Skin Burn Extensive Clinical Trial
Official title:
Evaluation Of Enoxaparin Pharmacokinetic For Thromboprophylaxis In Burn Care Patients
OVERVIEW:
- Thromboembolisms represent a serious and feared complication in hospitalized patients.
- Several factors make the ICU patient population at increased risk of venous
thromboembolism.
- A high incidence of thromboembolic events is starting to emerge from recent medical
literature in the burn patient.
- Actual guidelines for thromboprophylaxis in burn care patients are based on multiple
non-burn patient trials.
- Burn patient physiology is radically different than that of general ward hospitalized
patients
- Since the actual chemical thromboprophylaxis have not been evaluated in the burn
patient, it is of interest to assess their efficacy in patients with severe burns.
- Hence, the pharmacokinetic characterization of heparins (a well accepted mode of
thromboprophylaxis) in burn patients could guide future quality of care for this
subclass of patients.
Our proposal is based on the conviction that anti-Xa activity of low-molecular-weight
heparins in the burn patients do not correlate with levels described to prevent
thromboembolic events in the general hospitalized population.
The investigators aim to:
1. To evaluate pharmacokinetics and pharmacodynamics of low-molecular-weight heparins
(enoxaparin), with anti-Xa levels in severely burned patients receiving
thromboprophylaxis.
2. To determine the correlation between antithrombotic activity of heparins and the
different metabolic phases of the thermally injured patient.
Deep venous thrombosis (DVT) has taken a prevalent place in medical literature over the past
decades. In an attempt to decrease its impact on hospitalized patients, multiple trials have
tried to better define its frequency and consequences on a very broad range of patients. The
differences between these sub populations of ill individuals influence greatly the occurrence
of venous thrombotic events (VTE).
Critically ill patients are predisposed to VTEs. The nature of the disease may have an
important impact on the risk for DVT. Mechanical ventilation, central line placement,
surgery, vasopressors and immobilization are some of the realities of ICU patients. They
contribute to the enhanced chance for thromboembolic complications in this population, either
by venous stasis (immobilization), endothelial injury (surgery…) or hypercoagulability.
Trauma patients represent a subclass of critical care patients with a high incidence of DVT.
It has been evaluated as high as 44,1% even in patients with thrombotic prophylaxis with
low-dose unfractioned heparin.
Burn patient are also at increased risk of deep vein thrombosis and pulmonary embolisms.
Recent prospective trials in burn patients have described an incidence of thromboembolic
complications in the range of 6 to 60%. Autopsy evaluations are also in favor of an elevated
incidence of thrombotic events in thermally injured patients(37 to 60%).
At the present time, no trial has evaluated the efficacy of the pharmacologic methods used
for thromboprophylaxis in burned patients. Comparative efficacy between different patient
populations (including thermally injured patients) has never been undertook. Thus, the
investigators have to question the adequacy of present thromboprophylactic measures in burn
patients? Are the actual method of DVT and PE prophylaxis sufficient in severe burns?
The physiology of moderate to severe burns makes us believe it is not. In the early post burn
period, a massive fluid reanimation is initiated. The Starling forces are destabilized in
favor of an increased capillary leak to the interstitial space. The net effect is the
increase in free water in the interstitium and formation of important edema. The distance
between the epithelium and the vascular space is then potentially increased. Furthermore, the
central intravascular compartment of such individuals becomes very difficult to access. This
leads us to reconsider the efficiency of the subcutaneous route. In cases of severe
accumulation of interstitial fluid, can the subcutaneous administration of medications lead
to the desired therapeutic effect?
The investigators plan to compare the levels of anti-Xa levels between 3 patient populations:
severely burned patients (> 20%), medical ICU patients and general medical ward patients.
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