Non-invasive Respiratory Support in COVID-19: A Narrative Review

Acute respiratory failure secondary to COVID-19 pneumonia may require a variety of non-pharmacological strategies in addition to oxygen therapy to avoid endotracheal intubation. The response to all these strategies, which include high nasal flow, continuous positive pressure, non-invasive ventilation, or even prone positioning in awake patients, can be highly variable depending on the predominant phenotypic involvement. Deciding when to replace conventional oxygen therapy with non-invasive respiratory support, which to choose, the role of combined methods, definitions, and attitudes toward treatment failure, and improved case improvement procedures are directly relevant clinical questions for the daily care of critically ill COVID-19 patients. The experience accumulated after more than a year of the pandemic should lead to developing recommendations that give answers to all these questions.

Salivary Ferritin Changes in Patients with COVID-19

High ferritin serum levels can be found in patients with macrophage activation syndrome, and increased serum ferritin due to cytokine storm have been reported in severe COVID-19 patients. Saliva is being increasingly used in COVID-19 tests as a diagnostic sample for virus detection and quantification. This study aimed to evaluate the possible changes in ferritin in saliva in COVID-19 patients. In addition, the effects of different inactivation SARS-CoV-2 treatments in ferritin measurements in saliva, the correlation between ferritin in saliva and serum, and the possible effects of correction of ferritin values by total protein were assessed. Ferritin was measured in saliva from healthy (n = 30) and COVID-19 (n = 65) patients with severe, (n = 18) or mild (n = 47) disease, depending on the need for nasal flow oxygen or assisted respiration. Ferritin was also measured in paired serum and saliva samples (n = 32) from healthy and COVID-19 patients. The evaluated inactivation protocols did not affect the assay’s results except the addition of 0.5% SDS. Significantly higher ferritin was found in the saliva of COVID-19 patients (median; 25–75th percentile) (27.75; 9.77–52.2 µg/L), compared with healthy controls (4.21; 2.6–8.08 µg/L). Individuals with severe COVID-19 showed higher ferritin values in saliva (48.7; 18.7–53.9) than mild ones (15.5; 5.28–41.3 µg/L). Significant correlation (r = 0.425; p < 0.001) was found between serum and saliva in ferritin. Ferritin levels were higher in COVID-19 patients in serum and saliva, and the highest values were found in those patients presenting severe symptomatology. In conclusion, ferritin in saliva has the potential to be a biomarker to evaluate severity in patients with COVID-19.

Noninvasive Measurement of Tongue Pressure and Its Correlation with Swallowing and Respiration

Tongue pressure plays a critical role in the oral and pharyngeal stages of swallowing, contributing considerably to bolus formation and manipulation as well as to safe transporting of food from the mouth to the stomach. Smooth swallowing relies not only on effective coordination of respiration and pharynx motions but also on sufficient tongue pressure. Conventional methods of measuring tongue pressure involve attaching a pressure sheet to the hard palate to monitor the force exerted by the tongue tip against the hard palate. In this study, an air bulb was inserted in the anterior oral cavity to monitor the pressure exerted by the extrinsic and intrinsic muscles of the tongue. The air bulb was integrated into a noninvasive, multisensor approach to evaluate the correlation of the tongue pressure with other swallowing responses, such as respiratory nasal flow, submental muscle movement, and thyroid cartilage excursion. An autodetection program was implemented for the automatic identification of swallowing patterns and parameters from each sensor. The experimental results indicated that the proposed method is sensitive in measuring the tongue pressure, and the tongue pressure was found to have a strong positive correlation with the submental muscle movement during swallowing.

Efficacy and Safety of Two Different Flow Rates of Nasal High-Flow Therapy in Preterm Neonates ≥28 Weeks of Gestation: A Randomized Controlled Trial

Objective The study aimed to compare the efficacy and safety of two different nasal high-flow rates for primary respiratory support in preterm neonates Study Design In this single-center, double-blinded randomized controlled trial, preterm neonates ≥28 weeks of gestation with respiratory distress from birth were randomized to treatment with either increased nasal flow therapy (8–10 L/min) or standard nasal flow therapy (5–7 L/min). The primary outcome of nasal high-flow therapy failure was a composite outcome defined as the need for higher respiratory support (continuous positive airway pressure [CPAP] or mechanical ventilation) or surfactant therapy. Results A total of 212 neonates were enrolled. Nasal high-flow failure rate in the increased flow group was similar to the standard flow group (22 vs. 29%, relative risk = 0.81 [95% confidence interval: 0.57–1.15]). However, nasal flow rate escalation was significantly more common in the standard flow group (64 vs. 43%, p = 0.004). None of the infants in the increased flow group developed air leak syndromes. Conclusion Higher nasal flow rate (8–10 L/min) when compared with lower nasal flow rate of 5 to 7 L/min did not reduce the need for higher respiratory support (CPAP/mechanical ventilation) or surfactant therapy in moderately and late preterm neonates. However, initial flow rates of 5 L/min were not optimal for most preterm infants receiving primary nasal flow therapy. Key Points

LINKING CHRONIC OTITIS MEDIA AND NASAL OBSTRUCTION: A CFD APPROACH

ABSTRACT OBJECTIVES: To investigate a possible relationship between altered nasal flow and chronic otitis media (COM) using computational fluid dynamics (CFD). DESIGN: Retrospective cohort sample of CT scans from patients with COM and controls without COM to compare the results of various nasal airflow parameters determined by CFD between a group of patients with COM (N=60) and a control group of subjects without any evidence of ear disease (N=81). MAIN OUTCOME MEASURES: The CT were subjected to various procedures to carry out CFD studies, determining the resistance to nasal flow, the proportion of flow through the right and left nasal cavity, and two nondimentional estimators. The results of CFD studies between patients with COM and controls were compared. RESULTS AND CONCLUSIONS: Whereas only 12.3% of the controls had CFD alteration (10 out of 81), 43.3% of the patients suffering COM displayed alterations of our nondimentional parameters (26 out of 60). According to our results, the incidence of alterations in nasal airflow by studying with CFD is significantly higher in patients with COM than in controls IMPLICATIONS: To our knowledge, this is the first paper linking nasal cavity and COM using a CFD approach. Our results support the hypothesis that nasal flow alterations could be implicated in the etiopathogenesis of the COM.

