BACKGROUND: The present study aims to determine the impact of different cuff diameters on the cuff pressure of endotracheal tubes (ETTs) when the trachea is adequately sealed.
METHODS: In the present single-center clinical trial, adult patients who underwent cardiothoracic surgery were assigned to use ETTs from 2 brands (GME and GZW). The primary endpoint comprised of the following: cuff diameter, inner diameter of the ETT, manufacturer, and the number of subjects with tracheal leakage when the cuff pressure was 30 cm H2O.
RESULTS: A total of 298 patients were assigned into 2 groups, based on the 2 distinct brands of ETTs: experimental group (n = 122, GME brand) and control group (n = 176, GZW brand). There were no significant differences in baseline characteristics. However, the cuff diameter was significantly smaller in the control group, when compared to the experimental group (P = .001), and the incidence of tracheal leakage was significantly higher in the control group (P = .001). Furthermore, the GME brand ETT had a significantly larger cuff diameter, when compared to the GZW brand ETT.
CONCLUSIONS: The cuff size would mismatch the tracheal area in clinical practice. Therefore, chest computed tomography is recommended to routinely evaluate the tracheal cross-sectional area during anesthesia, in order to ensure the appropriate cuff size selection.

OBJECTIVE: A low expression of club cell secretory protein (CC16) and high levels of proinflammatory cytokines at preterm birth are associated with airway inflammation and more severe neonatal lung disease. The present study aimed to investigate if low levels of CC16, proinflammatory cytokines and vascular endothelial growth factors (VEGF) in tracheal aspirate early after birth were associated with lung function impairment at school age.
METHODS: Participants were 20 children, born very preterm (median gestational age 25+3 weeks+days, IQR: 24+1-27+0 weeks+days), who had tracheal aspirates collected during mechanical ventilation in their first day of life. CC16, cytokines, VEGF and matrix metalloproteinase-9 were measured in the tracheal aspirate and later correlated to results from advanced lung function measurements at 12 years of age.
RESULTS: Low levels of CC16 and high levels of the proinflammatory cytokines IL-1β and TNF-α in tracheal aspirate were associated with airway obstruction at school age but not with other lung function parameters. The correlation with airway obstruction was even stronger when the ratio between the respective proinflammatory cytokine and CC16 was used. In addition, low levels of VEGF and CC16 were associated with impaired diffusion capacity of the lung.
CONCLUSIONS: An imbalance in inflammatory mediators and growth factors in the lungs at birth may have consequences for airway function and vasculature at school age in preterm born children.

OBJECTIVE: There was no evidence regarding the relationship between septic shock and tracheal injury scores. Investigate whether septic shock was independently associated with tracheal injury scores in intensive care unit (ICU) patients with invasive ventilation.
METHODS: Prospective observational cohort study.
METHODS: Our study was conducted in a Class III hospital in Hebei province, China.
METHODS: Patients over 18 years of age admitted to the ICU between 31 May 2020 and 3 May 2022 with a tracheal tube and expected to be on the tube for more than 24 hours.
METHODS: Tracheal injuries were evaluated by examining hyperaemia, ischaemia, ulcers and tracheal perforation by fiberoptic bronchoscope. Depending on the number of lesions, the lesions were further classified as moderate, severe or confluent.
RESULTS: Among the 97 selected participants, the average age was 56.6±16.5 years, with approximately 64.9% being men. The results of adjusted linear regression showed that septic shock was associated with tracheal injury scores (β: 2.99; 95% CI 0.70 to 5.29). Subgroup analysis revealed a stronger association with a duration of intubation ≥8 days (p=0.013).
CONCLUSIONS: Patients with septic shock exhibit significantly higher tracheal injury scores compared with those without septic shock, suggesting that septic shock may serve as an independent risk factor for tracheal injury.
BACKGROUND: ChiCTR2000037842, registered 03 September 2020. Retrospectively registered, https://www.chictr.org.cn/edit.aspx?pid=57011&htm=4.

We established primary porcine nasal, tracheal, and bronchial epithelial cells that recapitulate the physical and functional properties of the respiratory tract and have the ability to fully differentiate. Trans-well cultures demonstrated increased transepithelial electrical resistance over time the presence of tight junctions as demonstrated by immunohistochemistry. The nasal, tracheal, and bronchial epithelial cells developed cilia, secreted mucus, and expressed sialic acids on surface glycoproteins, the latter which are required for influenza A virus infection. Swine influenza viruses were shown to replicate efficiently in the primary epithelial cell cultures, supporting the use of these culture models to assess swine influenza and other virus infection. Primary porcine nasal, tracheal, and bronchial epithelial cell culture models enable assessment of emerging and novel influenza viruses for pandemic potential as well as mechanistic studies to understand mechanisms of infection, reassortment, and generation of novel virus. As swine are susceptible to infection with multiple viral and bacterial respiratory pathogens, these primary airway cell models may enable study of the cellular response to infection by pathogens associated with Porcine Respiratory Disease Complex.

