Necrotizing fasciitis is an uncommon soft-tissue infection, usually caused by toxin-producing, virulent bacteria, which is characterized by widespread fascial necrosis with relative sparing of skin and underlying muscle. It is accompanied by local pain, fever, and systemic toxicity and is often fatal unless promptly recognized and aggressively treated. The disease occurs more frequently in diabetics, alcoholics, immunosuppressed patients, i.v. drug users, and patients with peripheral vascular disease, although it also occurs in young, previously healthy individuals. Although it can occur in any region of the body, the abdominal wall, perineum, and extremities are the most common sites of infection. Introduction of the pathogen into the subcutaneous space occurs via disruption of the overlying skin or by hematogenous spread from a distant site of infection. Polymicrobial necrotizing fasciitis is usually caused by enteric pathogens, whereas monomicrobial necrotizing fasciitis is usually due to skin flora. Tissue damage and systemic toxicity are believed to result from the release of endogenous cytokines and bacterial toxins. Due to the paucity of skin findings early in the disease, diagnosis is often extremely difficult and relies on a high index of suspicion. Definitive diagnosis is made at surgery by demonstration of a lack of resistance of normally adherent fascia to blunt dissection. Treatment modalities include surgery, antibiotics, supportive care, and hyperbaric oxygen. Early and adequate surgical debridement and fasciotomy have been associated with improved survival. Initial antibiotic therapy should include broad aerobic and anaerobic coverage. If available, hyperbaric oxygen therapy should be considered, although to our knowledge, there are no prospective, randomized clinical trials to support this. Mortality rates are as high as 76%. Delays in diagnosis and/or treatment correlate with poor outcome, with the cause of death being overwhelming sepsis syndrome and/or multiple organ system failure.

There has been dramatic resurgence of interest in surgical treatment of emphysema, particularly "lung volume reduction" procedures. Recent studies have demonstrated improvements in pulmonary function, lung mechanics, exercise tolerance, and quality of life in selected patients following volume reduction procedures. However, considerable uncertainty remains regarding overall benefit, optimal patient selection, operative techniques, and duration of response. This summarizes current approaches to lung volume reduction surgery, available clinical outcome information, selection criteria, and physiologic mechanisms of response, and discusses the potential role for surgical volume reduction in treatment of emphysema. Recent data appear to support the efficacy of bilateral staple lung volume reduction surgery in patients with severe symptomatic heterogeneously distributed emphysema. Further studies will be needed to determine relative value of different operative techniques and benefit in patients with other clinical presentations.

Clinicians tend to underestimate potential modest benefits of chemotherapy. They are often reluctant to refer patients for chemotherapy, perhaps because they expect the side effects to outweigh any perceived benefits. However, patients are much more ready to accept chemotherapy, even when the likely benefits are small. Quality of life, change in performance status, and relief of tumor-related symptoms are important additional parameters of treatment assessment. Taking account of these other factors will help clinicians balance quality and quantity of life in patients with metastatic non-small cell lung cancer.

The role of oncogenes and antioncogenes in lung tumorigenesis is discussed in this review, with particular emphasis on their prognostic significance. Mutations in the ras family of oncogenes, overexpression of the myc and neu families of oncogenes, and mutations of p53, the recessive tumor suppressor gene, occur with differing frequencies in small cell lung cancer and non-small cell lung cancer, and are usually associated with a poor prognosis. Loss of heterozygosity, notably on chromosomes 3p, 5q, 9p, 13q, and 17p, is a common feature in lung carcinomas and its importance is also discussed.

Despite extensive investigation, biological treatments for non-small cell lung cancer (NSCLC) remain largely undeveloped. The lack of satisfactory models has frequently led to inadequate phase II studies and to small and inconclusive phase III trials. Nonuniformity of trials has prevented clearer conclusions from being reached by meta-analysis. In general, immunotherapy has failed to fulfill expectations for clinical usefulness. The benefit with this approach, if any, seems to be marginal, but it is not clear whether this is a result of lack of activity or faulty clinical testing. The future of biological agents in cancer treatment lies in ongoing advances in molecular biology, for example in making tumors more immunogenic. Another avenue of further clinical research includes novel forms of therapy with monoclonal antibodies. Adequate models for testing and appropriate clinical trial settings could clarify the role of biological agents in NSCLC.

