摘要:

Acute respiratory failure in advanced chronic obstructive pulmonary disease is characterized by worsening dyspnea, increased amount of bronchial secretions and impairment of gas exchange with an elevated resting Paco2, acidemia, and hypoxemia, requiring intensive treatment. Ventilatory failure, secondary to respiratory muscle fatigue, results from an imbalance between neuromuscular competence and mechanical load on the respiratory system. The most common causes for this imbalance are airway inflammation and infection, pneumonia, pneumothorax, left ventricular failure, pulmonary embolism, thoracic trauma, sedative drugs, and surgery. Many patients require hospitalization. Admission to an intensive care unit must be considered if any one of the following is present: (1) severe dyspnea not responsive to initial therapy; (2) confusion, lethargy, or respiratory muscle fatigue; (3) persistent or worsening hypoxemia, despite supplemental oxygen, or respiratory acidosis (pH

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The spectrum of human disease caused byAspergillusspecies includes hypersensitivity reactions, colonization syndromes, and invasive disease. Thus, it is one of the most interesting infectious agents encountered in humans, and its importance is underscored by recent autopsy studies that have noted an increasing incidence in immunocompromised hosts. The recognition and diagnosis of the various forms of aspergillosis are based on the clinical and radiographic patterns of disease. Treatment is based on the clinical syndrome; steroids are used in hypersensitivity illness, occasionally surgery for mycetomas complicated by bleeding, and antifungal pharmacotherapy in invasive disease. Outcome varies depending on the clinical syndrome.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Workplace exposures to cobalt, usually in combination with other materials, can cause asthma or pulmonary fibrosis, or in rare instances, both diseases. Workers at risk include (1) those engaged in the manufacture of “hard metal,” a mix of powdered tungsten carbide to which 6% to 15% cobalt is added and then heated to high temperatures. Hard metal has a very high temperature resistance and a hardness approximating that of diamonds; (2) workers who machine hard metal objects; (3) gem polishers in the diamond industry who use cobalt-faced polishing disks; and (4) those who use cobalt-containing materials in high-temperature metallurgy. Asthma, although uncommon, is more frequent than pulmonary fibrosis and resembles occupational asthma from other exposures. No clear-cut immunologic mechanisms have been identified. The pulmonary fibrosis is unique in that some cases are associated with a characteristic multinucleated giant cell in the alveolar spaces. This same cell can be found in the bronchoalveolar lavage fluid. When present in a patient with a known exposure, no additional diagnostic procedures are needed. Other cases of lung fibrosis secondary to exposure to cobalt-containing materials lack this distinctive cell and are indistinguishable from the usual nonspecific form of lung fibrosis. There is nonspecific therapy for these diseases. Early recognition of the cause, prompt removal from additional exposure no matter how small, and the usual therapy for either the airway or the parenchymal disease should be instituted promptly.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Pulmonary complications, both infectious and noninfectious, are an important cause of morbidity and mortality in patients with acute leukemia. Because respiratory diseases, in this subset of immunosuppressed hosts, may progress rapidly to respiratory failure, an expeditious evaluation is required. A noninvasive diagnostic approach based on the knowledge of the most probable etiologic factors; the radiographic patterns of the lung disease; the platelet, neutrophil, and leukocyte counts; the state of the hematologic malignancy at the time when pulmonary infiltrate appears; and the previous exposure to chemotherapy/recombinant human granulopoietic factors may help in the selection of an empiric therapy. However, clinicians must understand that clinical diagnoses are often incorrect. If progression of the disease process occurs, an invasive procedure (fiberoptic bronchoscopy with bronchial brushing, transbronchial biopsy, and bronchoalveolar lavage and/or open lung biopsy) must be considered to establish the precise diagnosis, but only if the results have a chance of influencing outcome. The sensitivity of these invasive diagnostic tests can be altered by previous empiric or prophylactic therapies, and they have the potential to cause morbidity and mortality.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Weaning patients from mechanical ventilation can be challenging after serious trauma, decompensated chronic lung disease, or severe catabolic illness, such as life-threatening infection. Hyper-metabolism, catabolism, and abnormal substrate utilization during the acute phase of illness often cause loss of weight and lean body mass. Therefore, the metabolic and nutritional needs of these patients are of much concern. Electrolyte abnormalities, specifically hypophosphatemia, hypomagnesemia, hypokalemia, and hypocalcemia, can each cause respiratory muscle weakness. Repletion of these electrolytes should begin early in the weaning period. The concern about malnutrition is occasioned by human and animal studies describing malnutrition-associated respiratory muscle weakness, emphysema-like parenchymal changes, reduced endurance, and increased susceptibility to pulmonary infections. Therefore, nutritional support is an important adjunctive therapy for patients weaning from mechanical ventilation. Yet, it must be viewed as a double-edged sword. Used properly, nutritional support can assist in improving and restoring the function of the respiratory system, but used improperly, for example, in excessive quantities, it can have detrimental effects. Nutritional intake must be carefully monitored to avoid overfeeding, excessive fluid retention, and electrolyte imbalance. Caloric intake and nutrient composition may need adjustment as patients pass from the acute to convalescent phases of their illness.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

