Cough Function Research Articles

Respiratory morbidity, healthcare utilisation and cost of care at school age related to home oxygen status

The aim of the study was to determine whether respiratory morbidity, lung function, healthcare utilisation and cost of care at school age in prematurely born children who had bronchopulmonary dysplasia (BPD) were influenced by use of supplementary oxygen at home after neonatal intensive care unit discharge. Healthcare utilisation and cost of care in years5 to 7 and respiratory morbidity (parent-completed respiratory questionnaire) and lung function measurements at least at age 8years were assessed in 160 children. Their median gestational age was 27 (range 22-31) weeks and 65 of them had received supplementary oxygen when discharged home (home oxygen group). The home oxygen group had more outpatient attendances (p = 0.0168) and respiratory-related outpatient attendances (p = 0.0032) with greater related cost of care (p = 0.0186 and p = 0.0030, respectively), their cost of care for prescriptions (p = 0.0409) and total respiratory related cost of care (p = 0.0354) were significantly greater. There were, however, no significant differences in cough, wheeze or lung function results between the two groups. Prematurely born children who had BPD and supplementary oxygen at home after discharge had increased healthcare utilisation at school age. Whether such children require greater follow, in the absence of excess respiratory morbidity, merits investigation.

S118 Acute hemispheric stroke patients have reduced functional residual capacity and cough flow rates

IntroductionCough is a complex manoeuvre, requiring coordinated action of the respiratory and upperairway musculature. The mechanisms of impaired cough following hemispheric stroke are unclear. Reduced functional residual capacity (FRC) may...

Acute ischaemic hemispheric stroke is associated with impairment of reflex in addition to voluntary cough

Cough function is impaired after stroke; this may be important for protection against chest infection. Reflex cough (RC) intensity indices have not been described after stroke. RC, voluntary cough (VC) and respiratory muscle strength were studied in patients within 2 weeks of hemispheric infarct. The null hypotheses were that patients with cortical hemisphere stroke would show the same results as healthy controls on: 1) objective indices of RC and VC intensity; and 2) respiratory muscle strength tests. Peak cough flow rate (PCFR) and gastric pressure (P(ga)) were measured during maximum VC and RC. Participants also underwent volitional and nonvolitional respiratory muscle testing. Nonvolitional expiratory muscle strength was assessed by measuring P(ga) increase after magnetic stimulation over the T₁₀ nerve roots (twitch T₁₀ P(ga)). Stroke severity was scored using the National Institutes of Health Stroke Scale (NIHSS; maximum = 31). 18 patients (mean ± sd age 62 ± 15 yrs and NIHSS score 14 ± 8) and 20 controls (56 ± 16 yrs) participated. VC intensity was impaired in patients (PCFR 287 ± 171 versus 497 ± 122 L·min⁻¹) as was VC P(ga) (98.5 ± 61.6 versus 208.5 ± 61.3 cmH₂O; p < 0.001 for both). RC PCFR was reduced in patients (204 ± 111 versus 379 ± 110 L·min⁻¹; p < 0.001), but RC P(ga) was not significantly different from that of controls (179.0 ± 78.0 versus 208.0 ± 77.4 cmH₂O; p = 0.266). Patients exhibited impaired volitional respiratory muscle tests, but twitch T₁₀ P(ga) was normal. VC and RC are both impaired in hemispheric stroke patients, despite preserved expiratory muscle strength. Cough coordination is probably cortically modulated and affected by hemispheric stroke.

Secondhand smoke exposure alters K+ channel function and intrinsic cell excitability in a subset of second‐order airway neurons in the nucleus tractus solitarius of young guinea pigs

Extended exposure to secondhand smoke (SHS) in infants and young children increases the incidence of cough, wheeze, airway hyper-reactivity and the prevalence and earlier onset of asthma. The adverse effects may result from environmentally-induced plasticity in the neural network regulating cough and airway function. Using whole-cell patch-clamp recordings in brainstem slices containing anatomically identified second-order lung afferent neurons in the nucleus tractus solitarius (NTS), we determined the effects of extended SHS exposure in young guinea pigs for a duration equivalent to human childhood on the intrinsic excitability of NTS neurons. SHS exposure resulted in marked decreases in the intrinsic excitability of a subset of lung afferent second-order NTS neurons. The neurons exhibited a decreased spiking capacity, prolonged action potential duration, reduced afterhyperpolarization, decrease in peak and steady-state outward currents, and membrane depolarization. SHS exposure effects were mimicked by low concentrations of the K+ channel blockers 4-aminopyridine and/or tetraethyl ammonium. The data suggest that SHS exposure downregulates K+ channel function in a subset of NTS neurons, resulting in reduced cell excitability. The changes may help to explain the exaggerated neural reflex responses in children exposed to SHS.

