High Flow Nasal Oxygen (HFNO), swallowing and dysphagia in adults: A narrative review with implications for ICU clinical practice and future research

The use of high flow nasal oxygen (HFNO) in clinical practice is increasing with robust evidence of its respiratory benefits. Swallowing is known to be heavily coordinated with breathing, in addition to sharing a physical pathway in the upper airway. Applying HFNO via these spaces may also have an impact on the swallowing process. Yet, there is a lack of literature regarding the effect of HFNO on swallowing and on dysphagia. This narrative review aims to summarise the existing literature, draw conclusions on important clinical questions where possible and set the scene for future research. A database search was conducted on 24/01/2024 across CINAHL, Medline and Embase. Due to paucity of literature, studies with adult participants within and outside of ICU were included, and references cross-checked. Conference abstracts were also included. The search was repeated on 5/6/2024. Twelve articles were included in direct data comparison, in addition to studies examining the biomedical effect of HFNO that is, the impact of HFNO on the physiology of the oropharynx and swallow function. The authors conclude that whilst studies are limited in numbers and some results controversial, indications are that HFNO may demand adaptations to swallowing and some patients may not have this capability to adapt. HFNO should not be a barrier to a swallow assessment, irrespective of flow rate and the decision to assess should be based on overall patient presentation, as with any other population. Instrumental swallowing assessment is recommended to confirm any detrimental or beneficial impact of HFNO on swallow function. Robust research and guidelines are needed.

Navigating Nutrition Complexity in Critical Care: A Focus on Swallowing Function and Rehabilitation

During the past decade, there has been an increased research focus on the prevalence, nature, and impact of newly acquired critical illness dysphagia. Disordered function can impact the safety and efficiency across all stages of the swallow mechanism, with detrimental impacts on patients' body systems, function, and participation. Accurate assessment of swallow function is key to informed diagnosis and enhances intervention planning. We discuss the current evidence base around dysphagia pathophysiology with a detailed discussion considering the modes of ventilation commonly received in intensive care units. Assessment and management across critical illness are evaluated and future research efforts are presented.

Swallowing during provision of helmet ventilation: Review and provisional multidisciplinary guidance

Use of noninvasive ventilation provided by a helmet increased globally during and after the COVID-19 pandemic. This approach may reduce need for intubation and its associated clinical complications in critically ill patients. Use of helmet interface minimizes virus aerosolization while enabling verbal communication, oral feeding and coughing/expectoration of secretions during its administration. Although improved oral hydration is a recognized benefit of helmet NIV, relatively little is known about the safety and efficiency of swallowing during helmet NIV. Risk of aspiration is a key consideration given the fragile pulmonary status of critically ill patients requiring respiratory support, and therefore the decision to initiate oral intake is best made based on multidisciplinary input. We reviewed the current published evidence on NIV and its effects on upper airway physiology and swallowing function. We then presented a case example demonstrating preservation of swallowing performance with helmet NIV. Last, we offer provisional multidisciplinary guidance for clinical practice, and provide directions for future research.

Respiratory support effect on pharyngeal area in patients with amyotrophic lateral sclerosis: A fluoroscopic comparison of NIV, helmet/CPAP, and high-flow nasal cannula

The global use of noninvasive respiratory support provided by different supportive ventilation delivery methods (SVDMs) has increased, but the impact of these devices on the upper airway structures of patients with amyotrophic lateral sclerosis (ALS) is not known. We aimed to compare the pharyngeal cross-sectional area during spontaneous breathing with four different SVDMs: intranasal masks, oronasal masks, high-flow nasal cannula (HFNC), and helmet in patients with ALS. We compared measures of the pharyngeal area during spontaneous breathing and SVDM use. The greatest increase was observed with intranasal mask use, followed by HFNC, oronasal mask, and helmet respectively. In conclusion, upper airway opening in patients with ALS is enhanced by positive pressure with intranasal masks and HFNC, showing promise for increasing pharyngeal patency. Future studies should explore its applicability and effectiveness in maintaining long-term pharyngeal patency, especially in this population with bulbar weakness.

Assessment, Diagnosis, and Treatment of Dysphagia in Patients Infected With SARS-CoV-2: A Review of the Literature and International Guidelines

Purpose Speech-language pathologists are playing a crucial role in the assessment and management of patients infected with severe acute respiratory syndrome coronavirus 2. Our goal was to synthesize peer-reviewed literature and association guidelines from around the world regarding dysphagia assessment and management for this specific population. Method A review of publications available in the PubMed database and official guidelines of international groups was performed on May 23, 2020. The information was synthesized and categorized into three content areas for swallowing: clinical evaluation, instrumental assessment, and rehabilitation. Results Five publications were identified in the PubMed database. Following title, abstract, and full-text review, only three publications met inclusion criteria: two reviews and one narrative report. Additionally, 19 international guidelines were reviewed. To assess swallowing, a modified clinical evaluation was recommended and only following a risk assessment. Instrumental assessments were often considered aerosol generating, especially transnasal procedures such as endoscopy and manometry. For this reason, many associations recommended that these examinations be performed only when essential and with appropriate personal protective equipment. Guidelines recommended that intervention should focus on compensatory strategies, including bolus modification, maneuvers/postural changes, and therapeutic exercises that can be conducted with physical distancing. Respiratory training devices were not recommended during rehabilitation. Conclusions International associations have provided extensive guidance regarding the level of risk related to the management of dysphagia in this population. To date, there are no scientific papers offering disease and/or recovery profiling for patients with dysphagia and coronavirus disease 2019. As a result, research in this area is urgently needed.