Hyperresponsiveness of the extrathoracic airway in patients with captopril-induced cough

Laryngeal Dysfunction: Assessment and Management for the Clinician

The larynx is one of the most highly innervated organs in humans and serves a number of vitally important, complex, and highly evolved biological functions. On a day-to-day basis, the larynx functions autonomously, addressing several roles including airway protection, swallowing, and phonation. In some situations the larynx appears to adopt a functional state that could be considered maladaptive or "dysfunctional." This laryngeal dysfunction can underpin and account for a number of respiratory symptoms that otherwise appear incongruous with a clinical disease state and/or contribute to the development of symptoms that appear "refractory" to treatment. These include conditions associated with a heightened tendency for inappropriate laryngeal closure (e.g., inducible laryngeal obstruction), voice disturbance, and chronic cough. Recognition of laryngeal dysfunction is important to deliver targeted treatment and failure to recognize the condition can lead to repeated use of inappropriate treatment. Diagnosis is not straightforward, however, and many patients appear to present with symptoms attributable to laryngeal dysfunction, but in whom the diagnosis has been overlooked in clinical work-up for some time. This review provides an overview of the current state of knowledge in the field of laryngeal dysfunction, with a focus on pragmatic clinical assessment and management.

Extrathoracic airway hyperresponsiveness as a mechanism of post infectious cough: case report

Post-infectious cough is a common diagnosis in people with chronic cough. However, the specific infectious aetiology and cough mechanisms are seldom identified.We report a case of chronic cough after Mycoplasma pneumoniae lower respiratory tract infection with extrathoracic airway hyperresponsiveness as the cough mechanism. Extrathoracic airway hyperresponsiveness may be a common mechanism in post-infectious cough which may be useful both diagnostically and therapeutically since chronic cough with extrathoracic airway hyperresponsiveness responds to speech pathology treatment.

Voice and upper airway symptoms in people with chronic cough and paradoxical vocal fold movement

Chronic cough (CC) and paradoxical vocal fold movement (PVFM) share several common features; however, there has been no systematic comparison of these two conditions. The aims of this study were to contrast and compare the symptom profiles of CC and PVFM, to clarify the relationship between the two conditions, and to explore how symptom characteristics could be used to design an individualized treatment program. Participants included 55 people with a combination of PVFM and CC that was refractory to medical treatment, 8 people with PVFM alone, 56 people with CC alone, 25 people with voice disorders, and 27 normal controls. Symptoms and descriptive features of CC, PVFM, and voice disorders were assessed via structured case history interview, symptom frequency, and severity ratings, ratings of activity limitation, and anxiety/depression ratings. Results indicated consistent overlap in the symptom profile between people with CC and those presenting with a combination of CC and PVFM. Participants with PVFM without cough and those with voice disorders overlapped with the participants with CC on some dimensions; however, there were still some significant differences between them. These data suggest that CC and PVFM are related and manifestations of a common underlying condition but that voice disorders are a discrete entity. Most participants had normal ratings on screening for anxiety and depression. Results indicated that there were no consistent psychiatric symptoms in any of the groups studied, and they do not support the label of psychogenic cough for CC that is refractory to medical treatment. Characteristics of CC such as nature and timing of the cough provide important information for developing behavioral treatment programs for individual patients who have exhausted medical options. A template has been provided that is a practical method of designing an integrated behavioral treatment program based on those individual patient characteristics.

Extrathoracic airway dysfunction in cough associated with gastroesophageal reflux

BACKGROUND

Cough associated with gastroesophageal reflux (GER) may originate in extrathoracic airway receptors made hypersensitive by acid-induced mucosal injury.

OBJECTIVE

We investigated the role of laryngeal disease and dysfunction in the pathogenesis of GER-associated cough in nonasthmatic patients.

METHODS

Seven patients with GER-associated cough were compared with 7 patients with GER but no cough. The patients underwent fiberoptic endoscopy for assessment of laryngitis and esophagitis (expressed by scores); esophageal manometry; 24-hour pH monitoring; lung function tests; and histamine inhalation challenge with assessment of bronchial threshold (concentration provoking 10% fall in FEV1 [PC10]), extrathoracic airway threshold (concentration provoking 25% fall in the maximal midinspiratory flow [PC25MIF50]), and cough threshold (concentration provoking 5 or more coughs PCcough). The patients were reevaluated after 3 months of medical treatment for GER.

RESULTS

Patients with cough, compared with those without cough, had significantly higher laryngitis scores (P = .002), lower esophageal sphincter pressures, longer time with pH below 4 (P = .003), greater number of episodes of reflux longer than 5 minutes (P = .016), longer esophageal clearance time (P = .048), and significantly lower PC25MIF50 (P = .005) and PCcough (P = .008) values. Laryngitis score was significantly inversely related to either PCcough (P < .001) or PC25MIF50 (P <.01) but not to PC10. Laryngitis score, PC25MIF50, and PCcough were all closely related to GER severity. After GER treatment, laryngitis, PC25MIF50, and PCcough were all significantly improved.

