The Influence of Airflow Via High-Flow Nasal Cannula on Duration of Laryngeal Vestibule Closure

The effects of noninvasive respiratory support on swallowing physiology, airway protection, and respiratory-swallow pattern in adults: A systematic review

PURPOSE

The use of noninvasive respiratory support- namely high flow of oxygen delivered via nasal cannula (HFNC), continuous positive airway pressure (CPAP), and noninvasive ventilation (NIV) - has been expanding in recent years. The physiologic mechanisms underlying each of these forms of support are generally well understood. In contrast, the effects on the sensorimotor mechanisms of swallowing movements, and of breathing and swallowing coordination ─ critical elements of airway protection and bolus clearance ─ remain unclear. The purpose of this systematic review is to assess the existing evidence about the impact of noninvasive respiratory support on swallowing mechanics, airway protection, and respiratory-swallowing patterns in adults.

METHODS

Six databases (PubMed, EMBASE, Web of Science, Scopus, CINAHL and ProQuest Dissertations & Theses) were searched using predetermined terms. Inclusion criteria were: 1) adult humans 2) use of noninvasive respiratory support, and 3) assessment of swallowing.

RESULTS

We identified 8727 articles for screening; 15 met the inclusion criteria. Six studies assessed noninvasive respiratory support in healthy adults, and 9 assessed participants with heterogenous respiratory diagnoses including chronic obstructive pulmonary disease (COPD), obstructive sleep apnea (OSA), acute respiratory failure, and chronic respiratory failure due to neuromuscular disease. Risk of bias was assessed using a modified NIH Quality Assessment Tool. In healthy adults, results demonstrated mixed effects of HFNC and CPAP on measures of swallowing function, airway protection, and respiratory swallowing patterns. Negative effects on respiratory-swallowing patterns were reported with NIV. In adults with heterogeneous respiratory diagnoses, six studies reported that HFNC, CPAP, or nasal NIV improved measures of swallowing and respiratory-swallowing patterns. HFNC has mixed effects on swallowing measures in ICU patients. NIV increased atypical respiratory-swallowing patterns in patients with stable COPD.

CONCLUSIONS

Due to small sample sizes and the wide variation in study designs, the impact of noninvasive respiratory support on swallowing, airway protection, and respiratory-swallowing patterns cannot be confidently assessed based on the current evidence. Future studies using standardized, validated, and reproducible methods to assess the impact of noninvasive respiratory support on swallowing physiology and airway protection are warranted.

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.

Nutrition during noninvasive respiratory support

PURPOSE OF REVIEW

The use of noninvasive techniques [noninvasive ventilation (NIV) or high flow nasal cannula (HFNC) oxygen therapy] to support oxygenation and/or ventilation in patients with respiratory failure has become widespread, even more so since the coronavirus disease 2019 pandemic. The use of these modalities may impair the patient's ability to eat. "To breath or to eat" may become a dilemma. In this review, we identify the patients at risk of malnutrition that require medical nutritional therapy and understand the mechanisms of function of the devices to better give adapted nutritional indications for noninvasive ventilation or high flow nasal cannula.

RECENT FINDINGS

The Global Leadership Initiative for Malnutrition has been validated in the Intensive Care setting and can be used in patients requiring NIV. Many patients are underfed when receiving noninvasive ventilation therapies. HFNC may impair the swallowing ability and increase dysphagia while NIV may improve the swallowing reflexes. New technology preventing reflux and ensuring enteral feeding efficacy may increase the medical nutrition therapy safety and provide near-target energy and protein provision.

SUMMARY

The patient requiring noninvasive ventilation presents one of the most challenging nutritional challenges. The main steps to improve nutrition administration are to assess nutritional status, evaluate the presence of dysphagia, choose the most adequate tool of respiratory support, and adapt nutritional therapy (oral, enteral, or parenteral) accordingly.

Effects of high-flow nasal therapy on swallowing function: a scoping review

Background

High-flow nasal therapy is widely used in patients with respiratory failure in different clinical settings, but the effect of high-flow nasal therapy on respiratory-swallow coordination is unknown. Understanding this relationship is crucial, considering the necessity for patients to maintain adequate nutrition during daytime high-flow nasal therapy. This scoping review aims to synthesise available data on the effects of high-flow nasal therapy flow rates on swallowing function and the possible risk of aspiration during treatment, focusing on knowledge and evidence gaps.

