Medical tests are procedures intended to detect, diagnose, characterize, or monitor a specific medical condition. Understanding the accuracy of a medical test is a critical part of informed decision-making in patient management, as it allows clinicians to appreciate the types of errors a medical test might be prone to making and how often it makes them. Designing a study to assess the performance of a medical test, however, presents unique challenges, from acquiring a reference standard to dealing with the complexities that arise when the test involves an interpretation by a human reader. This article provides an overview of design considerations in this context, including common biases and how to avoid them, statistical considerations, and reporting guidelines. A short list of questions is also provided, which can serve as a quick reference for anyone designing, implementing, or reviewing a study that intends to assess the performance of a medical test.

To reduce the spread of the severe acute respiratory syndrome coronavirus 2, many pulmonary function testing (PFT) laboratories have been closed or have significantly reduced their testing capacity. Because these mitigation strategies may be necessary for the next 6 to 18 months to prevent recurrent peaks in disease prevalence, fewer objective measurements of lung function will alter the diagnosis and care of patients with chronic respiratory diseases. PFT, which includes spirometry, lung volume, and diffusion capacity measurement, is essential to the diagnosis and management of patients with asthma, COPD, and other chronic lung conditions. Both traditional and innovative alternatives to conventional testing must now be explored. These may include peak expiratory flow devices, electronic portable spirometers, portable exhaled nitric oxide measurement, airwave oscillometry devices, and novel digital health tools such as smartphone microphone spirometers and mobile health technologies along with integration of machine learning approaches. The adoption of some novel approaches may not merely replace but could improve existing management strategies and alter common diagnostic paradigms. With these options comes important technical, privacy, ethical, financial, and medicolegal barriers that must be addressed. However, the coronavirus disease 19 pandemic also presents a unique opportunity to augment conventional testing by including innovative and emerging approaches to measuring lung function remotely in patients with respiratory disease. The benefits of such an approach have the potential to enhance respiratory care and empower patient self-management well beyond the current global pandemic.

Treatment of hypoxemic respiratory failure (HRF) and ARDS is complex. Standardized management of HRF and ARDS may improve adherence to evidence-informed practice and improve outcomes.

Decisions about lung cancer screening are inherently complex and create a need for methods to convey the risks and benefits of screening to patients.

Studies have demonstrated that high-flow nasal cannula (HFNC) prevents intubation in acute hypoxic respiratory failure when compared with conventional oxygen therapy (COT). However, the data examining routine HFNC use in the immediate postoperative period are less clear.

Central venous catheterization is routinely performed in the ICU to obtain venous access for hemodynamic monitoring, parenteral nutritional support, hemodialysis, and delivery of fluids and vasoactive medications. Although central venous catheters can be lifesaving, their insertion is not without risk. Historically, central veins were accessed using landmark-based techniques, but the medical literature strongly supports the use of ultrasound guidance. The purpose of this article is to review the basic principles of real-time ultrasound-guided internal jugular and femoral catheter placement. An approach for incorporating these tools into clinical practice is presented, along with illustrative figures and video.

Chest CT may be used for the diagnosis of coronavirus disease 2019 (COVID-19), but clear scientific evidence is lacking. Therefore, we systematically reviewed and meta-analyzed the chest CT imaging signature of COVID-19.

This is an update of the section on complications that are associated with coughing in the 2006 CHEST cough guidelines that addresses two aims: (1) to systematically identify and thematically categorize the diverse complications of cough by providing a guide for future studies and (2) to identify gaps in the literature for future research.

Community-acquired pneumonia (CAP) guidelines have improved the treatment and outcomes of patients with CAP, primarily by standardization of initial empirical therapy. But current society-published guidelines exclude immunocompromised patients.

Smoking is associated with one of five deaths in the United States. Multimodality tobacco treatment increases rates of successful cessation by at least 20%. The coronavirus disease 2019 pandemic has put a halt to many inpatient and outpatient medical visits that have been deemed nonessential, including tobacco treatment. The transition to telehealth has been wrought with challenges. Although data on the association between coronavirus disease 2019 and tobacco products are mixed, the overall health consequences of tobacco point towards increased risk of morbidity and death that is associated with the virus. This leaves smoking as one of the few readily modifiable risk factors in an environment understandably not set up to prioritize cessation. A military health facility on Fort Eustis in Virginia runs a successful tobacco treatment program and adapted it to pandemic times. This article describes the process and lessons learned from this initiative. The model is applicable and scalable to government and civilian health centers as health care adapts to a new normal.

