Inferior vena cava filters for primary prophylaxis: when are they indicated?

Update on the Pharmacological Actions of Enoxaparin in Nonsurgical Patients

Low-molecular-weight heparins are a class of drugs derived from the enzymatic depolymerization of unfractionated heparin that includes enoxaparin. Several studies have been performed on enoxaparin in recent years, in particular for the prevention and treatment of venous thromboembolism and for the treatment of acute coronary syndrome. Furthermore, the use of enoxaparin has been extended to other clinical situations that require antithrombotic pharmacological prevention, such as hemodialysis and recurrent abortion. In this review, we report the main clinical experiences of using enoxaparin in the prevention of VTE in nonsurgical patients.

Prophylactic Inferior Vena Cava Filters for Venous Thromboembolism in Adults With Trauma: An Updated Systematic Review and Meta-Analysis

Background: Trauma is an independent risk factor for venous thromboembolism (VTE). Due to contraindications or delay in starting pharmacological prophylaxis among trauma patients with a high risk of bleeding, the inferior vena cava (IVC) filter has been utilized as alternative prevention for pulmonary embolism (PE). Albeit, its clinical efficacy has remained uncertain. Therefore, we performed an updated systematic review and meta-analysis on the effectiveness and safety of prophylactic IVC filters in severely injured patients. Methods: Three databases (MEDLINE, EMBASE, and Cochrane) were searched from August 1, 2012, to October 27, 2021. Independent reviewers performed data extraction and quality assessment. Relative risk (RR) at 95% confidence interval (CI) pooled in a randomized meta-analysis. A parallel clinical practice guideline committee assessed the certainty of evidence using the GRADE approach. The outcomes of interest included VTE, PE, deep venous thrombosis, mortality, and IVC filter complications. Results: We included 10 controlled studies (47 140 patients), of which 3 studies (310 patients) were randomized controlled trials (RCTs) and 7 were observational studies (46 830 patients). IVC filters demonstrated no significant reduction in PE and fatal PE (RR, 0.27; 95% CI, 0.06-1.28 and RR, 0.32; 95% CI, 0.01-7.84, respectively) by pooling RCTs with low certainty. However, it demonstrated a significant reduction in the risk of PE and fatal PE (RR, 0.25; 95% CI, 0.12-0.55 and RR, 0.09; 95% CI, 0.011-0.81, respectively) by pooling observational studies with very low certainty. IVC filter did not improve mortality in both RCTs and observational studies (RR, 1.44; 95% CI, 0.86-2.43 and RR, 0.63; 95% CI, 0.3-1.31, respectively). Conclusion: In trauma patients, moderate risk reduction of PE and fatal PE was demonstrated among observational data but not RCTs. The desirable effect is not robust to outweigh the undesirable effects associated with IVC filter complications. Current evidence suggests against routinely using prophylactic IVC filters.

Indian Society of Critical Care Medicine Consensus Statement for Prevention of Venous Thromboembolism in the Critical Care Unit

Deep vein thrombosis (DVT) is a preventable complication of critical illness, and this guideline aims to convey a pragmatic approach to the problem. Guidelines have multiplied over the last decade, and their utility has become increasingly conflicted as the reader interprets all suggestions or recommendations as something that must be followed. The nuances of grade of recommendation vs level of evidence are often ignored, and the difference between a "we suggest" vs a "we recommend" is overlooked. There is a general unease among clinicians that failure to follow the guidelines translates to poor medical practice and legal culpability. We attempt to overcome these limitations by highlighting ambiguity when it occurs and refraining from dogmatic recommendations in the absence of robust evidence. Readers and practitioners may find the lack of specific recommendations unsatisfactory, but we believe that true ambiguity is better than inaccurate certainty. We have attempted to comply with the guidelines on how to create guidelines.1 And to overcome the poor compliance with these guidelines.2 Some observers have expressed concern that DVT prophylaxis guidelines may cause more harm than good.3 We have placed greater emphasis on large randomized controlled trials (RCTs) with clinical end point and de-emphasized RCTs with surrogate end points and also de-emphasized hypothesis generating studies (observational studies, small RCTs, and meta-analysis of these studies). We have de-emphasized RCTs in non-intensive care unit populations like postoperative patients or those with cancer and stroke. We have also considered resource limitation settings and have avoided recommending costly and poorly proven therapeutic options.

How to cite this article

Jagiasi BG, Chhallani AA, Dixit SB, Kumar R, Pandit RA, Govil D, et al. Indian Society of Critical Care Medicine Consensus Statement for Prevention of Venous Thromboembolism in the Critical Care Unit. Indian J Crit Care Med 2022;26(S2):S51-S65.

