Argatroban in Critically Ill Patients With Heparin Resistance

Critically ill patients with high risk for thrombosis or tromboembolic events with the presence of heparin resistance, treated at the Department for General and Surgical Critical Care Medicine of the Medical University Innsbruck, Austria will be enrolled in the study when meeting the inclusion- and exclusion criteria. If a patient meets the inclusion criteria and is recruited for the study, the patient will be randomized either to Group A or Group H.

All patients have to achieve a prophylactic aPTT-target range of an aPTT-level of 45 - 60 sec (Pathromtin® SL) within 6 to 8 hours.

Randomisation Group A:

If a Heparin resistance appears and the patient meets the inclusion and exclu-sion criteria, he/she will be enrolled. The Heparin administration will be stopped and Argatroban will be given and adjusted until the target aPTT-range is achieved.

Randomisation Group H - Standard therapy:

If a Heparin resistance appears and the patient meets the inclusion and exclu-sion criteria, he/she will be enrolled. The Heparin administration will be contin-ued and, if necessary increased. Hereby the maximum heparin dose is 1.500 IU per hour.

Therapy failure Group H:

Primary target failure at Visit 3 (6-8 hours):

If a patient of Group H does not achieve the target-aPTT within 6-8 hours, he/she will switch to Group A and will start with T1 (Baseline) and will follow the visits according to Group A until the final Visit 12 (T1 / day 30).

Maintenance failure after Visit 3:

Maintenance failure after 6-8 hours is defined as non-maintenance of the tar-get-aPTT until day 7 with a max. heparin dosage of 1.500 IU per hour. In this case, heparin therapy has to be changed to Argatroban.

The patient will start with T1 (Baseline) and will follow the visits according to Group A until the final Visit 12 (day 30) counting from the Baseline of Group A.

Therapy failure Group A:

If a patient of Group A does not achieve the target-aPTT within 6-8 hours or cannot maintain the target-aPTT in spite of 3 more adjustements during the further study period, the patient automatically drops out of the study.

The same is effective for patients who switched to the Group A after a therapy failure in Group H.

General:

Two hours after starting the Baseline investigations, patient's parameters in-cluding blood collections will be measured for the second time (T2). Additional measurements will be made at 6 hours (T3), 24 hours (T4), 48 hours (T5), 3 days (T6), 4 days (T7), 5 days (T8), 6 days (T9) and 7 days (T10) after Baseline and 6 h after study medication stop (T11). 30 days after inclusion in the study, a final investigation is planned (T12).