Can Sex Improve Nasal Function?—An Exploration of the Link Between Sex and Nasal Function

Objectives: This study was conducted to examine the impact of sexual activity on nasal breathing and compare such effect to that of a nasal decongestant. Methods: We evaluated nasal breathing at 5 different times: (1) before sexual activity (baseline), (2) immediately after sexual activity, (3) 30 minutes, (4) 1 hour (5), and 3 hours after sexual climax. Same measurements were taken on the second day following application of nasal decongestant spray. For evaluation of nasal breathing, we used a visual analogue scale (VAS). Additionally, we used a portable rhinometric device to measure resistance and nasal flow. Results: Nasal breathing improved significantly after sexual intercourse with climax to the same degree as after application of nasal decongestant for up to 60 minutes, as measured subjectively with the VAS (sex −3.6, P < .001; spray −3.2, P < .001). This was confirmed in the objective rhinometric data as mean nasal flow (mL/s) increased while resistance decreased immediately (flow sex +214, P < .001; flow spray +235, P < .001), 30 (flow sex +249, P < .001; flow spray +287, P < .001), and 60 minutes (flow sex +180, P < .001; flow spray +287, P < .001) post-intervention. Nasal breathing was back to the baseline level after 3 hours following sexual intercourse, while it continued to be improved for longer after application of nasal decongestant. Only participants having nasal obstruction (Nasal Obstruction Symptom Evaluation score >30) showed nasal function improvement after sex. Conclusions: Sexual intercourse with climax can improve nasal breathing to the same degree as application of nasal decongestant for up to 60 minutes in patients having nasal obstruction.

Articulatory Measures of Prosody

Prosodic research in speech production usually focuses on the way the prosodic structure influences the phonetic implementation of segmental and suprasegmental features. The realization of a tone, for instance, involves not only dynamic changes so as to regulate the vocal fold vibration to produce f0 contours, but also the movement of articulators to simultaneously produce consonants and vowels. Articulatory measuring techniques help us to directly observe how these two systems are coordinated in the spatio-temporal dimension. A number of such techniques are discussed, along with examples indicating how each technique may be or has been used to study various aspects of prosody. They include laryngoscopy and electroglottography to examine laryngeal events associated with vocal fold vibration; systems such as electromagnetic articulography, an optoelectronic device, electropalatography, and ultrasound systems to explore supralaryngeal articulatory events; and aerodynamic measurement systems to record oral/subglottal pressure and oral/nasal flow.

The benefits of a systematic assessment of respiratory health in illness susceptible athletes

Respiratory tract illness is a leading cause of training and in-competition time-loss in elite athletes. Asthma is known to be prevalent in athletes but the co-existence of other respiratory problems, in those deemed to be susceptible to respiratory tract illness, is unknown. The aim of this study was to apply a comprehensive prospective approach to identify respiratory problems and explore relationships in athletes with heightened respiratory illness susceptibility.UK World Class Performance Programme athletes prospectively completed a systematic review of respiratory health with validated questionnaires and respiratory-focussed investigations, including studies of nasal flow, exhaled nitric oxide, spirometry, bronchoprovocation testing and allergy testing.Systematic respiratory health assessment was completed by 122 athletes (55 females, age 24±4 year). At least one respiratory health issue, requiring intervention, was identified in 97 (80%) athletes and ≥2 abnormalities were found in 73 (60%). Sinonasal problems were the most commonly identified problem (49%) and 22% of athletes had a positive indirect bronchoprovocation test. Analysis revealed two respiratory health clusters; i) asthma, sinus problems and allergy and ii) laryngeal and breathing pattern dysfunction. Respiratory illness susceptible athletes had 3.6±2.5 episodes in the year prior to assessment and were more likely (as odds ratio [95% confidence intervals] to have allergy (2.6 [1.0–6.5]), sinonasal problems (2.6 [1.1–6.0]), and symptoms of laryngeal (5.4 [1.8–16.8] and breathing pattern dysfunction (3.9 [1.1–14.0] than non-susceptible athletes (all p<0.05).A systematic approach to respiratory assessment identifies a high prevalence and co-existence of multiple respiratory problems in illness-susceptible athletes.

Nasal airflow engages central olfactory processing and shapes olfactory percepts

Binding of airborne odour molecules to olfactory receptors at the top of the nasal cavity gives rise to our rich olfactory experience. Whether airflow plays a role in human olfactory perception beyond the transportation of odorants is scantly known. Combining psychophysical measures with strict controls of nasal flow parameters, we demonstrate in four experiments that the perceived intensity of a unilaterally presented odour decreases systematically with the amount of contralateral nasal airflow, in manners that are independent of odour flow rate, nasal pressure, perceived sniff vigour or attentional allocation. Moreover, the effect is due to the sensed rather than the factual amount of nasal flow, as applying a local anaesthetic to the contralateral nostril produces the same effect as physically blocking it. Our findings indicate that nasal flow spontaneously engages central olfactory processing and serves as an integral part of the olfactory percept in humans.