Disasters, including infectious disease outbreaks, are inevitable. Hospitals need to plan in advance to ensure that their systems can adapt to a rapidly changing environment if necessary. This review provides an overview of 10 general principles that hospitals and health-care systems should consider when developing disaster plans. The principles are consistent with an "all-hazards" approach to disaster mitigation. This approach is adapted to planning for a multiplicity of threats but emphasizes highly relevant scenarios, such as the coronavirus disease 2019 pandemic. We also describe specific ways these principles helped prepare our hospital for this pandemic. Key points include acting quickly, identifying and engaging key stakeholders early, providing accurate information, prioritizing employee safety and mental health, promoting a fully integrated clinical response, developing surge plans, preparing for ethical dilemmas, and having a cogent exit strategy for post-disaster recovery.

OSA is common among commercial vehicle operators (CVOs) in all modes of transportation, including truck, bus, air, rail, and maritime operations. OSA is highly prevalent and increases the risk of drowsiness-related crashes in CVOs. Internationally, specific regulations regarding its identification and management vary widely or do not exist; medical examiners and sleep medicine specialists are urged to use available guidance documents in their absence. Education, screening, prompt identification and treatment, and ongoing surveillance to ensure effective therapy can lower the risk of fatigue-related crashes.

Patients with autoimmune and/or inflammatory diseases (AIIDs) are prone to serious infectious complications such as Pneumocystis jirovecii pneumonia (PJP). In non-HIV patients, the prognosis is poorer, and diagnostic tests are of lower sensitivity. Given the low incidence of PJP in AIIDs, with the exception of granulomatosis with polyangiitis, and the non-negligible side effects of chemoprophylaxis, routine prescription of primary prophylaxis is still debated. Absolute peripheral lymphopenia, high doses of corticosteroids, combination with other immunosuppressive agents, and concomitant lung disease are strong predictors for the development of PJP and thus should warrant primary prophylaxis. Trimethoprim-sulfamethoxazole is considered first-line therapy and is the most extensively used drug for PJP prophylaxis. Nevertheless, it may expose patients to side effects. Effective alternative drugs such as atovaquone or aerosolized pentamidine could be used when trimethoprim-sulfamethoxazole is not tolerated or contraindicated. No standard guidelines are available to guide PJP prophylaxis in patients with AIIDs. This review covers the epidemiology, risk factors, and prevention of pneumocystis in the context of AIIDs.

Exertional dyspnea is a common complaint for patients seen in pulmonary, cardiac, and general medicine clinics, and elucidating the cause is often challenging, particularly when physical examination, echocardiography, radiography, and pulmonary function test results are inconclusive. Invasive cardiopulmonary exercise testing has emerged as the gold standard test to define causes of dyspnea and exertional limitation in this population. In this review, we describe the methods for performing and interpreting invasive cardiopulmonary exercise testing, with particular attention to the hemodynamic and blood sampling data as they apply to patients being evaluated for heart failure and pulmonary hypertension.

Bronchopulmonary dysplasia (BPD), first described by Northway in 1967, is a process of neonatal lung injury that is most strongly associated with prematurity. The "old" form of the disease associated with the oxidative damage and volutrauma from perinatal mechanical ventilation has been increasingly supplanted by a "new" form resulting from interrupted growth of the lung at earlier stages of fetal development. Given the significant improvement in the survival of children with BPD since the 1980s, many more of these patients are living into adulthood and are being seen in adult pulmonary practices. In this review, we present three brief vignettes of patients from our practice to introduce three of the major patterns of disease seen in adult survivors of BPD, namely, asthma-like disease, obstructive lung disease, and pulmonary hypertension. Additional factors shown to affect the lives of adult BPD survivors are also discussed. Finally, we discuss insights into the process of transitioning these complex patients from pediatric to adult pulmonary practices. As survivors of BPD enter adulthood and continue to require specialty pulmonary care, awareness of the disease's varied manifestations and responses to treatment will become increasingly important.

