Nebulizers are used commonly for inhaled drug delivery. Because they deliver medication through aerosol generation, clarification is needed on what constitutes safe aerosol delivery in infectious respiratory disease settings. The COVID-19 pandemic highlighted the importance of understanding the safety and potential risks of aerosol-generating procedures. However, evidence supporting the increased risk of disease transmission with nebulized treatments is inconclusive, and inconsistent guidelines and differing opinions have left uncertainty regarding their use. Many clinicians opt for alternative devices, but this practice could impact outcomes negatively, especially for patients who may not derive full treatment benefit from handheld inhalers. Therefore, it is prudent to develop strategies that can be used during nebulized treatment to minimize the emission of fugitive aerosols, these comprising bioaerosols exhaled by infected individuals and medical aerosols generated by the device that also may be contaminated. This is particularly relevant for patient care in the context of a highly transmissible virus.

Air pollution poses a risk to the respiratory health of individuals with COPD. Long- and short-term exposures to higher levels of particulate-rich air pollution are associated with increased COPD exacerbation, hospitalization, and mortality, collectively implicating air pollution as a cause of adverse COPD-related outcomes.

Current guidelines recommend initial monotherapy for pulmonary arterial hypertension (PAH) with cardiopulmonary comorbidities, despite limited available evidence to guide management.

A 51-year-old woman was referred to our hospital with progressive dyspnea on exertion for 2 months after COVID-19 vaccination (ChAdOx1-S [recombinant] vaccine). She did not have a cough, fever, hemoptysis, weight loss, or night sweats. She had no history of arthritis, rash, photosensitivity, or other signs of autoimmune disease. Chest radiograph revealed diffuse ground-glass opacities and bilateral pulmonary nodules. She denied any history of smoking, contact with individuals infected with TB, relevant hobbies, or exposure to domestic animals. She had no relevant medical history, was previously healthy, and worked as a chef.

A 19-year-old woman with no medical history who did not use tobacco presented to the hospital with post-COVID-19 cough for 2 months and new onset of shortness of breath and blood-tinged sputum. She was initially treated empirically for community-acquired pneumonia because her chest radiograph showed a right upper lobe infiltrate. Further CT scan imaging revealed a right hilar lymph node conglomerate and extensive lymphadenopathy. The patient left to pursue care at a facility that accepted her insurance. Two weeks later, the patient presented for severe left-sided lower back pain, and she was found to have new complete left lower lobe collapse, likely because of extrinsic compression of the left lower lobe bronchus. She was treated for pain, and she left for insurance reasons. Two months later, the patient presented with progressive shortness of breath and hemoptysis and a 23-kg weight loss over the past 4 months. Because of the patient's increasing medical needs, she was transferred to our institution, where she was admitted to the medical ICU.

A 28-year-old woman with a history of congenital hip dysplasia was referred for evaluation of recurrent bronchitis. She had undergone left hip replacement with titanium implants 11 years prior to presentation. The patient reported frequent bouts of bronchitis, sinusitis, and left-sided nontender facial swelling that started after the hip replacement surgery. She also reported nail discoloration of her left first toenail 1 year after this procedure, and nail discoloration of her right first toenail 3 years after the procedure. She was treated for onychomycosis without improvement. Review of symptoms was positive for chronic dry cough and facial tenderness but was negative for dyspnea, wheezing, or chest tightness. She previously had been diagnosed with common variable immunodeficiency based on low immunoglobulin levels, and the condition was maintained with monthly IV immunoglobulins but without any improvement or change in the frequency of sinusitis, bronchitis, or facial swelling. She did not use tobacco, and her family history was unremarkable.

A 38-year-old man presented to the ED complaining of persistent fever, dry cough, shortness of breath, and diarrhea for 7 days. He reported a history of OSA with inconsistent CPAP use, tobacco use of less than one pack per day, and daily e-cigarette use or "vaping." He denied any contact with ill people or recent travels and was up to date on recommended COVID-19 vaccinations. Prior to his presentation, he had been seen at an urgent care facility twice in the last week, where he was given IV fluids and prescribed steroids without improvement.

Airway closure is an underestimated phenomenon reported in hypoxemic respiratory failure under mechanical ventilation, during cardiac arrest, and in patients who are obese. Because airway and alveolar pressure are not communicating, it leads to an overestimation of driving pressure and an underestimation of respiratory system compliance. Airway closure also favors denitrogenation atelectasis. To date, it has been described mainly in patients with ARDS and those with obesity. We describe three cases of airway closure in patients with hydrostatic pulmonary edema caused by cardiogenic shock, highlighting its resolution in a limited period of time (24 h) as pulmonary edema resolved. The waveforms show a biphasic reopening that we refer to as the "uncorking effect". The detection of airway closure may require setting positive end-expiratory pressure at or above the airway opening pressure to avoid the overestimation of driving pressure.