Effects and Management of Odontogenic Infections on Pulmonary Infections

Carious and periodontal disease is strongly associated with pulmonary infections. Aspiration pneumonia often develops lung abscess and/or empyema, and sometimes leads to death in elderly patients. It is often repeatedly seen in most of elderly patients, which leads to general weakness, prolonged bed rest, and several complications. There are two pathophysiological factors for aspiration pneumonia. One is due to odontogenic infections: aspirated oral microorganisms reach pulmonary alveoli, grow, and develop their pathogenicity. The other is host factors: alcoholism, diabetes, or bedridden status reduces cough reflex, airway clearance, and functions of phagocytes. The prevention of aspiration pneumonia is significant from medical, social, and economical viewpoints, although the main management of pneumonia is antimicrobial chemotherapy. "Oral care" has recently been of interest as a control means for odontogenic infections and aspiration pneumonia. A dental hygienist and speech therapists in our hospital have implemented active intervention in oral care of patients with risk of aspiration pneumonia, which has made considerable achievements.

Impact of Expiratory Muscle Strength Training on Voluntary Cough and Swallow Function in Parkinson Disease

Cough provides high expiratory airflows to aerosolize and remove material that cannot be adequately removed by ciliary action. Cough is particularly important for clearing foreign particles from the airway in those with dysphagia who may be at risk for penetration/aspiration (P/A). Expiratory muscle strength training (EMST) was tested to improve cough and swallow function. Ten male participants, diagnosed with Parkinson disease (PD), with videofluorographic evidence of penetration or with evidence for aspiration of material during swallow of a thin 30-mL bolus, completed 4 weeks of an EMST program to test the hypothesis that EMST would improve cough and/or swallow function. Measured parameters from an airflow waveform produced during voluntary cough, pre-EMST and post-EMST, included inspiration phase duration, compression phase duration (CPD), expiratory phase peak flow (EPPF), expiratory phase rise time (EPRT), and cough volume acceleration (VA) [ie, the EPPF/EPRT ratio]. The swallow outcome measure was the degree of P/A during the swallow task. There was a significant decrease in the duration of the CPD and EPRT; the decrease in EPRT resulted in a significant increase in cough VA. Significant decreases in the P/A scores were found posttraining. The results demonstrate that EMST is a viable treatment modality for a population of participants with PD at risk of aspiration.

Association between Cough and Cytology of Bronchoalveolar Lavage Fluid and Pulmonary Function in Horses Diagnosed with Inflammatory Airway Disease

The objective of this study was to examine the relationship between chronic cough, pulmonary mechanical function, bronchial hyper-responsiveness, and peripheral airway inflammation in adult performance horses with nonseptic inflammatory airway disease (IAD). We hypothesized that horses with a presenting complaint of cough have a higher percentage of inflammatory cells on bronchoalveolar lavage (BAL), greater airway obstruction, and airway hyper-responsiveness (AHR) than do horses without cough. ANIMALS/SAMPLE POPULATION: Adult performance horses (n = 137) referred for evaluation of signs of IAD including cough or exercise intolerance (university hospital patients) and BAL samples (n = 142) taken in first opinion practice. A descriptive, retrospective cohort analysis was performed to evaluate the association between chronic cough and pulmonary mechanical function, AHR, BAL cytology, patient signalment, and comorbid features (multivariable logistic regression). Cough was significantly more prevalent in horses >7 years, and best characterized by a high BAL neutrophil count (>5%) and nasal discharge. Lung function mechanics, abnormal thoracic auscultation, and exercise intolerance did not retain statistical significance in the logistical regression analysis of cough. Although AHR was not related to neutrophilic airway inflammation (BAL neutrophils >5%), it was significantly associated with BAL mast cells >2%. Our data support that neutrophilic airway inflammation may potentiate cough without further changing respiratory mechanical function in IAD. In contrast, mast cell release increased AHR without affecting the incidence of cough. Cough may be used as an indicator of neutrophilic airway inflammation in the presence of low-grade nonseptic respiratory disease.

