Quality management in the prophylaxis of venous thrombembolism--results of a survey including 464 medical and surgical patients.

BACKGROUND: We surveyed the quality of risk stratification politics and monitored the rate of entries to our company-wide protocol for venous thrombembolism (VTE) prophylaxis in order to identify safety concerns. PATIENTS AND METHODS: Audit in 464 medical and surgical patients to evaluate quality of VTE prophylaxis. RESULTS: Patients were classified as low 146 (31 %), medium 101 (22 %), and high risk cases 217 (47 %). Of these 262 (56.5 %) were treated according to their risk status and in accordance with our protocol, while 9 more patients were treated according to their risk status but off-protocol. Overtreatment was identified in 73 (15.7 %), undertreatment in 120 (25,9 %) of all patients. The rate of incorrect prophylaxis was significantly different between the risk categories, with more patients of the high-risk group receiving inadequate medical prophylaxis (data not shown; p = 0.038). Renal function was analyzed in 392 (84.5 %) patients. In those patients with known renal function 26 (6.6 %) received improper medical prophylaxis. If cases were added in whom prophylaxis was started without previous creatinine control, renal function was not correctly taken into account in 49 (10.6 %) of all patients. Moreover, deterioration of renal function was not excluded within one week in 78 patients (16.8 %) and blood count was not re-checked in 45 (9.7 %) of all patients after one week. There were more overtreatments in surgical (n = 53/278) and more undertreatments in medical patients (n = 54/186) (p = 0.04). Surgeons neglected renal function and blood controls significantly more often than medical doctors (p-values for both < 0.05). CONCLUSIONS: We found a low adherence with our protocol and substantial over- and undertreatment in VTE prophylaxis. Besides, we identified disregarding of renal function and safety laboratory examinations as additional safety concerns. To identify safety problems associated with medical VTE prophylaxis and "hot spots" quality management-audits proved to be valuable instruments.

Standardized exchange of clinical documents--towards a shared care paradigm in glaucoma treatment.

OBJECTIVES: The exchange of medical data from research and clinical routine across institutional borders is essential to establish an integrated healthcare platform. In this project we want to realize the standardized exchange of medical data between different healthcare institutions to implement an integrated and interoperable information system supporting clinical treatment and research of glaucoma. METHODS: The central point of our concept is a standardized communication model based on the Clinical Document Architecture (CDA). Further, a communication concept between different health care institutions applying the developed document model has been defined. RESULTS: With our project we have been able to prove that standardized communication between an Electronic Medical Record (EMR), an Electronic Health Record (EHR) and the Erlanger Glaucoma Register (EGR) based on the established conceptual models, which rely on CDA rel.1 level 1 and SCIPHOX, could be implemented. The HL7-tool-based deduction of a suitable CDA rel.2 compliant schema showed significant differences when compared with the manually created schema. Finally fundamental requirements, which have to be implemented for an integrated health care platform, have been identified. CONCLUSIONS: An interoperable information system can enhance both clinical treatment and research projects. By automatically transferring screening findings from a glaucoma research project to the electronic medical record of our ophthalmology clinic, clinicians could benefit from the availability of a longitudinal patient record. The CDA as a standard for exchanging clinical documents has demonstrated its potential to enhance interoperability within a future shared care paradigm.

Enhanced platelet aggregation with TRAP-6 and collagen in platelet aggregometry in patients with venous thromboembolism.