CONCLUSIONS

These findings suggest that GER-associated cough is strongly associated with laryngeal disease and dysfunction consequent to acid reflux injury in nonasthmatic patients.

A systematic evaluation of mechanisms in chronic cough

We tested the hypothesis that hyperresponsiveness of the upper airway (UAHR) is present in patients with chronic cough of diverse etiology. We determined the frequency of bronchial hyperresponsiveness (BHR), hyperresponsiveness of the upper airway, sputum eosinophilia, pulmonary aspiration, and psychological symptoms in adults with chronic cough. Consecutive adults (n = 30) presenting to a tertiary referral clinic with chronic cough were compared with a group of 20 asymptomatic adults. Measurements included histamine provocation testing with measurement of flow volume curves to determine inspiratory and expiratory airflow obstruction; hypertonic saline induced sputum for analysis of eosinophils, mast cells and lipid-laden macrophages; and a validated psychological symptom questionnaire. Symptomatic rhinitis and gastroesophageal reflux were common causes of chronic cough. BHR occurred in seven patients (23%) and in no control subjects (p < 0.05). UAHR occurred in 40% of patients with cough and in four (20%) control subjects (p > 0.05). Eosinophils were present in the sputum of more patients with cough than control subjects (50% versus 19%; p < 0.05). High degrees of eosinophilia were present in six patients with cough, including three without BHR. No subject had significant lipid-laden macrophages. There was greater somatization in patients with chronic cough; ten subjects scored in the clinically significant range (p < 0.05). Abnormalities in one or more of these tests were 7.67-fold (95% CI 1.83-34.52) more likely to occur in cough patients than control subjects. We conclude that chronic cough is a nonspecific symptom that is associated with several apparently unrelated mechanisms. These include UAHR, somatization, BHR, and eosinophilic bronchitis. UAHR cannot be implicated as a single unifying mechanism. These findings emphasize the need to systematically evaluate several different causes of cough in patients who present with chronic cough.

Are asthma-like symptoms due to bronchial or extrathoracic airway dysfunction?

Patients with asthma-like symptoms may not have asthma but obstruction of the extrathoracic airway (EA). To evaluate if dysfunction of the EA causes asthma-like symptoms, we assessed bronchial and EA responsiveness to inhaled histamine in 441 patients who presented with at least one of three key symptoms--cough, wheeze, dyspnoea--but had neither documented asthma nor bronchial obstruction. The histamine concentrations causing a 20% fall in forced expiratory volume in 1 s (PC20FEV1) and a 25% fall in maximal mid-inspiratory flow (PC25MIF50) were used as respective thresholds of bronchial and EA responsiveness. Values 8 mg/mL or less indicated bronchial (B-HR) or EA hyper-responsiveness (EA-HR). The influence of concurrent upper respiratory tract diseases, such as post-nasal drip (PND), pharyngitis, laryngitis and sinusitis, was also assessed. We found four response patterns to the histamine challenge: EA-HR in 26.5% of the patients, B-HR in 11.1%, combined EA-HR and B-HR in 40.6%, and no-HR in 21.8%. Cough was reported by 79% of the patients, wheeze by 53%, and dyspnoea by 40%. Patients with cough as the sole presenting symptom (34.2%), as compared with those with wheeze and/or dyspnoea (20%), had significantly greater probability of having EA-HR (OR 5.35, 95% CI 3.25-8.82) and lower probability of having B-HR (OR 0.45, CI 0.28-0.70); patients with cough plus wheeze and/or dyspnoea (45.8%) had significantly greater probability of having both EA-HR and B-HR than either those with cough alone (OR 2.48, CI 1.49-4.13), or those with wheeze and/or dyspnoea but not cough (OR 1.74, CI 1.36-2.22). EA-HR alone or combined with B-HR was strongly associated with EA diseases, particularly pharyngitis and PND. Cough was significantly associated with PND, either when it was the sole symptom (OR 2.16, CI 1.14-4.09) or when it was combined with wheeze and/or dyspnoea (OR 3.53, CI 1.97-6.33). Our results suggest that extrathoracic airway dysfunction may account for asthma-like symptoms, particularly chronic cough. This abnormality seems to be sustained by chronic diseases of the upper respiratory tract.

Reproducibility of angiotensin converting enzyme inhibitor induced cough: a double-blind randomised study

1. The reproducibility of angiotensin converting enzyme inhibitor induced cough was examined in a double-blind cross over study in patients previously shown to have exhibited this side effect. 2. Ninety-seven patients who had experienced angiotensin converting enzyme inhibitor cough within the last 2 years were challenged with enalapril 20 mg daily for 4 weeks to establish eligibility. Eighty-eight of 97 (91%) patients experienced a repeat of their cough symptoms. Sixty-four patients entered the double-blind part of the study where they were treated with enalapril 20 mg and a renin inhibitor for up to 4 weeks in random order. These periods were separated by a minimum 4 week placebo wash out. 3. Of 59 evaluable patients who received enalapril a second time, 37 (62.7%) experienced cough again. Of 62 patients on the renin inhibitor 16 (25.8%) experienced cough, however as it was not equi-efficacious to enalapril no valid comparison could be made. 4. Angiotensin converting enzyme inhibitor cough is not reproducible within patients, as other factors are involved in the aetiology. Objective testing with blinded assessment together with symptom reporting, would give a more accurate measure of the incidence, and mechanism of this side effect.

