Introduction Venous thromboembolism (VTE) includes both pulmonary embolism (PE) and deep venous thrombosis (DVT) Most are clinically silent US incidence DVT= 200,000/yr PE= 50,000/yr Risk factors for thromboembolism Virchow's triad venous stasis hypercoagulable state intimal injury primary hypercoagulopathies (inherited) MTHFR/C677T/TT gene mutation carries highest risk factor V Leiden mutation antithrombin III deficiency protein C deficiency protein S deficiency activated protein C resistance elevated factor VIII hyperhomocysteinemia prothrombin II G20210A secondary factors (acquired) malignancy recently been associated with up to 20% of all new diagnoses of VTE elevated hormone conditions recombinant erythropoeitin hormone replacement oral contraceptive therapy late pregnancy elevated antiphospholipid antibody conditions lupus anticoagulant anticardiolipin antibody history of thromboembolism obesity aging CHF varicose veins smoking general anesthetics (vs. epidural and spinal) immobilization increased blood viscosity rapid increase in INR following unopposed initiation of warfarin therapy in arthroplasty patients hypothesized to occur due to the warfarin-induced decline in protein C occurring before warfarin's antithrombotic effect occurs (protein C has a half-life of 6-8 hours and factor II has a half-life of 48-120 hours). no increase in DVT has been associated with the use of tranexamic acid (TXA) Pathophysiology Mechanism of clot formation stasis fibrin formation thromboplastin (aka Tissue Factor (TF), platelet tissue factor, factor III, or CD142) is released during dissection which leads to activation of the extrinsic pathway and fibrin formation clot retraction propagation Prophylaxis Overview prevention of deep vein thrombosis (DVT) and pulmonary embolism (PE) is most important factor in decreasing morbidity and mortality prophylaxis treatment should be determined by weighing risk of bleeding vs risk of pulmonary embolus AAOS risk factors for major bleeding bleeding disorders history of a recent gastrointestinal bleed history of a recent hemorrhagic stroke AAOS risk factors for pulmonary embolus hypercoagulable state previous documented pulmonary embolism DVT prophylaxis is recommended for all arthroplasty patients; for standard patients, not recommended for upper extremity procedures, arthroscopic, and isolated fractures at knee and below the use of pharmacologic prophylaxis and mechanical compression received a moderate strength recommendation from the AAOS Prophylaxis in Hip & Knee Arthroplasty Prophylaxis in hip & knee replacement VTE prophylaxis recommended for all THA and TKA patients AAOS and American College of Chest Physicians developed guidelines but do not recommend an optimal regimen; an individualized ppx regimen balancing efficacy and safety based on risk factor should be implemented mechanical prophylaxis compressive stockings recommended pneumatic compression devices are recommended by the AAOS across all risk (low to high risk of either bleeding or pulmonary embolism) groups undergoing total hip or total knee arthroplasty increase venous return and endothelial-derived fibrinolysis decrease venous compliance and venous stasis chemoprophylaxis American Academy of Orthopaedic Surgeons (AAOS) and American College of Chest Physicians (ACCP) support ASA as a monotherapy medical treatment see anticoagulation section below Spine Surgery Prophylaxis no clear consensus regarding utilization or timing of VTE prophylaxis measures after spine surgery risks of VTE must be weighed against postoperative bleeding and epidural hematoma formation patients with a spinal cord injury and prolonged immobilization are at increased risk early mobilization is recommended, along with pneumatic compression devices chemoprophylaxis should be considered for patients with longer surgical times, multilevel thoracolumbar surgery, and anterior thoracolumbar approaches Shoulder Arthroplasty Prophylaxis early mobilization mechanical prophylaxis, regional anesthesia LMWH/heparin until ambulatory if increased risk, not for routine use in UE surgery ASA/antiplatelet agents are not adequate ppx F&A Surgery Prophylaxis the risk of VTE was not found to be lowered by thromboprophylaxis in a study of 20,043 adult patients the greatest risk of activation of the clotting cascade during total hip arthroplasty occurs during insertion of the femoral component;