One of the frequent problems encountered by pulmonary physicians, the workup of a solitary pulmonary nodule (SPN), is marred by subjectivity and uncertainty. The decision to remove a potentially curable malignant lesion is dependent on a multitude of radiographic and clinical variables, as is the decision to prospectively observe a potentially benign nodule. Physicians often err because there are too many variables to incorporate into the decision-making. This article reviews the current concepts in the evaluation of SPNs. Radiologic appearance (size, shape, calcification, and growth rate) and clinical characteristics (age, smoking, prior history of malignancy, and symptoms) used in differentiating benign from malignant SPNs are reviewed. Bayesian analysis, an objective approach incorporating the relative-risks of each variable, is discussed. We propose that by incorporating this approach into an algorithm, the workup of SPNs can be more objective and cost-efficient.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Chronic pulmonary hypertension, whether primary or secondary, is characterized by a sustained increase in resistance to pulmonary blood flow accompanied by an increase in pulmonary artery pressure. The purpose of this article is to provide a concise overview of contemporary pharmacotherapy for chronic pulmonary hypertension. Important aspects of patients' management including how to initiate pharmacotherapy, guidelines for dosing and dose adjustment, and monitoring therapeutic effects are beyond the scope of this article.Current concepts suggest that pulmonary vasoconstriction coupled with blood vessel wall remodeling and in situ thrombosis play an important role in the pathogenesis of chronic pulmonary hypertension. Hence, the primary goal in heating patients with this condition is to alleviate these processes. Anticoagulants, calcium channel blockers, and prostacyclin are used to treat patients with primary pulmonary hypertension. Although their long-term salutary effects are yet to be firmly established, shorter follow-up studies have noted marked improvement in hemodynamic status, quality of life, and survival of these patients. In secondary forms of chronic pulmonary hypertension, particularly those associated with hypoxia, continuous supplemental oxygen, calcium channel blockers, prostacyclin, and treatment of the underlying condition(s) show promise.Clearly, further studies are warranted to elucidate the mechanisms underlying the pathogenesis of chronic pulmonary hypertension so that more efficient and safer drugs can be developed. The primary endpoint is improvement in quality of life and long-term survival of patients with this condition.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Abstracts from LiteratureSYNOPSIS:Patients with suspected sleep apnea/hypopnea syndrome can be studied initially at home with a portable monitor.Screening in this manner is both reliable and cost-effective when compared with traditional methodsSOURCE:Parra 0 et al. Should patients with sleep apnea/hypopnea syndrome be diagnosed and managed on the basis of home sleep studies? Eur Respir J 1997;10: 1720–4CommentaryThe estimated prevalence of SAHS varies from 2% to 4% of the total population (Pack AI. Obstructive sleep apnea. Adv Intern Med 1994; 39:517–67; Young T et al. The occurrence of sleep disordered breathing among middle-aged adults. N Engl J Med 1993;328: 1230–5). Morbidity is related to loss of alertness and cardiovascular complications. It has been shown that patients with severe SAHS are at two to seven times increased risk of having a motor vehicle accident (Home J et al. Sleep related vehicle accidents. BMJ 1995;310: 565–7), with many patients at increased risk for early death. Although the full extent of cardiovascular risk is unknown, most studies do indicate an increased prevalence of systemic hypertension in these patients (Hla KM et al. Sleep apnea and hypertension: a population based study. Ann Intern Med 1994;120:382–8). The potential social and medical costs of this disease are also staggering

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID