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R C Bone

Publications and source records attributed to R C Bone.

At least 73 records · Page 4Linked to original sources
PubMed1993

Role of tumor necrosis factor-alpha in disease states and inflammation.

OBJECTIVE: To review the animal and human data defining the role of tumor necrosis factor (TNF) in the pathogenesis of the septic shock syndrome, the systemic inflammatory response syndrome, and related pathologic states. DATA SOURCES: The international English language literature from 1975 to present formed the basis for this review. MEDLINE was used to identify pertinent animal and human studies. STUDY SELECTION: Those animal and human studies that focused on the mechanisms of action of TNF, its role in the inflammatory cytokine network, and the potential uses of anti-TNF therapies were emphasized. DATA EXTRACTION: Animal studies were selected based on the relevance of the model to the pathogenesis of the human systemic inflammatory response syndrome. Where they provided supportive evidence, human studies were selected on the basis of study design. DATA SYNTHESIS: TNF plays a major role in systemic inflammatory response syndrome secondary to infection, burns, trauma or hemorrhagic shock, and pancreatitis. TNF influences the outcome of other infectious processes, including allograft rejection, ischemia-reperfusion injury, delayed-type hypersensitivity, and granuloma development. The administration of anti-TNF antibodies, soluble TNF receptors, and related fusion proteins may limit organ damage and decrease mortality rate. CONCLUSIONS: Although the regulated release of TNF may exert normal physiologic effects, the uncontrolled production of TNF may lead to organ dysfunction and death. TNF mediates a variety of other physiologic processes that are unrelated to sepsis syndrome. New anti-TNF therapies appear to attenuate the injurious actions of TNF.

Animals↗
PubMed1993

Gram-negative sepsis: a dilemma of modern medicine.

Gram-negative sepsis is an increasingly common problem, with up to 300,000 cases occurring each year in the United States alone. Despite the ongoing development of new antibiotics, mortality from gram-negative sepsis remains unacceptably high. To stimulate earlier therapeutic intervention by physicians, a new set of broad definitions has been proposed to define the systemic inflammatory response characteristic of sepsis. In this review, the signs and symptoms of this progressive, injurious process are reviewed and its management is discussed, as are the mechanisms by which bacterial endotoxin triggers the biochemical events that lead to such serious complications as shock, adult respiratory distress syndrome, and disseminated intravascular coagulation. These events often occur even when appropriate antimicrobial therapy has been instituted. An increased understanding of the structure of endotoxin and its role in the development of sepsis, together with advances in hybridoma technology, has led to the development of monoclonal antibodies that bind to endotoxin and significantly attenuate its adverse effects. These agents promise to substantially reduce the morbidity and mortality associated with gram-negative sepsis.

Anti-Bacterial Agents↗
PubMed1993

Respiratory dyskinesia presenting as acute respiratory distress.

Incapacitating respiratory distress was the presenting manifestation of a choreiform movement disorder. Because the patient also had asthma, respiratory distress was at first mistakenly attributed to this condition. Despite vigorous asthma management, there was no improvement. However, once the neurologic condition was recognized, use of specific therapy (haloperidol and reserpine) resulted in rapid and sustained remission of respiratory symptoms.

Adult↗
PubMed1993

Analysis of indications for intensive care unit admission. Clinical efficacy assessment project: American College of Physicians.

OBJECTIVE: To formulate recommendations for the development of intensive care unit (ICU) admission policies. DESIGN: Literature review of published reports over the period 1966 to 1991 pertaining to admission criteria for intensive care or coronary care units (CCUs). PATIENTS: Studies identifying patients least likely to benefit from ICU or CCU admission were analyzed. Patient populations of interest included adults (> or = 18 years of age) with medical conditions possibly requiring intensive care; trauma patients were excluded. MEASUREMENTS AND MAIN RESULTS: Of 970 articles identified as being pertinent to intensive care, only two case-control studies used the direct method of measuring the effect of ICU intervention on mortality. No studies were found that compared outcomes of low-risk patients treated in a CCU vs those treated in alternative hospital locations, and none identified patients with a very high probability of a bad outcome. CONCLUSIONS: The use of decision-making models for ICU and CCU admissions must be tested in prospective, randomized clinical trials. Critical care units and ICUs should be studied separately. Existing studies of early discharge from CCUs need to be summarized and evaluated. The triaging of ICU patients to alternative hospital locations needs to be evaluated, as do existing predictive models for early triage decision-making.

