Unfractionated heparin infusion for treatment of venous thromboembolism based on actual body weight without dose capping.

Controversy exists regarding the use of dose capping of weight-based unfractionated heparin (UFH) infusions in obese and morbidly obese patients. The primary objective of this study was to compare time to first therapeutic activated partial thromboplastin time (aPTT) in hospitalized patients receiving UFH for acute venous thromboembolism (VTE) among three body mass index (BMI) cohorts: non-obese (< 30 kg/m2), obese (30-39.9 kg/m2), and morbidly obese (⩾ 40 kg/m2). In this single-center, retrospective cohort study, patients were included if they ⩾ 18 years of age, had a documented VTE, and were on an infusion of UFH for at least 24 hours. Weight-based UFH doses were calculated using actual body weight. A total of 423 patients met the inclusion criteria, with 230 (54.4%), 146 (34.5%), and 47 (11.1%) patients in the non-obese, obese, and morbidly obese cohorts, respectively. Median times to therapeutic aPTT were 16.4, 16.6, and 17.1 hours in each cohort. Within 24 hours, the cumulative incidence rates for therapeutic aPTT were 70.7% for the non-obese group, 69.9% for the obese group, and 61.7% for the morbidly obese group (obese vs non-obese: HR = 1.02, 95% CI: 0.82-1.26, p = 0.88; morbidly obese vs non-obese: HR = 0.87, 95% CI: 0.62-1.21, p = 0.41). There was no significant difference in major bleeding events between BMI groups (obese vs non-obese, p = 0.91; morbidly obese vs non-obese, p = 0.98). Based on our study, heparin dosing based on actual body weight without a dose cap is safe and effective.

Testicular vein thrombosis: Incidence of recurrent venous thromboembolism and survival.

PURPOSE: Testicular vein thrombosis (TVT) etiology, recurrence, and survival were compared with lower extremity deep vein thrombosis (DVT) in order to determine whether treatment guidelines for DVT could be applied to TVT. PATIENTS AND METHODS: An inception cohort of patients with confirmed TVT (January 1995-October 2015) was compared to a control group of patients with lower extremity DVT matched by age, gender, and diagnosis date. RESULTS: Thirty-nine men with TVT were identified; 15 (38%) with isolated TVT. Left testicular vein was affected in 77% patients; there were no cases of bilateral TVT. Cancer was over twofold more common in TVT patients (59% vs 28%, P = .01). Most cancers (78%) involved organs in proximity to the testicular vein. Although TVT patients were less frequently treated with anticoagulants (49% vs 97%, P = .0001), recurrence rates were similar to DVT group (TVT 4.2 vs DVT 1.1 per 100 patient-years, P = .11). Despite higher cancer prevalence, survival rates were similar between groups (31% vs 28%; P = .34). Major bleeding events were rare (one patient per group). CONCLUSIONS: Identifying TVT should prompt a search for a regional malignancy. Despite the high cancer prevalence and low utilization of anticoagulants, recurrent venous thrombosis and mortality rates are similar to DVT patients.

Three-month cumulative incidence of thromboembolism and bleeding after periprocedural anticoagulation management of arterial vascular bypass patients.

The objective of this study was to determine 3-month cumulative incidence of peri-procedural thromboembolism (TE) including graft occlusion, and peri-procedural bleeding for chronically anticoagulated vascular bypass graft (BG) patients requiring temporary warfarin interruption for an invasive procedure. Appropriate peri-procedural management of patients receiving chronic warfarin therapy to preserve lower extremity arterial BG patency is unknown. In a protocol driven, cohort study design, all BG patients referred to the Mayo Clinic Thrombophilia Center for peri-procedural anticoagulation (1997-2007) were followed forward in time to estimate the 3-month cumulative incidence of TE and bleeding. Decisions to provide "bridging" low molecular weight heparin (LMWH) were individualized based on estimated risk of TE and bleeding. There were 78 BG patients (69 ± 10 years; 38% women), of whom 73% had a distal autogenous and 53% had prosthetic BG; 45% received antiplatelet therapy. Peri-procedural LMWH was prescribed for 77% of patients and did not vary by BG distal anastomosis location or type. The 3-month cumulative incidence of TE was 5.1% (95% CI 1.4-12.6), including two BG occlusions, one DVT, and one myocardial infarction. Major bleeding occurred in 1 patient (1.28%, 95% CI 0.0-6.94). One patient died due to heart failure. TE and bleeding did not differ by bridging status. The 3-month cumulative incidence of TE among BG patients in whom warfarin is temporarily interrupted for an invasive procedure may be higher than in other "bridging" populations (atrial fibrillation, prosthetic heart valve, venous thromboembolism). This finding underscores the often tenuous nature of distal bypass grafts necessitating an aggressive approach to peri-procedural anticoagulation management.

