Prevalence of Arnold nerve reflex in subjects with and without chronic cough: Relevance to Cough Hypersensitivity Syndrome.

INTRODUCTION: Cough is induced by stimulation of structures innervated by the vagus nerve, including the upper and lower airways and distal esophagus. The Arnold nerve reflex describes cough resulting from stimulation of the external auditory canal, which is innervated by the auricular branch of the vagus. We have recently reported the increased prevalence of this reflex in adults, but not children, with chronic cough, relative to healthy adult and pediatric subjects. The prevalence of the Arnold nerve reflex in patients with pulmonary disease but without chronic cough has not been investigated previously. METHODS: Three hundred adults and 100 children with chronic cough, 50 adults with stable pulmonary disease but without chronic cough, as well as 100 adult and 100 pediatric volunteers, underwent evaluation consisting of stimulation of the external auditory canal of each ear with a cotton-tipped applicator. Cough occurring within 10 s of stimulation was considered induced by the intervention. RESULTS: Arnold's nerve reflex was present in 23.3% of adults and 3% of children with chronic cough. The prevalence of the reflex was 2% among healthy adults and children. In adults with chronic cough, Arnold's nerve reflex was observed more commonly in women (29.3%) than men (10.5%), and was unilateral in the majority of patients (88.6%). In patients with respiratory disease but without chronic cough, Arnold nerve reflex was present in 2%. CONCLUSIONS: The greater than 11-fold prevalence of the Arnold nerve reflex in adults with chronic cough compared with healthy volunteers and adults with respiratory disease but without chronic cough, supports the concept of the Cough Hypersensitivity Syndrome (CHS), in which vagal hypersensitivity is proposed to underlie chronic refractory cough. The absence of increased prevalence among children with chronic cough suggests that CHS is an acquired condition, perhaps triggered by viral respiratory infection or other environmental factor.

Prehospital Frailty and Screening Criteria for Palliative Care Services in Critically Ill Older Adults: An Observational Cohort Study.

Background: The use of formalized criteria (or triggers) for palliative care services (PCSs) has been associated with increased use of PCSs in the intensive care unit (ICU). Objective: To explore the utility/validity of frailty as a trigger for providing PCSs. Design: This is a prospective cohort study. Setting/Subjects: Older adults (age ≥50 years) admitted to ICUs were enrolled. Measurements: We measured frailty using the Clinical Frailty Scale. We reviewed electronic health records for the presence/absence of six evidence-based triggers, the use and quality of specialty palliative care (SPC), and markers of primary palliative care (PPC). We used descriptive statistics to describe the differences in PPC, SPC, and six-month mortality by frailty and by the presence/absence of triggers. Results: In a study population of 302 older adults, mean (standard deviation) age 67.2 years (10.5), 151 (50%) were frail and 105 (34.8%) had ≥1 trigger for PCSs. Of the 151 (55.6%) frail patients, 84 had no triggers for PCSs, despite a 46.4% six-month mortality in this group. Patients with ≥1 trigger had higher rates of SPC than those without (39.1% vs. 18.3%, p < 0.001); frail patients also had higher SPC than nonfrail patients (32.5% vs. 18.5%, p = 0.006). Patients with ≥1 trigger had higher rates of PPC than those without (66.7% vs. 44.2%, p < 0.001); no statistically significant difference in PPC was found by frailty (56.3% vs. 47.7%, p = 0.134). Conclusion: The rates of PCSs and six-month mortality by frailty are consistent with frailty being a valid trigger for PCSs in ICUs; the high prevalence of frailty relative to triggers suggests that ways to increase PCSs would be needed.

The Global Impact of Asthma in Adult Populations.

Asthma is a disease characterized by chronic airway inflammation, leading to intermittent symptoms of wheeze, dyspnea, cough and chest tightness in combination with variable expiratory airway obstruction. Clinical diagnosis is usually established based on the presence of symptoms and documented variability in expiratory airflow limitation as measured by pulmonary function testing. Presently, asthma is a major chronic disease affecting approximately 334 million people worldwide. The epidemic spares no age group, race or ethnicity; however ethnicity and socioeconomic status do influence the prevalence, morbidity and mortality of asthma in the United States and various countries throughout the world. Moreover, asthma places a huge burden at the societal, financial and health-care levels of multiple nations.

Prevalence of Arnold Nerve Reflex in Adults and Children With Chronic Cough.

BACKGROUND: Cough originates from stimulation of structures innervated by the vagus nerve, including the airways and distal esophagus. Arnold nerve reflex describes the induction of cough by stimulation of the external auditory canal, which is innervated by the auricular branch of the vagus. Historically, the prevalence of this reflex has been reported in the range of 2% to 3% on the basis of studies of outpatients in otolaryngology practices, but has not been investigated in healthy volunteers or in patients with chronic cough. METHODS: Two hundred adults and 100 children with chronic cough, as well as 100 adult and 100 pediatric volunteers, underwent evaluation consisting of stimulation of the external auditory canal of each ear with a cotton-tipped applicator. Cough occurring within 10 seconds of stimulation was considered induced by the intervention. RESULTS: Arnold nerve reflex was present in 25.5% of adults and 3% of children with chronic cough. The prevalence of the reflex was 2% among healthy adults and children. In adults with chronic cough, Arnold nerve reflex was observed more commonly in women (31.6%) than men (12.5%) and was unilateral in the majority of patients (90.2%). CONCLUSIONS: The greater than 12 fold prevalence of Arnold nerve reflex in adults with chronic cough compared with healthy volunteers supports the concept of cough hypersensitivity syndrome (CHS), in which vagal hypersensitivity is proposed to underlie chronic refractory cough. The absence of increased prevalence among children with chronic cough suggests that cough hypersensitivity syndrome is an acquired condition, perhaps triggered by viral respiratory infection or other environmental factor.