Adult↗
PubMed1993

Analysis of indications for early discharge from the intensive care unit. Clinical efficacy assessment project: American College of Physicians.

OBJECTIVE: To formulate recommendations for the development of early intensive care unit (ICU) discharge criteria for low-risk monitor patients. DESIGN: Literature review of published reports over the period 1966 to 1991 pertaining to ICU discharge criteria. PATIENTS: Studies identifying patients admitted to ICUs who could be characterized as low risk. Patient populations of interest included adults (> or = 18 years of age) with low-risk medical or mixed medical/surgical conditions; cardiac care unit and burn patients were excluded. MEASUREMENTS AND MAIN RESULTS: Of 1,492 articles identified as being pertinent to ICU discharge, only 2 studies (by the same group of investigators) were found that distinguished low-risk populations among medical and mixed medical/surgical ICU patients. The physiologic component of the Acute Physiology and Chronic Health Evaluation (APACHE) was used in both of these studies to ascertain the degree of risk. No studies were found that compared outcomes of low-risk patients remaining in the ICU after 24 h with those transferred to other hospital locations. CONCLUSIONS: Objective methods (such as APACHE III) should be used to identify low-risk patients at 24 h post-ICU admission. A multicenter study should be conducted to compare outcomes on patients identified as low risk who are randomly assigned to alternative hospital locations for treatment versus those assigned to continued ICU treatment until routine ICU discharge. Mortality and quality of life data should be used as outcome measures (prior to ICU admission and 6 months post-ICU discharge).

Adult↗
PubMed1993

The technique of small-catheter pleural aspiration. A new, less invasive method for draining pneumothoraces.

Small-catheter aspiration may be preferable to chest tube drainage in many patients with primary spontaneous or iatrogenic pneumothoraces, as well as in some patients with pneumothoraces resulting from minor trauma. It is also less invasive than chest tube drainage, allows greater control over the rate of air removal, and produces less patient discomfort. Following administration of a local anesthetic, the catheter can be inserted into the pleural space using either a trocar or modified Seldinger technique. Addition of a Heimlich valve (with or without a suction device) permits continued air removal. Complications are infrequent and generally minor.

Catheterization↗
PubMed1993

Techniques for weaning a patient from mechanical ventilation; when to begin, what method to use, and how to predict outcome.

A variety of methods have been employed to help wean patients from prolonged ventilatory support. Although synchronized intermittent mandatory ventilation is probably the most widely used, it has not been shown to be clearly superior to T piece or pressure support weaning. Regardless of the method you choose, begin weaning before the patient's lung function has returned to normal or baseline levels and end when the patient shows the minimum capacity necessary to sustain himself off the ventilator. The patient's response to the change in the level of ventilatory support governs the rapidity of weaning. The rapid shallow breathing index can be useful in predicting weaning outcome, as is the patient's ability to tolerate a weaning trial.

Contraindications↗
PubMed1993

Techniques for chest tube insertion and pleurodesis. An updated look at two common procedures.

Chest tube insertion is warranted for drainage of large exudative pleural effusions, empyemas, hemothoraces, or chylothoraces, and for some pneumothoraces or parapneumonic effusions. Chest tubes may also be used to instill sclerosing agents to prevent recurrent malignant effusions or pneumothorax. There are no absolute contraindications to tube thoracostomy; however, if time allows, effort should be made to correct any coexisting hemorrhagic disorders before the procedure is performed. Pleurodesis may be contraindicated in patients who are expected to undergo lung surgery. The incisional method is safest for chest tube insertion and pleurodesis; bear in mind, however, that some patients with pneumothorax may be better treated with small-caliber drainage.

Chest Tubes↗
PubMed1993

Endotoxin alters the expression of extracellular matrix proteins by cultured endothelial cells.

