Prevention Of Postoperative Venous Thromboembolism Research Articles

SP2.6 - Improvements in patient discharge efficiency and safety: the impact of a dedicated Clinical Pharmacist in an Emergency General Surgery team

Abstract Introduction Efficiency in management of acute surgical admissions is related to safe clinical practice combined with good patient flow, optimising use of limited capacity. Preventable morbidity and discharge delays may significantly compromise outcomes for Emergency General Surgery (EGS) teams managing increasing numbers of admissions. Aim To investigate the effectiveness of a prescribing pharmacist employed within an EGS team in a DGH, with specific focus on patient discharge times by facilitating discharge prescription efficiency, including venous thromboembolism (VTE) prophylaxis. Methods Data was collected for two separate 1-month time periods in 2021 (Period A), before the appointment of a pharmacist and in 2023 (Period B), after pharmacist appointment. Data was analysed for (i) differences in times related to ‘to take home’ (TTH) medication prescription and (ii) prescribing of post-operative extended enoxaparin prophylaxis (EEP) following discharge. Results Mean time for prescription of TTH medications during working hours in Period A was 100 minutes (n=133, range 0-433 minutes) compared with 67 minutes (n=120, range 0-416 minutes) in Period B. Pharmacist prescribing accounted for 51.6% of TTH prescriptions with a mean prescription time of 18.6 minutes (range 0-389 minutes). During Period A, 36% of patients (n=48) who had a VTE assessment mandating EEP received this on discharge compared to 100% in Period B (n=31). Conclusions This data highlights an improvement in prescribing of TTH medications since appointment of a dedicated EGS pharmacist. The consequences of such improvements include more rapid patient flow, better patient experience and heightened patient safety by prevention of post-operative VTE through EEP.

Lower Limb Doppler Ultrasound Prior to Pneumatic Compression for the Prevention of Pulmonary Embolism in Gynecological Cancer Patients: A Retrospective Cohort Study.

Venous thromboembolism, which includes deep-vein thrombosis and pulmonary embolism, is the third most common cardiovascular disease after myocardial infarction and stroke. This study aimed to determine the effect of Doppler ultrasound on the prophylaxis and prevention of postoperative venous thromboembolism in gynecological oncology. This is a retrospective cohort study of procedures performed at King Abdulaziz Medical City in Jeddah, Saudi Arabia, between 2016 and 2021. The study included all patients diagnosed with gynecological cancers who underwent major cancer resection. A total of 295 eligible patients were enrolled and divided into two groups: the first group consisted of 104 patients who were screened for deep vein thrombosis using lower limb Doppler ultrasound prior to their gynecologic oncology surgery, while the second group included 190 patients who were not screened. The prevalence of pulmonary embolism and/or deep vein thrombosis was found to be eight out of 104 patients (7.7%) in the group screened for deep-vein thrombosis using lower limb Doppler ultrasound prior to their gynecologic oncology surgery. In the group that was not screened, one out of 190 patients (0.5%) developed deep vein thrombosis. The prevalence of postoperative pulmonary embolism and/or deep-vein thrombosis was reported in four out of 104 screened patients (3.8%) and in three out of 190 patients (1.6%) in the unscreened group. This study concluded that Doppler screening did not change the incidence of pulmonary embolism and/or deep-vein thrombosis postoperatively, but it may be helpful in detecting these conditions preoperatively. Therefore, Doppler screening for deep-vein thrombosis before surgical procedures in gynecological oncology could be considered after clinical assessment of the patient. To improve the study and address its limitations, a larger sample size would help to further investigate and identify relevant factors and determine their significance.

Best Practices for Optimizing Patients Undergoing Surgical Procedures to Prevent Postoperative Venous Thromboembolism: A Quality Improvement Project.

