This document discusses deep vein thrombosis (DVT) surveillance in patients with traumatic brain injury (TBI) or spinal cord injury (SCI). It outlines several challenges with diagnosing DVT in these patients, as clinical signs may be absent or difficult to assess due to their injuries. The Wells clinical prediction rule and D-dimer testing can help estimate DVT risk, though D-dimer may be elevated due to non-thrombotic factors as well. Ultrasound is the test of choice to diagnose DVT when suspected, while imaging like CT angiography or pulmonary angiography can identify pulmonary embolisms. More research is needed to develop optimal screening algorithms for this high-risk population.

1. Role of DVT surveillance in
TBI/SCI
Dr Amit Agrawal, MCh
Department of Neurosurgery
Narayana Medical College and Hospital
Chintareddypalem, Nellore (AP), India

2.  Conflict of interest: None

3.  The clinical diagnosis of DVT is non-unspecific
 It has been suggested that a clinical prediction rule
incorporating signs, symptoms and risk factors, can be
accurately applied to categorize patients as low, moderate or
high probability for DVT*
 Alternatively, the same rule can be used to categorize patients
as ‘DVT likely’ or ‘DVT unlikely’ **
The clinical diagnosis of DVT
*Wells PS. Integrated strategies for the diagnosis of venous thromboembolism. J
Thromb Haemost 2007; 5 (Suppl. 1): 41-50
**Wells et al. Evaluation of D-Dimer in the diagnosis of suspected deep-vein thrombosis.
N Engl J Med 2003; 349: 1227-35.

4.  Pulmonary embolism
 Tachycardia
 Tachypnea
 MS changes
 Diaphoresis
 Deep vein thrombosis
 Extremity pain
 Fever
 Localized edema/swelling
 Warmth/erythema
Clinical Presentation

5.  Wells score has been used to predict DVT risk in hospitalized
patients*
 It has been shown that the Wells score linearly correlates with
the incidence of DVT in trauma patients**
Wells score
*Bendinelli C, Balogh Z. Postinjury thromboprophylaxis. Curr Opin Crit Care. 2008;14:673-
8.
*Spain et al. Venous thromboembolism in the high-risk trauma patient: do risks justify
aggressive screening and prophylaxis? J Trauma. 1997;42:463-7.
**Modi et al. Wells criteria for DVT is a reliable clinical tool to assess the risk of deep
venous thrombosis in trauma patients. World J Emerg Surg. 2016;11:24.

6. Wells Clinical Prediction Rule
Wells PS. Integrated strategies for the diagnosis of venous thromboembolism. J Thromb
Haemost. 2007 ;5 Suppl 1:41-50.

7.  Blood gas – respiratory alkalosis, hypoxemia
Laboratory Findings

8.  D-dimer, a degradation product of cross-linked fibrin*
 Typically elevated with acute VTE
 D-dimer levels may also be increased by a variety of non-thrombotic
conditions
 Recent major surgery
 Hemorrhage
 Trauma
 Malignancy
 Sepsis
 D-dimer levels increase with age and through pregnancy
 Patients with leg symptoms compatible with DVT should initially have
a determination of pretest probability **
D-dimer for the diagnosis of DVT or PE
*Bombeli et al. Evaluation of an optimal dose of low-molecular-weight heparin for thromboprophylaxis in pregnant women at risk of thrombosis using
coagulation activation markers. Haemostasis 2001; 31: 90-8.
*Bosson et al. Quantitative high D-dimer value is predictive of pulmonary embolism occurrence independently of clinical score in a well-defined low risk
factor population. J Thromb Haemost 2005; 3: 93-9.
*Bosson et al. Deep vein thrombosis in elderly patients hospitalized in subacute care facilities. A multicenter cross-sectional study of risk factors,
prophylaxis and prevalence. Arch Intern Med 2003; 163: 2613-8.
*Righini et al. Effects of age on the performance of common diagnostic tests for pulmonary embolism. Am J Med 2000; 109: 357-61.
**Wells PS. Integrated strategies for the diagnosis of venous thromboembolism. J Thromb Haemost 2007; 5 (Suppl. 1): 41-50

9.  CXR – Nonspecific, peripheral wedge defect
 CT Angio Chest – filling defect(s)
Radiology Findings

10.  The test of choice for clinically suspected DVT is the highly
specific venous ultrasound*
 A positive result is sufficiently predictive in most patients that
treatment can be initiated*
 The exceptions are patients with a previous history of DVT and
low pretest probability in which the positive predictive value is
less**
Imaging tests for DVT
*Lensing et al. Detection of deep-vein thrombosis by real-time B-mode ultrasonography. N Engl J Med 1989; 320: 342-5.
* Cogo et al. Compression ultrasonography for diagnostic management of patients with clinically suspected deep vein thrombosis:
prospective cohort study. Br Med J 1998; 316: 17-20.
* Heijboer et al. A comparison of real-time compression ultrasonography with impedance plethysmography for the diagnosis of
deep-vein thrombosis in symptomatic outpatients. N Engl J Med 1993; 329: 1365-9.
* Anand et al. Does this patient have deep vein thrombosis? JAMA 1998; 279: 1094-9.
**Wells et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet 1997; 350: 1795-8.

11.  Pulmonary angiography is regarded as the gold standard*
 Although the procedure is usually well tolerated
 It is invasive, expensive and requires a skilled radiologist and a
cooperative patient
 A negative result does not entirely exclude VTE**
 Ventilation-perfusion (V/Q) lung scanning has been the imaging
procedure of choice**
 A high-probability lung scan has an 8590% predictive value
 A normal scan essentially excludes the diagnosis of PE
Imaging procedures for pulmonary
embolism
*Hudson ER, Smith TP, McDermott VG, Newman GE, Suhocki PV, Payne CS, Stackhouse DJ. Pulmonary angiography performed with iopamidol:
complications in 1,434 patients. Radiology 1996; 198: 61-5.
*Stein PD, Athanasoulis C, Alavi A, Greenspan RH, Hales CA, Saltzman HA, Vreim CE, Terrin ML, Weg JG. Complications and validity of pulmonary
angiography in acute pulmonary embolism. Circulation 1992; 85: 462-8.
**Henry JW, Relyea B, Stein PD. Continuing risk of thromboemboli among patients with normal pulmonary angiograms. Chest 1995; 107: 1375-8.
**PIOPED Investigators. Value of the ventilation/perfusion scan in acute pulmonary embolism. Results of the prospective investigation of
pulmonary embolism diagnosis (PIOPED). JAMA 1990; 263: 2753-9.

12. Suggested algorithm
Modi et al. Wells criteria for DVT is a reliable clinical tool to assess the risk of deep venous
thrombosis in trauma patients. World J Emerg Surg. 2016;11:24.

13.  The major limitations are that there are only few studies which
addresses the issues related to DVT and PE in TBI and SCI
patient population
 In patients with TBI and SCI clinical signs may not be present or
difficult to assess and interpret
 There is a need for clinical trials to develop algorithms to
identify the easier and less expensive protocols
Challenges