Preoperative testing before noncardiac surgery: guidelines and recommendations.

Preoperative testing (e.g., chest radiography, electrocardiography, laboratory testing, urinalysis) is often performed before surgical procedures. These investigations can be helpful to stratify risk, direct anesthetic choices, and guide postoperative management, but often are obtained because of protocol rather than medical necessity. The decision to order preoperative tests should be guided by the patient's clinical history, comorbidities, and physical examination findings. Patients with signs or symptoms of active cardiovascular disease should be evaluated with appropriate testing, regardless of their preoperative status. Electrocardiography is recommended for patients undergoing high-risk surgery and those undergoing intermediate-risk surgery who have additional risk factors. Patients undergoing low-risk surgery do not require electrocardiography. Chest radiography is reasonable for patients at risk of postoperative pulmonary complications if the results would change perioperative management. Preoperative urinalysis is recommended for patients undergoing invasive urologic procedures and those undergoing implantation of foreign material. Electrolyte and creatinine testing should be performed in patients with underlying chronic disease and those taking medications that predispose them to electrolyte abnormalities or renal failure. Random glucose testing should be performed in patients at high risk of undiagnosed diabetes mellitus. In patients with diagnosed diabetes, A1C testing is recommended only if the result would change perioperative management. A complete blood count is indicated for patients with diseases that increase the risk of anemia or patients in whom significant perioperative blood loss is anticipated. Coagulation studies are reserved for patients with a history of bleeding or medical conditions that predispose them to bleeding, and for those taking anticoagulants. Patients in their usual state of health who are undergoing cataract surgery do not require preoperative testing.

Bridging with glycoprotein IIb/IIIa inhibitors for periprocedural management of antiplatelet therapy in patients with drug eluting stents.

OBJECTIVE: To describe outcomes when glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors are used as bridging antiplatelet therapy for surgical procedures in patients with drug eluting stents (DES). BACKGROUND: The optimal management of patients with DES who require surgical procedures prior to completion of antiplatelet therapy is unclear. In high risk patients, the use of GP IIb/IIIa inhibitors as bridging therapy while antiplatelet therapy is held has been described, but safety and efficacy data remain sparse. METHODS: A pharmacy database was used to identify GP IIb/IIIa inhibitor orders at our hospital between January 1, 2007 and July 31, 2009. Indication for GP IIb/IIIa inhibitor administration and other clinical data were gathered through retrospective review of medical records. End points assessed were stent thrombosis, major bleeding, minor bleeding, postoperative acute coronary syndrome, and death within 30 days. RESULTS: Four thousand one hundred seventy-six separate orders for GP IIb/IIIa inhibitors were identified (January 1, 2007 to July 31, 2009). Six patients underwent non-cardiac and thirteen underwent cardiac surgery. Clopidogrel was discontinued a median of 6 days before surgery and 2 days prior to initiating GP IIb/IIIa inhibitor. All bridging patients were treated with eptifibatide infusion prior to procedure. There were no stent thromboses, deaths, or acute coronary syndrome events. Major bleeding occurred in 7 (53.9%) cardiac surgery patients and none of the non-cardiac surgery patients, while minor bleeding occurred in 1 (7.7%) and 1 (16.6%) patients, respectively. CONCLUSIONS: In patients with DES, who require cessation of clopidogrel before surgery, bridging with GP IIb/IIIa inhibitors appears effective in preventing adverse cardiac outcomes but may be associated with bleeding in patients undergoing cardiac surgery.