Introduction Current studies suggest that both chemical and mechanical venous thromboembolism (VTE) prophylaxis is underused, which is concerning due to the potential lethality of VTEs. The Caprini risk score is a preoperative VTE risk assessment that determines a patient's risk of enduring a VTE. The objective of this study was to examine postoperative cases of VTE to determine if accurate VTE risk stratification was performed and whether appropriateVTE prophylaxis was administered. Methods A retrospective analysis was conducted on 23 reported cases of VTE that occurred at a Central Florida hospitalfrom April 1, 2021, to March 31, 2022. Relevant demographic and medical information was gathered from each patient chart to calculate an individual Caprini risk score and determine the type of chemical VTE prophylaxis that was received. Results Out of 23 reported cases of VTE in surgical patients, 17 were ultimately determined to have suffered VTE associated with their hospitalization and surgery. Thirteen out of 17 (76%) received appropriate perioperative chemical deep vein thrombosis (DVT) prophylaxis based on the calculated Caprini risk score and corresponding recommendations. Four out of 17 (24%) were determined to have received insufficient perioperative chemical DVT prophylaxis. Conclusion Consistent utilization of a DVT/pulmonary embolism (PE) risk stratification tool, such as the Caprini risk score calculator, is essential in the prevention of postoperative VTE. Hospitalscan improve the utilization of such a tool and thereby reduce the number of embolic events by making it more visible and accessible to the overseeing provider in the electronic medical record (EMR).

EGS P24 Extended Thromboprophylaxis in the Prevention of Postoperative Venous Thromboembolism after Emergency Surgery

Abstract Background Venous thromboembolism (VTE) after emergency laparotomy is a significant cause of morbidity and mortality. Where extended thromboprophylaxis is used in the post-operative care of patients with colorectal malignancy or pelvic surgery, no such guideline exists for the patient undergoing emergency laparotomy. Arguably emergency laparotomy has one of the highest associated death rates of all types of surgery, greater than that of major elective GI surgery and involves high risk patients. The objective of this study is to ascertain the incidence of symptomatic VTE after emergency laparotomy within current thromboprophylaxis regimens at a district general hospital and consider the benefits of extended regimes in this patient cohort. Methods A database of all patients who underwent emergency laparotomy over a 12 month period from January 2019 to December 2019 was retrospectively analysed. The primary outcome was the incidence of symptomatic VTE within 90 days of emergency laparotomy. This was cross-referenced to known patient risk factors for thromboembolism. Results A total of 113 patients underwent emergency laparotomy during this period. Those who had multiple laparotomies and were duplicated or who died were excluded, leaving a total of 94 patients, 55 female and 39 male. 80 patients underwent a VTE prophylaxis regimen using perioperative and postoperative low-molecular-weight heparin (LMWH) based on their weight. The average length of stay was 18 days. 20 patients had an inpatient stay greater than 28 days and, therefore, received extended prophylaxis during their admission. 21 patients were given prolonged anticoagulation on discharge to complete a total of 28 days, 14 of these had suspected cancer intraoperatively, 6 were previously already anticoagulated. The postoperative VTE incidence was 6, 4 were diagnosed during admission and so received prolonged anticoagulation on discharge. 2 patients were not given prolonged VTE prophylaxis on discharge. Conclusions An extended VTE prophylaxis regimen using low-molecular-weight heparin is simple and effective and an accepted practice in the management of post operative colorectal cancer patients. A randomised control trial is likely needed to further explore the use of extended low molecular weight heparin in the postoperative care of emergency laparotomy patients.

Supporting patients on new direct oral anticoagulant medicines

Initially launched in 2008 for primary prevention of post-operative venous thromboembolism (VTE), direct oral anticoagulants (DOACs) represent a major advancement in anticoagulation​[1–4]​. The number of licensed DOACs and indications has now increased to include treatment or recurrence of deep vein thrombosis, pulmonary embolism and thromboprophylaxis of stroke in patients with atrial fibrillation (AF)​[2–11]​. Compared with […]

Comparison of out-of-pocket cost between apixaban and enoxaparin for extended-duration venous thromboembolism prophylaxis in gynecologic oncology patients