Methods

PubMed, Scopus, Web of Science and Google Scholar databases were searched from inception to 30 May 2023 for studies reporting data on swallowing assessment in healthy adults or patients with acute or chronic respiratory failure receiving high-flow nasal therapy. Data on study design, patients' characteristics and quality outcomes were extracted.

Results

Eight studies were included, four including cohorts of healthy volunteers (n=148) and four including patients with acute or chronic respiratory failure (n=151). Study designs, patient populations and quality outcome measures were heterogeneous. Two studies indicated improvement while four articles showed impairment in swallowing function during high-flow nasal therapy; two studies showed that patients' overall clinical picture and underlying medical conditions influenced swallowing-breathing coordination rather than high-flow nasal therapy per se.

Conclusion

This scoping review found limited and controversial evidence on the impact of high-flow nasal therapy on swallowing function. Remarkably, methods for swallowing function assessment were quite heterogeneous. Additional research is required to test the effect of high-flow nasal therapy on respiratory-swallowing coordination.

Assessment of Swallowing Function in Healthy Adults While Using High-Flow Nasal Cannula

OBJECTIVE

Despite widespread use of high flow nasal cannula (HFNC) for respiratory support, the effect of HFNC on swallowing physiology is poorly understood. Flow rates that permit safe swallowing have not been established. We aim to assess if healthy individuals have diminished swallowing function and safety at high flow rates.

STUDY DESIGN

Repeated measures with planned data collection.

SETTING

Outpatient dysphagia clinic.

METHODS

Swallowing function in a cohort of healthy individuals was assessed using Flexible Endoscopic Evaluation of Swallowing (FEES). Participants' safety of swallowing was assessed with different textures under randomized rates of HFNC (0, 30, 40, 50, and 60 LPM). Swallowing trials included quantities of thin liquids, mildly-thick liquids, and purees. Trials were scored using the Penetration-Aspiration Scale (PAS). Pearson chi-square tests were used to test for correlation between PAS result, flow rate, and consistency across each quantity of material.

RESULTS

Twenty-seven subjects were enrolled. Forty-one percent were male with mean age of 34 years (11 standard deviation). Ninety-nine percent (267/270), 97% (n = 263/270), and 99% (399/405) of 1 sip swallows, 3 sip swallows, and 5 mL swallows, respectively, were safe. There was no significant correlation between swallow safety and flow rate using Pearson Chi-Square test across all consistencies and across all quantities of materials (P > 0.05). Of note, out of all subtrials, the thin liquid, 3 sips trial at 60 LPM, had the largest percent of unsafe swallows (14%).

CONCLUSION

Our results suggest rate of aspiration is not significantly affected by high flow nasal cannula in healthy individuals.

Positive relief of stroke patients with dysphagia under cluster nursing strategy

For exploring the positive relief effect and application value of cluster nursing strategies on stroke patients with dysphagia in rehabilitation medicine. A retrospective analysis was conducted on 70 patients with stroke dysphagia admitted to the Rehabilitation Medicine Department of our hospital from June 2021 to November 2022; by comparison, patients were separated into intervention group (IG) and control group (CG) according to different degrees of swallowing difficulty, and nutritional nursing interventions were conducted on the selected research subjects. It was given routine care in the CG and a cluster nursing strategy in the IG, with a total intervention time of 5 months. Before intervention, general information of all patients was compared. Before and after intervention, the incidence of aspiration, nutritional biochemical indicators (hemoglobin, total serum protein, albumin, prealbumin, total cholesterol), grip strength, Swallowing Quality of Life score, etc were collected from the 2 groups of patients. Finally, the specific benefits were analyzed through statistical results to evaluate the intervention effect. After intervention, the explicit aspiration rate of the participants in this experiment significantly decreased, and the difference among the participants in this experiment was statistically significant (P < .05); the implicit aspiration rate was not statistically significant (P > .05). In the comparison of nursing expenses, the CG spent 5403.57 ± 815.51 yuan, while the IG spent 5237.10 ± 758.35 yuan. There was a statistically marked disparity among the participants in this experiment (t = 52.41, P < .001). In the comparison of hospitalization expenses, the cost of the CG was 9236.05 ± 3236.08 yuan; The cost of the IG was 9538.59 ± 4985.21 yuan, and there was a marked disparity among the participants in this experiment (P < .001). The significant statistical significance exists (P < .05) in the 5 indicators of hemoglobin, total protein, prealbumin, albumin, and total cholesterol, quality of life scores, and patient physical efficacy in both groups. The intervention study of cluster nursing strategy for stroke patients with dysphagia in rehabilitation medicine can effectively reduce the incidence of overt aspiration and ultimately improve their quality of life. It has high clinical application value.