Effect of expiratory muscle strength training on elderly cough function

Age-related loss of muscle strength, known as sarcopenia, in the expiratory muscles, along with reductions in lung elastic recoil and chest wall compliance decreases the intrathoacic airway pressure as well as expiratory flow rates and velocity, greatly impacting an elderly person's ability to generate the forces essential for cough. This study examined the effects of a 4-week expiratory muscle strength training (EMST) program on maximum expiratory pressure (MEP) and cough function in 18 healthy but sedentary elderly adults. MEP significantly increased after the EMST program from 77.14 ± 20.20 to 110.83 ± 26.11 cm H 2O. Parameters measured during reflexive coughs produced by capsaicin challenge, indicated that compression phase duration significantly decreased (from 0.35 ± 0.19 to 0.16 ± 0.17 s), peak expiratory flow rate decreased (from 4.98 ± 2.18 to 8.00 ± 3.05 l/s) and post-peak plateau integral amplitude significantly increased (from 3.49 ± 2.46 to 6.83 ± 4.16 l/s s) with the EMST program. EMST seems to be an effective program to increase the expiratory muscle strength in the sedentary elderly, which contribute to an enhanced cough function.

Gastro-oesophageal reflux and aspiration of gastric contents in adult patients with cystic fibrosis

Background:Gastro-oesophageal reflux (GOR) is increased in cystic fibrosis (CF), but its prevalence, characteristics, association with gastric aspiration and respiratory impact are not well characterised. We investigated acid and weakly acidic...

Assisted cough - Physiotherapie zur Verbesserung der Sekretexpektoration

Pulmonary complications are the most common causes of mortality in patients with severe inspiratory and/or expiratory muscle weakness. An inspiratory tidal volume below 1500 ml and a peak cough flow below 160 L/min result in mucus retention and increase the risk of pneumonia. An intact cough function is pivotal for airway clearance during acute and chronic airway infections with increased mucus production as well as for protection against endotracheal aspirations. Effective cough requires that all of its phases work or are effectively supported. Non-invasive assistance of inspiration can be provided by manual hyperinflation, air stacking, glossopharyngeal breathing or mechanical insufflation. Safe and effective methods of expiration assistance include manual thorax and abdominal compression, manual self-assistance as well as mechanical insufflation-exsufflation. The use of these non-invasive inspiratory and expiratory muscle aids can decrease the risk of pulmonary complications in patients with severe ventilatory muscle weakness.

Abdominal stimulation for respiratory support in tetraplegia: A tutorial review

Neuromuscular stimulation of the abdominal wall muscles can provide respiratory support in tetraplegia, where the main expiratory muscles are affected by paralysis. Stimulation may be applied by simple surface stimulation, resulting in a uniform muscle contraction which can help to improve expiratory function for coughing and breathing. In this review, an overview of methods and approaches available for abdominal muscle stimulation is given. Studies are discussed which show that this technique can lead to improvements in expiratory flow and tidal volume, resulting in enhanced cough and breathing functions. Approaches are introduced which aim to integrate abdominal stimulation with the subject's own voluntary breathing functions. These are illustrated with experimental results from the evaluation of automatic stimulation methods in tetraplegic patients. Clinical significance and applications are discussed and future developments are outlined.

Clinical differentiation between resistant asthma and chronic bronchiolitis: testing a practical approach.

Intractable asthma is a challenging clinical problem. This study was conducted to determine whether a subset of patients with Intractable asthma may be misdiagnosed and have a form of bronchiolitis instead and also to determine the effectiveness of macrolide therapy in these patients. Seventy six patients with Intractable asthma were re-treated with recommended maximal doses of oral prednisolone for 5 days, beclomethasone, cromolyn sodium, salbutamol and ipratropium bromide for 30 days. Thirty five patients were considered as unresponsive and constituted the study group. They underwent high-resolution CT (HRCT) scan following which they were offered with video-assisted thoracoscopic surgical biopsy. Group 1 (n= 27) refused biopsy and each was treated with macrolide therapy, while Group 2 (n=8) underwent biopsy, and then received macrolide therapy. The patients were treated and followed for three months. The study group consisted of 27 patients, with a mean age of 46.9 +/- 11.1 years. The mean duration of time between the onset of symptoms and the start of this study was 8.1 years. In group 2, no patient had pathologic findings of asthma, and 7/8 had a form of bronchiolitis. There was significant improvement in dyspnea, cough and pulmonary function indices at the end of the 3-month in both groups (p< 0.001). Our results suggest that patients with Intractable asthma could be misdiagnosed and some of them have some forms of chronic bronchiolitis. We believe that any patient who does not respond to standard treatments for Intractable asthma should be evaluated with expiratory HRCT; those with significant air trapping should be considered for a course of macrolide therapy or biopsy for better identification of the underlying disease.

