Coagulation Activation by Hyperosmolar Agents in Intracranial Hypertension

Osmotherapy is commonly used in the treatment of intracranial hypertension (ICH) due to a variety of causes, including head trauma, intracranial neoplasia, infection or hemorrhage, and status epilepticus. The principle goal of osmotherapy is to shift fluid from the intracellular into the extracellular compartment using intravenous hyperosmolar agents, thereby reducing brain edema and improving cerebral perfusion pressure. Although 10-20% mannitol is considered the gold standard hyperosmolar agent in the treatment of ICH, mannitol-induced osmotic diuresis may cause hypovolemia and reduction in cerebral perfusion pressure. In recent years, 3.0-7.5% hypertonic saline (HTS) has gained popularity in the treatment of ICH as it has less pronounced diuretic effects and therefore does not cause hypovolemia. Indeed, in the face of hypovolemic shock and traumatic brain injury, HTS provides the advantage of volume expansion, restoring adequate cerebral perfusion pressures, and reducing brain edema, which makes it superior to mannitol in trauma patients with shock.

Both mannitol and HTS have been shown to interfere with whole blood coagulation and platelet function. This is in part due to dilutional coagulopathy. Furthermore, 7.2% HTS may directly disturb both fibrin formation and platelet function, and mannitol may interfere with coagulation by reducing clot strength. In addition, hyperosmolarity is supposed to lead to impairment of both whole blood coagulation and platelet function . In consequence, the safety of using these agents in patients with ICH and intracranial hemorrhage remains unclear. Previous in vitro studies in humans have demonstrated anticoagulant effects of both mannitol and HTS, although one clinical study failed to demonstrate any negative effect on hemostasis using either solution in patients undergoing elective intracranial surgery. However, in vivo studies in a clinical setting are lacking.

• Mannitol (Drug): Therapy is administered according to the clinical gold standard and until reaching and maintaining serum sodium levels between 145 e 155 meq/l and an osmolarity <320.
• Hypertonic saline solution (Drug): Therapy is administered according to the clinical gold standard and until reaching and maintaining serum sodium levels between 145 e 155 meq/l and an osmolarity <320.

Primary outcomes

• Changes in coagulation parameters [Before osmotic therapy (time 0), after 12 hrs infusion (time 1)]: Coagulation parameters such as thrombin and prothrombin time, fibrinogen, thrombin generation time will be measured in plasma by ELISA test or on whole blood by thromboelastography

Secondary outcomes

• Changes in inflammation markers [Before osmotic therapy (time 0), after 12 hrs infusion (time 1)]: Inflammation markers such as C reactive protein, interleukin 6, P-selectin. E-selectin will be measured in plasma

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* Indication to osmotic therapy for cerebral edema / non-traumatic intracranial hypertension
* Age 18 - 80 years
* Body temperature between 35.5 ° C and 37.5 °C

Exclusion Criteria:

* Congenital or acquired disorders of hemostasis
* Clinical history of abnormal bleeding
* Hematologic or Renal diseases (acute or chronic renal failure II-III stage)
* Chronic or recent therapy with antiplatelet and/or anticoagulants
* Taking corticosteroids or nonsteroidal anti-inflammatory drugs (less than 4 weeks)
* Administration of macromolecular vascular filling solutions (less than 4 weeks)
* History of recent venous / arterial thromboembolic disease (less than three months)
* Moderate-severe liver dysfunction
* Anemia (hb <10 mg/dl)
* Recent transfusions (less than three months)
* Hyponatremia (Na <135 meq/l)
* Hypernatremia (Na> 155 meq/l)

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• Licia Iacoviello, MD, PhD, Study chair, IRCCS Neuromed
• Fulvio Aloj, MD, Principal investigator, IRCCS Neuromed