QUESTIONS 1 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.244) A 59-year-old patient undergoing total hip arthroplasty has a genetically inherited thrombophilia disorder. In this disorder, a variant co-factor cannot be inhibited by activated protein C causing overproduction of thrombin. What is this patients clotting disorder? Tested Concept QID: 4879 Type & Select Correct Answer 1 Factor V Leiden 71% (2613/3695) 2 Antithrombin III deficiency 12% (459/3695) 3 Familial dysfibrinogenemia 2% (88/3695) 4 Protein S deficiency 12% (454/3695) 5 Congenital deficiency of plasminogen 1% (43/3695) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ12.206) A 52-year-old male underwent a right total knee arthroplasty 3 days ago and reports new onset dyspnea. His vitals signs include a temperature of 98.8, pulse of 133, blood pressure of 130/77, respiratory rate of 28, and oxygen saturation of 91% on room air. A chest radiograph shows atelectasis. Which of the following findings is most likely also present? Tested Concept QID: 4566 Type & Select Correct Answer 1 Hyperchloremic metabolic acidosis 8% (303/4000) 2 Jugular venous distention with tracheal deviation 4% (142/4000) 3 EKG demonstrating S-wave in lead I Q-wave in lead III T-wave inversion in lead III 74% (2940/4000) 4 Pleural effusion with pleural/serum protein >0.5 and pleural/serum LDH > 0.6 5% (198/4000) 5 Increased carbon monoxide diffusing capacity (DLCO) 9% (376/4000) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ10.67) A 67-year-old man complains of low-grade fevers and calf pain 2 weeks following a total knee arthroplasty. What is the next appropriate step in management of this patient? Tested Concept QID: 3154 Type & Select Correct Answer 1 Plethysmography of lower extremity 1% (20/2909) 2 MRI of lower extremity 0% (9/2909) 3 CT angiography of lower extremity 1% (22/2909) 4 Venous ultrasonography 95% (2755/2909) 5 Knee aspiration to evaluate for septic joint 3% (97/2909) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ10.189) A 30-year-old male with Protein C deficiency sustains a large subarachnoid hemorrhage and bilateral calcaneus fractures after falling off of a roof. The patient has been in the intensive care unit for 5 days for monitoring of his head injury. All of the following factors are appropriate reasons to obtain a helical chest CT scan EXCEPT: Tested Concept QID: 3282 Type & Select Correct Answer 1 Elevated alveolar-arterial gradient (> 20 mm Hg or 2.7 kPa) on arterial blood gas 9% (292/3092) 2 Pulse oximetry reading of 99% with respiratory rate of 35 breaths/min 29% (884/3092) 3 Pulse rate of 125 beats/min with new onset right bundle branch block 9% (286/3092) 4 Paco2 > 35 mm Hg (or 4.7 kPa) on arterial blood gas 46% (1427/3092) 5 Pao2 < 80 mm Hg (or 10.7 kPa) on arterial blood gas 6% (178/3092) L 4 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ09.265) The 2009 AAOS Clinical Guideline on prevention of pulmonary embolism in patients undergoing total hip or knee arthroplasty recommends classifying patients as having either a "standard" or "elevated" risk of bleeding complications. The presence of all of the following qualify a patient as having an "elevated" risk of major bleeding EXCEPT? Tested Concept QID: 3078 Type & Select Correct Answer 1 History of hemophilia 2% (26/1648) 2 History of protein C deficiency 82% (1356/1648) 3 History of a recent gastrointestinal bleed 7% (118/1648) 4 History of a recent hemorrhagic stroke 4% (59/1648) 5 History of Von Willebrand's Disease 5% (84/1648) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ08.144) Which of the following is NOT a component of Virchow's triad? Tested Concept QID: 530 Type & Select Correct Answer 1 Thrombocytopenia 8% (116/1523) 2 Platelet dysfunction 2% (37/1523) 3 Hypercoagulability 1% (8/1523) 4 Venous stasis 2% (24/1523) 5 Neither thrombocytopenia (answer 1) nor platelet dysfunction (answer 2) are components of Virchow's triad 88% (1334/1523) L 2 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK This is an AAOS Self Assessment Exam (SAE) question. Orthobullets was not involved in the editorial process and does not have the ability to alter the question. If you prefer to hide SAE questions, simply turn them off in your Learning Goals. (SAE07HK.61) Familial (Leiden) thrombophilia is of importance in joint arthroplasty because of an abnormality in the clotting cascade. Which of the following statements best describes the condition? Tested Concept QID: 6021 Type & Select Correct Answer 1 It is a disease caused by an abnormality of platelets that leads to increased blood clotting. 