The vagus nerve (VN), the “great wondering protector” of the body, comprises an intricate neuro‐endocrine‐immune network that maintains homeostasis. With reciprocal neural connections to multiple brain regions, the VN serves as a control center that integrates interoceptive information and responds with appropriate adaptive modulatory feedbacks. While most VN fibers are unmyelinated C‐fibers from the visceral organs, myelinated A‐ and B‐fiber play an important role in somatic sensory, motor, and parasympathetic innervation. VN fibers are primarily cholinergic but other noncholinergic nonadrenergic neurotransmitters are also involved. VN has four vagal nuclei that provide critical controls to the cardiovascular, respiratory, and alimentary systems. Latest studies revealed that VN is also involved in inflammation, mood, and pain regulation, all of which can be potentially modulated by vagus nerve stimulation (VNS). With a broad vagal neural network, VNS may exert a neuromodulatory effect to activate certain innate “protective” pathways for restoring health.

Vagus Nerve and Vagus Nerve Stimulation, a Comprehensive Review: Part I: Headache

Clinical manifestations of COVID-19 are varied in the general population. This study aimed to systematize the literature regarding clinical manifestations of patients with confirmed COVID-19. A systematic review of the literature was conducted. A total of 8070 scientific productions were found in the databases. Among the studies, 184 met the initial inclusion criteria, with a total of 114,046 patients. After complete reading, 32 studies that did not report clinical manifestations were excluded. The 152 publications finally included a total of 41,409 individuals from at least 23 countries and 26 different clinical manifestations were reported. In percentage terms, 6 symptoms had a general prevalence greater than or equal to 25%, namely, fever (58.66%), cough (54.52%), dyspnea (30.82%), malaise (29.75%), fatigue (28.16%) and sputum/secretion (25.33%). Neurological symptoms (20.82%), dermatological manifestations (20.45%), anorexia (20.26%), myalgia (16.9%), sneezing (14.71%), sore throat (14.41%), rhinitis (14.29%), goosebumps (13.49%), headache (12.17%), chest pain (11.49%) and diarrhea (9.59%) were other common symptoms. Only one study reported dermatological manifestations. The least frequent sign/symptom was hemoptysis (1.65%). In studies with more than 100 patients, the 3 main symptoms were fever (57.93%), cough (54.21%), and dyspnea (30.64%). Dermatological manifestations do not appear among the main symptoms. The identification of all clinical manifestations of COVID-19 is essential for an early diagnosis and the adoption of preventive measures.

/pdf/clinical-manifestations-of-covid-19-in-the-general-2ncclenbln.pdf

Clinical manifestations of COVID-19 in the general population: systematic review.

The COVID-19 pandemic presents global challenges transcending boundaries of country, race, religion, and economy. The current gold standard method for COVID-19 detection is the reverse transcription polymerase chain reaction (RT-PCR) testing. However, this method is expensive, time-consuming, and violates social distancing. Also, as the pandemic is expected to stay for a while, there is a need for an alternate diagnosis tool which overcomes these limitations, and is deployable at a large scale. The prominent symptoms of COVID-19 include cough and breathing difficulties. We foresee that respiratory sounds, when analyzed using machine learning techniques, can provide useful insights, enabling the design of a diagnostic tool. Towards this, the paper presents an early effort in creating (and analyzing) a database, called Coswara, of respiratory sounds, namely, cough, breath, and voice. The sound samples are collected via worldwide crowdsourcing using a website application. The curated dataset is released as open access. As the pandemic is evolving, the data collection and analysis is a work in progress. We believe that insights from analysis of Coswara can be effective in enabling sound based technology solutions for point-of-care diagnosis of respiratory infection, and in the near future this can help to diagnose COVID-19. Â© 2020 ISCA

/pdf/coswara-a-database-of-breathing-cough-and-voice-sounds-for-1cmdqrpdc0.pdf

Coswara - A database of breathing, cough, and voice sounds for COVID-19 diagnosis

Many patients with idiopathic pulmonary fibrosis (IPF) complain of chronic refractory cough. Chronic cough is a distressing and disabling symptom with a major impact on quality of life. During recent years, progress has been made in gaining insight into the pathogenesis of cough in IPF, which is most probably “multifactorial” and influenced by mechanical, biochemical and neurosensory changes, with an important role for comorbidities as well. Clinical trials of cough treatment in IPF are emerging, and cough is increasingly included as a secondary end-point in trials assessing new compounds for IPF. It is important that such studies include adequate end-points to assess cough both objectively and subjectively. This article summarises the latest insights into chronic cough in IPF. It describes the different theories regarding the pathophysiology of cough, reviews the different methods to assess cough and deals with recent and future developments in the treatment of cough in IPF.

https://err.ersjournals.com/content/errev/25/141/278.full.pdf

Cough in idiopathic pulmonary fibrosis

SummaryBackground
Rate of perioperative respiratory complications between tracheal intubation (TI) and laryngeal mask airway remains unclear during pediatric anesthesia.

Objectives
The aim of the present meta-analysis was to compare the perioperative respiratory complications between laryngeal mask airway and TI.

Methods
A meta-analysis of available controlled studies comparing laryngeal mask airway to TI was conducted. Studies including patients with airway infection were excluded. Data from each trial were combined to calculate the pooled odds ratios (OR) or mean difference (MD) and 95% confidence intervals.

Results
The meta-analysis was performed on 19 studies. In 12 studies, patients were given muscle relaxation, and in 16 studies, ventilation was controlled. During recovery from anesthesia, the incidence of desaturation (OR = 0.34 [0.19–0.62]), laryngospasm (OR = 0.34 [0.2–0.6]), cough (OR = 0.18 [0.11–0.27]), and breath holding (0.19 [0.05–0.68]) was lower when laryngeal mask airway was used to secure the airway. Postoperative incidences of sore throat (OR = 0.87 [0.53–1.44]), bronchospasm (OR = 0.56 [0.25–1.25]), aspiration (1.33 [0.46–3.91]) and blood staining on the device (OR = 0.62 [0.21–1.82]) did not differ between laryngeal mask airway and TI. Results were homogenous across the studies, with the exceptions of blood staining on the device.

Conclusions
This meta-analysis found that the use of laryngeal mask airway in pediatric anesthesia results in a decrease in a number of common postanesthetic complications. It is therefore a valuable device for the management of the pediatric airway.

Supraglottic airway devices vs tracheal intubation in children: a quantitative meta-analysis of respiratory complications.

Coughing is an important defensive reflex that occurs through the stimulation of a complex reflex arc. It accounts for a significant number of consultations both at the level of general practitioner and of respiratory specialists. In this review we first analyze the cough reflex under normal conditions; then we analyze the anatomy and the neuro-pathophysiology of the cough reflex arc. The aim of this review is to provide the anatomic and pathophysiologic elements of evaluation of the complex and multiple etiologies of cough.

/pdf/anatomy-and-neuro-pathophysiology-of-the-cough-reflex-arc-o4odv23jij.pdf

Antonio Alfieri

Papers

Anatomy and neuro-pathophysiology of the cough reflex arc