A Survey of Feeding Practices During High-Flow Nasal Cannula Oxygen Therapy

BACKGROUND

High-flow nasal cannula (HFNC) oxygen therapy is used to deliver warm and humidified gases to patients in respiratory failure. A purported advantage of HFNC oxygen therapy is that it can allow for oral feeding while on the device, although few data support this practice. The purpose of this study was to identify practices and opinions with regard to feeding practices during HFNC oxygen therapy.

METHODS

A survey related to the practice and opinions of feeding practices during HFNC oxygen therapy was developed and sent to respiratory therapists, speech-language pathologists, physicians, advanced practice providers, and registered dietitians.

RESULTS

Respondents included 307 professionals from 14 different countries. Most respondents worked in an academic/teaching hospital (n = 174 [56.7%]) with patients ages ≥ 18 years (n = 282 [91.9%]). Most respondents stated that their institution did not have a specific feeding protocol for HFNC oxygen therapy (n = 246 [80.4%]) and felt that patients could have an oral diet during HFNC oxygen therapy if not in imminent danger of being intubated (n = 264 [86.3%]). Fewer than half of the respondents felt that patients should have a bedside/clinical swallow examination before eating and/or drinking during HFNC oxygen therapy (n = 143 [46.7%]). By profession, most physicians/advanced practice providers (n = 67 [59.3%]), respiratory therapists (n = 37 [62.7%]) and half of the registered dietitians (n = 16 [50%]) felt that bedside/clinical swallow examinations were unnecessary before eating and/or drinking with HFNC, but speech-language pathologists were in favor (n = 77 [75.5%]).

CONCLUSIONS

Most facilities did not have a protocol to guide feeding practices when HFNC oxygen therapy is used. Most clinicians felt that an oral diet is safe for stable patients not in danger of being intubated. In general, speech-language pathologists felt that patients on HFNC oxygen therapy should undergo a bedside/clinical swallow examination before eating and/or drinking.

The upper airway parameters: the potential diagnostic clues for congenital intrathoracic lesions

BACKGROUND

The diagnosis of congenital intrathoracic lesions still has limitations. The airway development was influenced by intrathoracic factors. Whether the diagnostic value of the upper airway parameters in congenital intrathoracic lesions has not been confirmed.

OBJECTIVES

We aimed to compare fetal upper airway parameters between normal fetuses and fetuses with intrathoracic lesions, and we tried to verify its diagnostic value in intrathoracic lesions.

METHODS

This was an observational case-control study. In the control group, 77 women were screened at 20-24 weeks' gestational age, 23 were screened at 24-28 weeks' gestational age, and 27 were screened at 28-34 weeks' gestational age. In the case group, 41 cases were enrolled (6 cases of intrathoracic bronchopulmonary sequestration, 22 of congenital pulmonary airway malformations, and 13 of congenital diaphragmatic hernia). Fetal upper airway parameters (tracheal width, the narrowest lumen width, and width of the subglottic cavity and laryngeal vestibule) were measured using ultrasound equipment. The correlations between fetal upper airway parameters and gestational age, and the differences in fetal upper airway parameters between cases and controls, were analyzed. The standardized airway paraments were acquired, and their potential diagnostic value for congenital intrathoracic lesions were analyzed.

RESULTS

The fetal upper airway parameters of both groups were positively correlated with the gestational age: The control group, tracheal width (R² = 0.569, p < 0.001), narrowest lumen width (R² = 0.429, p < 0.001), subglottic cavity width (R² = 0.551, p < 0.001), laryngeal vestibule width (R² = 0.349, p < 0.001). The case group (tracheal width R² = 0.474, p < 0.001) narrowest lumen width (R² = 0.425, p < 0.001), subglottic cavity width (R² = 0.623, p < 0.001), laryngeal vestibule width (R² = 0.347, p < 0.001). Fetal upper airway parameters of the cases group were smaller than those of the controls group. The tracheal width in fetuses with congenital diaphragmatic hernia was the smallest among the other case groups studied. The standardized tracheal width has the best diagnostic value for congenital intrathoracic lesions in the standardized airway paraments (the area under the ROC curve was 0.894), and has a high diagnostic value for congenital pulmonary airway malformations and congenital diaphragmatic hernia (the area under the ROC curve was 0.911 and 0.992, respectively).

