摘要:

The association of α1-antitrypsin deficiency with chronic lung disease has led to extensive research into the pathogenic processes involved. The majority of evidence still indicates that human neutrophil elastase is a significant mediator of bronchial and interstitial lung damage. This destructive process is restricted to the immediate area around the neutrophil and can only be partially blocked by physiologic concentrations of inhibitors. Understanding the process involved has led to the conceptualization of treatment or preventative strategies that depend on the condition being treated.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Among criteria used to choose the suitable drugs in treating respiratory infections, tissue concentrations achieved at the many pulmonary sites of infection should be correlated with clinical outcomes in patients. Concentrations of antibiotics vary widely in relation to their physico-chemical characteristics and the different sites of potential infection. Many experimental models have provided information about the local distribution of antibiotics in lung parenchyma, bronchial mucosa, epithelial lining fluid, and alveolar macrophages (collected by means of bronchoalveolar lavage). However, the data collected from these studies in animal models or in patients need interpretation in terms of clinical significance. Newer approaches have analyzed the results of these studies in terms of pharmacodynamic activities in sites of infection. Pharmacodynamic parameters should take into account the following: (1) the nature of the organisms involved in respiratory infection and their location in bronchial mucosa or lumen, the alveolar space, or the intracellular space; (2) the ability of the different antibiotic classes to concentrate in interstitial tissues, in secretions or intracellularly, depending on their liposolubility and degree of ionization; and (3) the kinetics of antibiotic concentrations and their persistence in or rapid elimination from respiratory tissues and fluids. From these data, together with the measurement of minimal inhibitory concentrations (MICs) of antibiotics for the pathogens, several pharmacodynamic parameters can be established: the inhibitory quotient (tissue concentration/MIC ratio), the time above MIC, and the postantibiotic effect, all of which are considered to be good predictors of clinical efficacy of antibiotic regimens. Other features of antibiotics that can provide additional favorable factors include the potential for antibiotic delivery at pulmonary infection sites by neutrophils (loaded in serum with liposoluble antibiotics such as new macrolides dirithromycin and azithromycin) or the increasing development of “targeted delivery” by using newer liposome carriers. Thus, despite interpretive problems, increasing knowledge in antibiotic behavior in tissues and fluids and improvement in interpretation of experimental data have permitted us to confer clinical significance to these data.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Although occupational asthma (OA) probably accounts for 5% to 10% of the cases of asthma in adults, it is widely believed to be underreported. More than 200 agents are known or suspected to cause OA, and close to 8 million manufacturing and service sector workers are potentially exposed to one or more of those agents in the United States. In the investigation of a case of work-related asthma, aggravation of preexisting asthma needs to be distinguished from OA. Clinically, two main forms of OA are presently recognized: one is induced by respiratory irritants, and there is essentially no latency between exposure and development of symptoms. The other form is induced by a variety of agents, which cause the disease by a known (e.g., allergic, pharmacologic) or unknown mechanism, different from irritation, and a latency period can be recognized between exposure and symptoms. Although many cases of work-related asthma may require evaluation by experienced occupational specialists, early investigation of suspected cases by primary care practitioners and pulmonologists offers the best hope for increasing the detection of the condition and offering effective treatment. In this article, guidelines for initial evaluation and diagnosis are discussed.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Thoracic trauma is the cause of 25% of deaths in trauma patients. Those produced by penetrating injuries must be distinguished from those due to blunt injuries. Life-threatening situations must be diagnosed and treated during the initial assessment After the patient is stabilized, the assessment is aimed at diagnosing specific injuries. From a surgical point of view, approximately 85% of thoracic trauma patients require a minor procedure, such as chest tube thoracostomy, as a definitive treatment Respiratory failure itself may present early as a result of lung contusion or late, associated with lung compromise in the systemic inflammatory response syndrome. In the case of multiple rib fractures, with or without flail chest, aggressive