<h3>Objectives:</h3> To compare out-of-pocket cost between apixaban and enoxaparin for prevention of postoperative venous thromboembolism (VTE) in gynecologic oncology patients. Current guidelines recommend low molecular weight heparin for thromboprophylaxis following gynecologic cancer surgery, but new evidence suggests that oral apixaban may provide another safe and effective alternative. Recent publications have suggested apixaban more cost-effective, however these data do not evaluate out-of-pocket cost. <h3>Methods:</h3> This retrospective study was approved by the institutional QIAB. Patients undergoing open surgery for gynecologic malignancy qualified for this study. Test claims for apixaban 2.5 mg by mouth twice daily and enoxaparin 40 mg subcutaneously daily for 28 days were submitted for each patient prior to surgery. Patient copays, number of patients requiring prior authorization, and number of patients without prescription insurance were collected. <h3>Results:</h3> A total of 86 consecutive patients had test claims sent for both apixaban and enoxaparin thromboprophylaxis between July 2020 and October 2020. The average patient out-of-pocket cost to complete 28 days of apixaban prophylaxis was $73.95 (median $42.84, range $0-448.45). The average patient cost to complete 28 days of enoxaparin prophylaxis was $38.08 (median $10, range $0-260.91). Partial fills were allowed for 4 of 5 enoxaparin prescriptions that required prior authorization. A total of 5 apixaban prescriptions (5.8%) required prior authorization for full 28 days. A total of 5 patients (5.8 %) did not have prescription insurance. Cash price for enoxaparin was nearly double the cash price of apixaban. A total 6 patients' (7 %) insurance was not contracted with our pharmacy. A single patient (1.2%) required enoxaparin via specialty pharmacy. A total of 2 patients (2.3 %) were enrolled in the institution's financial assistance per the institution. <h3>Conclusions:</h3> Patients prescribed extended-duration venous thromboembolism prophylaxis may face higher out-of-pocket costs with apixaban than with enoxaparin. Prior authorizations can often take 48 to 72 hours for approval. Sending test claims prior to surgery can help identify prescriptions that will need prior authorizations so prescriptions can be sent earlier to avoid discharge delays and patient nonadherence. There may not be a one size fits all solution and individualized patient care should be considered. Future research areas should evaluate patient adherence with a twice daily oral pill vs a once daily injection.

Nadroparin Plus Compression Stockings versus Nadroparin Alone for Prevention of Venous Thromboembolism in Cerebellopontine Angle Tumour Excisions: A Cohort Study.

Both compression stockings and low molecular weight heparin (LMWH) are used for the prevention of post-operative venous thromboembolism (VTE) in cerebellopontine angle (CPA) tumour excisions. In an attempt to optimise the prophylactic treatment in these patients, we compared LMWH (nadroparin) plus compression stockings to nadroparin as single therapy. Patients undergoing CPA tumour excision in the period between January 2014 and November 2015 received nadroparin as a single therapy. Patients treated since November 2015 received, in addition to this therapy, peri-operative compression stockings as VTE prophylaxis due to a change in protocol. VTE was defined as symptomatic deep vein thrombosis or pulmonary embolism and was confirmed via radiological imaging or autopsy. A total of 146 consecutive patients were reviewed. Treatment groups were comparable with respect to demographics and risk factors. Six of the 60 patients (10.0%; 95% confidence interval [CI] 3.8-20.5) receiving nadroparin single therapy developed symptomatic VTE. One out of 86 patients (1.2%; 95% CI 0-6.3) treated with combination therapy developed VTE (p = 0.019) with a risk difference of 8.8% (95% CI 1.43-19.0). In comparison to combination therapy, nadroparin single therapy showed a relative risk of 8.6 (95% CI 1.1-69.6). Adding compression stockings to peri-operative nadroparin, as a prophylactic strategy for thromboembolic complications in patients undergoing surgical intervention for CPA tumours, was associated with a significant reduction in the occurrence of VTE.

Interaction Between Low-Dose Aspirin and Nonsteroidal Anti-Inflammatory Drugs Can Compromise Aspirin's Efficacy in Preventing Venous Thrombosis Following Total Joint Arthroplasty.

