Definition of Chronic Cough and GERD - Research Paper Example

? of The of the Science Paper/Project Proposal Pediatrics has recently been faced with numerous GERD and chronic cough related complications in their patients. Fortunately, the many studies and publications on the relationship between GERD and chronic cough have helped pediatrics to treat and mange GERD-related chronic cough better. However, there are still debates on the causal links between GERD and chronic cough, prompting the writing of this state of the science paper, which seeks to explore the already researched and published findings on the subject. Hopefully, the literatures and study findings reviewed will highlight the causal link between these conditions so that the management and treatment of infants, children, and adolescents with GERD and GERD-related chronic cough could be made more accessible and effective. In this state of the science paper, different types of literatures will be reviewed, among them books, magazines, electronic and print articles from public and institutional libraries. The paper will focus on the various issues on the topic on which stakeholders agree and disagree, mentioning any gaps therein. Specifically, the causal link between GERD and chronic cough in pediatric patients will be explored. In this context, the paper will introduce the topic then discuss the history of the GERD-Chronic cough links, review the available literatures on epidemiology, statistics, and the clinical features of the conditions. Finally, the paper will explore the different perceptions adopted by respiratory and gastroenterology studies and publications. Outline of Content Areas I. Definition of chronic cough and GERD II. Causes, signs, and symptoms of GERD and chronic cough III. Epidemiology of GERD and chronic cough IV. The causal link between GERD and chronic cough V. Clinical Features of GERD and Cough Databases www.medicinenet.com www.sciencedaily.com www.nature.com www.cdc.gov/datastatistics www.mediplus.co.uk www.hhs.gov/ Introduction Pediatrics refers to the medical profession concerned with the health care of infants and children. However, the profession covers even adolescent health care in some instances. A health care provider specializing in child, infant and adolescent care is thus referred to as a pediatrician. Gastroesophageal reflux disease (GERD) and chronic cough are examples of the many diseases that pediatricians encounter in their professional interaction with infants and children. GERD is a condition characterized by food (solid or liquid) already in the stomach being thrown back into the esophagus, causing irritation and the commonest and most obvious symptom of GERD, heartburn (Orlando, 2007). Once food is eaten and drawn into the stomach, the muscular fibers referred to as the lower esophageal sphincter (LES) prevent the food from moving back into the esophagus. If the LES fails to close well, the swallowed food leaks back into the esophagus, a process known as reflux or gastroesophageal reflux, which in more serious situations could lead to esophageal damage. The risk factors associated with GERD include alcohol, obesity, pregnancy, scleroderma, smoking, and medications such as beta-blockers and calcium channel blockers (high blood pressure or heart disease), and sedatives (Schiffman, 2011). Symptoms of GERD include nausea, wheezing, cough, regurgitation, hoarseness, feelings of food being stuck behind the breastbone, and heartburn. The condition may be increased by eating, stooping, bending, and lying down while it is relieved by antacids. Complications that result from GERD include asthma, Barrett's esophagus, and chronic cough or hoarseness. A chronic cough on the other hand is a persistent cough. Chronic cough, though an indication of underlying diseases, is a major cause of health facility visits among infants and children. Among the causes of cough are sinus infections, allergic rhinitis, asthma, and esophageal reflux of stomach contents. It is the causal relationship between GERD and chronic cough in pediatric patients that is the focus of this state of science paper. Specifically, this paper explores the knowledge published on the causal link between chronic cough and GERD, by scholars and researchers, the strengths and weaknesses of these publications and researches, current researches and publications, and the gaps therein. Literature Review To obtain knowledge and researches done so far on the causal links between chronic cough and GERD among pediatric patients, a variety of sources were considered. These literary source included books, newspapers, scientific publications, scholarly journals, internet articles, and institutional and public libraries. In most of the reviewed literatures, it could be noted that two general approaches and perceptions have been adopted by the respiratory and the gastroenterology stakeholders of GERD-Chronic cough research and publication (Orlando, 2007). Nonetheless, both sides seem to concur that a causal link does exist between GERD and chronic cough in children and adults. One easily identifiable gap is that not much information is available on children and infant chronic cough patients as it is on adult patients (Orlando, 2007). The reason for this scenario is that most researches have targeted adult patients. However, the few cases of child-based researches and publication, coupled with the extrapolation of these findings to the case of pediatric patients indicate that the link is similar in infants and children). A lot of literatures have been written and researches carried out to help establish the causal relationship and the co-existence of cough and gastroesophageal reflux disease (GERD). However, it