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Biomedical subjects

George M Rodgers

Publications and source records attributed to George M Rodgers.

At least 19 recordsLinked to original sources
PubMed2007

Management of cancer-associated thrombotic microangiopathy: what is the right approach?

A 49-year-old Caucasian woman presented with features suggestive of thrombotic microangiopathy (TMA). She did not respond to treatment with repeated plasma exchange and corticosteroids. A bone marrow biopsy revealed presence of metastatic carcinoma. A limited autopsy revealed presence of breast cancer with rib metastases. Though severe deficiency of von Willebrand factor-cleaving protease was initially proposed as a key pathogenetic factor for thrombotic thrombocytopenic purpura, subsequent studies involving patients with cancer-associated TMA did not find as severe a deficiency of von Willebrand factor-cleaving protease as is seen in idiopathic cases of thrombotic thrombocytopenic purpura. Here we address one approach of management of these patients with cancer-associated TMA.

Anemia, Hemolytic↗
PubMed2007

Superwarfarin poisoning: a report of two cases and review of the literature.

Superwarfarins are anticoagulant rodenticides similar to warfarin, but which have various substituted phenyl groups replacing the terminal methyl group, resulting in a fat-soluble, long-acting anticoagulant that is nearly 100 times more potent than the parent compound. Since their development, many accidental and intentional cases of consumption have been reported. We describe two cases of consumption, one related to unknown etiology, and the other related to utilization of the superwarfarin to potentiate a drug of abuse. The clinical manifestations including bleeding symptoms and abnormal coagulation assays are discussed. The differential diagnosis is quite broad, and includes all causes of vitamin K deficiency, factor deficiency or inhibitor, disseminated intravascular coagulation (DIC), and liver disease. Differentiating superwarfarin ingestion from the other causes can be quite difficult, but extremely important, as management requires prolonged administration of vitamin K. Other treatment options are discussed as well including, fresh frozen plasma (FFP), and recombinant factor VIIa. Finally, the significance of "lacing" drugs of abuse with superwarfarin to potentiate their effect is discussed, as well as the complications that could develop from such a habit.

4-Hydroxycoumarins↗
PubMed2007

A second case of prothrombin Puerto Rico I in the United States.

Prothrombin deficiency is a very rare autosomal recessive bleeding disorder associated with mild to severe bleeding symptoms. We identified this bleeding disorder in a US-born patient as due to prothrombin Puerto Rico I. Unlike other prothrombin deficiencies, prothrombin Puerto Rico I is a series of concordant polymorphisms found in people of Puerto Rican descent with a much higher frequency than those prothrombin deficiencies found in the general population. This case underscores the importance of family history in identifying rare bleeding disorders.

Female↗
PubMed2006

The treatment of venous thromboembolism in special populations.

Anticoagulant therapy for the typical venous thromboembolism patient is straightforward with predictably favorable outcomes. However, for certain patients with venous thromboembolism, there remains uncertainty and controversy about optimal treatment. These controversial areas include venous thromboembolism patients with: heparin resistance, renal insufficiency, morbid obesity, cancer, antiphospholipid antibody syndrome, recurrent thrombosis despite appropriate anticoagulation, and patients with unprovoked VTE who may or may not benefit from thrombophilia testing. This review summarizes the current data for these special patient populations with venous thromboembolism and provides our recommendations for management.

Anticoagulants↗
PubMed2006

Argatroban dosing of patients with heparin-induced thrombocytopenia and an elevated aPTT due to antiphospholipid antibody syndrome.

OBJECTIVE: To describe the clinical characteristics, management, and outcomes of patients with heparin-induced thrombocytopenia with thrombosis (HITTS) or without thrombosis (HIT) who also had an elevated baseline activated partial thromboplastin time (aPTT) due to antiphospholipid antibody syndrome (APS). CASE SUMMARY: Four patients with HIT/HITTS and an elevated baseline aPTT due to APS were identified. Two patients had venous thrombosis, 1 had limb ischemia, and 1 had isolated HIT. All 4 were managed with a weight-based fixed dose of argatroban without laboratory monitoring. None of the patients had thrombotic or bleeding complications once therapy was initiated. DISCUSSION: Management of patients with HIT/HITTS and an abnormal baseline aPTT due to APS is problematic. We review alternative management strategies, such as monitoring direct thrombin inhibitors with the ecarin clotting time or thrombin inhibition time or using an alternative anticoagulant, such as fondaparinux. As of March 13, 2006, none of these management strategies has been evaluated in a clinical trial for this patient population. We report the successful use of weight-based, fixed-dose argatroban without laboratory monitoring in patients with APS. CONCLUSIONS: Use of a fixed-dose argatroban regimen without laboratory monitoring is a potential management strategy for patients with HIT/HITTS and an elevated baseline aPTT due to APS.