Total joint arthroplasty is a rapid recovery procedure with patients optimized quickly in preparation for discharge. Two significant postoperative goals are effective pain management and prevention of postoperative venous thromboembolism (VTE). Low-risk patients receive aspirin 81 mg twice daily for VTE prophylaxis; this dosing regimen has been reduced over the past few years from 325 mg to 162 mg to 81 mg twice daily. Unless contraindications exist, all patients receive multimodal pain management that includes the use of celecoxib or meloxicam. Upon reduction of the aspirin dose to 81 mg twice daily, we rapidly identified 2 patients who developed a pulmonary embolus when celecoxib or meloxicam was administered concurrently with aspirin. The interaction between nonsteroidal anti-inflammatory drugs (NSAIDs) and low-dose aspirin varies among the different NSAIDs. It is also highly dependent on numerous factors, including time of administration, dose of aspirin, and both pharmacodynamics and dose of the NSAID. Real-world outcomes of concomitant administration of NSAIDs with low-dose aspirin led to increased incidence of VTE, possibly due to competitive inhibition of aspirin at platelet receptor sites. This interaction was mitigated by altering the administration times of both agents.

Lessons Learned: Using the Caprini Risk Assessment Model to Provide Safe and Efficacious Thromboprophylaxis Following Hip and Knee Arthroplasty.

Two of the more common potential complications after arthroplasty are venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolus (PE), and excess bleeding. Appropriate chemoprophylaxis choices are essential to prevent some of these adverse events and from exacerbating others. Risk stratification to prescribe safe and effective medications in the prevention of postoperative VTE has shown benefit in this regard. The Department of Orthopaedic Surgery at Syosset Hospital/Northwell Health, which performs over 1200 arthroplasties annually, has validated and is using the 2013 version of the Caprini Risk Assessment Model (RAM) to stratify each patient for risk of postoperative VTE. This tool results in a culling of information, past and present, personal and familial, that provides a truly thorough evaluation of the patient’s risk for postoperative VTE. The Caprini score then guides the medication choices for thromboprophylaxis. The Caprini score is only valuable if the data is properly collected, and we have learned numerous lessons after applying it for 18 months. Risk stratification requires practice and experience to achieve expertise in perioperative patient evaluation. Having access to pertinent patient information, while gaining proficiency in completing the Caprini RAM, is vital to its efficacy. Ongoing, real time analyses of patient outcomes, with subsequent change in process, is key to improving patient care.

Efficacy and safety of anticoagulant prophylaxis for prevention of postoperative venous thromboembolism in Japanese patients undergoing laparoscopic colorectal cancer surgery.

AimTo investigate the efficacy and safety of anticoagulant prophylaxis to prevent postoperative venous thromboembolism (VTE) during laparoscopic colorectal cancer (CRC) surgery, which is unknown in Japanese patients.MethodsWe conducted this randomized controlled trial at nine institutions in Japan from 2011 to 2015. It included 302 eligible patients aged 20 years or older who underwent elective laparoscopic surgery for CRC. Patients were randomly assigned to an intermittent pneumatic compression (IPC) therapy group or to an IPC + anticoagulation therapy group. Anticoagulation therapy comprised fondaparinux or enoxaparin for postoperative VTE prophylaxis. Postoperative VTE was diagnosed based on enhanced multi‐detector helical computed tomography. The primary endpoint was VTE incidence, including asymptomatic cases, the secondary endpoint was incidence of major bleeding, and we conducted an intention‐to‐treat analysis. This study is registered in UMINCTR (UMIN000008435).ResultsPostoperative VTE incidence was 5.10% with IPC therapy (n = 157) and 2.76% with IPC + anticoagulant therapy (n = 145; P = .293). We identified no symptomatic VTE cases. The major bleeding rates were 1.27% with IPC alone and 1.38% with the combination (P = .936). The overall bleeding rates were 7.69% for enoxaparin and 13.6% for fondaparinux (P = .500), and there were no bleeding‐related deaths.ConclusionAnticoagulant prophylaxis did not reduce the incidence of VTE and the incidence of major bleeding was comparable between the two groups. Usefulness of perioperative anticoagulation was not demonstrated in this study. Pharmacological prophylaxis must be restricted in Japanese patients with higher risk of VTE.

