Comparison between nasal and intravenous desmopressin for the treatment of aminosalicylic acid-induced platelet dysfunction:

Desmopressin acetate in intracranial haemorrhage

Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N = 4) or multiple (N = 6) doses of acetylsalicylic acid and 3 patients (control group) who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P ≤ 0.05. Results. (1) Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2) The platelet function worsened again after three hours. (3) There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients.

[Antiplatelet therapy after coronary stenting and its importance in total joint arthroplasty]

Coronary stenting is an effective treatment for reopening atherosclerotic occlusions of coronary arteries. Depending on the manifestation of coronary artery disease (stable CAD or acute coronary syndrome) and on the type of implanted stent, dual antiplatelet therapy is recommended for a period of 4 weeks to 12 months. In this period total joint replacement is associated with high blood loss and high perioperative morbidity. Therefore antiplatelet therapy is often discontinued and replaced by higher dosages of heparin for prophylactic anticoagulation. However, with this treatment regimen protection of the stent is doubtful and there is a high risk of stent thrombosis with myocardial infarction. The surgery should be scheduled after the dual antiplatelet therapy is replaced by lifelong aspirin therapy. On the other hand, if surgery cannot be postponed perioperative bridging of dual antiplatelet therapy can be conducted to minimize bleeding complications with the best possible stent protection. Lifelong therapy with aspirin should not be discontinued in any case.

Platelet function analyzer (PFA)-100 closure time in the evaluation of platelet disorders and platelet function

BACKGROUND

Closure time (CT), measured by platelet function analyzer (PFA-100) device, is now available to the clinical laboratory as a possible alternative or supplement to the bleeding time test.

AIM

On behalf of the Platelet Physiology Subcommittee of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis (ISTH-SSC), a working Group was formed to review and make recommendations on the use of the PFA-100 CT in the evaluation of platelet function within the clinical laboratory.

METHODS

The Medline database was searched to review the published information on the PFA-100 CT in the evaluation of platelet disorders and platelet function. This information, and expert opinion, was used to prepare a report and generate consensus recommendations.

RESULTS

Although the PFA-100 CT is abnormal in some forms of platelet disorders, the test does not have sufficient sensitivity or specificity to be used as a screening tool for platelet disorders. A role of the PFA-100 CT in therapeutic monitoring of platelet function remains to be established.

CONCLUSIONS

The PFA-100 closure time should be considered optional in the evaluation of platelet disorders and function, and its use in therapeutic monitoring of platelet function is currently best restricted to research studies and prospective clinical trials.