Natural language processor as a tool to assess heparin induced thrombocytopenia awareness.

The life-threatening consequences of heparin induced thrombocytopenia (HIT) may be prevented with early recognition, prompt heparin withdrawal and direct thrombin inhibitor use. To determine the level of HIT awareness, electronic term recognition software can be used to query the electronic medical record (EMR) to assess the thought process and test ordering behavior of health care providers confronted with falling platelet counts. We sought to assess the awareness of HIT in a large teaching institution using these tools. Mayo Clinic databases were queried to identify a cohort of hospitalized adults receiving heparin (06/1/08-06/1/09). Serial platelet counts for each patient were scrutinized for a 50% decrement from baseline. "Clinician awareness" was defined by mention of HIT (determined by electronic term recognition software) within the hospital record by any member of the healthcare team or requisition of platelet factor 4/heparin antibody testing. During this time period, 34,694 adults were hospitalized and 24,956 received heparin. Only 3,239 (13%) patients had more than 1 platelet count during the hospital stay. Of 199 patients (6.1%) with ≥50% platelet count drop, clinician awareness was 36%. The absolute platelet count was the only independent variable associated with HIT awareness (P < 0.001). Both appropriate platelet count monitoring and HIT awareness are low at this large teaching institution. Software tools for monitoring awareness and providing realtime alerts of significant platelet count decrements may be useful.

Periprocedural anticoagulation management of patients with venous thromboembolism.

OBJECTIVE: Patients with venous thromboembolism (VTE) often require temporary warfarin interruption for an invasive procedure. The incidence of thromboembolism and bleeding related to periprocedural anticoagulation management of such patients is unknown. METHODS AND RESULTS: In a protocol-driven, inception cohort design study, all VTE patients (n=775) referred for periprocedural anticoagulation management (1997-2007) were followed-up to estimate the 3-month cumulative incidence of thromboembolism and bleeding. Patients were stratified by thrombus acuity (acute, <30 days; subacute, 31-90 days; or chronic > or =91 days). Decisions to provide "bridging" low-molecular-weight heparin were based on estimated thromboembolism and bleeding risk. Low-molecular-weight heparin was more often administered in acute (87%) and subacute (81%) VTE compared to chronic VTE (59%; P<0.001). The 3-month cumulative incidence of thromboembolism (1.8%), major hemorrhage (1.8%), and mortality (1.7%) were low and did not differ by management strategy. Active cancer was the only independent predictor of thrombotic recurrence (HR, 4.86; 95% CI, 1.6-14.5; P=0.005), major hemorrhage (HR, 6.8; 95% CI, 2.1-21.7; P=0.001), and death (HR, 32.7; 95% CI, 4.3-251.2; P=0.0008). CONCLUSIONS: Thromboembolism, bleeding, and death among VTE patients in whom anticoagulation is temporarily interrupted for an invasive procedure is low. Cancer patients require particular care given their propensity for both clotting and bleeding.

Perioperative Venous Thromboembolism Prophylaxis.

Venous thromboembolism (VTE) is a preventable cause of postoperative morbidity and mortality; however, audits suggest that the use of thromboprophylaxis is underused. In this review, we describe our approach to prevention of postoperative VTE and provide guidance on how to formulate an optimal VTE prophylaxis plan. We recommend that all patients undergo thrombosis- and bleeding-risk assessment as part of their preoperative evaluation. The risk of thrombosis can be estimated based on patient- and procedure-specific factors, using validated risk-assessment models such as the Caprini score. There are no validated models to predict perioperative bleeding; however, several risk factors have been proposed. Patients should ambulate early and frequently after surgery. We recommend no additional prophylaxis in patients at very low risk of VTE (Caprini score 0). Patients at low risk of VTE (Caprini 1 to 2) are recommended to receive either mechanical or pharmacological prophylaxis. Patients at moderate (Caprini 3 to 4) to high risk of VTE (Caprini ≥5) are recommended pharmacological prophylaxis either alone or combined with mechanical prophylaxis. Patients at high risk of bleeding should receive mechanical prophylaxis until their risk of bleeding is reduced and pharmacological prophylaxis can be reconsidered. Populations for which the Caprini score has not been validated (such as orthopedic surgery) are recommended prophylaxis based on individual and procedure-specific risk factors. Prophylaxis is typically continued until the patient is ambulatory or until hospital dismissal; however, longer durations can be considered in certain circumstances (high-risk patients undergoing malignant abdominopelvic operations, bariatric operations, and certain orthopedic operations).