treatment must be started to avoid unnecessary mechanical ventilation. This treatment must involve systemic, local, or combined analgesia (to avoid lung hypoventilation because of pain and letting the patient cough properly), physiotherapy, oxygen supplement, and judicious volume infusion (avoiding overexpansion and hypovolemia). When the patient needs mechanical ventilation, the strategy must avoid ventilator-induced lung injury. Mechanical ventilation is indicated when respiratory failure has not been controlled with initial treatment and never with the concept of pneumatic wall stabilization. Thoracic computed tomography is an important tool in diagnosis and quantification of lung damage. Myocardial contusion and diaphragmatic rupture remain as intrathoracic injuries associated with a difficult diagnosis. Other injuries require specific diagnostic procedures based on clinical suspicion, such as to the aorta and great vessels.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The pregnant critically ill patient poses many challenges to the critical care physician. An understanding of normal maternal and fetal physiology is paramount to the appropriate care of the mother and the fetus. The pregnant patient has unique considerations regarding common intensive care unit procedures, such as endotracheal intubation and cardiopulmonary resuscitation. Finally, the critical care physician must be knowledgeable about certain disorders unique to this patient population, such as preeclampsia and amniotic fluid embolism. This article reviews the maternal-fetal physiology and diagnostic and therapeutic considerations of the major disorders that lead to admission to the intensive care unit.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The technology of gene transfer has seen rapid progress in recent years, and there are many ways in which this could eventually be applied to the treatment of disease. Respiratory diseases, including both genetic diseases, such as cystic fibrosis and α1-antitrypsin deficiency, and acquired diseases, such as cancer and dysfunctional airway immune responses, have proven to be interesting potential targets for gene therapy. Viral-based gene transfer systems including retroviral, adenoviral, and adeno-associated viral vectors and nonviral gene transfer systems using cationic liposomes or receptor-ligand interactions have all been assessed for their application to the treatment of respiratory disease. In many cases, the preclinical data have been sufficiently encouraging to allow testing in clinical trials, particularly in individuals with cystic fibrosis and various forms of lung cancer. Although most of these clinical trials have established “proof of principle,” clearly showing gene transfer, the interpretation of the clinical efficacy of this technology is still open to debate, with each method of gene transfer having its advantages and disadvantages. However, given the increasing research commitment to this enabling technology, it is likely that gene therapy will be a realistic approach to the treatment of at least some respiratory diseases in the not too distant future.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Smoke inhalation is responsible for most fatalities due to burn injuries. It should be considered in any fire victim who had been entrapped in an enclosed space or been unconscious during a fire. Ginical manifestations are variable and may differ among victims of a single fire as well as among separate fire locations. Arterial blood gas measurements, chest radiographs, pulmonary function testing, and bronchoscopy can provide early clues. Fire smoke from residential or structural fires, urban wildfires, forest fires, and transportation accidents contains a mixture of particulate matter, thermal loads, carbon monoxide, hydrogen cyanide, nitrogen oxides, and irritating gases. Each of these constituents of fire smoke may give increase to respiratory and systemic toxicities and, thus, must be considered in every victim of smoke inhalation. Management of patients with smoke inhalation injury includes administration of antidotal therapy when indicated, maintenance of airway patency and stability, provision of oxygen, aggressive pulmonary toilet, and stabilization of hemodynamic status.

ISSN:1068-0640    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

SYNOPSIS: Continuous positive airway pressure (CPAP) is effective therapy for the obstructive sleep apnea syndrome (OSAS). Diagnosis and treatment of OSAS with CPAP typically involves a minimum of two overnight polysomnographic (PSG) investigations in a sleep center. The first study diagnoses OSAS whereas the second is used to titrate an effective level of CPAP. The implementation of a self-adjusting automatic CPAP device makes it possible to titrate CPAP at home and avoid a second PSG study.SOURCE: Series F, Marc I. Efficacy of automatic continuous positive airway pressure therapy that uses an estimated required pressure in the treatment of the obstructive sleep apnea syndrome.

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