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Biomedical subjects

R L Bick

Publications and source records attributed to R L Bick.

At least 19 recordsLinked to original sources

Diagnostic efficacy of the D-dimer assay in disseminated intravascular coagulation (DIC).

The D-Dimer (D-D) assay for measuring cross-linked fibrin degradation products is now available for the clinical laboratory. We combined this assay with other tests to assess patients with diagnosed or suspected DIC. Also, a small group of patients (20) with deep venous thrombosis (DVT) were studied. The D-D test, antithrombin-III assay, FDP titer, fibrinopeptide-A level, protamine sulfate test, fibrinogen, prothrombin time, and activated partial thromboplastin time were used. The D-D test was abnormal in 93.7%, the AT-III level was abnormal in 87.5%, the fibrinopeptide-A level was abnormal in 89.5%, and the FDP titer was elevated in 83.7% of patients with DIC. When assessing patients found not to have confirmed DIC the D-D assay was abnormal in 20%, the AT-III level was abnormal in 6%, and the fibrinopeptide-A level was elevated in 13%. We conclude the D-Dimer assay to be a useful molecular marker of hemostasis in diagnosing DIC and this test will often discriminate between those patients with or without DIC, especially when used with the AT-III and fibrinopeptide-A assays. Of the battery of tests used in this study, the most useful, in descending order of efficacy, appear to be the D-dimer assay (93.7% abnormal), the fibrinopeptide-A titer (89.5% abnormal), the AT-III level (87.5% abnormal), and the FDP titer (83.7% abnormal). Of the global tests, the diagnostic efficacy of the prothrombin time activated partial thromboplastin time, and protamine sulfate test were no greater than chance and appear to be of little use in aiding in a diagnosis of DIC. Also, the D-Dimer assay is similar in cost to the FDP titer and is cost effective for the routine clinical laboratory.

Disseminated Intravascular Coagulation

Platelet function defects: a clinical review.

Platelet dysfunction, especially acquired forms, are common causes of hemorrhage, especially in association with trauma and surgery. Although the hereditary platelet function defects are generally quite rare, hereditary storage pool disease is common enough to be suspected in an individual, usually a child, with characteristic historical and clinical findings. The acquired platelet function defects, especially those resulting from drugs, are very common and should promptly be suspected in patients developing easy and spontaneous bruising, mild to moderate mucosal membrane hemorrhage, or unexplained bleeding associated with trauma or surgery. The template bleeding time is generally useful as a screening test of platelet function, but a normal template bleeding time, in the presence of a suggestive history, suggestive clinical findings, or in the patient frankly bleeding, is not reliable and platelet aggregation or lumi-aggregation should be done in appropriate clinical situations. The mainstay of therapy for essentially all these defects, if bleeding is significant, is the liberal infusion of appropriate numbers of platelet concentrates. The acquired platelet function defects, of course, should also be managed by attempts to treat or control the underlying disease, if possible, and offending drugs or potentially offending drugs should promptly be discontinued.

Blood Platelets

Coagulation abnormalities in malignancy: a review.

As outlined in this review, patients with cancer may harbor many alterations of hemostasis. These are multifaceted and must be taken into account when trying to control hemorrhage or thrombosis in cancer patients. Often, hemorrhage or thrombosis is the final fatal event in many patients with metastatic solid tumor or hematologic malignancies. Patients with malignancy present a major clinical challenge in this new era of oncologic awareness and more aggressive care, which has led to prolonged survival for patients and a longer time frame during which these complications may develop. Therefore, these complications are occurring more commonly. It is important to realize that these alterations of hemostasis exist and must be approached in a sequential and logical manner with respect to diagnosis; only in this way can responsible, efficacious, and rational therapy be delivered to patients. By far the most common alteration of hemostasis in malignancy is that of hemorrhage associated with thrombocytopenia, either drug-induced, radiation-induced, or from bone marrow invasion. However, hemorrhage resulting from DIC is also quite common and may present as hemorrhage, thrombosis, thromboembolus, or any combination thereof. Many antineoplastic drugs and radiation therapy may lead to or significantly enhance hemorrhage in patients with malignancy. Thrombosis, also commonly seen in patients with malignancy, is often a manifestation of low-grade DIC, conspicuous as an intravascular thrombotic or thromboembolic event instead of an intravascular proteolytic (hemorrhagic) event. When suspecting this, confirmatory laboratory evidence must be sought and the patient treated appropriately. When approaching the patient with malignancy and either hemorrhage or thrombosis, all the potential defects in hemostasis must be taken into account, defined from the laboratory standpoint, and treated in as precise and logical manner as possible.

Blood Coagulation Disorders

Acquired platelet function defects.

