Computational Modelling of Cough Function and Airway Penetrant Behavior in Patients with Disorders of Laryngeal Function

Upper Airway Assessment and Responses During Mechanically Assisted Cough

When the ability to cough is impaired, secretion clearance may be assisted and augmented with mechanical insufflation-exsufflation (MI-E). In some individuals, the efficacy of MI-E may be hampered by counterproductive upper airway reactions, where the airways close in response to positive pressures. To fully utilize the therapeutic potential inherent in the MI-E technology, we need a better understanding of the pathophysiology behind these untoward reactions. There is increasing interest in monitoring and measuring upper airway responses to MI-E and how such information can be used to optimize MI-E settings. The purpose of this narrative review is to increase the theoretical understanding of the larynx as a respiratory organ, summarize the current literature in the area, and provide insight into how this knowledge can affect current clinical practice.

Effect of Chin-down-plus-larynx-tightening maneuver on swallowing function after minimally invasive esophagectomy: A randomized controlled trail

Background

The incidence of swallowing abnormality was high after minimally invasive esophagectomy (MIE) for esophageal cancer (EC). Few reports, however, focused on interventions for dysphagia after esophagectomy.

Aim

The purpose of this research was to estimate the effect of Chin‐down‐plus‐larynx‐tightening maneuver on swallowing function for patients receiving esophagectomy.

Method

This was a 2‐arm, parallel‐group, single‐blind randomized clinical trial, performed in patients suffered from EC from November 2018 to January 2020. Patients were randomly assigned to the intervention group (IG) or the control group (CG). The participants in CG received routine care, and the IG received Chin‐down‐plus‐larynx‐tightening maneuver during feeding. The incidence of choking cough, swallowing function, and dietary outcomes were evaluated before and after intervention for 7 days.

Results

A total of 237 EC cases were enrolled and randomized to the IG (n = 118) or CG (n = 119). There was no significant difference between the two groups in terms of demographic and clinical characteristics. Postoperative choking cough occurred in 5 of 118 cases (4.24%) in IG and 18 of 119 cases (19.4%) in CG, the differences showed statistically significant (P < .001). The analysis showed that the participants in the IG compared with the CG have more total caloric intake of 24 hours and higher K/R (the ratio of calories oral achieved to total calories required of body) significantly from D1 to D7 of intervention (P < .05).

Conclusion

The findings suggest that the Chin‐down‐plus‐larynx‐tightening maneuver can improve swallowing function recovery and oral total food intake and calories in EC patients undergoing MIE.

CFD Simulation of Airflow Dynamics During Cough Based on CT-Scanned Respiratory Airway Geometries

The airflow dynamics observed during a cough process in a CT-scanned respiratory airway model were numerically analyzed using the computational fluid dynamics (CFD) method. The model and methodology were validated by a comparison with published experimental results. The influence of the cough peak flow rate on airflow dynamics and flow distribution was studied. The maximum velocity, wall pressure, and wall shear stress increased linearly as the cough peak flow increased. However, the cough peak flow rate had little influence on the flow distribution of the left and right main bronchi during the cough process. This article focuses on the mathematical and numerical modelling for human cough process in bioengineering.