Search PubMed⌕ Search

Biomedical subjects

R S Irwin

Publications and source records attributed to R S Irwin.

At least 19 recordsLinked to original sources
PubMed2002

Chronic cough due to gastroesophageal reflux disease: efficacy of antireflux surgery.

BACKGROUND: Gastroesophageal reflux disease (GERD) can be overlooked as the cause of chronic cough (CC) when typical gastrointestinal symptoms are absent or minimal. We analyzed the outcomes of Nissen fundoplication (NF) for patients who failed medical therapy for CC attributable only to GERD (G-CC). We performed a prospective outcome evaluation of 21 consecutive patients with G-CC undergoing NF from 1997 to 2000 at a tertiary care university hospital. MATERIALS AND METHODS: Twenty-one patients without prior antireflux surgeries had G-CC diagnosed by a clinical profile and 24-h pH monitoring showing a cough-reflux correlation. Respiratory symptoms alone were present in 53% of patients. NF was performed when G-CC persisted despite intensive medical therapy, including an antireflux diet. Preoperatively, all patients underwent 24-h pH monitoring, esophageal manometry, barium swallow, gastric emptying study, bronchoscopy, and upper endoscopy. NF was utilized in all cases, laparoscopically in 18. Before and after surgery, patients graded their cough severity using the Adverse Cough Outcome Survey (ACOS). Quality of life was measured using the Sickness Impact Profile (SIP). RESULTS: Postoperatively, 18 patients (86%) reported an improvement of their cough. G-CC considerably improved in 16/21 patients (76%), with complete resolution in 13 patients (62%). Mild to moderate improvement was found in 2 patients (10%). Patient-reported cough severity (ACOS) and quality of life (SIP) both significantly improved early (6-12 weeks) postoperatively and persisted during the long-term (1 year) follow-up. The average hospital length of stay was 1.78 +/- 0.2 (l-4) days for the laparoscopic (n = 18) and 6.3 +/- 1.2 (4-8) days for the open surgery (n = 3) groups. CONCLUSION: Twenty-four-hour esophageal pH monitoring is a valuable tool for preoperative cough-reflux correlation. Antireflux surgery is effective in carefully selected patients whose refractory CC is attributable only to GERD. NF controls the severity of cough while improving the quality of life. Outcomes are further enhanced using laparoscopic procedures with shorter hospital stays.

Chronic Disease↗
PubMed2001

Cough and gastroesophageal reflux: identifying cough and assessing the efficacy of cough-modifying agents.

From a symptom research standpoint, much has been learned about the management of cough in general and cough caused by gastroesophageal reflux disease in particular. Yet, before further advances can be made in our understanding of how to best manage patients with this common symptom, methodologic challenges remain to be solved. One of the most basic is the development of valid and reliable methods by which to identify cough, assess its impact on patients, and assess the efficacy of cough therapies. Herein, we review the characteristics of cough that relate to its assessment and how the effect of drug treatment on cough has been assessed. Perspective is provided on evaluating the efficacy of cough-modifying agents and the optimal method for identifying a cough and linking it with a reflux event. Investigators should use both subjective and objective methods, because they have the potential to measure different aspects of cough. Subjective measures, such as a cough-specific quality-of-life instruments, are likely to best reflect the severity of cough from the patient's standpoint, because a subjective response most likely integrates both cough frequency and intensity. The ideal objective method should allow cough to be automatically counted over 24 hours in an ambulatory setting. Although it is theoretically possible to design and construct such a device that is also relatively unobtrusive, reliable, and accurate, one is not yet available.

Antitussive Agents↗
PubMed2001

Symptom research on chronic cough: a historical perspective.

This review provides a perspective on how research on the management of cough has evolved, looks at key methodologic lessons that have been learned from this research and how they may relate to the management of other symptoms, identifies important methodologic challenges that remain to be solved, and lists important questions that still need to be answered. Three important methodologic lessons have been learned. First, cough must be evaluated systematically and according to a neuroanatomic framework. Second, the response to specific therapy must be noted to determine the cause or causes of cough and to characterize the strengths and limitations of diagnostic testing. Third, multiple conditions can simultaneously cause cough. Among the three methodologic challenges that still need to be solved are 1) definitively determining the diagnostic accuracy and reliability of 24-hour esophageal pH monitoring and how best to interpret pH test results, 2) definitively determining the role of nonacid reflux in cough due to gastroesophageal reflux disease, and 3) developing reliable and reproducible subjective and objective methods with which to assess the efficacy of cough therapy. Numerous important clinical questions are still unanswered: What role do empirical therapeutic trials play in diagnosing the cause of chronic cough? What is the most cost-effective approach to the diagnosis and treatment of chronic cough: empirical therapeutic trials or laboratory testing-directed therapeutic trials? How often is environmental air pollution, unrelated to allergies or smoking, responsible for chronic cough?

Clinical Protocols↗
PubMed2000

The cough reflex and its relation to gastroesophageal reflux.