Characteristics and quality of rotation-specific resident learning goals: a prospective study.

Background: Residents are expected to develop the skills to set learning goals. Setting learning goals is part of self-regulated learning, setting the foundation for creating a learning plan, deploying learning strategies, and assessing their progress to those goals. While effective goal setting is essential to resident self-regulated learning, residents struggle with setting learning goals and desire faculty assistance with goal setting.Objective: We aimed to characterize the topics and quality of residents' rotation-specific learning goals.Design: We conducted a prospective study of 153 internal medicine residents, assessing 455 learning goals for general medicine inpatient rotations. We coded learning goal themes, competencies, and learning domains, and assessed quality using the validated Learning Goal Scoring Rubric. We compared topic categories, competencies, learning domains, and quality between the first and second months of postgraduate (PGY)-1 residents and between PGY-1 and PGY-3 residents. We assessed factors associated with learning goal completion.Results: The overall response rate was 80%. The top three learning goal categories were patient management, specific diseases related to general medicine, and teaching skills. There were no changes in learning goal characteristics between PGY-1 months (p ≥ 0.04). There were differences between PGY-1 and PGY-3 residents' learning goals in patient management (28% vs 6%; p < .001), specific disease conditions (19% vs 3%; p < .001), and teaching skills (2% vs 56%; p < .001). There was no difference in learning goal quality between PGY-1 months (1.63 vs. 1.67; p = 0.82). The PGY-3 learning goals were of higher quality than PGY-1 learning goals for the 'specific goal' item (1.38 vs. 0.98, p = 0.005), but not for other items or overall (all p ≥ 0.02). Residents reported 85% (297/347) learning goal completion.Conclusions: Resident rotation-specific learning goals reflect a broad array of topics. Residents' learning goal quality was low and residents may benefit from guidance to support residents' learning goals.

Apixaban and Rivaroxaban in Patients With Acute Venous Thromboembolism.

OBJECTIVE: To compare the clinical efficacy and safety of apixaban with those of rivaroxaban for the treatment of acute venous thromboembolism (VTE). PATIENTS AND METHODS: Consecutive patients enrolled in the Mayo Thrombophilia Clinic Registry (between March 1, 2013, and January 30, 2018) and treated with apixaban or rivaroxaban for acute VTE were followed forward in time. The primary efficacy outcome was VTE recurrence. The primary safety outcome was major bleeding; the second safety outcome was clinically relevant nonmajor bleeding (CRNMB); and the third was a composite of major bleeding or CRNMB. RESULTS: Within the group of 1696 patients with VTE enrolled, 600 (38%) were treated either with apixaban (n=302, 50%) or rivaroxaban (n=298, 50%) within the first 14 days of VTE diagnosis and who completed at least 3 months of therapy or had a study event. Recurrent VTE was diagnosed in 7 patients (2.3%) treated with apixaban and in 6 (2%) treated with rivaroxaban (adjusted hazard ratio [aHR], 1.4; 95% CI, 0.5-3.8). Major bleeding occurred in 11 patients (3.6%) receiving apixaban and in 9 patients (3.0%) receiving rivaroxaban (aHR, 1.2; 95% CI, 0.5-3.2). Clinically relevant nonmajor bleeding was diagnosed in 7 patients (2.3%) receiving apixaban and in 20 (6.7%) receiving rivaroxaban (aHR, 0.4; 95% CI, 0.2-0.9). The rates of composite major bleeding or CRNMB were similar (aHR, 0.6; 95% CI, 0.3-1.2). Most study events occurred in patients with cancer. CONCLUSION: In the setting of a standardized, guideline-directed, patient-oriented clinical practice, the efficacy and safety of apixaban and rivaroxaban for the treatment of acute VTE were comparable.