UNASSIGNED: To determine the association between pre-bronchoscopy time of illness and post-bronchoscopy discharge time in pediatric patients with foreign body aspiration.
UNASSIGNED: Retrospective cohort study. Medical records were studied and reviewed at the Pediatric Emergency Hospital of Lima, Peru. We reviewed 324 medical records, and selected 183 because they had the diagnosis of foreign body aspiration and complete data. Fisher\'s exact test and Mann Whitney U test were used for the bivariate analysis, while Poisson regression was used to calculate the Relative Risk (RR) and its 95% confidence interval (CI).
UNASSIGNED: We included 183 patients, of whom 65.6% were men with a mean age of 2.4 years. The most frequent location of the foreign body was the right bronchial tree and most of them were made of organic material. The majority (72.7%) of patients were discharged before 24 hours. We found an association between the time of illness prior to bronchoscopy and post-bronchoscopy discharge time (RR: 2.94, 95%CI: 1.72 - 5.01).
UNASSIGNED: The time of illness prior to bronchoscopy and the length of hospital stay after removal of the foreign body were significantly associated when adjusted for age, sex, type of foreign body and mouth sweep maneuver as a rescue measure. Our findings are relevant because they highlight the importance of early care, timely diagnosis and early management of pediatric patients.
UNASSIGNED: Determinar la asociación entre el tiempo de enfermedad previo a broncoscopia y el tiempo de alta posbroncoscopia en pacientes pediátricos con aspiración de cuerpo extraño.
UNASSIGNED: Estudio de cohorte retrospectivo. El estudio y la revisión de historias clínicas se realizó en el Hospital de Emergencias Pediátricas de Lima, Perú. Se revisaron 324 historias clínicas, de las cuales, 183 historias fueron seleccionadas por contar con diagnóstico de cuerpo extraño en vías aéreas y estar adecuadamente llenadas. Para el análisis bivariado se utilizó la prueba exacta de Fisher y U de Mann Whitney, mientras que para el cálculo del riesgo relativo (RR) y su respectivo intervalo de confianza (IC) al 95% se utilizó regresión de Poisson.
UNASSIGNED: Se incluyeron 183 pacientes, de los cuales, el 65,6% fueron hombres con una media de 2,4 años. La localización más frecuente fue el árbol bronquial derecho y cuerpo extraño de material orgánico. La mayoría (72,7%) de pacientes tuvieron un alta temprana antes de las 24 horas. Se encontró una asociación entre el tiempo de enfermedad previo a la broncoscopia y el tiempo alta posbroncoscopia (RR: 2,94, IC 95%: 1,72-5,01).
UNASSIGNED: Existe una asociación estadísticamente significativa entre el tiempo de enfermedad previo a la broncoscopia y el tiempo de estancia hospitalaria posextracción del cuerpo extraño al ajustar por edad, sexo tipo de cuerpo extraño y maniobra de boca como medida de rescate. Este hallazgo es relevante debido a que pone en evidencia la importancia de una atención temprana, diagnóstico oportuno y manejo precoz en el paciente pediátrico.

The risk of endotracheal tube (ETT) placement includes endobronchial intubation and subglottic injury. This study aimed to describe the lengths of lower airway parameters related to cuff location and vocal cord markings in different adult-sized ETTs. Eighty cadavers were examined for the lengths of the lower airway, including their correlations and linear regressions with height. Thirty adult-sized ETTs from seven different brands were examined for Mark-Cuff and Mark-Tip distances. The depth of ETT placement was simulated for each brand using vocal cord marking. The mean (standard deviation) lengths from the subglottis, trachea, vocal cord to mid- trachea, and vocal cord to carina were 24.2 (3.5), 97.9 (8.6), 73.2 (5.3), and 122.1 (9.0) mm, respectively. Airway lengths were estimated as: (1) subglottis (mm) = 0.173 * (height in cm) - 3.547; (2) vocal cord to mid-trachea (mm) = 0.28 * (height in cm) + 28.391. There were variations in the Mark-Cuff and Mark-Tip distances among different ETTs. In the simulation, endobronchial intubation ranged between 2.5 and 5% and the cuff in the subglottis ranged between 2.5 and 97.5%. In summary, the lower airway parameters were height-related. ETT placement using vocal cord marking puts the patient at a high risk of cuff placement in the subglottis.

