摘要:

The traveling public includes many individuals who have limited cardiopulmonary reserve or are dependent upon technology such as portable supplemental oxygen for daily activities. Unfortunately, many physicians are not aware of the physiologic stresses, especially hypobaric hypoxia, to which passengers are exposed. Typical cabin altitudes are between 5000 and 8000 ft, which may cause significant hypoxemia in people with limited pulmonary or cardiac reserves. The occurrence of hypoxemia while at high altitudes can be predicted from various formulas, although a high altitude simulation test, in which hypobaric hypoxia is simulated by using hypoxic gas mixtures (15.1% oxygen to simulate 8000 ft), is easy to perform and has the advantages of allowing the patient to experience this degree of hypoxemia and enabling the physician to adjust the amount of supplemental oxygen that would be necessary while in flight. When the technology-dependent pulmonary patient is traveling by air, land, or sea, special arrangements need to be made before travel so that oxygen supply, as well as electrical adaptors, equipment adaptors, emergency facilities, extra medications, and special insurance, is available at each stop. If a patient is properly prepared, even one who depends on technology can enjoy a “bon voyage”.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Macrolides are frequently used in the treatment of lower respiratory tract infections. Problems with erythromycin use, including limitations in bacteriologic spectra, pharmacokinetics, and side effects, have led to the introduction of two new macrolides, clarithromycin and azithromycin. The newer macrolides are generally better tolerated and have expanded antibacterial spectra, making them effective second-line agents in many cases of lower respiratory tract infection. The activity of clarithromycin and azithromycin against atypical mycobacteria has increased the treatment options available for treating these increasingly frequent infections.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Although eosinophils play an important role in host defense mechanisms, they also are involved in many inflammatory conditions. Many pulmonary inflammatory disorders are characterized by tissue infiltration with eosinophils, with or without peripheral blood eosinophilia. Treatment often includes immunosuppression with corticosteroids, but precise diagnosis is necessary for treatment planning and prognosis. In this article, the biology of the eosinophil and several of the pulmonary eosinophilic syndromes is reviewed. In addition to the classic pulmonary eosinophilic syndromes (e.g., Churg-Strauss syndrome, allergic bronchopulmonary aspergillosis, chronic eosinophilic pneumonia), two newly described syndromes, eosinophilia-myalgia syndrome and idiopathic acute eosinophilic pneumonia, are discussed. Emphasis is placed on the clincial presentation, differential diagnosis, histologic features, and treatment strategies.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The noninvasive cardiac evaluation of patients with chronic obstructive lung disease can provide useful prognostic and diagnostic information. A variety of technologies are available for this purpose. Traditionally, the routine chest radiograph and the electrocardiogram have been used to look for evidence of right ventricular hypertrophy and pulmonary hypertension in patients suspected of having cor pulmonale. Neither test is sufficiently sensitive or specific to be of clinical value except in severe cases. Echocardiography has been extremely useful in the evaluation of patients with chronic obstructive lung disease. Although a technically excellent study is often impossible in this population, an adequate examination that can provide clinically useful information is possible in the majority of patients. Right atrial and ventricular enlargement and right ventricular hypertrophy are easily identified on the two-dimensional echocardiographic examination. A quantitative assessment of pulmonary artery pressures can be performed using Doppler echocardiography. Although a quantitative assessment of ventricular ejection fraction is cumbersome when using echocardiographic techniques, a qualitative assessment of both left and right ventricular ejection function is routinely performed. Echocardiography also can be used to evaluate nonpulmonary-related cardiac pathologies that may be contributing to a patient's symptoms.In those patients for whom echocardiography is not feasible, radionuclide ventriculography can provide an accurate assessment of ventricular ejection fraction and an estimate of ventricular size. Imaging techniques such as magnetic resonance imaging and ultrafast computed tomography are far better at providing precise anatomical information, including the occurrence of chamber enlargement and hypertrophy. Unfortunately, the high cost of these technologies has limited their widespread availability.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

In the daily practice of pulmonary and critical care medicine, termination of life support is a common issue. During the past decade, withholding and withdrawing life support has increased remarkably among pulmonary and critical care physicians. Many patients are admitted to the intensive care unit even though they are part of a population with a high mortality rate. The goal of the health care team is to decide whether to try saving the patient who may live or to help the dying patient die with peace and dignity. Four principles of biomedical ethics play a role in end-of-life decision making: beneficence, nonmaleficence, autonomy, and justice. In addition, physicians must possess certain virtues to provide outstanding health care: benevolence, compassion, respect for humanity, prudence, truthfulness, and trustworthiness. During the past 2 decades, numerous court cases have helped to shape the practice of medicine concerning withholding and withdrawing life support. This article reviews the ethical decision making related to withholding and withdrawing basic and advanced life support and the issues dealing with advance directives and euthanasia.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