Cough in specific populations (paediatric patients, elderly patients and patients with underlying disease)

Cough in specific populations (paediatric patients, elderly patients and patients with underlying disease)

Advances in the development of TRPV1 antagonists

Transient receptor potential V1 (TRPV1) is a nonspecific cation channel subject to polymodal activation. TRPV1, originally termed vanilloid receptor 1, can be activated by the prototypical vanilloid capsaicin as well as decreases in extracellular pH and increases in temperature. The neuronal expression and biology surrounding TRPV1 suggest that it plays a significant role in the establishment and maintenance of various pain states as well as a potential role for TRPV1 in cough and bladder function. This review outlines the potential mechanism(s) by which activation of TRPV1 leads to pain and hyperalgesia, lessons learned via the development of antagonists and the current status of the development of therapeutic entities for validation within a clinical setting.

Tutorial on maximum inspiratory and expiratory mouth pressures in individuals with idiopathic Parkinson disease (IPD) and the preliminary results of an expiratory muscle strength training program1

Respiratory symptoms are recognized as sequelae of motor dysfunction in idiopathic Parkinson's disease (IPD) and these symptoms have the potential to cause problems with swallow, cough, voice and speech. Specifically, maneuvers that require rapid activation and coordination of upper airway and chest wall musculature become progressively impaired as motor dysfunction progresses during the natural course of the disease. This study reports on the maximum inspiratory and expiratory pressures produced by 28 participants (average age 64) diagnosed with moderate to severe IPD (average stage 2.5 with a range of 2.0-3.0). All measures were collected during the "medication on" state. Outcomes of a specific respiratory muscle strength training technique for improving maximum expiratory pressure are reported for three of the patients in this study. Techniques that focus on strengthening the respiratory muscles in patients with IPD (other than with low load breathing exercises), have not been previously reported. The results of this pilot study demonstrate that respiratory muscle weakness may be an important factor in the respiratory complications in IPD and that respiratory muscle strength training has the potential to improve expiratory muscle strength for this population. This improvement has the potential to positively impact high forced respiratory activities, such as forced breathing maneuvers, swallow, cough and speech functions that require greater magnitude and duration of expiration.

Cough motor mechanisms

Cough is a defensive airway mechanisms which involves the sequential activation of several laryngeal and respiratory muscles in the generation of the typical four-phase motor pattern. Activation of such muscles can be considered to represent the "primary" cough motor mechanism, and its functional significance, although complex, appears to be fairly well established. Nonetheless, the outflows of cough are numerous, and may additionally involve the reflex or mechanical activation of other respiratory and non-respiratory motor systems. These additional, or "secondary", outflows of cough can mainly be regarded as being involved in either enhancing the defensive function of cough, or opposing the possible noxious effects exerted by the mechanical stresses of coughing. In addition, both the primary and secondary cough motor mechanisms are known to play multiple functional roles, thus considerably complicating the cough panorama. Finally, some of the secondary cough motor responses, such as the changes in the pattern of breathing, seem to be devoid of any favourable action and their functional meaning, if any, is not fully understood. Although it is well known that all patterns of cough can be produced voluntarily, the extent to which also volitional cough is accompanied by an array of motor responses similar to that of reflex cough remains to be elucidated.