has become rather difficult to ascertain the causes and effects of these conditions due to factors such as the occurrence of common symptoms in both cases. Furthermore, the ever-changing definition of GERD, insufficient equipment, and lack of randomized controlled trials also make it rather difficult to establish the causal links between chronic cough and GERD (Orlando, 2007). Consequent to these difficulties in ascertaining the causal and effect links between cough and GERD, opinions greatly vary between respiratory and gastroenterology stakeholders on the link between these conditions. Since historical times, a number of chronic cough prevention and management guidelines have been designed with some having more positive effects on patients than others do. Most involved in these guideline publications are American and European respiratory care stakeholders who also promote empirical treatment of gastroesophageal reflux disease (GERD) via medications such as proton pump inhibitors. On the contrary, guidelines by gastroenterological groups have not been clear enough on the relationship between GERD and cough as portrayed in respiratory publications (Orlando, 2007). Literatures and studies have elaborated quite a lot about GERD and chronic cough in pediatric patients. The History of GERD The causal relationship between chronic cough and GERD was first noted by Richard Irwin and his co-workers in 1981 when they carried out investigations on the range and frequency of the causes of chronic cough. After this study, these investigators realized that GERD was the fourth most common cause of chronic cough with 10% prevalence. As more advanced medical instruments and procedures were acquired, studies linked GERD with between 36% and 41% of cases of chronic cough. Currently, GERD stands the second most common cause of chronic cough (Sifrim et al, 2005). Consequent to the advent of these medical technologies and procedures, researchers have been able to elucidate the physiologic processes by which GERD causes cough. As mentioned earlier, GERD is caused by the regurgitation or reflux of gastric fluid into the esophagus and is characterized by frequent or unrelenting indigestion, an acidic or sour mouth or throat aftertaste, chest pain, coughing, wheezing, and difficulties in swallowing among other symptoms. According to the American College of Emergency Physicians, GERD accounts for about 60% of pediatric patient visits to the emergency room with non-heart related chest pain (Sifrim et al, 2005). If GERD is suspected due to severe abdominal and chest pain or discomfort, immediate medical treatment should be sought so that the physical causes of GERD are treated in time to evade more serious problems. Gastroesophageal reflux (GERD) has been found to be closely linked to chronic cough, which has more than twenty causes, which work in combinations in most cases of chronic cough. However, if treatments that are specific to the identified causes are applied, a resolution of up to 98% is often attained (Sifrim et al, 2005). As a matter of fact, Gastroesophageal reflux is a common cause of chronic cough, which may be improved or eliminated by the use of a GERD-specific therapy. GERD is a big concern to pediatrics since in at least 75% of the cases in which it causes chronic cough, it is often clinically silent. This situation is serious considering that GERD causes about 40% of the cases of chronic cough, not accounting for the clinically silent GERD (Irwin et al., 1998). Many literatures have sought to explain the pathophysiological mechanisms by which GERD causes chronic cough. Generally, the pathophysiology entails an esophagotracheobronchial cough reflex, non-acid gastric refluxate, esophageal dysmotility, and micro-aspiration. Due to the established links between chronic cough and GERD, there have been numerous evidence-based GERD-based guidelines for chronic cough diagnosis and management such as the one published by the American College of Chest Physicians in January 2006. Emphasized by this and other similar publications is the essence of starting on practical GERD therapies, combined with lifestyle changes and proton pump inhibition not only to identify but also to manage and treat GER-related chronic cough. According to the publication, these guidelines would lead to cough resolution within two weeks of a Proton Pump Inhibitor (PPI) therapy. However, it may last up to 50 days in some resistant cases. For non-responders to the above combination of therapies, the guideline recommends esophageal pH testing and impedance monitoring whereas for patients with non-acid GERD, the guideline recommends fundoplication. Epidemiology of GERD and Chronic Cough The other aspect of GERD and GERD-related chronic cough well covered in literatures and researches is their epidemiology. By studying patients’ responses to GERD therapies, researchers have been able to study the prevalence of GERD, reporting that GERD is currently the most common cause of chronic cough in pediatric and older patients. However, to establish whether GERD is the cause of a cough is a particularly difficult exercise since in many patients, there is more than one likely cause of chronic cough (Koufmanet al., 2010). For example, in a more recent study, it was revealed that up to 62% of pediatric chronic cough cases were found to have more than one cause. Interestingly, a single cause of chronic cough was found in 38% to 82% of the cases while two causes of cough were found in 18% to 62%. In Addition, three causes of cough were found in up to 42% of cases. In general, researches have shown that GERD causes chronic cough in about 25% of adults. Nonetheless, these data are subject to the definition and diagnosis