Platelet dysfunctions, especially acquired forms, are common causes of hemorrhage, especially when associated with trauma or surgery. Although the hereditary platelet function defects are generally quite rare, hereditary storage-pool disease is common enough to be suspected in an individual, usually a child, with characteristic historical and clinical findings. The acquired platelet function defects, especially those resulting from drugs, are very common and should promptly be suspected in patients developing easy and spontaneous bruising, mild to moderate mucosal membrane hemorrhage, or unexplained bleeding associated with trauma or surgery. The template bleeding time is generally useful as a screening test of platelet function, but a normal template bleeding time, in the face of a suggestive history, suggestive clinical findings, or in the patient frankly bleeding, is not reliable, and platelet aggregation or lumi-aggregation should be done in appropriate clinical situations. Also, prolongation of the template bleeding time is an unreliable predictor of clinical bleeding propensity. The mainstay of therapy for essentially all these defects, if bleeding is significant, is the liberal infusion of appropriate numbers of platelet concentrates. The acquired platelet function defects should also be managed by attempts to treat or control the underlying disease, if possible, and offending drugs or potentially offending drugs should immediately be stopped.

Blood Platelet Disorders

Drug-induced alterations of hemostasis and fibrinolysis.

The hemostatic and fibrinolytic systems contribute significantly to the overall pathophysiologic status of a patient in a given clinical setting. Drug modulation of these systems plays a crucial role in the facilitation of the therapeutic effects but may also produce bleeding or thrombotic disorders. Many drugs appear inert; they can, however, modulate both the hemostatic and fibrinolytic systems. Such effects depend on several factors, however, but are significant enough to be recognized for the optimal care of patients. Therefore, it is recommended that the hemostatic and fibrinolytic systems should be routinely monitored during drug delivery.

Anticoagulants

Disseminated intravascular coagulation.

Current concepts of the etiology, pathophysiology, clinical and laboratory diagnosis, and management of fulminant and low-grade DIC have been presented. Considerable attention has been devoted to interrelationships within the hemostasis system. Only by clearly understanding these pathophysiologic interrelationships can the clinician and laboratory scientist appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with DIC. Many therapeutic decisions to be made are controversial and will remain so until more is published about specific therapeutic modalities and survival patterns. Also, therapy must be highly individualized depending on the nature of DIC, age, etiology of DIC, site and severity of hemorrhage or thrombosis, and hemodynamic and other clinical parameters. Many syndromes that are organ-specific share common pathophysiology with DIC but are typically identified as an independent disease entity, such as hemolytic uremic syndrome, adult shock-lung syndrome, eclampsia, and many other isolated "organ-specific" disorders.

Disseminated Intravascular Coagulation

Anticardiolipin antibodies and thrombosis.

Anticardiolipin antibodies (ACLAs) are strongly associated with thrombosis and appear to be the most common of the acquired blood protein defects causing thrombosis. Although the precise mechanism(s) whereby ACLAs alter hemostasis to induce a hypercoagulable state remain unclear, several theories, as previously discussed, have been advanced. The most common thrombotic events associated with ACLAs are deep vein thrombosis and pulmonary embolus (type I syndrome), coronary or peripheral artery thrombosis (type II syndrome), or cerebrovascular/retinal vessel thrombosis (type III syndrome), and occasionally patients present with mixtures (type IV syndrome). The relative frequency of ACLAs in association with arterial and venous thrombosis strongly suggests that these should be looked for in any individual with unexplained thrombosis; all three idiotypes (IgG, IgA, and IgM) should be assessed. Also, the type of syndrome (I through IV) should be defined if possible, because this may dictate both type and duration of both immediate and long-term anticoagulant therapy.

Adult

Hypercoagulability and thrombosis.

This article has summarized known congenital and acquired alterations of hemostasis leading to thrombosis. Decreases in coagulation inhibitors, including antithrombin III, heparin cofactor II, and protein C and protein S, are of major importance in assessing patients with hypercoagulable states or patients with unexplained thrombosis. Newer assays for components of the fibrinolytic system, plasminogen, t-PA and t-PA inhibitor are also now readily available and are important for defining congenital or acquired fibrinolytic defects leading to hypercoagulability and thrombosis. By judicious use of these assays, combined with clinical evaluation, many patients with thrombosis will have an underlying etiologic blood protein defect defined. Delineating reasons for a thrombotic event is of obvious importance for planning long-term prophylactic therapy and for diagnosing and counseling afflicted family members. In this manner, newly found patients can be treated prophylactically before unalterable morbidity or mortality occurs.

Antithrombin III

Disseminated intravascular coagulation syndromes.

Current concepts of the etiology, pathophysiology, diagnosis and management of fulminant as well as low-grade disseminated intravascular coagulation have been presented. Considerable attention has been devoted to interrelationship within the hemostasis system. Only by clearly understanding these pathophysiological interrelationships can the clinician and laboratory scientists appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with disseminated intravascular coagulation. Many therapeutic decisions to be made in these patients are controversial and will remain so until more series of patients are published about specific therapeutic modalities and survival patterns. Also, therapy must be highly individualized depending on the nature of DIC, age, etiology of DIC, site and severity of hemorrhage or thrombosis and hemodynamic and other clinical parameters. Many syndromes which are organ specific share common pathophysiology with disseminated intravascular coagulation but are typically identified as an independent disease entity, such as hemolytic uremic syndrome, adult shock lung syndrome, eclampsia, and many other isolated "organ-specific" disorders. Many of these similar disorders, some systemic and some organ specific or multi-organ specific are listed in Table 8.

