Aspiration of solid food particles into lungs of patients with gastroesophageal reflux and chronic bronchial disease

Expert-level aspiration and penetration detection during flexible endoscopic evaluation of swallowing with artificial intelligence-assisted diagnosis

Flexible endoscopic evaluation of swallowing (FEES) is considered the gold standard in diagnosing oropharyngeal dysphagia. Recent advances in deep learning have led to a resurgence of artificial intelligence-assisted computer-aided diagnosis (AI-assisted CAD) for a variety of applications. AI-assisted CAD would be a remarkable benefit in providing medical services to populations with inadequate access to dysphagia experts, especially in aging societies. This paper presents an AI-assisted CAD named FEES-CAD for aspiration and penetration detection on video recording during FEES. FEES-CAD segments the input FEES video and classifies penetration, aspiration, residue in the vallecula, and residue in the hypopharynx based on the segmented FEES video. We collected and annotated FEES videos from 199 patients to train the network and tested the performance of FEES-CAD using FEES videos from other 40 patients. These patients consecutively underwent FEES between December 2016 and August 2019 at Fukushima Medical University Hospital. FEES videos were deidentified, randomized, and rated by FEES-CAD and laryngologists with over 15 years of experience in performing FEES. FEES-CAD achieved an average Dice similarity coefficient of 98.6[Formula: see text]. FEES-CAD achieved expert-level accuracy performance on penetration (92.5[Formula: see text]), aspiration (92.5[Formula: see text]), residue in the vallecula (100[Formula: see text]), and residue in the hypopharynx (87.5[Formula: see text]) classification tasks. To the best of our knowledge, FEES-CAD is the first CNN-based system that achieves expert-level performance in detecting aspiration and penetration.

Different clinical symptom patterns in patients with reflux micro-aspiration

Background

Pulmonary manifestation of gastro-oesophageal reflux disease (GORD) is a well-recognised entity; however, little primary reported data exists on presenting symptoms of patients in whom reflux micro-aspiration is confirmed. The aim of this study is to report symptoms and presenting patterns of a large group of patients with confirmed reflux micro-aspiration.

Patients and methods

Data was extracted from a prospectively populated database of patients referred to a tertiary specialist centre with severe, refractory or atypical reflux. Patients with reflux micro-aspiration on scintigraphy were included in this study. A separate group included patients with evidence of proximal reflux to the level of pharynx when supine and/or upright.

Results

Inclusion criteria were met by 243 patients with confirmed reflux micro-aspiration (33% males; mean age 59). Most common symptoms amongst patients with micro-aspiration were regurgitation (72%), cough (67%), heartburn (66%), throat clearing (65%) and dysphonia (53%). The most common two-symptom combinations were heartburn/regurgitation, cough/throat clearing, regurgitation/throat clearing, cough/regurgitation and dysphonia/throat clearing. The most common three-symptom combinations were cough/heartburn/regurgitation, cough/regurgitation/throat clearing and dysphonia/regurgitation/throat clearing. Cluster analysis demonstrated two main symptom groupings, one suggestive of proximal volume reflux symptoms and the other with motility/inflammatory bowel syndrome-like symptoms (bloat, constipation).

Conclusion

The combination of typical symptoms of GORD such as heartburn or regurgitation and a respiratory or upper aero-digestive complaint such as cough, throat clearing or voice change should prompt consideration of reflux micro-aspiration.

Patients with reflux micro-aspiration most commonly present with a combination of regurgitation and/or heartburn and cough and/or throat clearinghttps://bit.ly/3GM8cNS

The Relation Between the Presence of Aspiration or Penetration and the Clinical Indicators of Dysphagia in Poststroke Survivors

Objective

To examine the relation between the presence of penetration or aspiration and the occurrence of the clinical indicators of dysphagia. The presence of penetration or aspiration is closely related to the clinical indicators of dysphagia. It is essential to understand these relationships in order to implement proper diagnosis and treatment of dysphagia.