Each cough involves a complex reflex arc beginning with the stimulation of sensory nerves that function as cough receptors. There is evidence, primarily clinical, that the sensory limb of the reflex exists in and outside of the lower respiratory tract. Although myelinated, rapidly adapting pulmonary stretch receptors (RARs), also known as irritant receptors, are the most likely type of sensory nerve that stimulates the cough center in the brain, afferent C-fibers and slowly adapting pulmonary stretch receptors (SARs) also may modulate cough. RARS, C-fibers, and SARs have been identified in the distal esophageal mucosa; however, studies have not been performed to determine whether they can participate in the cough reflex. Although gastroesophageal reflux disease can potentially stimulate the afferent limb of the cough reflex by irritating the upper respiratory tract without aspiration and by irritating the lower respiratory tract by micro- or macroaspiration, there is evidence that strongly suggests that reflux commonly provokes cough by stimulating an esophageal-bronchial reflex. Theoretically, the pathways of this reflex may be modeled in a variety of ways, and these are speculated upon in this article. The predominant role of acid in triggering cough by means of this reflex is unclear because of conflicting results from provocative challenge studies. It is interesting to speculate that a distal esophageal-bronchial reflex evolved as an early warning defense so that coughing could be started, just in case the refluxate were to reach the inlet of the lower respiratory tract. That is, thinking teleologically, it is possible that an esophageal-bronchial reflex evolved as one of several mechanisms designed to protect the lungs from aspiration of gastric contents.

Bronchi↗
PubMed2000

Anatomical diagnostic protocol in evaluating chronic cough with specific reference to gastroesophageal reflux disease.

Using the anatomic, diagnostic protocol, the cause of chronic cough can be determined 88% to 100% of the time, leading to specific therapy with success rates of 84% to 98%. Gastroesophageal reflux disease (GERD), along with postnasal drip syndrome (PNDS) and asthma, is one of the three most common causes of chronic cough in all age groups. When GERD is the cause of chronic cough, there may be no gastrointestinal (GI) symptoms up to 75% of the time, and, in these cases, the term "silent GERD" is used. The most sensitive and specific test for GERD is 24-hour esophageal pH monitoring. In interpreting this test, it is essential not only to evaluate the duration and frequency of the reflux episodes but also to determine the temporal relationship between reflux and cough events. Patients with normal standard reflux parameters still may have reflux diagnosed as the likely cause of cough if a temporal relationship exists. The definitive diagnosis of cough resulting from GERD can only be made if cough goes away with antireflux therapy. When 24-hour esophageal pH monitoring cannot be done, an empiric trial of antireflux medical therapy is appropriate when GERD is a likely cause of chronic cough. It is likely in the following settings: patients with prominent GI symptoms consistent with GERD and/or those with no GI complaints and normal chest x-rays, who are not taking angiotensin-converting enzyme inhibitors and who are not smoking, and in whom asthma and PNDS have been excluded. However, if empiric treatment fails, it cannot be assumed that GERD has been ruled out as a cause of chronic cough; rather, objective investigation for GERD is recommended, because the empiric therapy may not have been intensive enough or it may have failed. In treating patients with chronic cough resulting from GERD, cough has been reported to resolve with medical therapy 70% to 100% of the time. Mean time to recovery may take as long as 161 to 179 days, and patients may not start to get better for 2 to 3 months. In patients who fail to respond to maximal medical therapy, antireflux surgery can be successful.

Chronic Disease↗
PubMed1999

Silencing chronic cough.

The cause can almost always be identified. Postnasal drip syndrome, asthma, or gastroesophageal reflux disease account for most cases. The differential diagnosis also includes ACE inhibitor therapy, pertussis, and, in up to 80% of patients, multiple causes. Response to treatment may offer diagnostic confirmation but can be slow in coming.

Adult↗
PubMed1998

Chronic obstructive pulmonary disease.

Acute exacerbations of underlying COPD are a common cause of respiratory deterioration. Developments have been made in preventive measures, but admission to hospital for acute exacerbations can be expected to remain common. Several expert consensus guidelines have been published to define the appropriate management of COPD patients. These consensus guidelines generally agree, but all acknowledge a lack of large well-controlled clinical studies, especially studies focusing on the management of acute exacerbations. Consequently, many potential controversies exist about the details of managing patients with acute exacerbations. Although studies of many fundamental aspects of management are still needed, the results of controlled clinical trials are sufficient to emphasise the importance of a careful clinical assessment, supplemental oxygen, inhaled bronchodilators to partially improve airway obstruction, corticosteroids to decrease the likelihood of treatment failures and to speed recovery, antibiotics, especially in severe patients, and non-invasive positive-pressure ventilation for treatment of acute ventilatory failure in selected patients.

Acute Disease↗
PubMed1998

From a prospective study of chronic cough: diagnostic and therapeutic aspects in older adults.