Disseminated Intravascular Coagulation

Disseminated intravascular coagulation syndromes.

Current concepts of the etiology, pathophysiology, diagnosis, and management of fulminant as well as low-grade disseminated intravascular coagulation have been presented. Considerable attention has been devoted to interrelationships within the hemostasis system. Only by clearly understanding these pathophysiological interrelationships can the clinician and laboratory scientists appreciate the divergent and wide spectrum of often confusing clinical and laboratory findings in patients with disseminated intravascular coagulation. Many therapeutic decisions to be made in these patients are controversial and will remain so until more series of patients are published concerning specific therapeutic modalities and survival patterns. In addition, therapy must be highly individualized depending upon the nature of DIC, age, etiology of DIC, site and severity of hemorrhage or thrombosis and hemodynamic and other clinical parameters. Many syndromes which are organ specific share common pathophysiology with disseminated intravascular coagulation but are typically identified as an independent disease entity, such as hemolytic uremic syndrome, adult shock lung syndrome, eclampsia, and many other isolated "organ-specific" disorders.

Disseminated Intravascular Coagulation

Vascular disorders associated with thrombohemorrhagic phenomena.

This paper has attempted to summarize the more common disease entities which may be accompanied by or may lead to a disorder of hemostasis and/or thrombosis. It is to be emphasized that the vascular component of hemostasis is often overlooked by clinicians caring for individuals with disorders in hemostasis and thrombosis. It is hoped that this brief summary will alert clinicians that the vasculature is equal in importance to the coagulation protein system and to platelets in leading to a hemorrhagic or thrombotic diathesis.

Amyloidosis

Thrombotic thrombocytopenic purpura. An extended editorial.

A hypothesis for the pathogenesis of TTP is developed, centered on the views and findings of Kwaan (Fig. 8). By a series of deductions, inferences, and extensions, an attempt has been made to define considerably more restrictively than heretofore a TTP paradigm of clinical (Tables 1,2,3) and laboratory (Table 4) features. Revisions may be required in the future as increase of knowledge indicates. By similar methods rational, exigent therapeutic measures are selected (Table 5). The innovative therapeutic use of plasma transfusion, as proposed by Byrnes and Lian and their co-workers, is compatible with the paradigm in all respects. The paradigm discriminates for authentic cases of TTP among spurious if similar entities. Such sequestration will constitute a homogeneous universe of case material appropriate for study. The prospective use of the TTP paradigm defined in this papd therapeutic protocol, jointly developed, may accelerate our knowledge and improve our effectiveness in this lethal, if uncommon, disease [49,76,111,170].

Blood Platelets

Disseminated intravascular coagulation and related syndromes: etiology, pathophysiology, diagnosis, and management.

Disseminated intravascular coagulation (DIC) is being recognized with increased frequency and not only are newer diagnostic modalities becoming available for this syndrome, but newer, some controversial, methods of management are also being recognized and may prove to increase survival in DIC. In addition, several syndromes classically considered separate, definitive disease entities, may actually share similar or identical pathophysiology to DIC. This review summarized current, as well as controversial aspects of etiology, pathophysiology, clinical and laboratory diagnosis, and management of DIC. In addition, a brief discussion of syndromes which may share similar or identical pathophysiology to DIC is included.

Anemia, Hemolytic

Alterations of hemostasis associated with malignancy: etiology, pathophysiology, diagnosis and management.

As outlined in this paper, the patient with disseminated malignancy suffers many alterations of hemostasis; in addition, hemorrhage or less commonly thrombosis is the final clinical event in many of these patients. Patients with malignancy present a major clinical challenge in this day of new oncological awareness and more aggressive care. Thus, it is important to realize that these alterations of hemostasis do exist and they must be approached in a logical manner with respect to diagnosis as well as efficacious therapy. By far the most common alteration of hemostasis in malignancy is that of hemorrhage associated with thrombocytopenia either drug-induced or from bone marrow invasion. However, hemorrhage due to disseminated intravascular coagulation is also quite common. In addition, many antineoplastic drugs, as well as radiotherapy, may lead to hemorrhage in these patients. Thrombosis, which is also commonly seen in the patient with malignancy, is usually a manifestation of disseminated intravascular coagulation manifest as an intravascular thrombotic rather than an intravascular proteolytic event. When suspecting this, confirmatory laboratory evidence must be sought and the patient treated apropriately. When approaching the patient with malignancy and either hemorrhage or thrombosis, all of the potential defects in hemostasis must be taken into account, defined from the laboratory standpoint, and treated in as precise a manner as possible.

Blood Coagulation Disorders