Methods

Fifty-eight poststroke survivors were divided into two groups: patients with or without penetration or aspiration. Medical records and videofluoroscopic swallowing examinations were reviewed. The occurrence of clinical indicators of dysphagia between two groups was analyzed with Cross Tabulation and the Pearson chi-square test (p<0.05).

Results

Poststroke survivors with penetration or aspiration had significantly high occurrences of delayed initiation of the swallow (p=0.04) and reduced hyolaryngeal elevation (p<0.01) than those without penetration or aspiration.

Conclusion

The results of this study indicate that delayed initiation of the swallow is a strong physiological indicator of penetration or aspiration during the oral stage of swallowing in poststroke survivors. For the pharyngeal stage of swallowing, hyoid and laryngeal elevation is a key event related to occurrence of penetration or aspiration. Clinical indicators should be investigated further to allow appropriate implementation of treatment strategies for stroke survivors.

Airway pH monitoring in patients with suspected obstructive sleep apnoea using the Dx-pH oropharyngeal probe: preliminary report of a prospective cohort study

OBJECTIVES

To investigate the laryngopharyngeal reflux (LPR) episodes and pH values in patients with suspected obstructive sleep apnoea (OSA) using the Dx-pH oropharyngeal probe.

DESIGN

Prospective cohort study.

SETTING

Tertiary medical centre.

PARTICIPANTS

Forty patients with complaint of snoring or suspected OSA were prospectively enrolled to receive full nocturnal polysomnography (PSG). The patients were divided into 2 groups: a simple snorers group if the Respiratory Disturbance Index (RDI) was < 5 and an OSA group if the RDI was ≥ 5.

MAIN OUTCOME MEASURES

The patients simultaneously received Dx-pH oropharyngeal probe monitoring for 12 h from about 6 pm to 6 am of the next day. The number of LPR events was recorded if the nadir of rapid pH drops was below pH 5.0 and 5.5. The difference of LPR events between the two groups and the difference of LPR events between awake and sleep periods in each group were analysed, respectively.

RESULTS

There were 18 (45%) patients diagnosed as OSA with a mean RDI of 28.7, and 22 patients (55%) diagnosed as simple snorers. Between 2 groups, there were no significant differences in the LPR events and pH values during the awake period, sleep period or overall recording period. Comparison of the LPR events and minimum pH values between the awake period and the sleep period revealed there were no significant differences in either group.

CONCLUSION

Using the new sensitive Dx-pH oropharyngeal probe with PSG, we found that OSA does not correlate with a higher incidence of LPR episodes.

Association between Helicobacter pylori and asthma: a meta-analysis

OBJECTIVE

Helicobacter pylori infection is recognized as a worldwide public health threat. Some studies have suggested that individuals with asthma have a lower rate of H. pylori infection, but the relation remains controversial. This meta-analysis was carried out to quantify the association between H. pylori infection and asthma.

METHODS

Published information on the prevalence of H. pylori in individuals with asthma was collected to assess the potential associations between H. pylori infection and the risk of asthma. Fourteen eligible studies were selected for analysis. Data on the study populations, detection method of H. pylori, and publication year were summarized. Meta-regression models and subgroup analyses were established to screen the factors resulting in heterogeneity.

RESULTS

Of the 106 articles retrieved, 14 fulfilled the inclusion criteria. The 14 studies involved 28 283 patients, with a total H. pylori infection rate of 40.53%. This meta-analysis found a significantly lower rate of H. pylori infection in the asthmatics than in the controls (odds ratio=0.84, 95% confidence interval: 0.73-0.96, P=0.013). Subgroup analysis indicated a similar infection rate of CagA-positive H. pylori infection in the asthmatic group and the control group (odds ratio=0.73, 95% confidence interval: 0.41-1.28, P=0.03).

CONCLUSION

The pooled data suggest that asthmatics have a significantly lower rate of H. pylori infection. Large-scale and multicenter studies should be carried out to further determine the relation between this bacterium and allergic disorders.

