Ultrasound guidance commonly is used for the placement of central venous catheters (CVCs). The Agency for Healthcare Research and Quality recommends the use of ultrasound for CVC placement as one of its 11 practices to improve patient care. Despite increased access to portable ultrasound machines and comfort with ultrasound-guided CVC access, fewer clinicians are familiar with ultrasound-guided techniques of arterial catheterization. The goal of this systematic review and meta-analysis was to determine the utility of real-time two-dimensional ultrasound guidance for radial artery catheterization.

Omalizumab is a humanized monoclonal anti-IgE for the treatment of severe allergic asthma. Because omalizumab targets an immune system molecule, there has been particular interest in the drug's safety.

Indirect challenges cause the release of endogenous mediators that cause the airway smooth muscle to contract and the airways to narrow. Airway sensitivity to indirect challenges is reduced or even totally inhibited by treatment with inhaled corticosteroids (ICS), so a positive response to an indirect stimulus is believed to reflect active airway inflammation. The indirect challenges commonly used in pulmonary function laboratories include exercise, eucapnic voluntary hyperpnea, hypertonic (4.5%) saline, and mannitol. Exercise was the first test to be standardized and was used to identify exercise-induced bronchoconstriction (EIB). The inhibition of EIB in young children by sodium cromoglycate led to the concept that mast cells were important very early in the onset of asthma. All of these indirect challenges are associated with the release of mast cell mediators (eg, prostaglandins, leukotrienes, and histamine). The hypertonic saline and mannitol challenges arose from the concept that EIB was caused by an increased osmolarity of the airway surface with release of mediators. These osmotic aerosols simplified testing with indirect challenges in the laboratory, improving the potential to identify currently active asthma. Although hyperresponsiveness to indirect challenges is frequently associated with a sputum eosinophilia, it is not a prerequisite because the mast cell is the most important source of mediators. The mechanism for ICS reducing hyperresponsiveness to indirect challenges likely involves both mast cells and eosinophils. Indirect challenges are appropriate to inform further on both the pathogenesis of asthma and the role of antiinflammatory agents in its treatment.

Direct bronchoprovocation challenges (eg, methacholine), which act directly on a specific airway smooth muscle receptor, are the most commonly performed challenge tests. Cut points have been arbitrarily selected to give high sensitivity and negative predictive values. In subjects with clinically current symptoms (within a few days) who inhale methacholine without deep inhalations, a normal methacholine test (provocative concentration causing a 20% fall in FEV(1) [PC(20)] > 16 mg/mL) rules out (current) asthma with reasonable certainty. A positive test in the moderate or greater range (PC(20) < 1 mg/mL) has high specificity and positive predictive value, comparable to the indirect challenges. Values between these levels are consistent with, but not diagnostic of, asthma. The positive predictive value (for clinical asthma) will increase the closer the PC(20) is to 1 mg/mL, the higher the pretest probability is for asthma and the more the methacholine-induced symptoms resemble the naturally occurring symptoms. Direct challenges are more sensitive and less specific than indirect challenges (exercise, adenosine monophosphate, mannitol, etc).

The two key pathophysiologic features of asthma are bronchial hyperresponsiveness (BHR) and airway inflammation. Symptoms and lung function are the most accessible clinical markers for the diagnosis of asthma as well as for assessing asthma control using the most effective treatment of asthma, inhaled corticosteroids (ICS). However, BHR and inflammation usually take longer to resolve using ICS compared with symptoms and lung function. BHR can be assessed using "direct" stimuli that act on the airway smooth muscle (eg, methacholine) or "indirect" stimuli that require the presence of airway inflammation (eg, exercise, osmotic stimuli). Although there are practical limitations in using BHR to assess asthma control, efforts have been made to make BHR more accessible and standardized. Some studies have demonstrated that treatment aimed to decrease BHR with direct stimuli can lead to improved asthma control; however, it often results in the use of higher doses of ICS. Furthermore, BHR to direct stimuli does not usually resolve using ICS because of a fixed component. By contrast, BHR with an indirect stimulus indicates a responsive smooth muscle that occurs only in the presence of inflammation sensitive to ICS (eg, mast cells, eosinophils). BHR to indirect stimuli does resolve using ICS. Because ICS target both key pathophysiologic features of asthma, assessing indirect BHR in the presence of ICS will identify resolution or persistence of BHR and airway inflammation. This may provide a more clinically relevant marker for asthma control that may also lead to improving the clinical usefulness of ICS.

