Question 25

A 39-year-old female has just been admitted to your unit with severe multiple injuries following a motor vehicle accident. Her injuries are right sided frontal intra-cerebral haemorrhage (ICH), multiple rib fractures with bilateral flail segments and lung contusions, grade III liver laceration, bilateral pubic rami and sacral fractures. She has a BMI of 39.

a) Outline the advantages and disadvantages of methods available to reduce the risks of pulmonary embolism (PE) in this patient. (40% marks)

On day 4 of the patient’s ICU admission, they develop multiple pulmonary emboli.

b) Outline the rationale of inserting an IVC filter in this patient. (30% marks)

c) List the advantages and disadvantages of using an IVC filter in this patient. (30% marks)

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College answer

Not available.

Discussion

VTE prophylaxis in the bleeding-prone trauma patient is always challenging, especially in this situation where the head is involved (thus raising the stakes), further surgery may be required (eg. rib fixation), and the liver is involved (thus lowering the clotting factor levels).

The methods-advantages-disadvantages answer would probably work better as a table:

	Advantages	Disadvantages
Unfractionated heparin	Cheap Reversible Well-researched Effect can be monitored with APTT	May increase the risk of bleeding
Low molecular weight heparin	Single daily dose No need to monitor levels Cheap Partially reversible Appears to have an advantage over UFH in trauma patients	May increase the risk of bleeding Only partially reversible
Compression stockings	No increased risk of bleeding Cheap	Not appropriate in compartment syndrome or with lower limb injuries Effectiveness is limited (usually only effective when combined with a chemical VTE prophylaxis strategy)
Sequential pneumatic compression devices	No increased risk of bleeding	Increased cost Effectiveness is limited (usually only effective when combined with a chemical VTE prophylaxis strategy)

b) Rationale for IVC filter insertion:

Pulmonary embolism is common in trauma patients, and this patient is at a very high risk of further emboli
Given the intracranial and hepatic injuries, systemic therapeutic anticoagulation to prevent further emboli is relatively contraindicated
In this patient, further PE could be fatal considering the already compromised lung function (obesity, pulmonary contusions and flail segment)
A mechanical filter may prevent such fatal embolism at the cost of some filter-related complications
Thus, in this patient, the risk of filter-related complications weighs favourably against the risk of PE.

Advantages of the IVC filter

Can be inserted in patients with a contraindication to anticoagulation
May decrease the risk of fatal PE in a nonpharmacological fashion
Is retrievable, supposedly

Disadvantages of the IVC filter

Does not prevent or treat DVT; not a replacement for anticoagulation
Venous stasis of lower limbs will occur
Though retrievable, in practice fewer than 60% are ever retrieved.
Filter related complications, eg malposition, IVC damage, perforation, IVC thrombosis, and embolism of filter fragments. The filter may even migrate into the pulmonary artery.
It may offer no mortality benefit whatsoever.
In this patient with pelvic fractures, insertion of the filter may be challenging (i.e pelvic veins may be thrombosed)

References

Jacobs, Benjamin N., et al. "Unfractionated heparin versus low-molecular-weight heparin for venous thromboembolism prophylaxis in trauma." The journal of trauma and acute care surgery 83.1 (2017): 151.

PulmCCM: April 12, 2013. "Inferior vena cava filters: debatable benefit; rarely removed"

ACCP: Radiologic management of IVC filters, 2012

Prasad, Vinay, Jason Rho, and Adam Cifu. "The inferior vena cava filter: how could a medical device be so well accepted without any evidence of efficacy?." JAMA internal medicine 173.7 (2013): 493-495.

You, John J., et al. "Antithrombotic therapy for atrial fibrillation: antithrombotic therapy and prevention of thrombosis: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines." CHEST Journal 141.2_suppl (2012): e531S-e575S.

Sarosiek, Shayna, Mark Crowther, and J. Mark Sloan. "Indications, complications, and management of inferior vena cava filters: the experience in 952 patients at an academic hospital with a level I trauma center." JAMA internal medicine 173.7 (2013): 513-517.

Linsenmaier, Ulrich, et al. "Indications, management, and complications of temporary inferior vena cava filters." Cardiovascular and interventional radiology21.6 (1998): 464-469.

Baglin, T. P., J. Brush, and M. Streiff. "Guidelines on use of vena cava filters."British journal of haematology 134.6 (2006): 590-595.

Young, Tim, Hangwi Tang, and Rodney Hughes. "Vena caval filters for the prevention of pulmonary embolism." Cochrane Database Syst Rev 2.2 (2010).

Tola, Juan C., Robert Holtzman, and Lawrence Lottenberg. "Bedside placement of inferior vena cava filters in the intensive care unit." The American Surgeon65.9 (1999): 833-7.

Rohrer, Michael J., et al. "Extended indications for placement of an inferior vena cava filter." Journal of vascular surgery 10.1 (1989): 44-50.

These are the papers quoted at the end of the college answer:

Arcasoy, Selim M., and John W. Kreit. "Thrombolytic therapy of pulmonary embolism: a comprehensive review of current evidence." CHEST Journal 115.6 (1999): 1695-1707.

Goldhaber, Samuel Z. "Pulmonary Embolism" NEJM 339(2); 1998 p93·104

Greenfield, Lazar J., and Robert B. Rutherford. "Recommended reporting standards for vena caval filter placement and patient follow-up." Journal of vascular and interventional radiology 10.8 (1999): 1013-1019.

PREPIC Study Group. "Eight-year follow-up of patients with permanent vena cava filters in the prevention of pulmonary embolism the PREPIC (prévention du risque d’embolie pulmonaire par interruption cave) randomized study." Circulation 112.3 (2005): 416-422.

White, Richard H., et al. "A population-based study of the effectiveness of inferior vena cava filter use among patients with venous thromboembolism." Archives of Internal Medicine 160.13 (2000): 2033-2041.

Hemmila, Mark R., et al. "Prophylactic Inferior Vena Cava Filter Placement Does Not Result in a Survival Benefit for Trauma Patients." Annals of surgery 262.4 (2015): 577-585.

Sharifi, Mohsen, et al. "Role of IVC filters in endovenous therapy for deep venous thrombosis: the FILTER-PEVI (filter implantation to lower thromboembolic risk in percutaneous endovenous intervention) trial." Cardiovascular and interventional radiology 35.6 (2012): 1408-1413.

Ho, Kwok M., et al. "A multicenter trial of vena cava filters in severely injured patients." New England Journal of Medicine 381.4 (2019): 328-337.

Young, Tim, and Krishna Bajee Sriram. "Vena caval filters for the prevention of pulmonary embolism." Cochrane Database of Systematic Reviews 10 (2020).

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