Chronic cough: a multidisciplinary approach

BACKGROUND AND METHODS

Chronic cough is defined as a cough persisting for more than eight weeks. This condition generates significant healthcare and economic costs. It is associated with a spectrum of disorders across multiple medical specialties and can provide significant challenges for effective evaluation and management. The current literature was reviewed to gain further insight into chronic cough, including its relationship with sinonasal disease.

RESULTS

Within the reviewed literature, there was strong emphasis on post-nasal drip syndrome as a major causative factor.

CONCLUSION

Cough is the most common complaint for which adult patients seek medical consultation in primary care settings. Chronic cough is associated with a deterioration in the quality of patients' lives. Thorough assessment of a patient with a chronic cough relies on a multidisciplinary approach.

[Boundaries of the lung - Relationship to the gastrointestinal system]

The relation between the respiratory and gastrointestinal systems has been long recognized and depends on various anatomical, physiological and pathological mechanisms. The certain recognition of some interactions, such as the relation between asthma and gastroesophageal reflux, is more or less intuitive to the pulmonogist, whereas other areas of confluence are more easily missed, such as the relation between airway disorders and inflammatory bowel disease. The purpose of this article is to review the interaction between the lung and the gastrointestinal systems, as far as anatomy, physiology, pathology, clinical manifestations and therapeutical options go.

Does chronic microaspiration cause idiopathic pulmonary fibrosis?

Idiopathic pulmonary fibrosis is a diffuse fibrotic lung disease of unknown etiology with no effective treatment. Emerging data support a role for chronic microaspiration (ie, subclinical aspiration of small droplets) in the pathogenesis and natural history of idiopathic pulmonary fibrosis. However, the precise relationship between chronic microaspiration and idiopathic pulmonary fibrosis remains unknown. Gastroesophageal reflux, a presumed risk factor for microaspiration, has been strongly associated with idiopathic pulmonary fibrosis with an estimated prevalence of up to 90%. This review aims to describe the relationship between chronic microaspiration and idiopathic pulmonary fibrosis by laying out the clinical and biologic rationale for this relationship and exploring the scientific evidence available. The gaps in our current understanding of the diagnosis of chronic microaspiration and idiopathic pulmonary fibrosis and the ongoing uncertainties in management and treatment will be highlighted. Defining the role of chronic microaspiration in idiopathic pulmonary fibrosis is essential as it has potential clinical, pathobiological, and treatment implications for this deadly disease.

Characterization of the innate immune response to chronic aspiration in a novel rodent model

Background

Although chronic aspiration has been associated with several pulmonary diseases, the inflammatory response has not been characterized. A novel rodent model of chronic aspiration was therefore developed in order to investigate the resulting innate immune response in the lung.

Methods

Gastric fluid or normal saline was instilled into the left lung of rats (n = 48) weekly for 4, 8, 12, or 16 weeks (n = 6 each group). Thereafter, bronchoalveolar lavage specimens were collected and cellular phenotypes and cytokine concentrations of IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-10, GM-CSF, IFN-gamma, TNF-alpha, and TGF-beta were determined.

Results

Following the administration of gastric fluid but not normal saline, histologic specimens exhibited prominent evidence of giant cells, fibrosis, lymphocytic bronchiolitis, and obliterative bronchiolitis. Bronchoalveolar lavage specimens from the left (treated) lungs exhibited consistently higher macrophages and T cells with an increased CD4:CD8 T cell ratio after treatment with gastric fluid compared to normal saline. The concentrations of IL-1alpha, IL-1beta, IL-2, TNF-alpha and TGF-beta were increased in bronchoalveolar lavage specimens following gastric fluid aspiration compared to normal saline.