Teaching clinical reasoning is challenging, particularly in the time-pressured and complicated environment of the ICU. Clinical reasoning is a complex process in which one identifies and prioritizes pertinent clinical data to develop a hypothesis and a plan to confirm or refute that hypothesis. Clinical reasoning is related to and dependent on critical thinking skills, which are defined as one's capacity to engage in higher cognitive skills such as analysis, synthesis, and self-reflection. This article reviews how an understanding of the cognitive psychological principles that contribute to effective clinical reasoning has led to strategies for teaching clinical reasoning in the ICU. With familiarity with System 1 and System 2 thinking, which represent intuitive vs analytical cognitive processing pathways, respectively, the clinical teacher can use this framework to identify cognitive patterns in clinical reasoning. In addition, the article describes how internal and external factors in the clinical environment can affect students' and trainees' clinical reasoning abilities, as well as their capacity to understand and incorporate strategies for effective critical thinking into their practice. Utilizing applicable cognitive psychological theory, the relevant literature on teaching clinical reasoning is reviewed, and specific strategies to effectively teach clinical reasoning and critical thinking in the ICU and other clinical settings are provided. Definitions, operational descriptions, and justifications for a variety of teaching interventions are discussed, including the "one-minute preceptor" model, the use of concept or mechanism maps, and cognitive de-biasing strategies.

Bronchoscopy is a useful tool for the diagnosis of lesions near central airways; however, the diagnostic accuracy of these procedures for peripheral pulmonary lesions (PPLs) is a matter of ongoing debate. In this setting, electromagnetic navigation bronchoscopy (ENB) is a technique used to navigate and obtain samples from these lesions. This systematic review and meta-analysis aims to explore the sensitivity of ENB in patients with PPLs suspected of lung cancer.

Patients with severe bacterial infections often experience delay in receiving appropriate treatment. Consolidated evidence of the impact of delayed appropriate treatment is needed to guide treatment and improve outcomes.

The outbreak of vaping-related acute lung injury in the United States, named EVALI (e-cigarette or vaping product use associated acute lung injury), has reignited concerns about the health effects of vaping. Initial case reports of vaping-related lung injury date back to 2012, but the ongoing outbreak of EVALI began in the summer of 2019 and has been implicated in 2,807 cases and 68 deaths as of this writing. Review of the scientific literature revealed 216 patient cases that spanned 41 reports of parenchymal lung injury attributed to vaping. In this review, we detail the clinical, radiographic, and pathologic patterns of lung injury that are attributable to vaping and provide an overview of the scientific literature to date on the effects of vaping on respiratory health. Tetrahydrocannabinol was the most commonly vaped substance, and vitamin E acetate was found in BAL specimens from many affected individuals. However, no specific component or contaminant has been identified conclusively to date as the cause for the injury. Patients present with cough, dyspnea, constitutional symptoms, and GI symptoms. Radiologic and histopathologic findings demonstrate a spectrum of nonspecific acute injury patterns. A high index of suspicion combined with a good history are the keys to an accurate diagnosis. Treatment is supportive; the mortality rate is low, and most patients recover. Corticosteroids have been used with apparent success in patients with severe disease, but more rigorous studies are needed to clarify their role in the treatment of vaping-related lung injury.

The lung function laboratory frequently provides relevant information to the practice of pulmonology. Clinical interpretation of pulmonary function and exercise tests, however, has been complicated more recently by temporal changes in demographic characteristics (higher life expectancy), anthropometric attributes (increased obesity prevalence), and the surge of polypharmacy in a sedentary population with multiple chronic degenerative diseases. In this narrative review, we concisely discuss some key challenges to test interpretation that have been affected by these epidemiologic shifts: (a) the confounding effects of advanced age and severe obesity, (b) the contemporary controversies in the diagnosis of obstruction (including asthma and/or COPD), (c) the importance of considering the diffusing capacity of the lung for carbon monoxide (Dlco)/"accessible" alveolar volume (carbon monoxide transfer coefficient) in association with Dlco to uncover the causes of impaired gas exchange, and (d) the modern role of the pulmonary function laboratory (including cardiopulmonary exercise testing) in the investigation of undetermined dyspnea. Following a Bayesian perspective, we suggest interpretative algorithms that consider the pretest probability of abnormalities as indicated by additional clinical information. We, therefore, adopt a pragmatic approach to help the practicing pulmonologist to apply the information provided by the lung function laboratory to the care of individual patients.