The role of platelet hyperaggregability as a possible risk factor for venous thromboembolism is not well defined. Some authors described enhanced maximal platelet aggregation in platelet aggregometry as a contributing factor for arterial and venous thrombosis. This syndrome has been termed "sticky-platelet syndrome" (SPS). The diagnosis of SPS is based on the demonstration of platelet hyperaggregability in aggregometry after stimulation with epinephrine (EPI) and/or adenosine diphosphate (ADP). We investigated platelet hyperaggregability in platelet-rich plasma (PRP) of patients (n = 34) with unexplained venous thromboembolism in comparison to healthy individuals (n = 53). For analysis, platelet aggregometry was performed and the influence of epinephrine, adenosine diphosphate, collagen (Coll) and thrombin receptor-activated peptide (TRAP-6) as agonist were determined. Compared to the control group, patients with venous thromboembolism showed an enhanced maximal platelet aggregation with low concentrations of TRAP-6 (2 microM) and collagen (0.05 microM). In contrast, we could not detect an increased platelet aggregation with EPI or ADP. Our results indicate that platelet hyperaggregability may represent an independent risk factor in patients with otherwise unexplained venous thromboembolism. In our study, low concentrations of TRAP-6 and collagen are superior to EPI and ADP to define platelet hyperreactivity in platelet aggregometry.

A prospective study on the incidence and clinical relevance of heparin-induced antibodies in patients after vascular surgery.

The heparin-platelet factor 4-antibody assay, polyanion-platelet factor 4-antibody assay and heparin-induced platelet activation test are used for laboratory diagnosis of the immune form of heparin-induced thrombocytopenia. Fifty consecutive patients receiving heparin treatment for more than 5 days after vascular surgery were prospectively screened for heparin-induced thrombocytopenia antibodies, thrombocytopenia (daily platelet counts), deep-vein thrombosis (color-coded duplex sonography), and arterial reocclusion (clinical assessment). None of the patients developed thrombocytopenia or thrombosis in association with formation of heparin-induced thrombocytopenia antibodies. Despite the absence of clinical evidence of heparin-induced thrombocytopenia, many patients formed heparin-induced thrombocytopenia antibodies: 34% of the patients were positive in the heparin-platelet factor 4-antibody assay, 28% in the polyanion-platelet factor 4-antibody assay, 14% in the heparin-induced platelet activation test, and 54% with any of these tests. Patients predominantly developed IgM (24%) and IgA antibodies (16%), whereas IgG antibodies were found in 12% of patients. Whereas the majority of patients with positive ELISA assays had IgM and IgA antibodies, patients with a positive functional assay (heparin-induced platelet activation test) predominantly had IgG antibodies. We conclude that a high percentage of patients develop heparin-induced antibodies after vascular surgery without any clinical symptoms of heparin-induced thrombocytopenia. None of the assays therefore is predictive of the clinical manifestation of heparin-induced thrombocytopenia in asymptomatic patients. Therefore, the diagnostic specificity of both antigen and activation assays for heparin-induced thrombocytopenia appears to be relatively low in the vascular surgery patient population.

Determination of heparin-platelet factor 4-IgG antibodies improves diagnosis of heparin-induced thrombocytopenia.

Only a few patients with heparin-induced antibodies develop heparin-induced thrombocytopenia (HIT). In this study, we investigated whether different immunglobulin classes can be used to differentiate between antibody-positive patients with and without HIT. Four different patient populations were investigated: 32 patients with the immune type of HIT with thromboembolic complications, 13 patients with HIT without thromboembolism, 24 patients with heparin-platelet factor 4 (PF4) antibodies without clinical symptoms of HIT, and 20 heparin-treated patients with thrombocytopenia caused by other reasons. In all patients the immunglobulin mixture of IgG, IgM and IgA, and the single immunglobulin classes of heparin-PF4 antibodies, were investigated. No significant differences between HIT patients with thromboembolic complications and patients with isolated HIT were found concerning the different immunglobulin classes. Antibody-positive patients with HIT had significantly higher levels of IgG antibodies than those without HIT (P < 0.05), while they did not differ concerning IgM and IgA antibodies. By determining IgG antibodies, the specificity of the enzyme-linked immunosorbent assay (ELISA) system was increased without loss of sensitivity. Heparin-PF4-IgG antibodies can identify patients at risk of developing life-threatening HIT. Future ELISAs should only include this immunglobulin class, as the determination of the antibody mixture may lead to overestimation of HIT.