Conclusion

This represents the first description of the pulmonary inflammatory response that results from chronic aspiration. Repetitive aspiration events can initiate an inflammatory response consisting of macrophages and T cells that is associated with increased TGF-beta, TNF-alpha, IL-1alpha, IL-1beta, IL-2 and fibrosis in the lung. Combined with the observation of gastric fluid-induced lymphocyitic bronchiolitis and obliterative bronchiolitis, these findings further support an association between chronic aspiration and pulmonary diseases, such as obliterative bronchiolitis, pulmonary fibrosis, and asthma.

Omeprazole reduces the response to capsaicin but not to methacholine in asthmatic patients with proximal reflux

OBJECTIVE

To study the relationships between airway responsiveness to methacholine and capsaicin, proximal or distal reflux and the effects of short-term acid inhibition.

MATERIAL AND METHODS

Twenty-nine asthmatics, not taking steroids regularly, underwent respiratory symptom measurements, 24-h dual-probe pH monitoring, and challenges with methacholine and capsaicin. Challenges and symptom measurements were repeated after 12 days' omeprazole treatment (20 mg b.i.d.). The results (median and range) were expressed as PD20 methacholine (mg) and PD5 capsaicin (dose causing five coughs, nmol).

RESULTS

Seventeen patients presented pathological reflux in the distal esophagus, and 17 in the proximal esophagus. At baseline no correlation was found between PD20 or PD5 and reflux. Treatment with omeprazole did not change bronchial responsiveness to methacholine (basal: 0.16 mg, 0.02-1.27; omeprazole: 0.15 mg, 0.02-1.60); omeprazole decreased the tussive response to capsaicin (basal: 0.08 nmol, 0.08-2.46; omeprazole: 0.61 nmol, 0.08-9.84, p<0.001) only in patients with pathological reflux. The decrease was positively correlated with proximal acid exposure (r2=0.70, p<0.001). Omeprazole reduced asthma symptoms in patients with proximal reflux, cough in those with proximal or distal reflux.

CONCLUSIONS

In asthmatics, inhibition of gastric acid secretion does not influence bronchial hyperresponsiveness but decreases tussive sensitivity and this effect is related to proximal reflux.

The relationship between extraesophageal reflux (EER) and obstructive sleep apnea (OSA)

Obstructive sleep apnea (OSA) and extraesophageal reflux (EER) are common chronic diseases and share several similar risk factors. The prevalence of gastroesophogeal (GERD) in OSA patients is significantly higher than the general population; however, no temporal or causal relationship has ever been demonstrated between the two. The purpose of this review is to understand the association between obstructive sleep apnea (OSA) and extraesophageal reflux disease (EER) in the adult population. We conclude that CPAP treatment of OSA significantly reduces GERD symptoms and acidic pH exposure in the esophagus and this improvement with CPAP physiologically occurs in the presence or absence of OSA; and treatment of GERD in OSA patients improves the number of arousals during sleep, but only one study showed a significant difference in apnea.

Clinical implications of gastroesophageal reflux disease and swallowing dysfunction in COPD

The intimate anatomical and physiologic relationship between the upper airway and esophagus consists of complex interactions between various muscles and nerves with both voluntary and involuntary patterns of control. Alterations in this harmonic relationship can lead to swallowing abnormalities ranging from dysphagia to gross aspiration, gastroesophageal reflux disease (GERD) and chronic cough. There is a paucity of data regarding pathologic alterations in the upper airway-esophageal relationship in patients with COPD. The association between GERD and respiratory symptoms is well recognized in the setting of asthma; however, the nature of this relationship remains controversial. The association of GERD and COPD is even less clear. A review of the limited data on GERD and swallowing abnormalities in patients with COPD indicate that prevalence of GERD and esophageal disorders in patients with COPD is higher than in the normal population. However, its contribution to respiratory symptoms, bronchodilator use and pulmonary function in patients with COPD remains unknown. Although dysphagia and swallowing dysfunction on videofluoroscopic swallow evaluation are common in patients with COPD, their role as exacerbators of COPD remains to be elucidated. Further clinical research is necessary to evaluate the role of GERD and swallowing dysfunction in both stable and acute exacerbation of COPD.