Updates in venous thromboembolism management: evidence published in 2017.

Venous thromboembolism (VTE) management is rapidly evolving and staying up-to-date is challenging. We identified the most practice-informing articles published in 2017 relevant to the nonspecialist provider managing VTE. We performed a systematic search of the literature (Appendix A), limiting the search to a publication date of 2017. Two reviewers screened the 2735 resulting abstracts to identify high-quality, clinically relevant publications related to VTE management. One-hundred and six full-text articles were considered for inclusion. The five authors used a modified Delphi method to reach consensus on inclusion of seven articles for in-depth appraisal, following predetermined criteria of clinical relevance to nonspecialist providers, potential for practice change, and strength of the evidence.

Improving inpatient warfarin therapy safety using a pharmacist-managed protocol.

INTRODUCTION: Safe management of warfarin in the inpatient setting can be challenging. At the Mayo Clinic hospitals in Rochester, Minnesota, we set out to improve the safety of warfarin management among surgical and non-surgical inpatients. METHODS: A multidisciplinary team designed a pharmacist-managed warfarin protocol (PMWP) which designated warfarin dosing to inpatient pharmacists with guidance from computerised dosing algorithms. Ordering this protocol was ultimately designed as an 'opt out' practice. The primary improvement measure was frequency of international normalised ratio (INR) greater than 5; secondary measures included adoption rate of the protocol, a counterbalance INR metric (INR <1.7 three days after first inpatient warfarin dose), and complication rates, including bleeding and thrombosis events. An interrupted time series analysis was conducted to compare outcomes. RESULTS: Among over 50 000 inpatient warfarin recipients, the PMWP was adopted for the majority of both surgical and non-surgical inpatients during the study period (1 January 2005 to 31 December 2011). The primary improvement measure decreased from 5.6% to 3.4% for medical patients and from 5.2% to 2.4% for surgical patients during the preimplementation and postimplementation periods, respectively. The INR counterbalance measure did not change. Postoperative bleeding decreased from 13.5% to 11.1% among surgical patients, but bleeding was unchanged among medical patients. CONCLUSION: Our PMWP led to achievement of improved INR control for inpatient warfarin recipients and to less near-term bleeding among higher risk, surgical patients.

Evaluation of a quantitative D-dimer latex immunoassay for acute pulmonary embolism diagnosed by computed tomographic angiography.

OBJECTIVE: To determine the sensitivity and specificity of a quantitative plasma fibrin D-dimer latex immunoassay (LIA) for the diagnosis of acute pulmonary embolism. SUBJECTS AND METHODS: Study subjects were Mayo Clinic Rochester inpatients and outpatients with suspected acute pulmonary embolism; all had undergone quantitative D-dimer LIA testing and multidetector-row computed tomographic (CT) angiography between August 3, 2001, and November 10, 2003. Multidetector-row CT angiography was the diagnostic reference standard. RESULTS: Of 1355 CT studies, 208 (15%) were positive for acute pulmonary embolism. Median D-dimer levels were significantly higher for patients with acute pulmonary embolism (1425 ng/mL) than for patients without (500 ng/mL) (P<.001). The highest specificity that optimizes sensitivity for acute pulmonary embolism was achieved by using a discriminant value of 300 ng/mL, which yielded a sensitivity of 0.94 (95% confidence interval [CI], 0.89-0.97), a specificity of 0.27 (95% CI, 0.25-0.30), and a negative predictive value of 0.96 (95% CI, 0.93-0.98). CONCLUSION: The quantitative D-dimer LIA with a discriminant value of 300 ng/mL had high sensitivity and high negative predictive value but low specificity for the diagnosis of acute pulmonary embolism. On the basis of these results, we believe that a negative quantitative D-dimer LIA result and a low pretest probability of thromboembolism together are sufficient to exclude acute pulmonary embolism.

