Effect of viral upper respiratory tract infection on cough reflex sensitivity

Sobrerol in Managing Acute Respiratory Infections in Clinical Practice During the "Cold" Season: An Italian Primary Care Experience

Purpose

Acute upper respiratory infections (AURI) represent a daily challenge in primary care practice. Mucus production may impair during AURI. Sobrerol is a muco-active agent that improves rheological characteristics and exerts other ancillary activities. The aim of this retrospective case-series study was to compare the efficacy and safety of different uses of sobrerol (only oral, only nebulized, and combined or standard treatment for infections alone) in patients with AURIs.

Patients and Methods

The present clinical experience retrospectively collected clinical data of patients with AURIs visited by ten primary care doctors (pediatricians and general practitioners) over a long period. Patients could take standard therapy for infections, or as add-on: oral sobrerol, nebulized sobrerol, or combined oral and nebulized aerosol during the infection for 3 days.

Results

Patients treated with combined oral and nebulized sobrerol experienced less intense symptoms, mainly concerning cough (p < 0.001) and nasal complaints (p = 0.043). In addition, the patients taking the combined therapy reported a more rapid disappearance of cough and nasal symptoms at day 7 than patients treated with the other options (OR 4.47 and 3.16, respectively).

Conclusion

The current retrospective and observational study showed that a three-day combined (oral and nebulized) sobrerol course may represent a valuable add-on option in patients with AURIs.

Brainstem opioid peptidergic neurons regulate cough reflexes in mice

Cough is a vital defensive reflex for expelling harmful substances from the airway. The sensory afferents for the cough reflex have been intensively studied. However, the brain mechanisms underlying the cough reflex remain poorly understood. Here, we developed a paradigm to quantitatively measure cough-like reflexes in mice. Using this paradigm, we found that prodynorphin-expressing (Pdyn+) neurons in the nucleus of the solitary tract (NTS) are critical for capsaicin-induced cough-like reflexes. These neurons receive cough-related neural signals from Trpv1+ vagal sensory neurons. The activation of Pdyn+ NTS neurons triggered respiratory responses resembling cough-like reflexes. Among the divergent projections of Pdyn+ NTS neurons, a glutamatergic pathway projecting to the caudal ventral respiratory group (cVRG), the canonical cough center, was necessary and sufficient for capsaicin-induced cough-like reflexes. These results reveal that Pdyn+ NTS neurons, as a key neuronal population at the entry point of the vagus nerve to the brainstem, initiate cough-like reflexes in mice.

The role of neutrophils in chronic cough

Chronic cough is a common disorder lasting more than 8 weeks and affecting all age groups. The evidence supporting the role of neutrophils in chronic cough pathology is based on many patients with chronic cough developing airway neutrophilia. How neutrophils influence the development of chronic cough is unknown. However, they are likely involved in multiple aspects of cough etiology, including promoting airway inflammation, airway remodeling, hyper-responsiveness, local neurogenic inflammation, and other possible mechanisms. Neutrophilic airway inflammation is also associated with refractory cough, poor control of underlying diseases (e.g., asthma), and insensitivity to cough suppressant therapy. The potential for targeting neutrophils in chronic cough needs exploration, including developing new drugs targeting one or more neutrophil-mediated pathways or altering the neutrophil phenotype to alleviate chronic cough. How the airway microbiome differs, plays a role, and interacts with neutrophils in different cough etiologies is poorly understood. Future studies should focus on understanding the relationship between the airway microbiome and neutrophils.

Risk factors for pharyngalgia and xerostomia undergoing supraglottic jet oxygenation and ventilation in gastrointestinal endoscopy: a retrospective study

Supraglottic jet oxygenation/ventilation (SJOV) can reduce hypoxemia in sedated endoscopy but may increase minor side effects like pharyngalgia and xerostomia. This study aimed to identify risk factors for pharyngalgia/xerostomia with SJOV during gastrointestinal endoscopy. From January 1 to December 31, 2021, 5313 patients with propofol sedation and SJOV underwent gastrointestinal endoscopy or removal of gastrointestinal polyps was analyzed retrospectively. Data included patient characteristics, operation details, postoperative adverse events, and potential risk factors for postoperative adverse events. Parameters considered as potential risk factors were identified based on study results published previously and based on the researcher's idea and clinical experience. The patient factors and the incidence of pharyngalgia/xerostomia at 30 min post-procedure were assessed. Descriptive statistics were calculated using SPSS software. Evaluation potential risk factors using univariate and multivariate logistic regression. Pharyngalgia/xerostomia occurred in 18.7% of patients at 30 min after procedure. A multivariable analysis showed that procedure time and pharyngalgia/xerostomia within 2 weeks were independent risk factors. Procedure time had the strongest association with postoperative pharyngalgia/xerostomia (OR, 8.09 [95% CI, 4.197-6.312]). No factors were significantly associated with hypoxemia risk (1.7% incidence). There were no barotrauma or other serious morbidity or mortality. Procedure duration and recent pharyngalgia/xerostomia increased risk of pharyngalgia/xerostomia with SJOV during endoscopy. Limiting SJOV duration may reduce side effects in susceptible patients. No predictors of hypoxemia were identified.