2% (5/243) 2 It is a disease caused by an abnormality of vascular endothelium that leads to increased blood clotting. 2% (4/243) 3 It is a disease caused by an abnormality of hepatic metabolism that leads to decreased production of factor V and decreased blood clotting. 4% (10/243) 4 It is a disease caused by an abnormality of factor V that leads to decreased inactivation of factor Va by activated protein C (aPC) and increased blood clotting. 90% (218/243) 5 It is a familial, genetic disease that requires placement of a Greenfield filter in all individuals who have the abnormality, prior to surgery. 0% (1/243) L 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ05.27) During total hip arthroplasty, which of the following interventions increases the risk of pulmonary ventilation-perfusion mismatch the greatest? Tested Concept QID: 64 Type & Select Correct Answer 1 Acetabular reaming 3% (59/2016) 2 Cement pressurization of the femoral canal 94% (1888/2016) 3 Use of a modular femoral stem 2% (32/2016) 4 Intra-operative sequential compressive device on the non-operative leg 1% (11/2016) 5 Posterior approach 1% (19/2016) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (OBQ05.172) A 65-year-old man undergoes total knee replacement and is found to have deep vein thrombosis two days later. What molecule is thought to be involved in this process when it is released during surgical dissection? Tested Concept QID: 1058 Type & Select Correct Answer 1 Prothrombin 37% (673/1843) 2 RANKL 1% (19/1843) 3 IL-1b 12% (223/1843) 4 Thromboplastin 46% (844/1843) 5 Factor XI 4% (78/1843) L 4 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ04.224) A 25-year-old healthy male is scheduled to undergo a a nine-level posterior spinal fusion for scoliosis. Administering preoperative recombinant erythropoietin would place the patient at increased risk of developing which of the following complications? Tested Concept QID: 1329 Type & Select Correct Answer 1 Acute renal failure 7% (50/734) 2 Increased bleeding time 4% (32/734) 3 Thrombotic event 81% (592/734) 4 Wound complications 3% (20/734) 5 Delayed spinal fusion 5% (36/734) L 2 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept (OBQ04.273) A 65-year-old female undergoes a total knee arthroplasty. In addition to chemoprophylaxis for deep vein thrombosis (DVT) prevention she is given pneumatic compression devices. Which of the following is associated with pneumatic compression devices? Tested Concept QID: 1378 Type & Select Correct Answer 1 Increased endothelial fibrinogenesis 6% (46/784) 2 Decreased bleeding times 0% (2/784) 3 Increased endothelial injury 3% (23/784) 4 Increased venous compliance 9% (67/784) 5 Increased venous blood flow 82% (644/784) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept
FREE PDF Chest. 2012 Feb;141(2 Suppl):e278S-325S. doi: 10.1378/chest.11-2404. [PMID]22315265[/PMID] Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Falck-Ytter Y1 Francis CW Johanson NA Curley C Dahl OE Schulman S Ortel TL Pauker SG Colwell CW Jr; American College of Chest Physicians. Basic Science - Thromboembolism (PE & DVT) Prophylaxis Falck-Ytter Y1, 41 views
All Videos (1) Podcasts (3) Login to View Community Videos Login to View Community Videos DVT Prophylaxis & Blood Conservation Strategies: My Plan For Most Of My Patients - Stefan W. Kreuzer, MD, MSc (OSET 2018) Basic Science - Thromboembolism (PE & DVT) Prophylaxis 7/26/2019 191 views (1) Question Session⎜Thromboembolism & Anticoagulation Orthobullets Team Basic Science - Thromboembolism (PE & DVT) Prophylaxis Listen Now 35:3 min 11/11/2019 40 plays (0) Basic Science⎪Thromboembolism (PE & DVT) Orthobullets Team Basic Science - Thromboembolism (PE & DVT) Prophylaxis Listen Now 27:43 min 10/31/2019 42 plays (2) Basic Science | Thromboembolism & Anticoagulation (ft. Dr. Adolph Yates) Team Orthobullets (J) Basic Science - Thromboembolism (PE & DVT) Prophylaxis Listen Now 11:45 min 10/18/2019 23 plays (0)