Updates in venous thromboembolism management: evidence published in 2016.

The management of venous thromboembolic disease (VTE) is rapidly evolving and staying updated on practice-changing evidence can be challenging. In an attempt to alleviate this daunting task, we sought to determine the most important practice-informing articles published in 2016 relevant to the non-specialist provider managing VTE. We performed a systematic search of the literature, limiting the search to a publication date of 2016 (see Supplementary Appendix). Two reviewers screened the 3819 resulting abstracts to identify high-quality, clinically relevant publications related to VTE management. Two hundred sixteen full-text articles were considered for inclusion. The five authors used a modified Delphi method to reach consensus on inclusion of 7 articles for in-depth appraisal, following predetermined criteria of clinical relevance to non-specialist providers, potential for practice change, and strength of the evidence.

Going Beyond Administrative Data: Retrospective Evaluation of an Algorithm Using the Electronic Health Record to Help Identify Bleeding Events Among Hospitalized Medical Patients on Warfarin.

To reliably assess quality, a standardized electronic approach is needed to identify bleeding events. The study aims were the following: (1) clinically validate an electronic health record-based algorithm for bleeding and (2) assess interrater results to determine validity and reliability. Data were analyzed before and after implementation of a pharmacist-managed warfarin protocol. Bleeding was based on ≥2 of 3 criteria: (1) diagnosis indicating bleeding, (2) lab value decrease suggesting bleeding, and (3) blood product use. All suspected bleeds (234) and a sample (58) not meeting criteria were compared with clinical review. There were 234 bleeding cases identified electronically. Reviewer agreement was 78.2% (κ = 0.565). Algorithm sensitivity was 93.9% and positive predictive value 46.2%. Algorithm identification was least accurate for those with only 2 criteria but good for those with all criteria. This study supports using multiple electronic criteria to identify bleeding events. However, cases having exactly 2 criteria may require manual review for validation.

Ovarian Vein Thrombosis: Incidence of Recurrent Venous Thromboembolism and Survival.

OBJECTIVE: To identify the risk of venous thromboembolism recurrence, major bleeding, and mortality in patients with ovarian vein thrombosis so as to better define optimal treatment strategies. METHODS: Patients with ovarian vein thrombosis (1990-2015) and age- and gender-matched patients with contemporary leg deep vein thrombosis (DVT) were assessed for differences in etiology, venous thromboembolism recurrence, and survival in a case-control study. RESULTS: Over the timeframe of this study, only 219 ovarian vein thrombosis cases were identified compared with 13,417 leg DVTs. Median duration of follow-up was 1.23 years (interquartile range 0.25-4.14). Pulmonary embolism was identified at presentation in 6% of patients with ovarian vein thrombosis and 16% of those with DVT (P=.001). Frequent causes of ovarian vein thrombosis included cancer, hormonal stimulation, surgery, and hospitalization. Cancer was twofold more frequent in patients with ovarian vein thrombosis (44% compared with 21%; P<.01). Despite being less frequently treated with anticoagulation (ovarian vein thrombosis 54% compared with DVT 98%, P<.001), venous thromboembolism recurrence rates were similar between groups (ovarian vein thrombosis 2.3 compared with DVT 1.8 per 100 patient-years, P=.49). A personal history of venous thromboembolism and preceding surgery was found to be an independent risk factor for venous thromboembolism recurrence among those treated with anticoagulation (hazard ratio 6.7, P=.04 and hazard ratio 13.6, P=.03, respectively). There was no significant difference in overall survival. CONCLUSION: Ovarian vein thrombosis is a rare thrombotic condition with an incidence 60-fold lower compared with leg DVT in our institution. The striking association with cancer adversely affects overall survival rates in patients with ovarian vein thrombosis. Venous thromboembolism recurrence rates argue for anticoagulation with a direct oral anticoagulant or vitamin K antagonist, particularly in those with a history of venous thromboembolism.