In order to understand changes that occur in the extracellular matrix during acute lung injury, we have observed the effects of endotoxin on cultured bovine pulmonary artery endothelial cells. Following treatment with endotoxin, endothelial cell monolayers altered their production of [3H] proline-labeled procollagen (types III and V), fibronectin, and a 43 kDa protein, Secreted Protein Acidic and Rich in Cysteines (SPARC). Following their secretion into the culture medium, these proteins were immunoprecipitated with specific antibodies for characterization and quantification. Our results show that endotoxin decreased the levels of procollagen and fibronectin, whereas the production of SPARC was augmented approximately twofold. Northern blot analyses revealed no changes in the expression of SPARC or beta-actin transcripts, whereas the expression of fibronectin transcript increased two- to threefold. Our data suggest that under acute exposure to endotoxin, cultured bovine pulmonary endothelial cells differentially change their expression of extracellular proteins.

Animals↗
PubMed1993

Issues in biomedical ethics.

Bioethics is the discipline of ethics dealing with moral problems arising in the practice of medicine and the pursuit of biomedical research. Physicians may confront ethical dilemmas regularly in their individual relationships with patients and in institutional and societal decisions on health care policy. Ethical problem solving requires the application of certain ethical rules and principles to specific situations. Although ethical theories differ, certain ethical rules and principles appear consistently. These include nonmaleficence, beneficence, respect for individual autonomy, confidentiality, and justice. This article discusses some of the ethical issues that arise in clinical practice, including informed consent, do-not-resuscitate orders, noninitiation and termination of medical therapy, genetic intervention, allocation of scarce health resources, and infection with the human immunodeficiency virus (HIV). Some of these problems require ethical analysis at the bedside; others require physician involvement on a broader level. Perspectives on the different ethical issues are presented; however, absolute answers to these ethical dilemmas are not provided. Interpretation of the ethical principles and the application of these principles to each clinical situation demands the thoughtful attention of the practitioner.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Modulators of coagulation. A critical appraisal of their role in sepsis.

Widespread intravascular coagulation is common in patients with sepsis. Coagulation abnormalities may result from exposure to endotoxin, from tumor necrosis factor alpha or interleukin 1 release, or from the actions of a more specific mediator, such as vascular permeability factor. The result is marked activation of the contact and coagulation systems; simultaneously, there is decreased fibrinolysis and depressed levels of the inhibitors of the contact and coagulation systems. Multiple agents are being studied to correct these abnormalities. Antithrombin III holds promise because it inhibits a number of factors important in contact and coagulation activation, not just thrombin. Plasminogen activators may prove helpful in increasing fibrinolysis during sepsis; because they have been associated with rebound thrombin generation, however, plasminogen activators may be most effective if used in conjunction with hirudin or a synthetic hirudin analogue. Bradykinin may offset hypotension in sepsis. Protein C may inhibit thrombin formation and also complex with plasminogen activator inhibitor 1, thereby promoting fibrinolysis. Other agents that may prove effective include alpha 1-antitrypsin Pittsburgh, C1-esterase inhibitor, monoclonal antibodies to contact factors, soybean trypsin inhibitors, thrombomodulin, prostaglandin I2, and aprotinin. There are no data to support the use of heparin or fibronectin, except in limited circumstances.

Animals↗
PubMed1992

Patients' preferences for intensive care.

OBJECTIVES: To determine patients' preferences for intensive care and to evaluate the influence of a recent ICU experience on preferences for future ICU treatment. DESIGN: Survey of nonrandomized patient sample using structured interviews. SETTING: Large, urban, tertiary academic medical center. PATIENTS: Eighty-four adult inpatients discharged from the medical ICU between June and August 1990. MEASUREMENTS: Agreement with life-supportive care under each of four potential outcome scenarios was assessed on a 5-point scale. An overall preference score was created by summing scores for the four items. Patients were also asked about their recent experiences in the ICU. RESULTS: Patients identified sources of stress associated with their ICU stay, yet most (76%) rated their ICU experience positively. Preferences for future intensive care varied with perceived outcome, and were strongest for health restoration and weakest for persistent vegetative states. No significant relationships were found between ICU preferences and any demographic or clinical variable except race. CONCLUSIONS: Patients tolerate intensive care well and desire it to restore health. Most patients modify their desire for intensive care if less favorable outcomes are likely. Patients' preferences for intensive care cannot be predicted from demographic features or previous ICU experiences.

Academic Medical Centers↗