BACKGROUND: Fetoscopic endoluminal tracheal occlusion (FETO) improves the survival rate in fetuses with severe congenital diaphragmatic hernia (CDH). We hypothesize that prenatal therapies into the trachea during FETO can further improve outcomes. Here, we present an ex vivo microinjection technique with rat lung explants to study prenatal therapy with nanoparticles.
METHODS: We used microsurgery to isolate lungs from rats on embryonic day 18. We injected chitosan nanoparticles loaded with fluorescein (FITC) into the trachea of the lung explants. We compared the difference in biodistribution of two types of nanoparticles, functionalized IgG-conjugated nanoparticles (IgG-nanoparticles) and bare nanoparticles after 24 h culture with immunofluorescence (IF). We used IF to mark lung epithelial cells with E-cadherin and to investigate an apoptosis (Active-caspase 3) and inflammatory marker (Interleukin, IL-6) and compared its abundance between the two experimental groups and control lung explants.
RESULTS: We detected the presence of nanoparticles in the lung explants, and the relative number of nanoparticles to cells was 2.49 fold higher in IgG-nanoparticles than bare nanoparticles (p < 0.001). Active caspase-3 protein abundance was similar in the control, bare nanoparticles (1.20 fold higher), and IgG-nanoparticles (1.34 fold higher) groups (p = 0.34). Similarly, IL-6 protein abundance was not different in the control, bare nanoparticles (1.13 fold higher), and IgG-nanoparticles (1.12 fold higher) groups (p = 0.33).
CONCLUSIONS: Functionalized nanoparticles had a higher presence in lung cells and this did not result in more apoptosis or inflammation. Our proof-of-principle study will guide future research with therapies to improve lung development prenatally.
METHODS: N/A TYPE OF STUDY: Animal and laboratory study.

OBJECTIVE: To compare the effectiveness of cylindrical-shaped and conical-shaped cuff catheters for airway closure using different pressure measurement methods at the lowest safe pressure and to guide the clinical application.
METHODS: Twenty-four patients with endotracheal intubation admitted to the intensive care unit (ICU) of Guangxi Medical University Cancer Hospital from December 2021 to January 2022 were enrolled. Leakage test in vitro was performed on the secretion on the patients\' cuff. The needle and plunger from 20 mL syringe was separated, the syringe was sealed with adhesive, and the syringe nozzle was filled thoroughly to create a tracheal model. Consecutively, both cylindrical-shaped and conical-shaped cuff catheters were inserted into the simulated trachea, and the cuff pressure was calibrated to 20 cmH2O (1 cmH2O ≈ 0.098 kPa) before commencing the experiment. The viscosity of the secretion on the patients\' cuff was classified (grade I was watery subglottic secretion, grade II was thick subglottic secretion, grade III was gel-like subglottic secretion), and the same viscosity secretion was injected into the catheter cuff. Utilizing a self-control approach, intermittent pressure measurement was initially conducted on both the cylindrical-shaped and conical-shaped cuff by improved pressure measurement method (intermittent pressure measurement group), followed by continuous pressure measurement experiment (continuous pressure measurement group). The leakage volume of the three viscosity subglottic secretions and the values of cuff pressure measurement of different shaped cuff catheters at 4, 6, 8 hours of inflation were recorded.
RESULTS: A total of 180 retention samples were extracted from 24 patients with tracheal intubation during ventilation, with 90 samples in each of the two groups using different pressure measurement methods, and 30 samples of retention materials with different viscosities in each group. In the intermittent pressure measurement group, at 4 hours of inflation, all samples of secretion with grade I and grade II on cylindrical-shaped cuff leaked, while 3 samples of secretion with grade III also leaked. For conical-shaped cuff, 28 samples of secretion with grade I leaked, only 2 samples of secretion with grade II leaked, and there was no leak for secretion with grade III. At 6 hours of inflation, all samples of the three viscosity secretions on different shaped cuffs leaked. The leakage was gradually increased with the prolongation of inflation time. In the continuous pressure measurement group, at 4 hours of inflation, all samples of secretion with grade I on cylindrical-shaped cuff leaked, while 29 samples of secretion with grade II leaked, and there was no leak for secretion with grade III. For the conical-shaped cuff, 26 samples of secretion with grade I leaked, and there was no leak for secretion with grade II and grade III. At 6 hours of inflation, the conical-shaped cuff still had no leak for secretion with grade III. As the inflation time prolonged, the leakage of subglottic secretion on different shaped cuffs in both groups was gradually increased. At 8 hours of inflation, all samples experienced leakage, but the leakage of subglottic secretion on different shaped cuffs in the continuous pressure measurement group was significantly reduced as compared with the intermittent pressure measurement group [leakage for secretion with grade III (mL): 1.00 (0.00, 1.25) vs. 2.00 (1.00, 2.00) on the cylindrical-shaped cuff, 1.00 (0.00, 1.00) vs. 2.00 (2.00, 2.00) on the conical-shaped cuff, both P < 0.01]. The values of pressure measurement of cuffs with different shapes at different time points of inflation in the continuous pressure measurement group were within the set range (20-21 cmH2O). The cuff pressure at 4 hours of inflation in the intermittent pressure measurement group was significantly lower than the initial value (cmH2O: 18.3±0.6 vs. 20.0±0.0 in the cylindrical-shaped cuff, 18.4±0.6 vs. 20.0±0.0 in the conical-shaped cuff, both P < 0.01), and the cuff pressure in both shaped cuffs showed a significant decrease tendency as inflation time prolonged. However, there was no statistically significant difference in values of pressure measurement between the different shaped cuff catheters.
CONCLUSIONS: Continuous pressure monitoring devices can maintain the effective sealing of conical-shaped cuff catheters at the lowest safe pressure. When using an improved pressure measurement method for intermittent pressure measurement and/or using a cylindrical cuff catheter, the target pressure should be set at 25-30 cmH2O, and the cuff pressure should be adjusted regularly.

