Respiratory symptoms among glass bottle workers--cough and airways irritancy syndrome?
Glass bottle workers have been shown to experience an excess of respiratory symptoms. This work describes in detail the symptoms reported by a cohort of 69 symptomatic glass bottle workers. Symptoms, employment history and clinical investigations including radiology, spirometry and serial peak expiratory flow rate records were retrospectively analyzed from clinical records. The results showed a consistent syndrome of work-related eye, nose and throat irritation followed after a variable period by shortness of breath. The latent interval between starting work and first developing symptoms was typically 4 years (median = 4 yrs; range = 0-28). The interval preceding the development of dysponea was longer and much more variable (median = 16 yrs; range = 3-40). Spirometry was not markedly abnormal in the group but 57% of workers had abnormal serial peak expiratory flow rate charts. Workers in this industry experience upper and lower respiratory tract symptoms consistent with irritant exposure. The long-term functional significance of these symptoms should be formally investigated. (+info)
Defining and analysing symptom palliation in cancer clinical trials: a deceptively difficult exercise.
The assessment of symptom palliation is an essential component of many treatment comparisons in clinical trials, yet an extensive literature search revealed no consensus as to its precise definition, which could embrace relief of symptoms, time to their onset, duration, degree, as well as symptom control and prevention. In an attempt to assess the importance of these aspects and to compare different methods of analysis, we used one symptom (cough) from a patient self-assessment questionnaire (the Rotterdam Symptom Checklist) in a large (>300 patient) multicentre randomized clinical trial (conducted by the Medical Research Council Lung Cancer Working Party) of palliative chemotherapy in small-cell lung cancer. The regimens compared were a two-drug regimen (2D) and a four-drug regimen (4D). No differences were seen between the regimens in time of onset of palliation or its duration. The degree of palliation was strongly related to the initial severity: 90% of the patients with moderate or severe cough at baseline reported improvement, compared with only 53% of those with mild cough. Analyses using different landmark time points gave conflicting results: the 4D regimen was superior at 1 month and at 3 months, whereas at 2 months the 2D regimen appeared superior. When improvement at any time up to 3 months was considered, the 4D regimen showed a significant benefit (4D 79%, 2D 60%, P = 0.02). These findings emphasize the need for caution in interpreting results, and the importance of working towards a standard definition of symptom palliation. The current lack of specified criteria makes analysis and interpretation of trial results difficult, and comparison across trials impossible. A standard definition of palliation for use in the analysis of clinical trials data is proposed, which takes into account aspects of onset, duration and degree of palliation, and symptom improvement, control and prevention. (+info)
Influence of central antitussive drugs on the cough motor pattern.
The present study was conducted to determine the effects of administration of centrally active antitussive drugs on the cough motor pattern. Electromyograms of diaphragm and rectus abdominis muscles were recorded in anesthetized, spontaneously breathing cats. Cough was produced by mechanical stimulation of the intrathoracic trachea. Centrally acting drugs administered included codeine, morphine, dextromethorphan, baclofen, CP-99,994, and SR-48,968. Intravertebral artery administration of all drugs reduced cough number (number of coughs per stimulus trial) and rectus abdominis burst amplitude in a dose-dependent manner. Codeine, dextromethorphan, CP-99,994, SR-48,968, and baclofen had no effect on cough cycle timing (CTtot) or diaphragm amplitude during cough, even at doses that inhibited cough number by 80-90%. Morphine lengthened CTtot and inhibited diaphragm amplitude during cough, but these effects were not dose dependent. Only CP-99,994 altered the eupneic respiratory pattern. Central antitussive drugs primarily suppress cough by inhibition of expiratory motor drive and cough number. CTtot and inspiratory motor drive are relatively insensitive to the effects of these drugs. CTtot can be controlled independently from cough number. (+info)
Cough and angiotensin II receptor antagonists: cause or confounding?
AIMS: Cough is one of the most frequent side effects associated with angiotensin converting enzyme inhibitors (ACEIs) but is not thought to be associated with losartan, an angiotensin II receptor antagonist (ARA). This study compares reports of cough with losartan and three ACEIs used in general practice. METHODS: Studies have been conducted for losartan, and three ACEIs enalapril, lisinopril and perindopril, using the technique of Prescription-Event Monitoring. Patients were identified using dispensed prescription data. Questionnaires were sent to patients' general practitioners 6 months after the date of first prescription. Cases of cough within the first 60 days of treatment with losartan resulting in withdrawal of the drug were followed up with additional questionnaires. Incidence rates for reports of cough were calculated. In order to reduce the impact of carry-over effects, rate ratios were calculated for first reports of cough between days 8 and 60 using losartan as the index drug. RESULTS: The cohort for each drug exceeded 9000 patients. Age and sex distributions and indications for prescribing the four drugs were similar. Cough was the most frequent reason for discontinuation of losartan and the most frequently reported event in the first month of treatment with this drug. When reports of cough between days 1-7 were excluded, rates of cough were significantly higher for the three ACEIs when compared with losartan (rate ratios 1.5, 4.8 and 5.7, all P<0.03). 101 patients had discontinued losartan due to cough. 91% of these had previously been prescribed an ACEI and 86% had previously experienced ACEI cough. CONCLUSIONS: Carry-over accounted for the observed excess of reports of cough with losartan. Rates of cough between days 8 and 60 were significantly higher for the three ACEIs compared with losartan. Confounding factors associated with comparative observational cohort studies are discussed. (+info)
Multifunctional laryngeal motoneurons: an intracellular study in the cat.