Otolaryngologic Symptom Severity Post SARS-CoV-2 Infection

Objective(s)

To assess laryngologic symptomatology following SARS-CoV-2 infection and determine whether symptom severity correlates with disease severity.

Methods

Single-institution survey study in participants with documented SARS-CoV-2 infection between March 2020 and February 2021. Data acquired included demographic, infection severity characteristics, comorbidities, and current upper aerodigestive symptoms via validated patient reported outcome measures.  Primary outcomes of interest were scores of symptom severity questionnaires. COVID-19 severity was defined by hospitalization status. Descriptive subgroup analyses were performed to investigate differences in demographics, comorbidities, and symptom severity in hospitalized participants stratified by ICU status. Multivariate logistical regression was used to evaluate significant differences in symptom severity scores by hospitalization status.

Results

Surveys were distributed to 5300 individuals with upper respiratory infections. Ultimately, 470 participants with COVID-19 were included where 352 were hospitalized and 118 were not hospitalized. Those not hospitalized were younger (45.87 vs. 56.28 years), more likely female (74.17 vs. 58.92%), and less likely white (44.17 vs. 52.41%). Severity of dysphonia, dyspnea, cough, and dysphagia was significantly worse in hospitalized patients overall and remained worse at all time points. Cough severity paradoxically worsened in hospitalized respondents over time. Dyspnea scores remained abnormally elevated in respondents even 12 months after resolution of infection.

Conclusion

Results indicate that laryngologic symptoms are expected to be worse in patients hospitalized with COVID-19. Dyspnea and cough symptoms can be expected to persist or even worsen by one-year post infection in those who were hospitalized. Dysphagia and dysphonia symptoms were mild. Non-hospitalized participants tended to have minimal residual symptoms by one year after infection.

Risk factors contributing to impaired cough-specific quality of life at the time of admission for coronavirus disease 2019 treatment

Background

Cough is the most common symptom of coronavirus disease 2019 (COVID-19). However, the factors contributing to impaired cough-specific quality of life (QoL) during the acute phase of COVID-19 infection remain unknown. We sought to identify such factors using the Japanese version of acute cough with the Leicester Cough Questionnaire (LCQ-acute).

Methods

Three hundred and two patients with COVID-19 admitted to Aichi Hospital between October 2020 and October 2021 completed the LCQ-acute at the time of admission. Clinical indices at the time of admission, such as presenting symptoms including cough, patient characteristics, disease severity, and biomarkers, were reviewed from the medical records. The impact of cough-specific QoL on clinical indices was assessed using two- or three-group comparisons and Pearson's correlation coefficient. Multivariate analysis was performed to determine the factors contributing to impaired cough-specific QoL at the time of admission for COVID-19 treatment.

Results

Two hundred and nine patients (69.2%) were coughing at the time of admission. Cough prevalence was highest, but cough-specific QoL was lowest at 8-11 days after onset. Multivariate analysis revealed that female sex, young age, gastrointestinal (GI) symptoms, and dysgeusia and/or dysosmia contributed to impaired cough-specific QoL at the time of admission for COVID-19 treatment, along with systemic and respiratory symptoms such as fever, higher C-reactive protein (CRP) levels, sputum, and dyspnea.

Conclusions

Female sex, young age, asthma, GI symptoms, dysgeusia, and/or dysosmia, along with systemic and respiratory symptoms, indicated impaired cough-specific QoL at the time of admission for COVID-19 treatment.

Treatment with the P2X3-Receptor Antagonist Gefapixant for Acute Cough in Induced Viral Upper Respiratory Tract Infection: A Phase 2a, Randomized, Placebo-Controlled Trial

INTRODUCTION

Available therapies for acute cough, a condition frequently caused by a viral upper respiratory tract infection (URTI), have shown limited evidence of efficacy. Gefapixant, a P2X3-receptor antagonist, has demonstrated efficacy and safety in studies of the treatment of refractory or unexplained chronic cough, but its efficacy for treating acute cough has not been previously studied.