Update in perioperative medicine: practice-changing evidence published in 2015.

Evidence in perioperative medicine is published in a wide variety of journals, given the multidisciplinary nature of its practice which spans medicine and its subspecialties, as well as surgery and anesthesiology. It can be difficult to identify new and important evidence, as perioperative practice continues to evolve in multiple areas such as medication management, anticoagulation and cardiac risk stratification, among others. New, high-quality evidence is published each year, and must be placed into the context of not only existing literature, but also practical real-world patient care. We sought to systematically identify, critically evaluate and concisely summarize the practice implications of 10 articles published in 2015 for the practicing perioperative clinician.

Clinical Study of an Online Tool for Standardizing Hospital Care.

We assessed if use of an online clinical decision support tool improved standardization and quality of care in hospitalized patients with lower extremity cellulitis (LEC). This was a 14-month preintervention and postintervention study of 85 LEC admissions. There was significantly higher usage of the online LEC care process model (CPM) in the postintervention phase (p < .001). There was a trend toward higher rates of appropriate antibiotic regimen in the postintervention group both initially and at discharge (p = .063 for both). A sensitivity analysis of CPM users versus nonusers demonstrated a significantly higher rate of appropriate initial antibiotics prescribed when the CPM was used (p < .001). Use of this online CPM was associated with improved standardization, as demonstrated by increased ordering of an appropriate initial antibiotic regimen for hospitalized patients with LEC.

Peri-procedural management of patients taking oral anticoagulants.

The use of oral anticoagulants is becoming increasingly common. For many years warfarin was the main oral anticoagulant available, but therapeutic options have expanded with the introduction of oral direct thrombin (dabigatran) and factor Xa inhibitors (apixaban, rivaroxaban, and edoxaban). Management of patients taking any oral anticoagulant in the peri-procedural period poses a challenge to medical and surgical providers because of the competing risks of thrombosis and hemorrhage. Bridging therapy has been used to minimize time without anticoagulation when warfarin is interrupted for invasive procedures, but validated strategies based on high quality data are lacking. Existing data suggest that the use of bridging therapy may increase the risk of bleeding for some patients without reducing the risk of thrombosis. Clinical trials are currently under way to answer these questions. Because the half lives and time to anticoagulant activity of newer oral anticoagulants are shorter than for warfarin, bridging therapy is not thought to be necessary with these agents. Peri-procedural management of patients taking these agents is complicated by the lack of demonstrated reversal agents in emergency situations, although specific antidotes are being developed and tested. Existing guidelines for peri-procedural management of patients on oral anticoagulants highlight the importance of individualized patient decision making and suggest strategies to minimize complications. From a patient's perspective, given the uncertainties surrounding optimal management, explicit discussions regarding risks and benefits of treatment options and demonstration of effective communication among medical and surgical providers are essential.

Prevention of venous thromboembolism in patients undergoing bariatric surgery.

Bariatric surgical procedures are now a common method of obesity treatment with established effectiveness. Venous thromboembolism (VTE) events, which include deep vein thrombosis and pulmonary embolism, are an important source of postoperative morbidity and mortality among bariatric surgery patients. Due to an understanding of the frequency and seriousness of these complications, bariatric surgery patients typically receive some method of VTE prophylaxis with lower extremity compression, pharmacologic prophylaxis, or both. However, the optimal approach in these patients is unclear, with multiple open questions. In particular, strategies of adjusted-dose heparins, postdischarge anticoagulant prophylaxis, and the role of vena cava filters have been evaluated, but only to a limited extent. In contrast to other types of operations, the literature regarding VTE prophylaxis in bariatric surgery is notable for a dearth of prospective, randomized clinical trials, and current professional guidelines reflect the uncertainties in this literature. Herein, we summarize the available evidence after systematic review of the literature regarding approaches to VTE prevention in bariatric surgery. Identification of risk factors for VTE in the bariatric surgery population, analysis of the effectiveness of methods used for prophylaxis, and an overview of published guidelines are presented.