Excessive inflammation is pathogenic in the pneumonitis associated with severe COVID-19. Neutrophils are among the most abundantly present leukocytes in the inflammatory infiltrates and may form neutrophil extracellular traps (NETs) under the local influence of cytokines. NETs constitute a defense mechanism against bacteria, but have also been shown to mediate tissue damage in a number of diseases.

A 44-year-old man with a history of asthma presented with intermittent convulsion of the right limb, fever in the late afternoon, and decreased exercise tolerance over 2 months. Occasional productive cough, no hemoptysis, and weight loss of nearly 6 kg were observed during this period. Neither chemotherapy nor oral immunosuppressive drugs had been administered, and no exposure to toxic substances was known. He was a cook and had smoked approximately one pack of cigarettes per day for the past 20 years. The living environment was relatively humid. The patient presented to a local hospital, where the workup was notable for low-density shadows in the left parieto-occipital lobe and a cavity in the right upper lobe of the lung with bilateral diffuse interlobular septal thickening and multiple patchy ground-glass opacities. The brain and lung lesions were 18F-fluorodeoxyglucose avid on PET/CT scan. Bronchoscopy with BAL and transbronchial biopsy were nondiagnostic. While preparing for another diagnostic procedure, the patient gradually developed increasing dyspnea and more frequent convulsions with the progression of lesions on the follow-up chest CT scan. The patient was transferred to our hospital.

In critically ill patients receiving mechanical ventilation, expiratory muscles are recruited with high respiratory loading and/or low inspiratory muscle capacity. In this case report, we describe a previously unrecognized patient-ventilator dyssynchrony characterized by ventilator triggering by expiratory muscle relaxation, an observation that we termed expiratory muscle relaxation-induced ventilator triggering (ERIT). ERIT can be recognized with in-depth respiratory muscle monitoring as (1) an increase in gastric pressure (Pga) during expiration, resulting from expiratory muscle recruitment; (2) a drop in Pga (and hence, esophageal pressure) at the time of ventilator triggering; and (3) diaphragm electrical activity onset occurring after ventilator triggering. Future studies should focus on the incidence of ERIT and the impact in the patient receiving mechanical ventilation.

Data assessing outcomes of patients with solid tumors demonstrating septic shock using the Third International Consensus Definitions for Sepsis and Septic Shock are scarce.

Improved methods are needed to risk-stratify patients with cystic fibrosis (CF) and reduced FEV1.

A shortage of beds in ICUs and conventional wards during the COVID-19 pandemic led to a collapse of health care resources.

Safe, effective, and easily implementable treatments that reduce the progression of respiratory failure in COVID-19 are urgently needed. Despite the increased adoption of prone positioning during the pandemic, the effectiveness of this technique on progression of respiratory failure among nonintubated patients is unclear.

The COVID-19 pandemic has strained health care systems and has resulted in widespread critical care staffing shortages, negatively impacting the quality of care delivered.

Atrial fibrillation (AF) is widely perceived to originate from the left atrium (LA). Whether increases in right ventricular (RV) afterload in older adults play an etiological role in AF genesis independent of LA and left ventricular (LV) remodeling is unknown.

A 37-year-old male patient was referred to our sleep laboratory with suspected sleep-disordered breathing. His partner reported periods of breathing arrest accompanied by an odd expiratory noise during sleep, occurring on a near to weekly basis. The patient stated that he was able to sleep well, did not have excessive daytime sleepiness, and was not subjectively aware of any disordered breathing at night. He had a history of structural epilepsy following perinatal trauma, with secondary generalized tonic/clonic seizures, preceded by sensory oral misperceptions. The patient was medicated with phenytoin (100 mg), and reported being seizure-free within the last year. He said that he was otherwise in good health.

An 11-month-old boy was admitted to our hospital because of "recurrent cough with intermittent dyspnea for more than 8 months, aggravated for 1 month." The baby began experiencing a recurrent milk-choking problem within 1.5 months after birth. He had been hospitalized four times, but the symptoms recurred. One month previously, the symptoms were aggravated and a chest CT scan performed at outside hospital showed interstitial changes. Pediatric bronchoscopy revealed bronchial inflammatory features, with hemosiderin-laden macrophages being found in BAL fluid (BALF). Also, periodic acid-Schiff (PAS) staining showed positive results, which indicated the possibility of pulmonary alveolar proteinosis (PAP) or idiopathic pulmonary hemosiderosis (IPH).

Atrial fibrillation (AF) is a common complication of sepsis. It is unclear whether norepinephrine, an α- and β-agonist, and phenylephrine, an α-agonist, are associated with different heart rates among patients with sepsis and AF.

Mortality historically has been the primary outcome of choice for acute and critical care clinical trials. However, undue reliance on mortality can limit the scope of trials that can be performed. Large sample sizes are usually needed for trials powered for a mortality outcome, and focusing solely on mortality fails to recognize the importance that reducing morbidity can have on patients' lives. The COVID-19 pandemic has highlighted the need for rapid, efficient trials to rigorously evaluate new therapies for hospitalized patients with acute lung injury. Oxygen-free days (OFDs) is a novel outcome for clinical trials that is a composite of mortality and duration of new supplemental oxygen use. It is designed to characterize recovery from acute lung injury in populations with a high prevalence of new hypoxemia and supplemental oxygen use. In these populations, OFDs captures two patient-centered consequences of acute lung injury: mortality and hypoxemic lung dysfunction. Power to detect differences in OFDs typically is greater than that for other clinical trial outcomes, such as mortality and ventilator-free days. OFDs is the primary outcome for the Fourth Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV-4) Host Tissue platform, which evaluates novel therapies targeting the host response to COVID-19 among adults hospitalized with COVID-19 and new hypoxemia. This article outlines the rationale for use of OFDs as an outcome for clinical trials, proposes a standardized method for defining and analyzing OFDs, and provides a framework for sample size calculations using the OFD outcome.