Airway hyperresponsiveness (AHR) is a clinical feature of asthma and is often in proportion to the underlying severity of the disease. To understand AHR and the mechanisms that contribute to these processes, it is helpful to divide the airway components that affect this feature of asthma into "persistent" and "variable" categories. The persistent component of AHR represents structural changes in the airway, whereas the variable feature relates to inflammatory events. Insight into how these interrelated components of AHR can contribute to asthma is gained by studying treatment effects and models of asthma provocation.

Although common in many Middle Eastern countries, water-pipe tobacco smoking, commonly known as water-pipe smoking (WPS), is increasingly popular in Western cultures. The primary objective of this study was to systematically review the effects of WPS on lung function. The secondary objective was to compare the effects of WPS and cigarette smoking on lung function.

Acute left ventricular (LV) dysfunction is common in the critical care setting and more frequently affects the elderly and patients with comorbidities. Because of increased mortality and the potential for significant improvement with early revascularization, the practitioner must first consider acute coronary syndrome. However, variants of stress (takotsubo) cardiomyopathy may be more prevalent in ICU settings than previously recognized. Early diagnosis is important to direct treatment of complications of stress cardiomyopathy, such as dynamic LV outflow tract obstruction, heart failure, and arrhythmias. Global LV dysfunction occurs in the critically ill because of the cardio-depressant effect of inflammatory mediators and endotoxins in septic shock as well as direct catecholamine toxicity. Tachycardia, hypertension, and severe metabolic abnormalities can independently cause global LV dysfunction, which typically improves with addressing the precipitating factor. Routine troponin testing may help early detection of cardiac injury and biomarkers could have prognostic value independent of prior cardiac disease. Echocardiography is ideally suited to quantify LV dysfunction and determine its most likely cause. LV dysfunction suggests a worse prognosis, but with appropriate therapy outcomes can be optimized.

International Classification of Disease coding is widely used by physicians, hospitals, health-care payers, and governments to assess the health of populations and as a means of reimbursement for medical care based on diagnosis and severity of illness. The current classification system, International Classification of Diseases, 9th ed (ICD-9), will soon be replaced by International Classification of Diseases, 10th ed (ICD-10). When the codes that relate to COPD and asthma are examined, the clinical relevance of the categories in International Classification of Disease coding must be questioned. In the future, a more simplified terminology that is consistent with clinical usage could improve accuracy and ease of coding. At present, however, clinicians should become familiar with the present ICD-9 and future ICD-10 codes so that their descriptions of illnesses in the medical records more accurately reflect current coding terminology.

Long-term use of supplemental oxygen improves survival in patients with COPD and severe resting hypoxemia. However, the role of oxygen in symptomatic patients with COPD and more moderate hypoxemia at rest and desaturation with activity is unclear. The few long-term reports of supplemental oxygen in this group have been of small size and insufficient to demonstrate a survival benefit. Short-term trials have suggested beneficial effects other than survival in patients with COPD and moderate hypoxemia at rest. In addition, supplemental oxygen appeared to improve exercise performance in small short-term investigations of patients with COPD and moderate hypoxemia at rest and desaturation with exercise, but long-term trials evaluating patient-reported outcomes are lacking. This article reviews the evidence for long-term use of supplemental oxygen therapy and provides a rationale for the National Heart, Lung, and Blood Institute Long-term Oxygen Treatment Trial. The trial plans to enroll subjects with COPD with moderate hypoxemia at rest or desaturation with exercise and compare tailored oxygen therapy to no oxygen therapy.

Concern about the quality and safety of health care persists, 10 years after the 1999 Institute of Medicine report To Err is Human. Despite growing awareness of quality and safety risks, and significant efforts to improve, progress is difficult to measure. Hospital leaders, including boards and medical staffs, are accountable to improve care, yet they often address this duty independently. Shared responsibility for quality and patient safety improvement presents unique challenges and unprecedented opportunities for boards and medical staffs. To capitalize on the pressure to improve, both groups may benefit from a better understanding of their synergistic potential. Boards should be educated about the quality of care provided in their institutions and about the challenges of valid measurement and accurate reporting. Boards strengthen their quality oversight capacity by recruiting physicians for vacant board seats. Medical staff members strengthen their role as hospital leaders when they understand the unique duties of the governing board. A quality improvement strategy rooted in synergistic efforts by the board and the medical staff may offer the greatest potential for safer care. Such a mutually advantageous approach requires a clear appreciation of roles and responsibilities and respect for differences. In this article, we review these responsibilities, describe opportunities for boards and medical staffs to collaborate as leaders, and offer recommendations for how boards and medical staff members can address the challenges of shared responsibility for quality of care.