of GERD applied. That is, if GERD diagnosis were done by barium esophagram, endoscopy, or history, about 10% of chronic cough patients would be found to have GERD (Poe & Kallay, 2003). If on the other hand a twenty-four hour esophageal testing were conducted, GERD would be found to cause about 40% of chronic cough cases. That GERD could be clinically silent in some patients has been a challenge to epidemiology studied on GERD and GERD-related cough. For an illustration, in Irwin’s study, it was observed that 43% of cough patients, as shown by their positive response to GERD therapy, reported not having experienced GERD symptoms such as heartburn or sour taste in mouth or throat. Thus, cases abound in which patients respond positively to GERD therapy while they did not have any prior encounter with GERD symptoms, making it a challenge to GERD epidemiology studies. There are several closely related clinical features of GERD and chronic cough that make them rather crucial issues for pediatrics given the causal links between them. Clinical Features of GERD and Cough The clinical features of GERD and cough are the other largely covered concepts in literatures and researches. Coughs that are at least partially caused by GERD have symptoms such as regurgitation or heartburn. In fact, consuming foods such as chocolate and peppermint or drugs such as alcohol, which have been shown to decrease LES pressure could imply and indicate the worsening of a GERD-related cough (Schiffman, 2011). According to Irwin and his colleagues, the clinical profile of individuals with GERD-related cough include normal chest radiographs, individuals not exposed to environmental irritants, non-smokers, and non-consumers of chronic cough-causing medications such as ACE inhibitors. Further, asthma has been ruled out for GERD-related cough patients since such coughs are not improved by aggressive asthma therapies or negative methacholine inhalation challenge test. Additionally, victims of GERD-related chronic cough do not suffer from upper airway cough syndrome since the cough does not improve under first-generation H1-antagonist therapy. In addition, a sinus computed tomography (CT) scan does not show any evidence of sinusitis. The other condition ruled out of GERD-related cough profile is non-asthmatic eosinophilic bronchitis, since the cough does not respond to inhaled or systemic corticosteroids. This profiling is further supported by the lack of eosinophils in sputum cytology. Therefore, the presence of the above symptoms in a pediatric patient should not be taken to suggest GERD-related cough. To evaluate whether a cough has been caused by GERD, it does not help to study the timing or the features of the cough. Whether a cough is at least partially caused by GERD could be ascertained by asking patients about the presence of classic esophageal GERD symptoms such as heartburn, regurgitation, and dysphagia (Schiffman, 2011). Among the external indication of the presence of GERD are dysphonia, sore throat, hoarseness (especially after eating), and globus (Elliot, 2012). The other features of GERD and GERD-related chronic cough in pediatric patients are nonproductive daytime cough, which lasts for 58 months and any cough that is aggravated by asthma medications that are considered causes of GERD such as calcium channel blockers, progesterone, inhaled 2-adrenergic agonists, and oral corticosteroids. To ascertain the existence of GERD, physical examination and outcome reports are highly recommended although such findings are often normal. For instance, rales, wheezing, and other features consistent with other pulmonary diseases are not observed in such examinations (Elliot, 2012). However, patients could cough during examinations and laryngeal inflammation on upper airway endoscopy could be detected. It is also important to conduct laboratory testing for GERD-related chronic cough patients. Laboratory tests are necessary to help eliminate other causes of cough and to confirm the presence of GERD. The recommended evaluations include chest radiograph, high-resolution CT chest scan, spirometry, sinus CT scan, upper airway examination, cardiac evaluation, sputum cytology, bronchoscopy, and pertussis evaluation. The chest radiograph test helps to establish the existence or the absence of an underlying pulmonary disease such as lung disease while high-resolution CT chest scan helps in the elimination of other pulmonary parenchymal causes of chronic cough (Feldman et al., 2010). On the other hand, sinus CT scan and upper airway examination are important in testing for sinusitis and upper airway cough syndrome. The cardiac evaluation step tests for the possibility of pulmonary edema. These tests may be done by primary care physicians, allergists, or pulmonologists Treatment for GERD-Related Chronic Cough The other vastly covered area on GERD and GERD-related chronic cough in literatures and researches is the conditions’ treatment and management. In many literatures, the efficacy of lifestyle changes, which result in weight loss for obese patients, has been well covered. Also stressed is the importance of acid-suppressive therapies using proton pump inhibitors. The dosage for this therapy is recommended to be 30 minutes before breakfast and thirty minutes before dinner. It is important for GERD-related chronic cough patients to adhere to this therapy until the cough improves or resolves (Feldman et al., 2010). When signs of improvement or resolution are observed, the physician may reduce the dosage to once a day or switch to other therapies such as H2-blocker. If even a high dosage of proton pump inhibitor (PPI) does result in cough resolution, the physician may add prokinetic agents (Feldman