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T Hardegger

Publications and source records attributed to T Hardegger.

4 recordsLinked to original sources

[Internal bleeding in patients on oral anticoagulants].

Five selected case reports of patients suffering from rather unusual bleeding complications during oral anticoagulant therapy are presented. The reported frequency of bleeding during oral anticoagulation varies greatly. An unacceptably high incidence of hemorrhages has been reported in North American studies of the early 1980ies. The therapeutic target INR of 2.5-4.9 in these series is comparable to that in European studies where bleeding occurred much less frequently. We suggest that the insensitive thromboplastin reagents used in North America are unsuited to guide coumarin dosage, because too many prothrombin time values were outside the INR target range. In contrast, most prothrombin time values in European studies where a sensitive thromboplastin reagent was used, were within the target range. A recent prospective investigation by 25 Swiss practitioners showed an acceptably low bleeding complication rate (2.1 hemorrhagic complications severe enough to necessitate hospitalization per 100 patient years). Observation of contraindications, regular control of the prothrombin time using a sensitive and correctly calibrated thromboplastin, participation of practitioners and hospital laboratories at quality control exercises and consideration of drug interferences with coumarins help to reduce the incidence of hemorrhagic side effects. In case of either a PT value outside the target range or manifest bleeding, the necessary measures have to be tailored to the individual situation considering the Quick value as well as the severity and localization of hemorrhage.

Abdominal Muscles↗

Fibrin glue in surgery: frequent development of inhibitors of bovine thrombin and human factor V.

We report on a 34-year-old woman whose plasma showed a marked prolongation of thrombin time (TT) (> 200 s) using bovine thrombin. The patient had previously been exposed twice to topical bovine thrombin contained in fibrin glue during cardiac surgery. TT was normal when human thrombin was used as reagent. The patient's purified IgG reacted with bovine prothrombin and bovine thrombin in immunoblotting studies but showed virtually no cross-reaction with human thrombin. In addition, following surgery, factor V clotting activity (FV:C) was reduced to 9% of normal. The inhibitor of bovine thrombin persisted over a period of more than a year, while the level of FV:C progressively returned to normal within this time period. Development of thrombin and FV:C inhibitors was also investigated in plasma of 34 consecutive patients who had undergone either cardiac surgery or neurosurgery with use of fibrin glue containing bovine thrombin. Eleven of 24 patients after cardiac surgery and two of 10 patients after neurosurgery presented with TT > or = 25 s (normal plasma 15 s). Two patients had been re-exposed to fibrin glue during cardiac re-operation and showed markedly prolonged TT (> 60 s). All 13 patients who had acquired a thrombin inhibitor also had low FV:C activity (10-60% of normal plasma), whereas FV:C activity remained in the normal range in the 21 patients with normal TT. Our findings indicate that development of inhibitors of bovine thrombin as well as co-immunization to factor V occurs frequently and is associated with the amount of applied fibrin glue and with the type of operation. Re-exposure to fibrin glue seems to enhance formation of inhibitors of bovine thrombin and human factor V.

Adult↗

[Thromboembolic diseases from the hematologic viewpoint: 13 case examples].

Numerous patients with a thromboembolic history are referred to our Central Haematology Laboratory for a complete investigation of thrombophilia. Among them, patients with idiopathic thromboembolism represent the largest group. In collaboration with the obstetrician we control pregnant women at increased risk for thromboembolic complications. Individuals with myeloproliferative disorders often suffer from thromboembolism and are investigated at our Laboratory as well. Thirteen illustrative cases are presented, which are of diagnostic and/or therapeutic interest for the practitioner.

Adult↗