Significant progress has been made in understanding the pathogenesis of pulmonary hypertension (PH) and developing therapeutic approaches for PH in recent years. Most of the currently available data regarding the prevalence, diagnosis, treatment, and prognosis of PH are from American and European populations. Whether these data are also valid in the Chinese population is still controversial. China has a relatively large population of patients with PH for clinical and basic research. However, many medical centers and hospitals in China have limited experience with PH diagnosis and treatment. Given the potential higher prevalence of PH in China than in the United States and European countries, it is critical to develop suitable, effective, and novel therapeutic approaches for Chinese patients. Measures for the detection and prevention of PH need to be put in place urgently for the management of PH in China.

Inflammation is likely a critical underlying etiology in many forms of severe pulmonary hypertension (PH), and schistosomiasis-associated PH, one of the most common causes of PH worldwide, is likely driven by the host response to parasite antigens. More than 200 million people are infected with schistosomiasis, the third most common parasitic disease, and approximately 1% of those chronically infected develop PH. Acute cutaneous infection causes inflammation at the site of parasite penetration followed by a subacute immune complex-mediated hypersensitivity response as the parasite migrates through the lungs. Chronic schistosomiasis infection induces a granulomatous inflammation around ova deposited in the tissue. In particular, Schistosoma mansoni migrates to the portal venous system and causes preportal fibrosis in a subset of individuals and appears to be a prerequisite for PH. Portal hypertension facilitates shunting of ova from the portal system to the pulmonary arterial tree, resulting in localized periovular pulmonary granulomas. The pulmonary vascular remodeling is likely a direct consequence of the host inflammatory response, and portopulmonary hypertension may be a significant contributor. New specific therapies available for PH have not been widely tested in patients with schistosomiasis and often are unavailable for those infected in resource-poor areas of the world where schistosomiasis is endemic. Furthermore, the current PH therapies in general target vasodilation rather than vascular remodeling and inflammation. Further research is needed into the pathogenic mechanism by which this parasitic infection results in pulmonary vascular remodeling and PH, which also may be informative regarding the etiology of other types of PH.

Insomnia disorder and obstructive sleep apnea are the two most common sleep disorders among adults. Historically, these conditions have been conceptualized as orthogonal, or insomnia has been considered a symptom of sleep apnea. Insomnia researchers have sought to exclude participants at risk for sleep-related breathing disorders (SRBD), and vice versa. In recent years, however, there has been a growing recognition of co-occurring insomnia disorder and SRBD and interest in the prevalence, consequences, and treatment of the two conditions when they co-occur. Although plagued by inconsistent diagnostic criteria and operational definitions, evidence from clinical and research samples consistently suggests high rates of comorbidity between the two disorders. More important, insomnia disorder and SRBD have additive negative effects. To date, only a few studies have explored the combined or sequential treatment of the conditions. Results support the importance of an integrated, interdisciplinary approach to sleep medicine. This article reviews the empirical literature to date and provides clinical recommendations as well as suggestions for future research.

ARDS is characterized by hypoxemic respiratory failure, which can be refractory and life-threatening. Modifications to traditional mechanical ventilation and nontraditional modes of ventilation are discussed in Part 1 of this two-part series. In this second article, we examine nonventilatory strategies that can influence oxygenation, with particular emphasis on their role in rescue from severe hypoxemia. A literature search was conducted and a narrative review written to summarize the use of adjunctive, nonventilatory interventions intended to improve oxygenation in ARDS. Several adjunctive interventions have been demonstrated to rapidly ameliorate severe hypoxemia in many patients with severe ARDS and therefore may be suitable as rescue therapy for hypoxemia that is refractory to prior optimization of mechanical ventilation. These include neuromuscular blockade, inhaled vasoactive agents, prone positioning, and extracorporeal life support. Although these interventions have been linked to physiologic improvement, including relief from severe hypoxemia, and some are associated with outcome benefits, such as shorter duration of mechanical ventilation, demonstration of survival benefit has been rare in clinical trials. Furthermore, some of these nonventilatory interventions carry additional risks and/or high cost; thus, when used as rescue therapy for hypoxemia, it is important that they be demonstrated to yield clinically significant improvement in gas exchange, which should be periodically reassessed. Additionally, various management strategies can produce a more gradual improvement in oxygenation in ARDS, such as conservative fluid management, intravenous corticosteroids, and nutritional modification. Although improvement in oxygenation has been reported with such strategies, demonstration of additional beneficial outcomes, such as reduced duration of mechanical ventilation or ICU length of stay, or improved survival in randomized controlled trials, as well as consideration of potential adverse effects should guide decisions on their use. Various nonventilatory interventions can positively impact oxygenation as well as outcomes of ARDS. These interventions may be considered for use, particularly for cases of refractory severe hypoxemia, with proper appreciation of potential costs and adverse effects.