We studied the patterns of membrane potential changes in laryngeal motoneurons (LMs) during vocalization, coughing, swallowing, sneezing, and the aspiration reflex in decerebrate paralyzed cats. LMs, identified by antidromic activation from the recurrent laryngeal nerve, were expiratory (ELMs) or inspiratory (ILMs) cells that depolarized during their respective phases in eupnea. During vocalization, most ELMs depolarized and most ILMs hyperpolarized. Some ILMs depolarized slightly during vocalization. During coughing, ELMs depolarized abruptly at the transition from the inspiratory to the expiratory phase. In one-third of ELMs, this depolarization persisted throughout the abdominal burst. In the remainder ("type A"), it was interrupted by a transient repolarization. ILMs exhibited a membrane potential trajectory opposite to that of type A ELMs during coughing. During swallowing, the membrane potential of ELMs decreased transiently at the onset of the hypoglossal burst and then depolarized strongly during the burst. ILMs hyperpolarized sharply at the onset of the burst and depolarized as hypoglossal activity ceased. During sneezing, ELMs and ILMs exhibited membrane potential changes similar to those of type A ELMs and ILMs during coughing. During the aspiration reflex, ELMs and ILMs exhibited bell-shaped hyperpolarization and depolarization trajectories, respectively. We conclude that central drives to LMs, consisting of complex combinations of excitation and inhibition, vary during vocalization and upper airway defensive reflexes. This study provides data for analysis of the neuronal networks that produce these various behaviors and analysis of network reorganization caused by changes in dynamic connections between the respiratory and nonrespiratory neuronal networks. (+info)
Influence of family factors on the incidence of lower respiratory illness during the first year of life.
In a study of a cohort of over 2000 children born between 1963 and 1965, the incidence of bronchitis and pneumonia during their first year of life was found to be associated with several family factors. The most important determinant of respiratory illness in these infants was an attack of bronchitis or pneumonia in a sibling. The age of these siblings, and their number, also contributed to this incidence. Parental respiratory symptoms, including persistent cough and phlegm, and asthma or wheezing, as well as parental smoking habits, had lesser but nevertheless important effects. Parental smoking, however, stands out from all other factors as the one most amenable to change in seeking to prevent bronchitis and pneumonia in infants. (+info)
Persistent cough: is it asthma?
The aim of this study was to determine if children in the community with persistent cough can be considered to have asthma. A validated questionnaire was given to the parents of 1245 randomly selected children aged 6-12 years. Atopy was measured with skin prick tests. Children with persistent cough had less morbidity and less atopy compared with children with wheeze. Although the syndrome commonly referred to as "cough variant asthma" could not be shown in this study, a significant number of children with persistent cough had been diagnosed as having asthma and were treated with asthma medications including inhaled corticosteroids. Studies are urgently needed to determine the appropriate treatment for children with persistent cough. (+info)
Gastro-oesophageal reflux related cough and its response to laparoscopic fundoplication.
BACKGROUND: This study was designed to determine prospectively the rate of cough before and after laparoscopic Nissen fundoplication performed for the control of gastro-oesophageal reflux disease. METHODS: One hundred and ninety five consecutive patients (76 men) of mean (SD) age 46.9 (14.1) years with proven gastro-oesophageal reflux disease, who were either on long term omeprazole (n = 187) or who had not responded to a trial of omeprazole (n = 8), took part in the study which was carried out in a university teaching hospital that included a regional respiratory referral centre. Patients underwent oesophageal manometry, 24 hour oesophageal pH testing, and symptom score evaluation by an independent observer before and six months after laparoscopic Nissen fundoplication. RESULTS: One hundred and thirty three patients presented with reflux symptoms and 62 with respiratory symptoms; 68% of patients complained of cough before surgery (86% with respiratory symptoms, 60% with gastrointestinal symptoms). The percentage reflux time in 24 hours fell significantly (p < 0.0001) from a mean (SD) of 9.38 (10.99)% to 1.22 (2.92)%, lower oesophageal sphincter tone rose significantly (p < 0.0001) from a mean (SD) of 7.71 (5.90) mm Hg to 21.74 (10.84) mm Hg, and the cough score fell from a median value of 8.0 (IQR 12.0) to 0 (IQR 3) following surgery. Of the patients with cough, 51% were cough free after surgery and 31% improved. The patients with respiratory symptoms had a higher cough score before (median 12.0 (IQR 5.5) versus 4.0 (IQR 8.75), p < 0.0001) and after surgery (median 1 (7.5) versus 0.0 (IQR 1.0), p = 0.0045) than those with gastrointestinal symptoms. CONCLUSIONS: Patients who present to gastroenterologists with severe reflux commonly complain of cough. Laparoscopic Nissen fundoplication is effective in the control of cough in patients with gastro-oesophageal reflux disease, with or without primary respiratory disease. (+info)