The strategy of zero-mortality due to postoperative VTE in patients with colorectal cancer.

511 Background: The best method of venous thromboembolism (VTE) prevention after surgery for colorectal cancer remains unclear. It is reported that about 20-40% of high-risk patients were diagnosed as DVT and 2-4% was diagnosed as PE and its mortality rate is 0.5-1.0%. The aim of this study is to evaluate the incidence of postoperative VTE patients with colorectal adenocarcinoma and to evaluate the efficacy of VTE preventive strategy. Methods: A total of 264 patients who had undergone curative surgical resection for colorectal cancer at Tokushima University Hospital were included in this study (n = 264 colon: rectum = 1:0.57). All patients were measured D-dimer preoperatively. When D-dimer was ≥ 1.1, lower extremities ultrasonography (US) was performed. All patients were treated with Heparin (10,000U/24h) continuously intravenous injection from the day of surgery, and administered Enoxaparin (2,000U/24h) subcutaneous injection after 24h of the operation. Results: In all 264 patients, 74 (28%) were D-dimer ≥ 1.1 and 16 (6%) diagnosed VTE in US (proximal:distal type n = 6:1). 239 (91%) were treated with postoperative anticoagulant therapy. 2 developed perioperative VTE (symptomatic: asymptomatic = 1:1) and after discharge 12 developed postoperative VTE and mortality rate of VTE was 0%. Univariate analysis indicated that obesity (BMI ≥ 25), hyperlipidemia and preoperative PE were risk factors for deep venous thrombosis (DVT) (p &lt; 0.0001, 0.014, 0.0135, respectively) and multivariate analysis revealed that obesity was an independent risk factor for postoperative DVT (p &lt; 0.0001). Conclusions: Obesity (BMI ≥ 25) was independent risk factor for postoperative VTE. Our preventive protocol including screening using D-dimer and lower extremities US and treatment with Enoxaparin is considered as effective for prevention of postoperative VTE.

Novel venous thromboembolic disease (VTED) prophylaxis for total knee arthroplasty-aspirin and fish oil.

