摘要:

Because chronic obstructive pulmonary disease (COPD) is a progressive disorder often characterized by recurrent episodes of respiratory failure, ethical dilemmas frequently arise regarding decisions to initiate mechanical ventilation in patients with COPD. Surprisingly, no statement exists from any professional organization pertaining to ethical issues unique to this patient population. In determining the potential benefits of mechanical ventilation in an individual patient with COPD, physicians should consider the outcome data from respiratory failure for this patient population in general. Multiple studies during the last 25 years indicate that sufficient numbers of patients with COPD survive for 1 to 2 years after a hospitalization for respiratory failure to warrant an overall aggressive therapeutic approach. In addition, no studies have identified any clinical features of patients with COPD-related acute respiratory failure that accurately identify those who are unlikely to benefit from intubation. Decisions regarding the withholding of support for patients with COPD and respiratory failure require joint deliberations by patients and their physicians based on timely and thoughtful communication of patients' health status and health care needs. These discussions are aided by the formulation of advance directives. Patients who are informed regarding their disease and prognosis can construct valid living wills and durable powers of attorney for health care that can guide end-of-life decision-making. Several barriers exist regarding the adoption of advance directives; physicians caring for patients with COPD can develop strategies to overcome these barriers and assist patients with their health care decisions

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Before the late 1940s, there was no effective chemotherapy for tuberculosis. Cavitary lesions were a sign of serious infection and signaled the failure of host defenses to contain the organisms. Efforts were made to mechanically close cavitary lesions with the hope that their closure might reestablish host containment of the organism. “Collapse therapy” was practiced in several forms: pneumothorax therapy, pneumoperitoneum, plombage, and thoracoplasty.This article focuses on the latter two modes of therapy, plombage and thoracoplasty, and their late complications. Thoracoplasty is deforming and often leads to kyphoscoliosis and restrictive pulmonary impairment. Patients may also occasionally manifest concomitant obstructive airways disease. These defects may be severe enough to contribute to cor pulmonale and respiratory failure. Plombage complications are caused by migration of the plomb and local compressive effect of the plomb. Plombs may erode through neighboring structures, become infected, compress the mediastinum or superior vena cava, or cause bronchopleural fistulas or paraffinoma.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Although cigarette smoking is the dominant cause of lung cancer throughout the world, occupational exposures continue to contribute to the causation of this rapidly fatal malignancy. Agents causally linked to lung cancer include arsenic, asbestos, chloro-methyl ethers, chromium, environmental tobacco smoke, nickel and nickel compounds, polycyclic aromatic hydrocarbons, radon, and vinyl chloride. Many other agents are probable or possible causes of lung cancer. This article covers the principal occupational carcinogens and addresses issues likely to be faced by pulmonologists as they provide care for patients with lung cancer. A key issue is the attribution of causation to a specific agent; however, it is unfortunate that we lack specific markers for individuals and need to rely on epidemiologic data for groups to make estimates for individuals of the probability of causation. Primary prevention through control of workplace exposures and smoking cessation will remain central in controlling the burden of occupational lung cancer.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Neurologic disorders have the potential to impair breathing during sleep through several mechanisms including disordered respiratory control, respiratory muscle weakness or failure, and upper airway obstruction. Sleep-disordered breathing resulting from these disorders may take the form of periodic central or obstructive apneas or hypopneas or sustained hypoventilation; all forms generally worsen during rapid eye movement sleep. Clinical manifestations commonly include nocturnal sleep disturbances such as insomnia and snoring and daytime symptoms such as hypersomnolence and cognitive impairment. Treatment depends on the specific pattern of respiratory impairment during sleep and may include ventilatory support modalities, nasal continuous positive airway pressure, or various pharmacologic maneuvers.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