Visceral Larva Migrans Associated With Earthworm Ingestion: Clinical Evolution in an Adolescent Patient

A 16-year-old girl developed a cough, hypereosinophilia (absolute eosinophil count: 32000/mm3), hypergammaglobulinemia, and multiple noncavitary pulmonary nodules 1 month after having ingested an earthworm on a dare. Spirometry revealed moderate restriction and reduced gas diffusion. Parabronchial biopsy demonstrated eosinophilic organizing pneumonitis with multiple eosinophilic microabscesses, and Toxocara titers were elevated (>1:4096). Ophthalmologic examination ruled out ocular larva migrans. The patient received a 10-day course of albendazole (400 mg orally twice daily) and demonstrated significant clinical improvement with resolution of cough and pulmonary function abnormalities. Her white blood cell count and hypergammaglobulinemia normalized within 20 days, yet eosinophils (absolute eosinophil count: 1780/mm3) and Toxocara serologies (>1:4096) remained elevated 3 months after completing antihelminthic therapy. In this instance, the ingested earthworm served as the paratenic carrier of Toxocara larvae from the soil to the patient. This case highlights the clinical evolution of pulmonary visceral larva migrans infection caused by Toxocara spp. associated with a discrete ingestion in an adolescent patient. In addition, it provides a rare opportunity to define the incubation period of visceral larva migrans and emphasizes the importance of education regarding sources of Toxocara infection.

Effectiveness of Cough Exercise and Expiratory Muscle Training: A Meta-analysis

Coughing is a defensive reflex action of the airway that removes foreign objects and mucus. Here, meta-analysis was performed to review the results of previous studies regarding the effects of coughing exercise and expiratory muscle training (EMT), and to examine the effectiveness of EMT in enhancing cough functions. A systematic literature search was performed using the EBMR, CINAHL, PEDro, MEDLINE, and Ichushi Web (NPO Japan Medical Abstracts Society) databases. Based on a methodological framework, a critical review was performed and summary effect sizes were calculated by applying the random effects model. Both the forced expiration technique (FET) and coughing alone significantly increased mucus clearance. EMT significantly increased expiratory muscle strength, suggesting that it is possible to improve cough effectiveness by EMT. Further studies with larger and more diverse sample groups are necessary to determine the effects of enhancing expiratory muscle strength on cough effectiveness.

Obstructive sleep apnea syndrome: A potential cause of lower airway obstruction in cystic fibrosis

A six-year-old healthy female with cystic fibrosis (CF) and pancreatic sufficiency presented with cough, weight loss, and lung function decline. Further history suggested obstructive sleep apnea, and nocturnal polysomnography (NPSG) confirmed this. Adenotonsillectomy resulted in resolution of clinical symptoms with return of normal lung function. This case establishes that obstructive sleep apnea syndrome (OSAS) may be a potential cause of lower airway inflammation and resulting weight loss in the young CF population.

CAR AND TRUCK TRAFFIC AND ADVERSE EFFECTS ON RESPIRATORY HEALTH IN CHILDHOOD. THE RESULTS OF A LARGE ITALIAN MULTICENTER SURVEY (SIDRIA 2)

ISEE-379 Introduction: A number of epidemiological studies have provided evidence that exposure to vehicular traffic increases the prevalence of bronchitis, cough and lung function deficit, and exacerbates pre-existing asthma. A specific role of diesel exhaust from heavy traffic has been suggested. The aim of this study was to evaluate separate and combined effects of cars and trucks traffic on the respiratory health of children. Methods: A survey (SIDRIA-2, Italian Studies on respiratory disorders in childhood and environment) was conducted in Winter-Spring 2002. Standardised, self administered questionnaires were used to collect information on several health outcomes and potential risk factors. A questionnaire filled in by parents was available for 33,632 subjects (response rate: 86.7%). Car and truck traffic in the street of residence was assessed with parental questionnaires. Results: Both traffic indicators (frequency of truck transit in the street of residence, frequency of car traffic in the street of residence) were weakly associated with current asthmatic symptoms. Exposure to continuous car passage and to continuous truck transit was significantly associated with persistent cough or phlegm (OR=1.36 95%CI=1.15–1.61; OR=1.82, 95%CI=1.54–2.16 respectively). Children exposed to both, continuous car traffic and frequent or continuous truck traffic, showed the highest risk of persistent cough or phlegm (OR= 1.59, 95%CI=1.39–1.82); children with only car traffic exposure showed an OR=1.34 (95%CI=1.01–1.77), while children exposed to truck traffic only showed an OR= 1.39 (95%CI=0.93–2.08). Conclusion: These analyses on the risk of persistent cough or phlegm confirm stronger associations with heavy traffic pollution, but show also an independent effect of car traffic. Funding: The SIDRIA-2 phase study was partially funded by the Italian Ministry of Health.