Idiopathic pulmonary fibrosis (IPF) is characterized by an increase in proteolytic enzymes, including matrix metalloproteinases that degrade the extracellular matrix and markers of localized inflammation. Protein fragments (neoepitopes) are detectable in the circulation.

Measurement of blood oxygen saturation (Spo2) and tissue oxygenation (Sto2) is routinely performed in clinical practice. Arterial blood gas analysis, although considered the gold standard for Spo2 estimation, requires arterial puncture, trained personnel, and laboratory backup. Currently, there is a lack of universally accepted and widely used methods for Sto2 measurement. Available noninvasive methods for Spo2 and Sto2 estimation have several limitations. Many technologies are under development to address this unmet clinical need.

Nocturnal hypoxemia commonly affects people with pulmonary fibrosis (PF).

Insomnia and OSA, together known as comorbid insomnia and OSA (COMISA), are highly prevalent sleep disorders, each of which has the potential to impair treatment efficacy for the other.

Weight loss in patients with fibrotic interstitial lung disease (F-ILD) is associated with poor prognosis, yet the impact of dietary input is unknown.

A subgroup of patients with obesity exhibits hypoventilation as a result of, among other mechanisms, a narrow, collapsible upper airway (UA), a reduced ventilatory drive during both wakefulness and sleep, and the loss of pharyngeal muscle tone during sleep. These features characterize obesity-hypoventilation syndrome (OHS). If left untreated, OHS is associated with significant morbidity and mortality. Besides lifestyle modifications, positive airway pressure (PAP) is the only available treatment, and it is often not well tolerated. Drugs designed to activate UA muscles such as atomoxetine and to stimulate breathing such as acetazolamide represent a potential novel strategy for treating OHS.

The role of cannabis smoking in lung cancer has long been underexplored due to its historical illegality and frequent co-use with tobacco. As cannabis use increases globally, particularly among younger individuals, understanding its impact on lung cancer is critical.

Atelectasis frequently occurs in patients with impaired consciousness who are being treated with invasive mechanical ventilation. It is mainly caused by secretion accumulation, which can lead to longer durations of ventilation and ICU stay.

Olfaction may be associated with lung health because of the anatomic and functional connections between the upper and lower airways, but empirical evidence is lacking.

Interstitial lung disease (ILD) is a term encompassing a wide array of pulmonary conditions characterized by inflammation and fibrosis of the pulmonary parenchyma. Pulmonary hypertension (PH) is frequently encountered in patients with fibrotic ILDs and poses unique difficulties for both diagnosis and management. Patients with ILD-associated pulmonary hypertension (ILD-PH) are complex, often ailing and presenting with multiple comorbidities whose individual contributions to the underlying PH can be challenging to disentangle. Evidence supporting treatment with PH-specific medications in ILD-PH is limited. This edition of "How I Do It" presents a longitudinal case-based discussion of ILD-PH to address these challenges, highlight pearls and pitfalls in the diagnostic workup of these patients, and provide a framework for the practical evidence-based approach to accurate diagnosis and management of these challenging cases.

Air pollution and extreme temperature exposure during pregnancy is associated with lung function in schoolchildren.

Breathlessness on exertion is a common, distressing, and limiting symptom that can be quantified on incremental cardiopulmonary exercise testing (CPET) using normative reference equations.

Many patients are unaware of the need to repeat lung cancer screening (LCS) annually despite shared decision-making. A health communication intervention was tested to improve patient knowledge, tobacco-related stigma, and self-efficacy in LCS.

Uptake of evidence-based practices (EBPs) in pulmonary and critical care medicine is frequently incomplete. To address these gaps, implementation scientists seek to understand the clinical and societal contexts in which innovations and EBPs are introduced. They also design and evaluate complex interventions to facilitate the adoption of an EBP in those contexts. We propose that well-established methods for analyzing hierarchical, observational data can complement and strengthen this process by identifying sources of practice variability. This paper reviews the dominant framework used to understand the clinical context of implementation programs, describes how measuring practice variability could help streamline this approach, and tests an assumption of the proposed combined methodology using observational data from a national study of patients on mechanical ventilation conducted by the Prevention and Early Treatment of Acute Lung Injury Network. We discuss how the combined approach can be used (1) to focus the search for determinants of practice, (2) to quantify the impact of evidence generation and evaluate the success of implementation projects, and (3) to facilitate comparisons between implementation strategies when multiple approaches are trialed simultaneously.