  A DVT that involves the popliteal vein, femoral vein, and the iliac veins. (above the knee)   It is important to note that you will see DVTs in the superficial femoral vein. In spite of the name, it is considered a deep vein and thrombosis located in this vein should be treated as a DVT. This has confused clinicians, because superficial thrombi are not treated unless the person is at an increased risk for clot progression. Proximal DVTs have a higher mortality rate and complication rate than distal DVTs. All proximal DVTs should be treated unless there is a contraindication to anticoagulation. Types of Deep Vein Thrombosis  Distal DVT  Is a DVT confined to the calf veins (below the knee)  Distal DVTs pose half the risk of causing a PE than proximal DVTs and many will resolve spontaneously without therapy. These do not always require treatment.  About 1/3 of distal DVTs will extend to the proximal vein and will typically do this within the first two weeks of diagnosis. Deep Vein Thrombosis Fun Facts  DVT typically starts in the calf veins  80% of symptomatic DVT are located in the proximal     veins 80% of distal DVT will resolve without anticoagulation 33% of distal DVT will extend to the proximal vein Propagation of a distal DVT is more likely to occur in someone who has ongoing risk factors A non-extending distal DVT rarely causes a PE, but proximal DVT frequently cause a PE DVT Clinical Evaluation  Physical findings: edema, erythema, pain and tenderness could be present but there are many causes for these symptoms. Symptoms are very nonspecific and a diagnosis of DVT cannot be made off of symptoms.  Homan’s sign is present in about 40% of cases, and is not very reliable. DVT Clinical Evaluation  Wells Clinical Prediction Rule for DVT  Clinical prediction rule designed to help stratify individuals into a low, moderate or high risk category for having a DVT  Inter observer reliability has not been studied  Use to help guide your evaluation  Score 2: high probability (53%)  Wells Clinical Prediction Rule for DVT Wells Score Risk Factor Score Active Cancer +1 Paralysis of lower limbs +1 Bedridden for > 3 days +1 Major surgery < 4 weeks +1 Local tenderness in lower limb +1 Entire leg swelling +1 Calf Swelling >3 cm +1 Pitting edema +1 Previous documented DVT +1 Collateral superficial veins +1 Other more likely diagnosis -2 Low probability (prevalence 5%): score of 2 Diagnostic Testing For DVT Diagnostic Test Comments Venography Gold standard Uses contrast and is invasive. It is painful and rarely used Compression Venous Ultrasound (CUS) Most commonly used test Sensitivity 97%, specificity 94% in symptomatic DVT Sensitivity in asymptomatic proximal DVT is only 60% CT scan Venography Radiation & contrast can be limiting Sensitivity 89-100% Specificity 94-100% Magnetic Resonance Venography Expensive and not widely available Uses gadolinium- use contraindicated in GFR < 30 For upper extremity DVT diagnosis begin with ultrasound If the person has reason other than DVT to have an elevated D-dimer, begin with ultrasound Pulmonary Embolus  Usually occurs from proximal DVTs in the lower extremities  90% of Acute PE arise from proximal DVTs  Clinical manifestations  Chest pain, shortness of breath, palpitations, hemoptysis, syncope, tachycardia, tachypnea, calf or leg swelling, wheezing, decreased breath sounds, rales, JVD.  Less than 1% of PE’s cause syncope  PE are a common cause of sudden cardiac arrest or circulatory collapse especially in pts younger than 65.   Large S wave in lead I, a Q wave in lead III, and inverted T wave in lead III- not present in all cases, maybe 20% S/S nonspecific and cannot be used for a diagnosis Pulmonary Embolus  Diagnostic Evaluation  Wells Criteria for PE         Clinical prediction rule to help determine the probability of a PE Score  Low Probability: < 2 points (3.4%)  Moderate Probability: 2-6 points (27.8%)  High probability: > 6 points (78.4%) Those with a low probability based on the Wells criteria should be further evaluated with a D-dimer. Use the D-dimer only in the appropriate patients. If it comes back negative the patient does not have a PE. If it is positive you should move forward with additional testing. Those with an intermediate probability based on the Wells criteria, if the patient is an appropriate candidate for a D-dimer order the D-dimer. If it is negative the patient does not likely have a PE. If it is positive, additionally testing is needed. Those with a high probability of a PE based on the Wells Criteria, then complete a CT Pulmonary Angiogram. If this is contraindicated (allergy, renal disease, high risk for contrast nephropathy, hypotension, advanced heart failure, inability to tolerate lying flat) then complete a VQ scan with or without a doppler of the lower extremities. Pulmonary angiogram CTA- pulmonary VQ scan Wells Clinical Prediction Rule for PE Wells Score for PE Risk Factor Score Suspected DVT +3 PE #1 Diagnosis +3 Heart Rate >100bpm +1.5 Immobilization > 3 Days or Surgery in the last 4 weeks +1.5 Previous DVT or PE +1.5 Hemoptysis +1 Malignancy