There has been an increased understanding, over the past 2 decades, that asthma is a chronic, immunologically mediated condition with a disturbance of the normal airway repair mechanism, which results in inflammatory changes and airway remodeling. The airway inflammation and remodeling together likely explain the clinical manifestations of asthma. The mechanisms by which the external environmental cues, together with the complex genetic actions, propagate the inflammatory process that characterize asthma are beginning to be understood. There is also an evolving awareness of the active participation of structural elements, such as the airway epithelium, airway smooth muscle, and endothelium, in this process. In tandem with this has come the realization that inflammatory cells respond in a coordinated, albeit dysfunctional manner, via an array of complex signaling pathways that facilitate communication between these cells; these structural elements within the lung and the bone marrow serve as reservoirs for and the source of inflammatory cells and their precursors. Although often viewed as separate mechanistic entities, so-called innate and acquired immunity often overlap in the propagation of the asthmatic response. This review examines the newer information on the pathophysiologic characteristics of asthma and focuses on papers published over the past 3 years that have helped to improve current levels of understanding.

A serum galactomannan (GM) assay has been approved for diagnosing invasive aspergillosis (IA). However, the role of the BAL-GM assay has not been well established. Therefore, we conducted a metaanalysis to determine the overall accuracy of BAL-GM in the diagnosis of IA.

The demand for sleep medicine services has grown tremendously during the last decade and will likely continue. To date, growth in demand has been met by growth in the number of new sleep centers. The need for more new centers will be dependent on market drivers that include increasing regulatory requirements, personnel shortages, integration of home sleep testing, changes in reimbursement, a shift in emphasis from diagnostics to treatment, and an increased consumer focus on sleep. The decision to open a new center should be based on understanding the market dynamics, completing a market analysis, and developing a business plan. The business plan should include an overview of the facility, a personnel and organizational structure, an evaluation of the business environment, a financial plan, a description of services provided, and a strategy for obtaining, managing, and extending a referral base. Implementation of the business plan and successful operation require ongoing planning and monitoring of operational parameters. The need for new sleep centers will likely continue, but the shifting market dynamics indicate a greater need for understanding the marketplace and careful planning.

Approximately 16% of deaths in patients with ARDS results from refractory hypoxemia, which is the inability to achieve adequate arterial oxygenation despite high levels of inspired oxygen or the development of barotrauma. A number of ventilator-focused rescue therapies that can be used when conventional mechanical ventilation does not achieve a specific target level of oxygenation are discussed. A literature search was conducted and narrative review written to summarize the use of high levels of positive end-expiratory pressure, recruitment maneuvers, airway pressure-release ventilation, and high-frequency ventilation. Each therapy reviewed has been reported to improve oxygenation in patients with ARDS. However, none of them have been shown to improve survival when studied in heterogeneous populations of patients with ARDS. Moreover, none of the therapies has been reported to be superior to another for the goal of improving oxygenation. The goal of improving oxygenation must always be balanced against the risk of further lung injury. The optimal time to initiate rescue therapies, if needed, is within 96 h of the onset of ARDS, a time when alveolar recruitment potential is the greatest. A variety of ventilatory approaches are available to improve oxygenation in the setting of refractory hypoxemia and ARDS. Which, if any, of these approaches should be used is often determined by the availability of equipment and clinician bias.

Spontaneous pneumomediastinum is an uncommon benign condition that is occasionally associated with air within the spinal canal. We describe a further case in a 14-year-old girl and suggest a classification system based on a detailed review of the previous literature. Forty-eight patients with spontaneous pneumomediastinum and intraspinal air accumulation (36 men and 12 women, age range 4-72 years, median age 18 years) were grouped into those with underlying lung disease (n = 13), those with other underlying etiologic factors (n = 22), and those arising spontaneously (n = 13). Neurologic symptoms or signs were noted in one case. The remaining cases were successfully managed conservatively. In spontaneous pneumomediastinum, accumulation of air within the spinal canal is self-limiting and benign. The same management is advised in spontaneous pneumomediastinum with and without intraspinal air accumulation.