Journal CHEST®
Long-Term Fine Particulate Matter Constituents Exposure, Genetic Susceptibility, and Incident Sleep Apnea
By Ge Yin, MBBS, and colleagues
This prospective cohort study by Yin and colleagues indicates that long-term exposure to specific constituents of fine particulate matter (PM2.5) significantly increases the risk of incident sleep apnea. They evaluated the differential contributors to PM2.5 and found that sulfate accounted for 58% of the pollutant-associated risk. Along with shifting focus from total particulate mass to constituent-specific toxicity, this study also demonstrated that genetic susceptibility, specifically the rs9937053 genotype, obesity (BMI ≥30 kg/m2), and urban dwelling, act synergistically with these chemical exposures to compound the risk. These data contribute to the rise of precision sleep medicine and help clinicians appropriately screen vulnerable individuals, along with providing epidemiological evidence for medical societies to lobby for source-specific emission controls.
Commentary by Harjinder Singh, MD, Member of the CHEST Physician Editorial Board
CHEST® Critical Care
Respiratory Muscle Motor Control in Patients Receiving Mechanical Ventilation
By Marine Van Hollebeke, PhD, and colleagues
This scoping review of 56 studies challenges a diaphragm-centric view of ventilator weaning by suggesting that weaning failure is better characterized by how respiratory muscles work together rather than diaphragm activation magnitude alone. Key findings include that failed weaning is associated with greater extradiaphragmatic muscle recruitment relative to the diaphragm and lower neuroventilatory and neuromuscular efficiency. The study also found that diaphragm contraction velocity measured by electrical activity of the diaphragm or manometry was consistently higher in patients with failed weaning compared with those who weaned successfully during a spontaneous breathing trial (SBT). Diaphragm contraction velocity measured by ultrasound during SBTs was highly variable and not associated with weaning outcomes. Extradiaphragmatic muscles may ultimately prove to be more reliable and accessible weaning biomarkers than diaphragm metrics alone. These findings suggest that clinicians should move beyond diaphragm-only assessment toward integrated evaluation of respiratory system muscle coordination and efficiency.
Commentary by Katherine Pendleton, MD, FCCP, Member of the CHEST Physician Editorial Board
CHEST® Pulmonary
Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration With 19-Gauge vs 21- or 22-Gauge Needle for Mediastinal Lymphadenopathy
By Héctor José Peroni, MD, and colleagues
This analysis addressed an important question in pulmonary medicine: In patients who underwent bronchoscopy due to mediastinal lymphadenopathy, did use of a 19-gauge endobronchial ultrasound (EBUS) needle increase diagnostic performance over the use of smaller needles (21- or 22-gauge)?
Initial findings from the SCOPE dataset showed no significant difference in diagnostic yield (DY) nor specimen adequacy between the 19-gauge vs 21- or 22-gauge needles. With propensity score matching analysis, the DY of EBUS-guided transbronchial needle aspiration procedures was 72.8% in the 21-/22-gauge group vs 73.4% in the 19-gauge group (difference, 0.6%; 95% CI, -8.1% to 8.7%; P = .88). With inverse probability of treatment weighting analysis, the DY was 69.6% in the 21-/22-gauge group vs 74.0% in the 19-gauge group (difference, 4.4%; 95% CI, -4.3% to 11.7%; P = .30). This retrospective observation study corroborated earlier prospective trials on similar findings of DY with 19-gauge needles vs smaller needles.
A prospective study published in 2021 in the Journal of Bronchology & Interventional Pulmonology found an overall DY per lymph node of 89.4% for 19-gauge vs 88.7% for 21-gauge (P = .71), proving no statistical difference.1 Another prospective randomized trial published in the Journal of the American Society of Cytopathology comparing 19-gauge and 22-gauge needles yielded 87.5% and 83.9%, respectively, (P = .625) for histopathologic examination, with no difference in DY with cytologic evaluation.2
The current evidence, combined with prior observational and prospective trials, suggests there is no significant difference in DY and clinical efficacy in using 19-gauge needles vs smaller needles. The operator may wish to consider factors other than only diagnostic performance when deciding on needle selection. Future studies should be prospective and randomized with larger sample sizes to detect smaller differences in diagnostic performance.
Commentary by Munish Luthra, MD, FCCP, Member of the CHEST Physician Editorial Board
References
1. Elmufdi FS, Peterson MK, Niccum D, Asche S, Ham K. Evaluating yield of 19 versus 21 G EBUS-TBNA needles: a prospective study. J Bronchology Interv Pulmonol. 2021;28(1):29-33. doi:10.1097/LBR.0000000000000674
2. Manley CJ, Kumar R, Gong Y, et al. Prospective randomized trial to compare the safety, diagnostic yield and utility of 22-gauge and 19-gauge endobronchial ultrasound transbronchial needle aspirates and processing technique by cytology and histopathology. J Am Soc Cytopathol. 2022;11(2):114-121. doi:10.1016/j.jasc.2021.10.003