CONCLUSION

Fetal upper airway parameters differ between normal fetuses and fetuses with intrathoracic lesions, and might offer potential diagnostic clues for congenital intrathoracic lesions.

The effects of flow settings during high-flow nasal cannula support for adult subjects: a systematic review

BACKGROUND

During high-flow nasal cannula (HFNC) therapy, flow plays a crucial role in the physiological effects. However, there is no consensus on the initial flow settings and subsequent titration. Thus, we aimed to systematically synthesize the effects of flows during HFNC treatment.

METHODS

In this systematic review, two investigators independently searched PubMed, Embase, Web of Science, Scopus, and Cochrane for in vitro and in vivo studies investigating the effects of flows in HFNC treatment published in English before July 10, 2022. We excluded studies that investigated the pediatric population (< 18 years) or used only one flow. Two investigators independently extracted the data and assessed the risk of bias. The study protocol was prospectively registered with PROSPERO, CRD42022345419.

RESULTS

In total, 32,543 studies were identified, and 44 were included. In vitro studies evaluated the effects of flow settings on the fraction of inspired oxygen (F_IO₂), positive end-expiratory pressure, and carbon dioxide (CO₂) washout. These effects are flow-dependent and are maximized when the flow exceeds the patient peak inspiratory flow, which varies between patients and disease conditions. In vivo studies report that higher flows result in improved oxygenation and dead space washout and can reduce work of breathing. Higher flows also lead to alveolar overdistention in non-dependent lung regions and patient discomfort. The impact of flows on different patients is largely heterogeneous.

INTERPRETATION

Individualizing flow settings during HFNC treatment is necessary, and titrating flow based on clinical findings like oxygenation, respiratory rates, ROX index, and patient comfort is a pragmatic way forward.

Treatment of Pediatric Patients With High-Flow Nasal Cannula and Considerations for Oral Feeding: A Review of the Literature

PURPOSE

High-Flow Nasal Cannula (HFNC) has become an increasingly common means of noninvasive respiratory support in pediatrics and is being used in infants and children with respiratory distress both inside and outside of the intensive care units. Despite the widespread use of HFNC, there remains a paucity of data on optimal flow rates and its impact on morbidity, mortality, and desired outcomes. Given the scarcity of information in these critical areas, it is not surprising that guidelines for initiation of oral feeding do not exist. This review article will review HFNC mechanisms of action, its use in specific populations and settings, and finally what is known about initiation of feeding during this therapy.

CONCLUSIONS

The practice of withholding oral feeding solely, because of HFNC, is not supported in the literature at the time of this writing, but in the absence of safety data from clinical trials, clinicians should proceed with caution and consider patient-specific factors while making decisions about oral feeding. Well-controlled prospective clinical trials are needed for development of best practice clinical guidelines and attainment of optimal outcomes.

Nutrition Therapy in Non-intubated Patients with Acute Respiratory Failure

PURPOSE OF REVIEW

A challenging aspect of the care for patients with acute respiratory failure is their nutrition management. This manuscript consists of a literature review on nutrition therapy in non-intubated patients with acute respiratory failure receiving high-flow nasal cannula oxygenation or non-invasive positive pressure ventilation.

RECENT FINDINGS

Studies show that non-intubated patients with acute respiratory failure either on non-invasive ventilation or high-flow nasal cannula are largely underfed in the initial phase of their hospitalization. Although data is limited, the available evidence suggests the feasibility of initiating oral diet in the majority of these patients in the early phase. Initial evaluation includes mental status evaluation, the Yale swallowing screening protocol, and an assessment of severity of illness. The goal should be to initiate oral diet within 24 h. If patient cannot initiate oral diet, the reason for not initiating oral diet should dictate the next step. For instance, if the reason is failure of the swallow screening, further evaluation with fiberoptic endoscopy is warranted. The inability to provide oral diet for a patient in respiratory distress may a harbinger of failure of non-invasive oxygen therapy and should prompt consideration for endotracheal intubation. We suggest placement of a small-bore feeding tube for enteral nutrition if patient is unable receive oral diet after 48 h.

CONCLUSIONS

The nutrition management of these patients is better provided by a multidisciplinary team in a protocolized manner.