METHODS

This was a phase 2a, randomized, double-blind, placebo-controlled, parallel-group, pilot study. Healthy volunteers were randomized 1:1 to receive twice-daily gefapixant 45 mg or placebo and inoculated with human rhinovirus 16 to induce URTI and cough. Participants were observed while quarantined for 7 days after the start of treatment. The primary endpoint was awake cough frequency on day 3, which was objectively measured with a cough-recording device. Secondary endpoints included change from baseline to day 3 in subjective cough severity measures (cough severity visual analog scale, Cough Severity Diary) and cough-specific quality of life (Leicester Cough Questionnaire-acute).

RESULTS

Of the 46 participants who met inclusion criteria [mean (standard deviation, SD) age, 24.6 (6.5) years; females, n = 8], 40 completed the study (gefapixant, n = 21; placebo, n = 19). There was no significant difference in awake cough frequency on day 3 between the gefapixant and placebo groups [least squares means, 2.4 versus 2.7 coughs per hour, respectively; mean difference (95% confidence interval, CI), -0.3 (-2.3, 1.7); P = 0.75]. There were no significant between-group differences for any of the secondary endpoints. Peak cough frequency was low and occurred later in the study than expected (days 4-5). The safety profile was consistent with that of previous studies of gefapixant.

CONCLUSION

Compared with placebo, gefapixant did not reduce the frequency or severity of acute cough secondary to induced URTI. Induced viral URTI produced mild symptoms, including lower cough frequency than observed in previous studies of patients selected for acute cough associated with naturally occurring URTI.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03569033; EudraCT, 2017-000472-28; protocol number, MK-7264-013.

Risk Factors for Perioperative Respiratory Adverse Events in Children with Recent Upper Respiratory Tract Infection: A Single-Center-Based Retrospective Study

Purpose

In pediatric patients, the most common reason for delaying surgical intervention is an upper respiratory tract infection (URI). To date, there has been no consensus regarding the optimal timeframe for deferring surgery in children with URI. We conducted this study to evaluate whether a URI symptom-free period and other risk factors affect the incidence of perioperative respiratory adverse events (RAEs).

Patients and Methods

The study population included 267 pediatric patients (aged 0 to 13 years) with a recent URI episode who underwent surgery under general anesthesia. Following a retrospective review of medical records, several risk factors including a URI symptom-free period for intra- and postoperative RAEs were analyzed using univariate and multivariate logistic regression analyses.

Results

RAEs occurred in 23 of 267 patients (8.6%). Univariate analysis revealed that abnormal preoperative chest images (odds ratio [OR], 7.48; 95% confidence interval [CI], 2.46–22.68, p < 0.001) and emergency operations (OR, 2.84; 95% CI, 1.03–7.81, p = 0.04) were associated with RAEs. Four variables (abnormal preoperative chest images, emergency operations, age under 1 year and symptom-free period of 7–13 days) with a significance of <0.20 in the univariate logistic regression analysis were selected as candidate risk factors for the multivariate model. Among the four variables, abnormalities in preoperative chest images (OR, 7.60; 95% CI, 2.28–25.3, p = 0.001) and a symptom-free period of 7–13 days (OR, 0.13; 95% CI, 0.02–0.88, p = 0.04) were independently associated with RAEs in multivariate logistic regression analysis.

Conclusion

For pediatric patients who require surgery and have a recent history of URI, procedures should be performed after a URI symptom-free period of at least 1–2 weeks. Confirming the absence of abnormalities in preoperative chest images can reduce the incidence of perioperative RAEs.

Effects of Oral Procaterol for Postinfectious Cough in Adults: Single-Centre, Randomized Double-Blind, Placebo-Controlled Trial

Background

Persistent cough following an upper respiratory tract infection (URTI) is common in clinical practice. We investigated the effects of procaterol on cough-specific quality of life (QoL) and peripheral-airway function among adults suffering from postinfectious cough (PIC).

Methods

This was a prospective, randomized, double-blinded placebo-controlled trial (NCT 02349919) conducted at a university hospital. Seventy-four non-asthmatic adults who had persistent post-URTI cough for ≥3 weeks were assessed by a physical examination, chest/paranasal sinus radiographs, spirometry, and impulse oscillometry (IOS) and were allocated to receive procaterol or placebo for 4 weeks. The Thai version of the Leicester Cough Questionnaire (LCQ-T), spirometry and IOS were assessed at baseline, 2 weeks, and 4 weeks.

Results

Mean LCQ-T total scores for the procaterol group (10.8) and placebo group (10.9) at baseline were not significantly different (P=0.821). After adjustment for baseline Borg Cough Scale score and post-nasal drip, the mean between-group difference was not significant for LCQ-T total score (-1.26; 95% confidence interval [CI], -2.69 to 0.17), physical domain score (-0.35; 95% CI, -0.76 to 0.06), psychological domain score (-0.53; 95% CI, -1.06 to 0.01), or social domain score (-0.38; 95% CI, -0.92 to 0.16). Large improvements in LCQ-T total score were reported in both groups after 2 weeks (procaterol, 4.21±2.73; placebo, 5.34±3.2), and 4 weeks (procaterol, 5.94±3.68; placebo, 7.07±3.44). No differences between groups were found in the mean changes of spirometry or IOS parameters after 4 weeks.

