A computational fluid dynamics simulation of liquid swallowing by impaired pharyngeal motion: bolus pathway and pharyngeal residue

Effectiveness of an evidence-based swallowing facilitation strategy for patients undergoing radiotherapy for head and neck cancer: a study protocol for a randomised controlled trial

INTRODUCTION

Dysphagia emerges as a frequent, persistent and enduring aftermath in individuals undergoing radiotherapy for head and neck cancer (HNC). Timely intervention becomes imperative to ameliorate prolonged dysphagia and curtail related complications. Among the evidence-grounded tactics, preventive swallowing training and proficient feeding management stand out as pivotal measures for precluding and mitigating dysphagia. However, past inquiries that amalgamated these dual interventions exhibited heterogeneous quality due to their restricted participant cohorts and a dearth of uniform, systematic and practicable procedural benchmarks.

METHOD/DESIGN

This randomised, parallel-controlled study enrols 94 patients diagnosed with HNC, who are undergoing radiotherapy either with or without concurrent chemotherapy. The patients will be randomly assigned to either the intervention group, which will receive a facilitation strategy to enhance swallowing function in conjunction with standard care, or the control group, which will receive typical radiotherapy care. Patient assessments will be conducted at three distinct time points: at the onset of radiotherapy (baseline), at the conclusion of radiotherapy and 3 months postradiotherapy. The primary outcome will revolve around measuring swallowing function, while secondary outcomes will encompass swallowing-related quality of life and nutritional status.

ETHICS AND DISSEMINATION

This research initiative received endorsement from the Shanghai Proton Heavy Ion Hospital Ethics Committee on 2 December 2 (Approval Number 2210-59-01). Throughout the recruitment process, patients will be acquainted with the primary aims and scope of the study. Their participation will be a voluntary choice, demonstrated by their informed consent form signatures. The outcomes of this study will be disseminated through publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

Clinical Trials.gov, ChiCTR2300067550, registered 11 January 2023.

Biomechanical mechanism of reduced aspiration by the Passy-Muir valve in tracheostomized patients following acquired brain injury: Evidences from subglottic pressure

Objective

Aspiration is a common complication after tracheostomy in patients with acquired brain injury (ABI), resulting from impaired swallowing function, and which may lead to aspiration pneumonia. The Passy-Muir Tracheostomy and Ventilator Swallowing and Speaking Valve (PMV) has been used to enable voice and reduce aspiration; however, its mechanism is unclear. This study aimed to investigate the mechanisms underlying the beneficial effects of PMV intervention on the prevention of aspiration.

Methods

A randomized, single-blinded, controlled study was designed in which 20 tracheostomized patients with aspiration following ABI were recruited and randomized into the PMV intervention and non-PMV intervention groups. Before and after the intervention, swallowing biomechanical characteristics were examined using video fluoroscopic swallowing study (VFSS) and high-resolution manometry (HRM). A three-dimensional (3D) upper airway anatomical reconstruction was made based on computed tomography scan data, followed by computational fluid dynamics (CFD) simulation analysis to detect subglottic pressure.

Results

The results showed that compared with the non-PMV intervention group, the velopharynx maximal pressure (VP-Max) and upper esophageal sphincter relaxation duration (UES-RD) increased significantly (P < 0.05), while the Penetration-Aspiration Scale (PAS) score decreased in the PMV intervention group (P < 0.05). Additionally, the subglottic pressure was successfully detected by CFD simulation analysis, and increased significantly after 2 weeks in the PMV intervention group compared to the non-PMV intervention group (P < 0.001), indicating that the subglottic pressure could be remodeled through PMV intervention.

Conclusion

Our findings demonstrated that PMV could improve VP-Max, UES-RD, and reduce aspiration in tracheostomized patients, and the putative mechanism may involve the subglottic pressure.

Clinical trial registration

[http://www.chictr.org.cn], identifier [ChiCTR1800018686].

Dysphagia in non-intubated patients affected by COVID-19 infection

Purpose

Patients affected by COVID-19 are assumed to be at high risk of developing swallowing disorders. However, to our best knowledge, data on the characteristics and incidence of dysphagia associated with COVID-19 are lacking, especially in non-intubated patients. Therefore, we investigated the onset of swallowing disorders in patients with laboratory-confirmed COVID-19 infection who have not been treated with invasive ventilation, in order to evaluate how the virus affected swallowing function regardless of orotracheal intubation.

Methods

We evaluated 41 patients admitted to the COVID department of our Hospital when they had already passed the acute phase of the disease and were therefore asymptomatic but still positive for SARS-CoV-2 RNA by RT-PCR. We examined patients’ clinical history and performed the Volume-Viscosity Swallow Test (VVST). Each patient also answered the Swallowing Disturbance Questionnaire (SDQ). After 6 months, we performed a follow-up in patients with swallowing disorders.

Results

Eight of 41 patients (20%) presented with dysphagia symptoms during hospitalization and 2 of them (25%) still presented a SDQ high score and swallowing disorders with liquid consistency after 6 months.

Conclusion

Non-intubated patients can experience various grades of swallowing impairment that probably directly related to pulmonary respiratory function alterations and viral direct neuronal lesive activity. Although these symptoms show natural tendency to spontaneous resolution, their impact on a general physical impaired situation should not be underestimated, since it can adversely affect patients’ recovery from COVID-19 worsening health outcomes.