Enalapril-induced cough in the emergency department

A case of enalapril-induced cough is reported. In the Emergency Department, the patient initially was misdiagnosed with bronchial asthma and, later, with early congestive heart failure, despite normal physical examination and investigations. The cough subsided within 5 days of cessation of enalapril. It is important to recognize this side effect in patients taking enalapril.

Clinical efficacy of perindopril in hypertension

1. Perindopril's effectiveness in mild to moderate hypertension was evaluated in three studies. 2. Perindopril was more effective than sodium restriction in reducing blood pressure, and the effects were additive. 3. Perindopril was as effective as atenolol in reducing blood pressure, and was well tolerated. 4. Perindopril lowered blood pressure to the same extent as enalapril at peak drug levels but had a greater effect at the trough level of the drugs. 5. Perindopril is an effective antihypertensive agent with an acceptable side-effect profile in people with hypertension.

Drug-induced pulmonary disease

OBJECTIVE

To review some of the types of drug-induced pulmonary disease reported in Australia.

DATA SOURCES

Reports of pulmonary side effects made to the Australian Adverse Drug Reaction Advisory Committee between December 1972 and March 1991. Reports of drug-induced pulmonary disease from other countries are also reviewed.

STUDY SELECTION

Only reports involving large patient numbers are included in the review to limit the bias likely from limited patient numbers.

DATA EXTRACTION

The incidence of adverse responses to a range of commonly used drugs from other countries is compared with reports to the Australian Adverse Drug Reaction Advisory Committee in the last 19 years.

DATA SYNTHESIS

Of adverse drug reactions reported in Australia in the last 19 years 7.7% were of a pulmonary side effect and 55% of these involved a syndrome of airway dysfunction. Bronchospasm and cough were the two most common symptoms of airway dysfunction and beta-blocking drugs and radio contrast media were the drug groups most commonly reported to cause them. These figures are similar to data reported from other countries. Some of the more commonly occurring types of drug-induced disease affecting either the airways or the lung interstices are reviewed.

CONCLUSIONS

Medical practitioners should maintain a high index of clinical suspicion that any unexplained pulmonary disease could be caused by a drug. Most of these reactions are reversible if the drug is withdrawn in time and if additional appropriate measures are taken as required.

Adverse effects of angiotensin converting enzyme (ACE) inhibitors. An update

The angiotensin converting enzyme (ACE) inhibitors are a group of effective drugs with a unique mechanism of action. These drugs have proven to be useful for hypertension and congestive heart failure. Early clinical trials of captopril used doses that are now known to be inappropriately high, and dose-related adverse effects were observed frequently. The recognition that lower doses are effective has reduced the incidence of adverse reactions and resulted in improved patient tolerance. When patients are properly selected and correctable risk factors are removed, serious side effects are uncommon. Unfortunately, the early reputation of nephrotoxicity persists, as does the belief that significant blood dyscrasias, endocrine effects and rash are serious risks for the average patient. After wide use of captopril, enalapril and lisinopril, and investigational trials of nearly a dozen newer agents, a sufficiency of clinical observation, experimental evidence and accurate postmarketing recording of events is accumulating to allow insight into the major toxicities with regard to more intelligent patient selection, more rational dosing and proper identification of risk factors. The most common adverse reactions are cough and skin rash. It appears that the agents are generally not cross-reactive with regard to skin rash, although it is not clear whether this effect is drug-specific or class-specific with regard to cough. Statistically but not clinically significant lowering of haemoglobin and hematocrit is common; these effects are inconsequential in most patients. Neutropenia, once thought to be prevalent, now appears to be so only in patients with autoimmune or collagen-vascular disease; the majority of patients outside these groups are at low risk. Hyperkalaemia is a frequent occurrence. This should not be surprising in view of the effect of the ACE inhibitors on plasma aldosterone. When dietary potassium intake is regulated and sources of altered potassium excretion are identified, hyperkalaemia is seldom a serious problem. Identification of sodium and water deficits allows correction before the drugs are started, and the frequency of hypotension and hyperkalaemia caused by the drugs is quite low if these factors are properly managed. An unexpected finding emerging in recent years is the dry cough associated with ACE inhibitor therapy. Its mechanism is not definitely known. Nonsteroidal anti-inflammatory drugs may control this symptom in some patients. The frequent observation of proteinuria in patients taking ACE inhibitors has gained notice and sometimes caused undue alarm. It is difficult to separate disease effects in diabetes and hypertension from true drug effects.(ABSTRACT TRUNCATED AT 400 WORDS)