BACKGROUND: Cough is the most common complaint for which adults see a physician in the ambulatory setting in the United States. An anatomical diagnostic protocol has been used since 1981 to evaluate patients with chronic cough. It has been shown to be effective in diagnosing the cause of cough and leading to specific treatment in a variety of adult populations but has never been evaluated specifically in a population of older adults. OBJECTIVES: To question whether the spectrum and frequency of causes of chronic cough and the response to therapy would be different in older adults. METHODS: Thirty patients at least 64 years of age with a history of cough lasting at least 3 weeks were prospectively evaluated with a protocol designed to detect diseases that stimulate the afferent limb of the cough reflex. The final diagnosis of the cause of chronic cough required fulfillment of pretreatment criteria and having cough disappear with specific therapy. When more than one disease fulfilled pretreatment diagnostic criteria, therapy was instituted in the order that these were fulfilled. Probability statistics were used to describe the testing characteristics of individual components of the diagnostic protocol in terms of sensitivity, specificity, positive predictive value, and negative predictive value as they applied to chronic cough. RESULTS: Forty causes of chronic cough were identified in all 30 patients. Postnasal drip syndrome, gastroesophageal reflux disease, and asthma were the most common causes of chronic cough, accounting for 85% of all causes found. Among patients with normal chest radiograph findings who were not cigarette smokers and not taking an angiotensin-converting enzyme inhibitor, postnasal drip syndrome, gastroesophageal reflux disease, and asthma accounted for 100% of all causes found. Specific therapy was successful in eliminating chronic cough in 100% of the patients studied. Except for barium esophagography, all laboratory tests for which information was available had sensitivities and negative predictive values of 100%. CONCLUSIONS: Postnasal drip syndrome, gastroesophageal reflux disease, and asthma accounted for 85% of all causes of chronic cough in older adults. Chronic cough caused substantial physical and emotional morbidity among older patients. The major value of performing objective testing in evaluating chronic cough is its ability to rule out specific diseases as a diagnostic possibility. The following clinical profile consistently predicts patients with cough attributable to gastroesophageal reflux disease: the patient has cough that has been persistently troublesome for at least 3 weeks; does not smoke cigarettes; does not take an angiotensin-converting enzyme inhibitor; does not have or has not responded to therapy for postnasal drip syndrome and asthma; and has normal or nearly normal findings and stable chest radiograph. The differences between what we observed regarding chronic cough in older adults and observations by ourselves and others regarding chronic cough in general are minor.

Aged↗
PubMed1998

Perforation of the right ventricle: a complication of blind placement of a chest tube into the postpneumonectomy space.

We were asked to review a case from an outside hospital in which there was inadvertent perforation of the right ventricle during the percutaneous placement of a chest tube. We present the case in the hopes that by doing so, others will avoid such a complication in the future. After reviewing the case, it appeared that the complication occurred because the physician was not knowledgeable about the anatomy of the postpneumonectomy space and the physician failed to use the safest procedure in placing the tube.

Bronchiectasis↗
PubMed1997

Interpretation of positive results of a methacholine inhalation challenge and 1 week of inhaled bronchodilator use in diagnosing and treating cough-variant asthma.

BACKGROUND: In diagnosing cough due to asthma, methacholine chloride inhalation challenge (MIC) interpreted in a traditional fashion has been shown to have positive predictive values from 60% to 82%. OBJECTIVE: To determine whether any features of positive results of an MIC or the results of a 1-week trial of inhaled beta-agonist therapy were helpful in predicting when the cough was due to asthma. METHODS: The study design was a prospective, randomized, double-blind, placebo-controlled, crossover format performed in adult, nonsmoking subjects, who were referred for diagnosis and treatment of chronic cough. The subjects had no other respiratory complaints or medical conditions for which they were taking medications, the results of baseline spirometry and chest roentgenograms were normal, and the results of MIC were positive. After obtaining baseline data, including MICs on 2 separate days, objective cough counting, and self-assessment of cough severity using a visual analog scale, subjects were randomized to receive 2 inhalations (1.3 mg) of metaproterenol sulfate or placebo by metered dose inhaler attached to a spacer device every 4 hours while awake. At 1 week, data identical to baseline were collected, and subjects received the other metered dose inhaler for 7 days. At 1 week, data identical to baseline were collected. After completion of the protocol, subjects were followed up in the clinic to observe the final response of the cough to specific therapy. RESULTS: Based on the disappearance of the cough with specific therapy, the cough was due to asthma in 9 of 15 subjects and nonasthma in 6 of 15 subjects. Baseline data were similar between groups. With respect to MICs, there were no significant differences between groups in the cumulative dose of methacholine that provoked a 20% decrease in forced expiratory volume in 1 second from the postsaline baseline value (PD20 values), slopes of dose-response curves, and maximal-response plateaus. Cough severity significantly improved after 1 week of metaproterenol use compared with the severity of the cough at baseline (P = .03) and with placebo (P = .02) only in subjects with asthma. CONCLUSIONS: No matter how the results are analyzed, positive MIC results, without observing response to therapy, are only consistent with asthma as the cause of the cough. The results are only diagnostic of asthma when they are followed by a favorable response to asthma therapy. After 1 week of inhaled beta-agonist, only the cough due to cough-variant asthma is significantly better.

Administration, Inhalation↗