No single new mode of ventilation has generated as much controversy as high frequency ventilation. Despite the presence of ample studies demonstrating both the theoretical and the practical benefits of these techniques, high frequency ventilation remains restricted to those centers with access to appropriate equipment and enthusiasm for the technique. The technique slipped into a dormant phase but is being revitalized recently with the advent of superior technology, stimulated in part by the success of high frequency ventilation in the pediatric venue. High frequency ventilators are not very complex. Most rely on solenoid valves to produce the small pulsations of gas. Three variables, inspiratory time, driving pressure, and frequency, allow the operator to independently control ventilation and oxygenation. Of the three, the inspiratory time has the greatest effect on mean airway pressure and, therefore, controls oxygenation to the greatest degree. Carbon dioxide elimination has been empirically determined to be dependent on the frequency of ventilation raised to the first power and the tidal volume raised to the second power.Recent animal data have demonstrated that tidal volumes, of the magnitude that are used during conventional ventilation, can increase fluid filtration in the alveoli and interstitium, even in normal lungs. Additionally, fewer hyaline membranes form when similar mean airway pressures are applied at high frequency when compared with conventional frequencies. These data resulted in the resurgence of high frequency ventilation. Presently, only a few Food and Drug Administration-approved high frequency ventilators are available in the United States for clinical use. Although significant clinical studies have recently been published that demonstrate the safety and efficacy of these devices, their impact on mortality for adult respiratory distress syndrome has not yet been determined.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The clinical and radiographic features of an unusual case of symptomatic tracheobronchial amyloidosis is presented, and the literature regarding amyloidosis involving the respiratory system is reviewed. In our patient, amyloidosis of the left upper lobe bronchus was associated with enlargement of the hilar and mediastinal lymph nodes. There was no evidence of amyloidosis elsewhere in the body. Amyloidosis confined to the respiratory system is much less common than systemic amyloidosis. Respiratory amyloidosis can be broadly classified into three groups: pulmonary, pleural, and mediastinal amyloidosis. Pulmonary amyloidosis can be further classified into parenchymal and tracheobronchial amyloidosis. Clinical presentation is quite variable. Nodular pulmonary amyloidosis may be discovered as an incidental finding on a chest radiograph. Alveolar-septal amyloidosis presents as respiratory failure. Submucosal plaques may result in stricture formation causing bronchial narrowing and atelectasis. Management of respiratory amyloidosis varies with the type of presentation. If the patient is asymptomatic, no action is required. The tracheobronchial amyloid, if causing atelectasis or stricture formation, can be treated with laser therapy. If laser therapy fails, surgery can be performed. Respiratory amyloidosis secondary to primary systemic amyloidosis may respond to melphalan and prednisolone therapy.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

SYNOPSISTwo recent observational studies from Europe describe significant improvement in empyema drainage through the use of repeated instillation of streptokinase (SK).SOURCEBouros D, et al. Role of streptokinase in the treatment of acute loculated parapneumonic pleural effusions and empyema. Thorax 1994;49:852–5. Taylor RFH, et al. Intrapleural streptokinase in the management of empyema. Thorax 1994;49:856–9.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

SYNOPSISReactive airways dysfunction syndrome (RADS), shares many of the clinical characteristics of asthma and may result in an intractable cough, wheezing, and recurrent dyspnea, even after a single exposure to a toxic inhalant. This well performed clinical-pathologic study suggests that, although RADS is often treated like asthma, its response to standard bronchodilator regimens is likely to he limited as a result of airway fibrosis.SOURCEGautrin D, et al. Is reactive airways dysfunction syndrome a variant of occupational asthma? J Allergy Clin Immunol 1994;93:12–22.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

SYNOPSISCardiac output declines as patients move from assisted to spontaneous ventilation, Data reported by Richard and colleagues suggest that the observed decline in ejection fraction results from a weaning-induced increase in afterload.SOURCERichard CH, et al. Left ventricular function during weaning of patients with chronic obstructive pulmonary disease. Intensive Care Med 1994;20:181–6.

ISSN:1068-0640    

出版商:OVID    

年代:1995

数据来源: OVID