Feasibility and Safety of Inhaled Heparin in Intubated and Mechanically Ventilated Patients: A Randomized Controlled Trial Comparing Three Doses of Inhaled Unfractionated Heparin.

Alveolar fibrin deposition is a hallmark of acute lung injury (ALI), Pulmonary coagulopathy is, the result of activation of coagulation and inhibition of fibrinolysis.
We hypothesize that unfractionated heparin could be of benefit in treatment of ALI. Intubated and mechanically ventilated patients may also benefit from such strategies since mechanical ventilation may cause injury very similar to ALI and pneumonia. Before future investigations of therapeutic effects of nebulized unfractionated heparin in mechanically ventilated patients with ALI can be performed this therapeutic strategy needs to be tested on its feasibility and safety. Therefore, in this study we will evaluate the feasibility and safety of treatment with inhaled heparin in intubated and mechanically ventilated patients without ALI. If safe, we will perform a new study in patients with ALI.

We hypothesize that unfractionated heparin could be of benefit in treatment of ALI. Delivering heparin directly to the pulmonary compartment may attenuate fibrin depositions more effectively while reducing the risk of bleeding as a result of systemic anticoagulant effects. Intubated and mechanically ventilated patients may also benefit from such strategies since mechanical ventilation may cause injury very similar to ALI and pneumonia.
Before future investigations of therapeutic effects of nebulized unfractionated heparin in mechanically ventilated patients with ALI can be performed this therapeutic strategy needs to be tested on its feasibility and safety. Therefore, in this study we will evaluate the feasibility and safety of treatment with inhaled heparin in intubated and mechanically ventilated patients without ALI. We consider treatment with inhaled heparin to be safe if non of the included patients show a >25% increase of area under the curve of serial anti-Xa measurements in plasma.
If treatment with inhaled heparin is safe, we will perform a new study in patients with ALI.

Administration of unfractionated heparin or placebo by aerosol generator (AeronebPro, Aerogen Inc., Sunnyvale, CA, USA) during mechanical ventilation. Bloodsamples and lungfluid will be collected before treatment and at 1, 3, 6 and 24 hours after the beginning of the last nebulization