Identifying risk factor for development of perioperative venous thromboembolism in patients with gastrointestinal malignancy

BACKGROUND

Current data suggests that decreasing VTE incidence may require focus on other factors. This study aimed to identify perioperative risk factors for VTE in patients undergoing surgery for gastrointestinal (GI) malignancy.

METHODS

Patients undergoing surgery for GI malignancy from 2013 to 2016 were grouped according to whether or not they developed a postoperative VTE, and groups were compared along demographic, perioperative, and outcome variables.

RESULTS

Patients who developed VTE were more likely to be older (67 ± 11 VTE vs. 61 ± 10 no VTE, p = 0.04), male (92% vs. 59%, p = 0.02), and have a history of atrial fibrillation (39% vs. 11%, p = 0.01). They also experienced higher intraoperative blood loss (328 ± 724 mL no VTE vs. 918 ± 1885 mL VTE, p = 0.01). On multivariable analysis, history of atrial fibrillation was independently associated with development of postoperative VTE (odds ratio = 3.83, 95% confidence interval = 1.13-13.05, p = 0.03).

CONCLUSION

A prior history of atrial fibrillation independently predicts increased risk of developing VTE after surgery for GI malignancy. Improving understanding of the underlying VTE pathophysiology in these patients can help guide effective prevention strategies.

Postoperative Anticoagulation After Neurologic Surgery

Management of anticoagulation and antiplatelet medications after neurosurgery can be complex, especially given that these patients have multiple medical comorbidities. In turn, neurosurgical patients are at high risk for the development of venous thromboembolism after surgery, so neurosurgeons must consider the use of pharmacologic prophylaxis. Developments in endovascular neurosurgery have produced therapies that require close management of antiplatelet medications to prevent postoperative complications. Any of these patient populations may need intrathecal access. This article highlights current strategies for managing these issues in the neurosurgical patient population.

Prophylactic inferior vena cava filters in patients with fractures of the pelvis or long bones

BACKGROUND

Which patients with fractures, if any, have a lower mortality with prophylactic inferior vena cava filters has yet to be established. The purpose of this investigation is to determine if patients with low-risk fractures might benefit from a prophylactic inferior vena cava filter.

METHODS

Administrative data was analyzed from the National (Nationwide) Inpatient Sample using ICD-9-CM codes. Included patients were aged 18 years or older with a primary diagnosis of non-complex fracture of the pelvis, or fracture of the femuralone, or fracture of the tibia and/or fibula.

RESULTS

From 2003-2012, 1,479,039 patients were hospitalized with low-risk fracture. The vast majority of patients with fracture, 1,461,378 of 1,479,039 (98.8%) did not receive an inferior vena cava filter. Among those who did not receive a filter, 1,446,489 of 1,461,378 (99.0%) did not develop deep venous thrombosis or pulmonary embolism. Pulmonary embolism without a filter occurred in 7207 of 1,461,378 (0.5%) and deep venous thrombosis occurred in 7682 of 1,461,378 (0.5%). Total in-hospital all-cause mortality in those who did not receive a filter was 15,683 of 1,461,378 (1.1%). An inferior vena cava filter was inserted in 17,661 of 1,479,039 (1.2%) of patients with fractures. Most of those who received an inferior vena cava filter, 12,025 of 17,661 (68.1%) did not develop pulmonary embolism or deep venous thrombosis. Total in-hospital all-cause mortality in all patients with an inferior vena cava filter was 516 of 17,661 (2.9%).

CONCLUSION

The evidence is against the use of a prophylactic inferior cava vena filter in patients with a non-complex pelvic fracture or single fracture of the femur or fracture of the tibia and/or fibula.

The Role of Inferior Vena Cava Filters in Cancer Patients

Cancer induces a hypercoagulable state and renders patients susceptible to venous thromboembolism. While anticoagulation remains the mainstay of treatment, many of these patients require placement of an inferior vena cava (IVC) filter, often due to a contraindication to or failure of anticoagulation. In this article, the available data on IVC filter usage in cancer patients will be reviewed.

Peripartum Primary Prophylaxis Inferior Vena Cava Filter Placement in a Patient with Stage IV B-Cell Lymphoma Presenting with a Pathologic Femur Fracture

Background Pulmonary embolus (PE) remains a leading etiology of maternal mortality in the developed world. Increasing utilization of retrievable inferior vena cava (IVC) filter placement currently includes pregnant patients. Case A 22-year-old woman at 27 weeks' gestation was diagnosed with Stage IV high-grade malignant B cell lymphoma following pathologic femur fracture. Significant risk factors for PE led to placement of primary prophylaxis IVC filter before cesarean delivery, open reduction and internal fixation of the fractured femur, and chemotherapy. Conclusion This case supports that primary prophylaxis placement of IVC filters in highly selected pregnant patients may assist in decreasing PE-associated maternal mortality.