Despite the demonstrated success of multiple anticoagulation therapies for post-operative prophylaxis of thromboembolic disease in lower extremity arthroplasties, each modality comes with a unique set of limitations. Thus, the ideal anticoagulation medication which provides adequate therapy with minimal cost, complications, or added patient work is yet to be defined. One promising novel thrombophylactic supplement is fish oil, as many preliminary clinical trials have demonstrated a protective effect of fish oil against thrombosis in multiple clinical settings. In addition, others have demonstrated synergistic effect when combined with aspirin. However, there are paucity of studies that compared combined aspirin and fish oil therapy for venous thromboembolism prophylaxis with other pharmacological agents, especially in the field of orthopaedics. Therefore, this study evaluated: (I) risk of post-operative deep vein thrombosis (DVT) and pulmonary embolism (PE), and (II) bleeding complications; among patients who had primary total knee arthroplasty (TKA) and received one of the following regimens: (i) 325 mg aspirin and mechanical pulsatile stocking; (ii) rivaroxaban; or (iii) 325 mg aspirin and 1,000 mg fish oil. This was a 6-year prospective study analyzing the postoperative thromboembolic prophylaxis received by patients who underwent primary TKA. Patients who had a previous history of thromboembolic disease were excluded from the study due to an increased risk of recurrent clot formation. A total of 850 patients were enrolled. A total of 300 patients enrolled between October 2011 and June 2013 received 325 mg aspirin and mechanical pulsatile stocking, while 250 patients enrolled between June 2013 and December 2014 received rivaroxaban. A total of 300 patients enrolled between January 2015 and July 2017 received 325 mg aspirin and 1,000 mg fish oil. Major venous thromboembolic events (VTEs) and bleeding complications within the first 90 days post-operatively were recorded in each cohort. The odds ratios (ORs) and 95% confidence intervals (CIs), for thromboembolic and bleeding events were calculated and compared between the aspirin and fish oil cohort vs. aspirin and pulsatile stocking cohort, and aspirin and fish oil cohort vs. rivaroxaban cohort. A P value of <0.05 was used to determine statistical significance. A total of 25 DVT events were recorded including 1 of 300 (0.33%) in the aspirin and fish oil cohort, 22 of 300 (7.33%) in the aspirin and pulsatile stocking cohort and 2 of 250 (0.8%) in the rivaroxaban cohort. When comparing ORs, patients who received aspirin and fish oil demonstrated significantly lower risk for thromboembolic events when compared to the aspirin and pulsatile stocking group (OR: 0.045; 95% CI: 0.0061-0.3394; P<0.05). When compared to the rivaroxaban cohort the ORs did not differ significantly (OR: 0.416; 95% CI: 0.0376-4.6223; P>0.05). In addition, no PE events were recorded in any of the cohorts. When compared to rivaroxaban, the fish oil and aspirin cohort demonstrated significantly lower incidence of bleeding episodes (1 of 300, 0.33% vs. 30 of 250 patients, 12%; OR: 0.0278; 95% CI: 0.0038-0.2051; P<0.05). No bleeding events were recorded in the aspirin and pulsatile stocking cohort. This study demonstrated the potentially synergistic anti-thromboembolic effect of aspirin and fish oil in the prevention of post-operative venous thromboembolism in primary TKA patients. Based on the results from this study, the authors conclude that the combination of aspirin and fish oil maybe an excellent thromboprophylactic modality for patients to use after TKA. These results warrant further, larger prospective studies analyzing the use of fish oil supplements in VTE prophylaxis.

Predictive factors for effectiveness and safety of enoxaparin for total knee arthroplasty in aged Japanese patients: a retrospective review

BackgroundThe aims of this study were to investigate predictive factors involved in effectiveness and safety of enoxaparin for prevention of postoperative venous thromboembolism in aged Japanese total knee arthroplasty (TKA) patients.MethodsJapanese patients over 65 years old who were administered enoxaparin for TKA were enrolled in this study. Their medical records were retrospectively reviewed. Data were corrected at the Izumi Regional Medical Center, from September 2009 to March 2014. Patients were stratified into groups according to whether enoxaparin was effective (no deep vein thrombosis event up to postoperative day 7) or not, and whether they had an adverse drug event (ADE) or not.ResultsA total of 128 patients were included in this study. One hundred five (82.0%) patients were in the effective group and 20 (15.6%) in the adverse drug event (ADE) group. Anemia (13 patients), abnormalities in liver function tests (4 patients), clinically relevant non-major bleeding (4 patients) and urticaria (1 patient) were observed as ADEs. Multivariate logistic regression analysis showed that the serum total protein level at postoperative day 1 (POD1, before enoxaparin administration), was associated with effectiveness of enoxaparin, while the serum total protein and hemoglobin level at POD1 were involved in ADE caused by enoxaparin.ConclusionsAlthough further large scale studies will be warranted, our results suggest that serum total protein level just before enoxaparin treatment for TKA relates to the effectiveness and safety of enoxaparin in a Japanese aged population. In addition, the results indicate that the development of anemia should be carefully monitored during enoxaparin treatment for TKA, particularly in patients with lower levels of serum hemoglobin before treatment.

Adaptation and Effects of the Evidence-based IPC Nursing Protocol on Prevention of Postoperative Venous Thromboembolism

Adaptation and Effects of the Evidence-based IPC Nursing Protocol on Prevention of Postoperative Venous Thromboembolism

Patient Knowledge of Risk and Prevention of Postoperative Venous Thromboembolism Using Mechanical Prophylaxis

Patient Knowledge of Risk and Prevention of Postoperative Venous Thromboembolism Using Mechanical Prophylaxis

Safety of fondaparinux for prevention of postoperative venous thromboembolism in urological malignancy: A prospective randomized clinical trial.