BACKGROUND: Benign airway stenosis (BAS) is a severe pathologic condition. Complex stenosis has a high recurrence rate and requires repeated bronchoscopic interventions for achieving optimal control, leading to recurrent BAS (RBAS) due to intraluminal granulation.
METHODS: This study explored the potential of autologous regenerative factor (ARF) for treating RBAS using a post-intubation tracheal stenosis canine model. Bronchoscopic follow-ups were conducted, and RNA-seq analysis of airway tissue was performed. A clinical study was also initiated involving 17 patients with recurrent airway stenosis.
RESULTS: In the animal model, ARF demonstrated significant effectiveness in preventing further collapse of the injured airway, maintaining airway patency and promoting tissue regeneration. RNA-seq results showed differential gene expression, signifying alterations in cellular components and signaling pathways. The clinical study found that ARF treatment was well-tolerated by patients with no severe adverse events requiring hospitalization. ARF treatment yielded a high response rate, especially for post-intubation tracheal stenosis and idiopathic tracheal stenosis patients.
CONCLUSIONS: The study concludes that ARF presents a promising, effective, and less-invasive method for treating RBAS. ARF has shown potential in prolonging the intermittent period and reducing treatment failure in patients with recurrent tracheal stenosis by facilitating tracheal mucosal wound repair and ameliorating tracheal fibrosis. This novel approach could significantly impact future clinical applications.

BACKGROUND: In pediatric patients due to shorter trachea suboptimal positioning of endotracheal tube (ETT) is seen in 20%-50% of patients triggering grave complications. We compared standard auscultation and ultrasound-guided lung sliding to confirm the position of ETT in children.
METHODS: Seventy-five pediatric patients between 2-8 years of age, American Society of Anesthesiologists physical status classification I and II scheduled for surgery under general anesthesia with endotracheal intubation were studied. The position of ETT was confirmed by chest auscultation for the breath sounds bilaterally and by ultrasound on the same sites for lung-sliding signs. The data obtained were compared to findings on waveform capnography. Study outcomes included position of the ETT; tracheal or esophageal, accuracy of diagnosis and time taken till confirming the diagnosis.
RESULTS: Compared to waveform capnography findings, an ultrasound revealed a sensitivity of 94.31%, a specificity of 72.33%, and an accuracy of 90.7% while that for standard auscultation were 82.8%, 47.28%, and 74.67%, respectively. The mean time taken for confirmation of ETT position was significantly shorter with waveform capnography (10.29 ± 2.25 s) compared to auscultation (12.96 ± 2.23 s) and ultrasonography (USG) (14.28 ± 3.77 s).
CONCLUSIONS: Confirmation of ETT position using USG or waveform capnography is essential because of high false results using standard auscultation alone. Ultrasound-guided lung sliding method is a simple, fast, and a reliable method used for detecting tube malposition.