Adult↗
PubMed2006

Acquired amegakaryocytic thrombocytopenic purpura.

Acquired amegakaryocytic thrombocytopenia is an unusual hematologic disorder characterized by thrombocytopenia in association with markedly diminished bone marrow megakaryocytes. We report a case that responded to treatment with cyclosporine but not to IL-11. The bone marrow biopsy, repeated after resolution of thrombocytopenia, showed normal number of megakaryocytes.

Bone Marrow Cells↗
PubMed2006

Pediatric reference intervals for uncommon bleeding and thrombotic disorders.

This study provides pediatric reference intervals and median values for factors II, V, VII, X, fibrinogen, alpha-2-antiplasmin (AP), antithrombin (AT), plasminogen, protein C (PC), and protein S (PS) for children 7 to 17 years of age. All analytes exhibited at least some age dependence in late childhood and adolescence either when compared against adult values or when medians for children were regressed against age.

Adolescent↗
PubMed2006

Elevated factor XI activity levels are associated with an increased odds ratio for cerebrovascular events.

High levels of factor XI have been implicated as a risk factor for deep venous thrombosis and possibly cardiovascular disease; however, the relationship between elevated factor XI activity and stroke has yet to be established. We retrospectively evaluated factor XI activity, factor XI antigen, and high-sensitivity C-reactive protein (hs-CRP) values in samples from 65 patients with stroke, 13 with transient ischemic attack (TIA), and 17 with venous thrombosis, younger than 55 years with normal prothrombin and partial thromboplastin times who underwent evaluation for a hypercoagulable state. Factor XI activity levels were more than normal in 22% of patients with stroke or TIA and 18% of patients with venous thrombosis, producing odds ratios of 5.3 and 4.1 for stroke or TIA and venous thrombosis, respectively. Factor XI activity levels correlate with factor XI antigen levels by Deming regression analysis (slope, 1.3; R = 0.667) and a lack of correlation of both with hs-CRP suggests that factor XI is not an acute phase reactant. Our findings suggest an association between elevated factor XI activity and stroke.

Adult↗
PubMed2006

Guidelines for the use of erythropoietic growth factors in patients with chemotherapy-induced anemia.

The use of erythropoietic growth factors to treat chemotherapy-induced anemia (CIA) has been increasing as clinicians become more aware of the ability of these drugs to improve the quality of life of patients with cancer. The cost associated with erythropoietic growth factor therapy makes its appropriate use a practical issue for physicians and hospitals. Clinical practice guidelines can benefit physicians by increasing practice efficiency, reducing medical errors, increasing the quality of medical care, and decreasing reimbursement problems. The American Society of Clinical Oncology and the American Society of Hematology, the European Organisation for Research and Treatment of Cancer, and the National Comprehensive Cancer Network (NCCN) have all published guidelines for using erythropoietic growth factors to treat CIA, and this article reviews and summarizes those guidelines. Of the three guidelines for the use of erythropoietic growth factors in CIA, the NCCN guidelines are based on the most recent data. Current evidence indicates that erythropoietic growth factors can increase hemoglobin levels, reduce the need for red blood cell transfusions, and improve quality of life; the effect of erythropoietic therapy on outcomes in patients with CIA is still being investigated.

Anemia↗
PubMed2005

Venous thromboembolism prophylaxis in medically ill patients and the development of strategies to improve prophylaxis rates.

Venous thromboembolism (VTE) is common but often unrecognized in medically ill patients. Over the past 5 years, three large-scale placebo-controlled trials enrolling a total of 5500 medically ill patients have highlighted the risk of VTE in this group. These trials have helped to define a specific at-risk patient profile, including those admitted to the hospital with severe congestive heart failure, respiratory illness, acute infection, and inflammatory bowel disease. We performed a retrospective review of patients admitted to the medical service at our tertiary care center to define how common the at-risk medical patient is and to evaluate and improve prophylaxis rates in this patient group. The study was conducted in two phases. Based on admission characteristics, patients were stratified into high-risk or low-risk groups for the development of VTE. During the pre-intervention phase, 75% of patients admitted to the medical service were characterized as increased risk for VTE, yet only 43% of these high-risk patients received prophylaxis of any sort. After interventions designed to increase awareness of VTE, we conducted a second review period. In this post-intervention phase, where 79% of patients were at risk for VTE, prophylaxis rates improved to 72%. Based on these results, we conclude that the majority of patients admitted to the medical service at our tertiary care center constitute a high-risk population that warrants consideration for VTE prophylaxis. Implementation of strategies to improve prophylaxis rates, including educational sessions and risk stratification guidelines, can be successful and improve identification and prophylaxis of this population.