To prospectively evaluate the safety of postoperative fondaparinux in comparison with low molecular weight heparin in patients undergoing uro-oncological surgery. The present study was a prospective, single-blind, non-inferiority randomized trial. A total of 359 patients undergoing surgery for urological malignancy were enrolled from January 2011 to December 2012. A total of 298 of these patients (fondaparinux group, 152; low molecular weight heparin group, 146) were evaluable for the intention-to-treat-analysis. Patients were randomly assigned to low-dose unfractionated heparin, 5000 units twice daily until postoperative day 1 plus either fondaparinux 2.5 mg once daily or low molecular weight heparin 2000 units twice daily until postoperative day 5. The primary end-point was postoperative bleeding as by independent review, and the study was powered to show the non-inferiority of fondaparinux versus low molecular weight heparin. The other adverse events were evaluated. D-dimer and soluble fibrin monomer complex levels were measured perioperatively. Bleeding occurred in 21 patients (12 in the fondaparinux group and 9 in low molecular weight heparin group, respectively). No significant differences were detected in the incidence of postoperative bleeding and the other adverse events between the two groups. The D-dimer was elevated on postoperative day 1 in one patient (16.6 μg/mL). In another patient, the soluble fibrin monomer complex was elevated (109 μg/mL). Fondaparinux is non-inferior to low molecular weight heparin with respect to risk of bleeding. The favorable safety profile of fondparinux supports its prophylactic use as an alternative to low molecular weight heparin after surgery for urological malignancy.

Prevention of Postoperative Venous Thromboembolism in Thoracic Surgical Patients: Implementation and Evaluation of a Caprini Risk Assessment Protocol

Venous thromboembolism (VTE) can be a devastating postoperative complication, with about one-third of VTEs occurring post-discharge. We previously retrospectively evaluated the Caprini VTE risk assessment model (RAM) in postoperative lung and esophageal cancer patients, demonstrating that "high risk" patients were more likely to have a postoperative VTE. In this study, we sought to implement the RAM protocol in thoracic surgical patients to evaluate adherence, safety, and VTE outcomes. This prospective cohort study at a large safety net hospital included all surgically treated patients within the thoracic surgery division beginning in July 2014. Per RAM protocol, patients with high risk scores were prescribed a total of 30 days of postoperative daily enoxaparin prophylaxis, and moderate risk patients received a total of 10 postoperative days. Adherence and outcome audits were conducted. A total of 126 patients were included for analysis. Provider adherence to RAM score calculation was 99.2% (125 of 126), with appropriate post-discharge prophylaxis prescribed in 96.0% of cases. Twenty-four patients scored high risk (19.2%), 60 were moderate risk (48.0%), and 41 scored low risk (32.8%). Patient adherence to post-discharge enoxaparin prophylaxis was 97.2%. The overall VTE rate was 2.3%, with no post-discharge VTEs or adverse bleeding events. Implementation of a VTE risk assessment protocol with extended course prophylaxis in high risk patients is safe and feasible for providers and thoracic surgical patients at a large safety net institution with a diverse patient population. Follow-up studies are needed to assess efficacy of the RAM in this surgical population.

