Journal CHEST®
Association Between Airway Mucus Plugs and Risk of Moderate-to-Severe Exacerbations in Patients With COPD
By Xueping Li, MD, and colleagues
This single-center prospective cohort study of 194 patients adds to the growing body of evidence that CT scan-detected airway mucus plugs in COPD are associated with an increased risk of future acute exacerbations of COPD (AECOPD). Risk rose in proportion to the number of affected pulmonary segments, with more extensive involvement (≥4) reflecting greater vulnerability. After adjusting for age, sex, BMI, smoking status, history of severe exacerbations, and FEV₁, investigators found that mucus plugs were independently associated with a higher one-year risk of moderate to severe AECOPD.
Mucolytics can play an important role in pharmacologic therapy of COPD, and these findings suggest that imaging could help identify patients most likely to benefit. Beyond informing patient selection for mucolytic therapy, quantification of mucus plug burden may also serve as a valuable tool for risk stratification in predicting future AECOPD.
Commentary by Megan Conroy, MD, MAEd, FCCP, Member of the CHEST Physician Editorial Board
CHEST® Pulmonary
Feasibility of Assessing the Abnormal Pediatric Airway Using Rotational Optical Coherence Tomography
By Sune Rubak, MD, PhD, and colleagues
Diagnosing abnormalities of the pediatric airways may be challenging for a variety of reasons. Optical coherence tomography (OCT) is a new catheter-based method that uses light near the infrared range to create detailed circumferential cross-sectional images. This prospective case series used OCT in nine pediatric patients with severe persistent respiratory symptoms and/or persistent radiologic abnormalities concerning for airway abnormalities. Results showed that OCT is a feasible method for visualizing and quantifying stenoses of the lower pediatric airway. In addition, the correction constant for optimal quantification was calculated and provided the possibility for precise interpretation of OCT measurements. More research is needed to evaluate the accessibility, safety, and accuracy of OCT in comparison with the CT scan and dynamic bronchoscopy, and on the implementation of OCT analysis to fully understand the potential application of OCT in the clinical evaluation of the abnormal pediatric airway.
Commentary by Anne Coates, MD, FCCP, Member of the CHEST Physician Editorial Board
CHEST® Critical Care
Association of Central Nervous System-Related Biomarkers With Hospital Delirium in Patients With Respiratory Failure in the ICU
By Andrew T. Pham, MD, and colleagues
A single-center prospective observational cohort study conducted at an academic medical center in Aurora, Colorado, assessed the association of biomarkers at the time of ICU admission with the prediction of delirium in patients with respiratory failure requiring ventilator support.
Delirium is highly prevalent in ICU patients with respiratory failure requiring mechanical ventilator support, occurring in about 73% of the study cohort, which remains strongly linked to morbidity, mortality, and prolonged hospital stays. From this study of 100 patients, two biomarkers showed strong associations with delirium at ICU admission: 1) neurofilament light chain (NF-L)—higher levels were positively associated with delirium, suggesting neuronal injury; 2) brain-derived neurotrophic factor (BDNF)—lower levels were negatively associated with delirium, suggesting reduced neuroprotection and impaired synaptic plasticity. NF-L correlated with worse clinical outcomes, including fewer ICU- and hospital-free days, while BDNF correlated with more hospital-free days, underscoring its potential role as prognostic indicator. Other CNS biomarkers studied (GFAP, S100B, CHI3L1, neurogranin, TREM2) did not show significant associations with delirium diagnosis.
Clinical implication: Measurement of BDNF and NF-L at ICU admission could serve as an adjunct for delirium risk prediction and may help identify subgroups of critically ill patients who could benefit from targeted delirium prevention strategies. Larger multicenter studies are needed before integration into routine practice.
Key takeaway: The most critical insight is that NF-L and BDNF are significantly associated with the development of delirium in critically ill patients with respiratory failure. This suggests delirium risk is not only clinical but also biologically detectable early in the ICU course.
Potentially practice-changing impact:
- Currently, delirium prediction relies on clinical risk factors and bedside screening, both of which have limited sensitivity and specificity.
- If validated in larger, multicenter studies, measuring BDNF and NF-L could provide an objective, rapid, laboratory-based method to stratify delirium risk at ICU admission.
- This could allow clinicians to:
- Identify high-risk patients early and intensify delirium prevention bundles.
- Allocate ICU resources more effectively (eg, nonpharmacologic interventions, staffing, monitoring).
- Move toward precision medicine in delirium care and tailoring interventions to biologically defined subgroups.
- This study lays the groundwork for biomarker-guided delirium prediction and prevention strategies—a significant shift from current purely clinical approaches.
Commentary by Dharani Narendra, MD, FCCP, Member of the CHEST Physician Editorial Board