Adolescent↗
PubMed2005

Parenteral iron therapy: a single institution's experience over a 5-year period.

Many patients require parenteral iron therapy for optimal correction of anemia, including cancer patients who require erythropoietic drugs. Available parenteral iron therapy options include iron dextran, iron gluconate, and iron sucrose. The purpose of this study is to summarize our institution's experience with parenteral iron therapy over a 5-year period, with a focus on comparative safety profiles. All patients receiving parenteral iron therapy over this period were included in the analysis. Chi-squared test and Fisher's exact test were used to compare the adverse event rates of each product. A total of 121 patients received 444 infusions of parenteral iron over this period. Iron dextran was the most commonly used product (85 patients) and iron sucrose was the least used (2 patients). Iron gluconate was used by 34 patients. Overall adverse event rates per patient with iron dextran and iron gluconate were 16.5% and 5.8%, respectively (P = .024). Premedication with diphenhydramine and acetaminophen before infusions of iron dextran reduced adverse event rates per infusion from 12.3% to 4.4% (P = .054). Test doses of iron dextran were used 88% of the time for initial infusions of iron dextran. All adverse events for all parenteral iron products were mild or moderate. There were no serious adverse events and no anaphylaxis was observed. Our results suggest that, if test doses and premedications are used, iron dextran is an acceptable product to treat iron deficiency.

Acetaminophen↗
PubMed2004

Parenteral iron therapy options.

Parenteral iron therapy is occasionally necessary for patients intolerant or unresponsive to oral iron therapy, for receiving recombinant erythropoietin therapy, or for use in treating functional iron deficiency. There are now three parenteral iron products available: iron dextran, ferric gluconate, and iron sucrose. We summarize the advantages and disadvantages of each product, including risk of anaphylaxis and hypersensitivity, dosage regimens, and costs. The increased availability of multiple parenteral iron preparations should decrease the need to use red cell transfusions in patients with iron-deficiency anemia.

Anemia, Iron-Deficiency↗
PubMed2004

Home prothrombin time monitoring: a literature analysis.

The anticoagulant activity of warfarin sodium is monitored by the prothrombin time (PT) using the international normalized ratio (INR). Standard oral anticoagulant therapy monitoring requires frequent patient visits to physicians' offices and/or laboratories to optimize warfarin dosage. Home PT monitoring by patients can increase testing frequency and may thus decrease complications associated with oral anticoagulant therapy. Clinical studies suggest that home PT monitoring is more effective than uncoordinated management and is as effective as care through specialized anticoagulation clinics for keeping INRs within a therapeutic range. There are accurate and reliable instruments available, but paramount to the success of home PT monitoring is sound patient selection, appropriate patient training, and consistent quality control.

Anticoagulants↗
PubMed2004

Analytic validation and clinical evaluation of the STA LIATEST immunoturbidimetric D-dimer assay for the diagnosis of disseminated intravascular coagulation.

To evaluate the diagnostic performance of a quantitative, immunoturbidimetric D-dimer assay and compare it with other components of the proposed International Society on Thrombosis and Haemostasis disseminated intravascular coagulation (DIC) diagnostic algorithm, we retrospectively analyzed the D-dimer, platelet count, prothrombin time, and fibrinogen results for all eligible hospitalized patients (n = 241) who had a D-dimer assay ordered during a 12-month period. A receiver operating characteristic (ROC) curve constructed from the maximum D-dimer measurement for all patients was significant (P < .001) with an area under the curve (AUC) of 0.94. The ROC curves of the other tests were each significant (P < .001), but the AUCs of the prothrombin time (0.74), fibrinogen level (0.70), and platelet count (0.67) did not approach that of the D-dimer. A D-dimer cutoff of 8.2 microg/mL (8,200 microg/L) optimized sensitivity and negative predictive value for the total population and patients with a predisposing condition. Validation against 286 additional patients in a separate analysis verified the diagnostic performance of the aforementioned cutoff. A sensitive, immunoturbidimetric D-dimer assay, by itself provides excellent sensitivity and negative predictive value for the diagnosis of DIC.

Adult↗