Twiddler's syndrome is a rare complication seen in patients with implanted pacemakers or defibrillators. The condition typically presents with device malfunction and occurs when the patient either consciously or unconsciously twists and rotates the implanted device in its pocket, resulting in torsion and dislodgement of the implanted lead. A case of twiddler's syndrome involving a transvenous defibrillation lead and an abdominally implanted defibrillator is described. This is the first report of this complication with this particular lead. The patient in this report was a middle-aged obese diabetic woman who presented 7 months after defibrillator implantation with device noncapture and intermittent nonsensing. Review of the literature reveals that the majority of patients with this complication are middle-aged obese women with a defibrillator pocket that exceeds the size of the defibrillator. Treatment measures are discussed both for the patient with this complication and for the patient at increased risk for its occurrence.

Pulmonary veno-occlusive disease (PVOD) was diagnosed in an adult following chemotherapy and bone marrow transplantation (BMT) for acute lymphoblastic leukemia. A medical literature review showed only three previous reports of PVOD following BMT occurring in children but no prior cases in adults.

Treatment of obstructive sleep apnea (OSA) has developed over the last 25 years from tracheostomy to a variety of options, including weight loss, nasal continuous positive airway pressure (N-CPAP), pharyngeal surgery, and medications. None of these options is definitive or curative, except possibly weight loss. The most widely prescribed treatment is N-CPAP, but recently published studies using objective measurement of patient compliance show less than ideal compliance. Attempts have been made to design pharyngeal surgery according to the site of upper airway collapse or narrowing, as identified by various techniques in wakefulness. How representative these studies are of upper airway physiology in sleep is questionable. Recent studies have shown improved surgical success in correcting OSA. However, disturbing data are available in a limited number of patients that demonstrate worsening of the OSA months after a favorable response to surgery. More studies assessing the long-term outcome of pharyngeal surgery are needed. Several pharmacologic agents have been used to treat OSA. Results with any particular agent are not better than with N-CPAP or surgery. However, studies of subgroups of patients with OSA in which a particular pharmacologic agent may be specifically indicated, such as thyroxine in hypothyroidism, have not been conducted (to our knowledge). An algorithm for the approach to treatment recommendations is presented. Basic to this algorithm is an objective presentation of therapeutic options to the patient with OSA and a respect for the patient's preferences.

We present the first case of mediastinitis and the third case of pneumonia attributed to Actinomyces odontolyticus. The first patient presented 10 months after single-lung transplant with a subacute apical infiltrate in the native lung and responded to therapy with oral penicillin. The second patient developed pyogenic mediastinitis 25 days after a heart-lung transplant and required sternal debridement and intravenous penicillin. We also review the literature on thoracopulmonary infections due to A odontolyticus.

The past 15 years have seen a rise in mortality and morbidity resulting from asthma, despite a concurrent rise in general knowledge about the disease. The step-care strategy recognized these changes in its approach to asthma management; however, this approach should be used only with attempts to control environmental allergens. Step-care therapy requires that patients be categorized by the severity of illness. Step-one therapy is used for mild, infrequent symptoms and involves treatment based primarily on inhaled bronchodilators. Step-two therapy is instituted in all asthmatics except the mildest cases; it involves treatment by inhaled corticosteroids, cromolyn, or nedocromil. Step-three treatment targets cases of severe asthma through the use of oral corticosteroids. In all phases of treatment, however, it should be remembered that patient education is of critical importance. Education improves patient compliance and is critical to the successful treatment of asthma.

Guidelines for the use of nebulizers outside of the hospital were developed at the request of the Health Care Financing Administration (HCFA) to assist in the preparation of Medicare criteria for reimbursement. The National Association for Medical Direction of Respiratory Care (NAMDRC) convened a consensus conference in Leesburg, Va, with physician representatives from the major medical organizations involved in adult and pediatric respiratory care. Members of the health-care industry also were invited to participate. After review of the pertinent references, members of the faculty were preassigned topics for presentations during the first day of the meeting. Three workshops were organized to address segments of the consensus statement and to develop written reports. Each report was reviewed by the entire group and then finalized. The Consensus Conference recommends that a metered-dose inhaler (MDI) with reservoir chamber is the preferred mode of aerosol therapy for patients outside of the hospital. The circumstances under which a small-volume nebulizer (SVN) may be appropriate are described. The medications that may be administered by SVN are identified with recommendations as to the usual doses to be prescribed. A cost analysis of the various modes of aerosol therapy is presented. These guidelines should be of value to physicians who are prescribing aerosol therapy in the home and also to policy makers who are developing guidelines for reimbursement.