Conclusion

Our study shows that procaterol is not effective in the treatment of PIC, in terms of improvement of cough-specific QoL or peripheral-airway function.

Mycobacterium tuberculosis Sulfolipid-1 Activates Nociceptive Neurons and Induces Cough

Pulmonary tuberculosis, a disease caused by Mycobacterium tuberculosis (Mtb), manifests with a persistent cough as both a primary symptom and mechanism of transmission. The cough reflex can be triggered by nociceptive neurons innervating the lungs, and some bacteria produce neuron-targeting molecules. However, how pulmonary Mtb infection causes cough remains undefined, and whether Mtb produces a neuron-activating, cough-inducing molecule is unknown. Here, we show that an Mtb organic extract activates nociceptive neurons in vitro and identify the Mtb glycolipid sulfolipid-1 (SL-1) as the nociceptive molecule. Mtb organic extracts from mutants lacking SL-1 synthesis cannot activate neurons in vitro or induce cough in a guinea pig model. Finally, Mtb-infected guinea pigs cough in a manner dependent on SL-1 synthesis. Thus, we demonstrate a heretofore unknown molecular mechanism for cough induction by a virulent human pathogen via its production of a complex lipid.

Upper Respiratory Tract Infection-Associated Acute Cough and the Urge to Cough: New Insights for Clinical Practice

Upper respiratory tract infection (URTI)-associated acute cough is the most common symptom both in children and adults worldwide and causes economic and social problems with significant implications for the patient, the patient's family, and the health care system. New pathogenic mechanisms in acute cough, including the urge to cough (UTC) mechanisms, have been recently identified. The brainstem neural network, pharyngeal sensory innervation, airway mechanical stimulation, inflammatory mediators, and postnasal drip actively participate in the onset and maintenance of acute cough and the urge to cough phenomenon. However, there is still no effective pharmacological treatment capable of interfering with the pathophysiologic mechanisms involved in URTI-associated acute cough. Moreover, severe adverse events frequently occur in administering such cough medications, mainly in children. New evidence has been provided concerning polysaccharides, resins, and honey as potential cough relievers with high antitussive efficiency, effect on the UTC, and minimal side effects.

A Cross-sectional Survey of the Clinical Manifestations and Underlying Illness of Cough

AIM

The aim of this study was to identify factors affecting the final diagnosis of cough.

MATERIALS AND METHODS

This study recruited 463 consecutive patients who visited five Japanese general hospitals due to cough from October 2006 to September 2007. Of these, 418 patients (90%) who completed a questionnaire designed to acquire data regarding clinical manifestations of cough were included.

RESULTS

Most patients with bronchial asthma had cough with seasonal variation and wheezing. Patients with gastro esophageal reflux disease suffered from heartburn and cough without daily or seasonal variation. Cough associated with sinobronchial syndrome was only observed in females and was linked to increased sputum. Patients with whooping cough were bothered by cough interrupting sleep and talking. Patients with cardiogenic cough had exertional dyspnea.

CONCLUSION

The specific items on our questionnaire relating to patient characteristics, complications, and triggers of cough, represent useful tools for diagnosing the primary disease producing cough.

Use of honey associated with Ananas comosus (Bromelin) in the treatment of acute irritative cough

OBJECTIVE

To evaluate the immediate improvement rate of irritative cough in patients treated with the combination of Ananas comosus extract and honey (Bromelin®) compared with the use of honey alone (placebo group).

METHODS

Pragmatic, double-blind, randomized, parallel-group study with children aged between 2 and 15 years, with irritative cough for at least 24hours. The double-blind assessment of cough was through the number of observed coughing episodes and intensity score for a period of 10minutes of observation. The decrease of one point in the mean total score was considered as a therapeutic effect.

RESULTS

There was a reduction in coughing episodes in both groups, as well as in the cough score after 30minutes of drug or honey administration. The change in clinical score above two points, which could indicate marked improvement, occurred in five patients in the bromelin group and only in one in the placebo group, but without significant difference. There were no adverse events.

CONCLUSIONS

The immediate improvement rate of irritative cough was similar in patients treated with combination of Ananas comosus extract and honey (Bromelin®) compared with the use of honey alone (placebo group). It is possible that honey has a therapeutic effect on mucus and cough characteristics (Clinical Trials: NCT01356693).