Efficacy and Safety of Weight-Adjusted Extended Duration Tinzaparin for Prevention of Post-Operative Venous Thromboembolism after Bariatric Surgery

Background: Patients having bariatric surgery are at moderate-to-high risk for post-operative venous thromboembolism (VTE), with pulmonary embolism representing the most common cause of post-operative death. The optimal dosing and duration of anticoagulant prophylaxis is uncertain.Aim: To evaluate the efficacy and safety of extended-duration, weight-adjusted tinzaparin for post-operative thromboprophylaxis after bariatric surgery.Methods: Retrospective cohort of 793 bariatric surgery patients who received routine post-operative weight-adjusted tinzaparin, 4,500-14,000 IU daily (75 IU/kg, rounded to the nearest pre-filled syringe) for 7 days after hospital discharge. The primary efficacy and safety outcomes were the frequency of VTE and major bleeding, respectively, within 30 days of surgery in patients receiving at least 1 dose of tinzaparin.Results: 793 patients who underwent bariatric surgery from 2009 to 2012 were reviewed. There were 44 (5.5%) patients excluded from analyses: need for therapeutic-dose anticoagulation (n=16); no post-operative tinzaparin (n=27); surgery aborted (n=1). There were 646 and 645 patients included in the 30-day efficacy and safety analyses, respectively (mean age, 44.6 years [SD 9.7], median body mass index, 47.1 kg/m2 [range: 19.4-81.0]). An additional 106 patients had outcome data only during hospital admission. VTE occurred in 1/645 patients (0.3%; pulmonary embolism) after hospital discharge and in 1/752 patients (0.1%; superior mesenteric vein thrombosis) in hospital. Major bleeding occurred in 12/645 patients (1.9%). Trough anti-Xa levels measured 7-10 days post-operatively were undetectable in 143/190 (75.3%) patients. In the other 47 patients the median trough anti-Xa level was 0.12 IU (range: 0.10-0.41).Conclusions: Weight-adjusted, extended-duration tinzaparin appears effective and safe for post-operative thromboprophylaxis after bariatric surgery. There was no drug accumulation with large doses of tinzaparin. DisclosuresSiegal:Interactive Forums Inc.: Other: created educational slides; Daiichi Sankyo: Other: participated in an advisory board; Boerhinger Ingelheim: Other: participated in an advisory board; Portola Pharmaceuticals: Other: participated in an advisory board. Douketis:Bayer: Consultancy; Actelion: Consultancy; Biotie: Other: Advisory board; Sanofi-Aventis: Honoraria; The Medicines Company: Other: Advisory board; Janssen: Consultancy; Daiichi-Sankyo: Consultancy; Bristol-Myers Squibb: Consultancy, Honoraria; Pfizer: Honoraria; Boehringer Ingelheim: Consultancy, Honoraria.

Evaluation of Factor Xa-Specific Chromogenic Substrate Assays and the Determination of Pharmacokinetics of Fondaparinux

Fondaparinux (FPX), a synthesized factor Xa inhibitor, is one of the most popular anticoagulants for the prevention of postoperative venous thromboembolism (VTE). Although routine monitoring is not required, the bleeding adverse events cannot be neglected, and the measurement of anti-Xa activity is expected to be monitored. The primary purpose of this study is to evaluate the performances of 2 chromogenic assays for the detection of anti-Xa activity. Furthermore, the pharmacokinetics of FPX was examined using chromogenic assays. Anti-Xa activity was measured using 2 FPX-based chromogenic substrates (S2222 and STA-Liquid Anti-Xa). The reproducibility, detection limits, linearity, and correlations between the substrates were examined using normal plasma doped with low and high concentrations of FPX formulation. In addition, anti-Xa activity in 235 clinical samples from 164 cases treated was measured, and the pharmacokinetics of FPX was evaluated. Both of the tested substrates were capable of accurately measuring the anti-Xa activity of FPX, with a lower limit of 0.05 μg/mL and a coefficient of variation of less than 10%. The repeated administration of FPX induced a gradual but significant increase in the anti-Xa activity, which was negatively correlated with body weight and estimated glomerular filtration rate. No significant correlation between the anti-Xa activity and the occurrence of postoperative VTE or bleeding event was observed. Anti-Xa activity can be successfully determined using 2 chromogenic assays and automated biochemical analyzers. The clinical significance of anti-Xa activity monitoring should be examined in the future study.

Toward the individual approach to the evaluation of risks and prevention of postoperative venous thromboembolism

Toward the individual approach to the evaluation of risks and prevention of postoperative venous thromboembolism