et al., 2010). Moreover, a high-dose of PPI is recommended for patients with dysphagia. Evidences for the Causal Link between GERD and Chronic Cough Past and recent studies and publications are evidences that cough’s and GERD’s co-existence is indisputable. In fact the co-existence is observed in both adults and children. Nonetheless, whether GERD causes cough or vice versa remains a contentious issues. That is, can the symptoms of cough be attributed to GERD? Notwithstanding these controversies and the resultant debates among stakeholders, GERD and cough remain serious health issues that continue to burden society, whether as isolated conditions or as a combined problem (Sifrim et al, 2005). As a matter of fact, chronic cough is not only an economic burden but it also accounts for a significant morbidity if current statistics is anything to go by. The two most common symptoms of cough and reflux are often cited as the reason the two conditions could be linked. Researchers concur, in most studies on the two conditions, that the equally high prevalence of these symptoms in populations could be an indication of the increased chances of these conditions occurring together. That is, in a group study targeting individuals with chronic cough, the chance that GERD could occur as an independent event is less than a quarter. Although the two symptoms may merely exist together, it has also been the interest of researchers to determine, which of the symptoms of cough and reflux come first. Just like in the issue of the co-existence of the symptoms, expert opinions vary on which of these symptoms come first (Koufmanet al., 2010). Research findings have indicated that approximately 70% of cough events in study subjects suffering from chronic cough occur independently of reflux while 30%occur within minutes of a reflux episode (Sifrim et al, 2005). The differences in opinions regarding the causal and effect links between GERD and cough are also noticeable in the publications of respiratory and gastroenterology stakeholders. Specifically, the differences are more pronounced in the adult respiratory and gastroenterological societies’ guidelines on the possible links between cough and GERD symptoms. For instance, while gastroenterological publications take a cautious approach in linking cough symptoms with GERD symptoms, their respiratory counterparts fundamentally endorse the cause-and-effect relationship between cough and GERD (Sifrim et al, 2005). Second, while the latest gastroenterological publications recommendations are chiefly based on meta-analysis and systematic reviews, cough publication guidelines tend to omitted meta-analysis data, which record same outcomes as the approach used by gastroenterology societies. There is also the argument among professionals that GERD could deceive as a chronic cough. Acid Reflux: GERD Can deception As Persistent Cough Research has shown that rather few people recognize that symptoms such as chronic cough and chest pain could be a result of acid reflux into the esophagus. This situation is particularly due to the fact that many people fail to experience the classic heartburn or acid regurgitation symptoms. In two studies presented at the 72nd ACG Annual Scientific Meeting, this often unrealized causal links between cough, GERD, and other unrelated health problems was brought light. One such unrelated problem was Emphysema. The first study was carried among 31 patients at Boston’s Brigham & Women's Hospital’s emergency rooms. The study targeted women with chest pain, measuring and recording their esophageal PH for two days. The study sought to establish any relationship between excessive PH and chest pain. The study’s findings of the diagnosis of the participants indicated that 57% of them had an abnormal reflux of acid that fits a GERD diagnosis. According to the lead investigator in this study Dr. Julia Liu, many a research has overlooked the influence of acid reflux in serious chest pain diagnosis and treatment. Nonetheless, Dr. Julia adds that patients should not have the assumption that all chest pains are caused by GERD and advises that an evaluation by a physician to rule out heart disease should be conducted. Conclusion GERD and chronic cough are some of the health problems that pediatricians handle. Past and recent studies and publications have worked in favor of pediatricians, more so regarding the links between GERD and chronic cough. Most of these studies and publications support the existence of a causal link between chronic cough and GERD, making the treatment of these two conditions rather easy. Sometimes, GERD combines with other factors to cause chronic cough, implying that other possible causes of chronic cough have to be eliminated via various examinations before a cough could be ascertain as GERD-related. This is to say, not all chronic coughs are caused by GERD and thorough diagnoses should be conducted. References Elliot, J. (2012). Medifocus guidebook on: gastroesophageal reflux disease. CreateSpace Independent Publishing Platform. Feldman, M. Friedman, L. S., Brandt, L. J. (2010). Sleisenger and Fordtran's Gastrointestinal and liver disease, ninth edition. Saunders. Koufman, J., Stern, J., and Bauer, M. M. (2010). Dropping acid: the reflux diet cookbook & cure Reflux Cookbooks. Orlando, R. C. (2007). Gastroesophageal reflux disease. Taylor & Francis. Schiffman, G. (2011). “Chronic Cough.” Retrieved on October 23, 2012 from http://www.medicinenet.com/chronic_cough/article.htm Sifrim, D., Dupont, L., Blondeau, K., Zhang, X., Tack, J., and Janssens, J. (2005). “Weakly Acidic Reflux in Patients with Chronic Unexplained Cough during 24 Hour Pressure, Ph, and Impedance Monitoring.” Gut, 54: 454. Read More