The inability to improve the high mortality rate (< 40%) of acute respiratory distress syndrome has forced many investigators to focus on the major etiologic event in this syndrome, namely lung edema formation. It is generally accepted that increased permeability of the alveolar epithelial-capillary endothelial barrier is the most prominent abnormality in the lungs during the early stages of this syndrome. This capillary leak is underestimated by the traditionally measured pulmonary capillary wedge pressure (PCWP). A better measure of microvascular pressure is pulmonary capillary pressure (Pc), which can be estimated by using a conventional pulmonary artery catheter. In healthy individuals, PCWP measuring the left-heart filling pressure is very close to Pc. However, in critically ill patients, the two may drift apart and even move in opposite directions. This may be particularly true when positive end-expiratory pressure is added. Therefore, estimates of the more accurate Pcshould be added to the routine measurements of PCWP. There is a preponderance of evidence that volume administration contributes to edema formation and should be kept to minimal amounts needed to maintain satisfactory left-heart filling pressure. Further, volume infusion not only has no added benefit but also causes elevated right-heart pressure. This exacerbates lung edema formation in acute lung injury as well as in other critical illnesses. Controversy continues regarding the use of colloids versus crystalloids. Although both can be used to achieve the same physiologic end points, a greater volume of crystalloid is needed to accomplish this. The clinical significance of this is uncertain.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

A wide variety of bronchoscopic modalities are currently available for management of patients with malignant airway disease. Knowledge of the strengths and limitations of these procedures will allow the selection of the most appropriate procedure for each specific patient and each specific airway lesion. Neodymi-um-yttrium-aluminum-garnet laser therapy is the most widely studied and used procedure. It produces immediate results in patients with exophytic endobronchial lesions, but it is not useful for extrinsic compression. Brachytherapy gives delayed results but has the advantage of treating submucosal and peribronchial disease. Endobronchial stents are especially useful in extrinsic compression, but the devices lack standardization and outcome studies. Cryotherapy is an inexpensive alternative to laser therapy but cannot be used in patients who require immediate palliation. Photodynamic therapy and endobronchial electrosurgery are still in the experimental stages. The final procedure choice should be based on the clinical presentation of the patient, the type and location of the lesion, and the experience and skill of the bron-choscopist

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

SYNOPSISAnalysis of pleural fluid for adenosine deaminase (ADA) showed a high sensitivity and specificity in two studies involving patients from areas with a high incidence of tuberculosis. The two studies generally agreed that when ADA is > 47 to 50 international units per liter tuberculosis is more likely. The measurement of ADA may reduce the need for some pleural biopsies>.SOURCEValdes L et al. Value of adenosine deaminase in the diagnosis of tuberculous pleural effusions in young patients in a region of high prevalence of tuberculosis. Thorax 1995;50:600–3. Burgess LJ et al. Use of adenosine deaminase as a diagnostic tool for tuberculous pleurisy. Thorax 1995;50:672–4.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

SYNOPSISIn a primary care setting, routine peak flow measurements in mild asthma did not result in improved pulmonary function or quality of life.SOURCEJones KP et al. Peak flow based asthma self-management: a randomized controlled study in general practice. Thorax 1995;50:851–7.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

SYNOPSISNew data suggest that we need to think more about transfusion requirements in critically ill patients. In a small randomized trial, mortality and organ dysfunction were not affected by specific liberal (hemoglobin levels, 10–12 g/dL) or restrictive (7–9 g/dL) end points of transfusion. This suggests that transfusing patients liberally in the absence of a specific ischemic organ dysfunction may not be warranted.SOURCEHebert PC et al. Transfusion requirements in critical care. JAMA 1995; 27:1439–44.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

SYNOPSISIn 229 patients admitted to a medical and respiratory intensive care unit, 15% had evidence of myocardial damage based on levels of cardiac troponin I, a myocardial regulatory protein found specifically in the heart. Only one third of these patients were diagnosed as having acute myocardial infarction. Mortality was increased in patients with myocardial injury.

ISSN:1068-0640    

出版商:OVID    

年代:1996

数据来源: OVID