treatment in the last 6 months or palliative care +1 Low probability (probability of PE 3.4%): score of < 2 Moderate Probability (Probability of PE 27.8%): score of 2-6 High Probability (Probability of PE 78.4%): score > 6 Treatment of VTE  Treatment of PE and DVT are essentially the same, anticoagulation. There are a number of things one should consider when treating of a person with VTE       What level of care is needed: Inpatient, versus outpatient, general medical floor versus critical care? Which VTEs require treatment. What it the risk of bleeding? Which anticoagulant should you use? How long should anticoagulant therapy be given? How should an unstable PE be treated? Treatment of VTE  What level of care is needed: Inpatient versus outpatient, general medical floor versus critical care?    Outpatient versus inpatient treatment is the main question related to the treatment of VTE that you have to answer. Outpatient care is appropriate for any person who is hemodynamically stable, at a low risk of bleeding, has normal renal function, will be compliant and has reliable follow up. Inpatient care is required for anyone who has intractable pain or a DVT that is causing a complete venous obstruction leading to impaired arterial flow. Treatment of VTE  What level of care is needed: Inpatient, versus outpatient, general medical floor versus critical care? i. Patients with a low risk PE may be treated at home provided they have access to medications, ability to access outpatient care and home circumstances are adequate. 1. Low risk is defined as a. Those clinically stable with good cardiopulmonary reserve b. No contraindications to anticoagulation such a recent bleeding, severe renal or liver disease or severe thrombocytopenia (5mm in length, involves multiple veins, > 7mm in maximum diameter); thrombosis close to proximal veins, there is no reversible provoking factor for DVT, active cancer, history of VTE, and inpatient status. c. Persons with isolated distal DVT and severe symptoms or risk factors should be anticoagulated.  UEDVT involving the axillary or more proximal veins should be treated. Treatment of VTE  When should anticoagulation therapy be initiated?  Once you have a diagnosis of VTE (DVT or PE) anticoagulation should start immediately, baring any contraindications.  Empiric treatment with parenteral anticoagulants may be given to individuals who you suspect of having a high probability of having a VTE while you obtain diagnostic test results.  In persons who have an intermittent risk of having a VTE, you can start parenteral anticoagulants empirically if the test results will take more than 4 hour.  In persons who have a low probability of VTE, treatment can wait until the test results have reported. Treatment of VTE  What is the risk of bleeding? Assessment of bleeding risk should be done prior to starting anticoagulation and on an ongoing basis during treatment.  There are many scores that have been developed to assess the risk of bleeding. Many of these scores are related to anticoagulation for patients with atrial fibrillation and do not necessary translate to anticoagulation for VTE. A VTE specific bleeding score has been developed but needs validation before it can be recommended for use. Treatment of VTE  What is the risk of bleeding? Assessment of bleeding risk should be done prior to starting anticoagulation and on an ongoing basis during treatment.  There are no standard recommendations as to what to do with this information and opinions vary. In general persons found to have a high risk of bleeding at 3 months should not be anticoagulated. Those with a low risk of bleeding at 3 months should be anticoagulated. Those with an intermittent risk of bleeding at 3 months there are varying opinions.  My recommendation to you is that if you identify some one who requires anticoagulation and has an intermittent or high risk of bleeding, to consult with your collaborating physician.  Treatment of VTE  What is the risk of bleeding? Assessment of bleeding risk should be done prior to starting anticoagulation and on an ongoing basis during treatment. Chart on the next slide  This chart gives you a list of factors which increase the risk of factors. The risk of bleeding is dependent upon the number of risk factors in relationship to the duration of the anticoagulation. For our purposes you just need to know the 0-3 months risk. Ultimately 0 risk factors is low risk 1 risk factor is moderate risk. 2 or more risk factors is high risk. You will see in practice that the majority of patients will be anticoagulated. You must educate the patient and the family about the risk and benefits. Involve the patient/family in the decision. Asses Risk of Bleeding Treatment of VTE  Which anticoagulant should you use?   First it is important to know that the goal of therapy is to prevent extension of the clot and a potentially fatal embolization of the clot and prevent recurrent DVT. Absolute Contraindication to anticoagulation include: Active bleeding  Severe bleeding diathesis  Platelet count < 50,000  In some instances