Extraesophageal manifestations of GERD

The association between gastroesophageal reflux disease (GERD) and extraesophageal disease is often referred to as extraesophageal reflux (EER). This article reviews EER, discussing epidemiology, pathogenesis, diagnosis, and treatment with a focus on the most studied and convincing EER disorders-asthma, cough, and laryngitis. Although EER comprises a heterogeneous group of disorders, some general characterizations can be made, as follows. First, although GERD's association with extraesophageal diseases is well-established, definitive evidence of causation has been more elusive, rendering epidemiological data scarce. Secondly, regarding the pathogenesis of EER, 2 basic models have been proposed: direct injury to extraesophageal tissue by acid and pepsin exposure or injury mediated through an esophageal reflex mechanism. Third, because heartburn and regurgitation are often absent in patients with EER, GERD may not be suspected. Even when GERD is suspected, the diagnosis may be difficult to confirm. Although endoscopy and barium esophagram remain important tools for detecting esophageal complications, they may fail to establish the presence of GERD. Even when GERD is diagnosed by endoscopy or barium esophagram, causation between GERD and extraesophageal symptoms cannot be determined. Esophageal pH is the most sensitive tool for detecting GERD, and it plays an important role in EER. However, even pH testing cannot establish GERD's causative relationship to extraesophageal symptoms. In this regard, effective treatment of GERD resulting in significant improvement or remission of the extraesophageal symptoms provides the best evidence for GERD's pathogenic role. Finally, EER generally requires more prolonged and aggressive antisecretory therapy than typical GERD requires.

Severity of acid gastroesophageal reflux assessed by pH metry: is it associated with respiratory disease?

About 50% of children with chronic respiratory diseases (RD) have "silent" gastroesophageal reflux (GER). Our purpose was to evaluate the possibility that RD in patients with GER reflects the presence of more severe acid reflux. We compared the severity of parameters from pH studies in children with chronic RD and "silent" GER, to children with signs of symptomatic gastrointestinal (GI) GER with and without RD. This study included 236 children (aged 1 month to 15 years) with abnormal 24-hr pH monitoring among 718 patients studied for suspected diagnosis of GER. Patients were divided into three groups. Group 1 consisted of children with chronic RD but without any GI symptoms of GER. Group 2 was comprised of children with symptomatic GI presentation of GER such as regurgitation, vomiting, heartburn, and failure to thrive, but without any signs or symptoms of RD. Group 3 included children with prevalent RD and concomitant signs of symptomatic GER. Patients with predominant GI manifestations (group 2) had a significantly higher fraction of time with pH <4 (P < 0.01), total time value of pH <4 (P < 0.05), and longest episode with pH <4 (P < 0.05). Esophageal clearance was significantly longer in group 1 patients than in the other two groups (P < 0.05). Patients with mixed disease (group 3) were similar to patients in group 2. Patients with GI symptoms had significantly worse scores for all parameters evaluated except esophageal clearance score, compared to patients without GI symptoms. Longer esophageal clearance was the only parameter associated with respiratory signs in patients with respiratory symptoms compared to those without. In conclusion, the presence of RD in pediatric patients with silent GER is related to longer esophageal clearance, but is not related to severity of reflux.

Possible mechanisms of influence of esophageal acid on airway hyperresponsiveness

Airway hyperresponsiveness is among the defining phenomena in asthma. In this article, 3 mechanisms are reviewed to explain how gastroesophageal reflux (GER) may influence airway hyperresponsiveness. First, microaspiration may cause not only direct tissue injury, but may also trigger vagal reflexes. Second, acid infusion of the esophagus in a dog model and in humans has been shown to result in vagally mediated reflexes leading to bronchoconstriction. These reflexes have been studied using immunohistochemical techniques. Third, neuroinflammatory reflexes have been found to play a role in airway responses through the release of tachykinins, including substance P and neurokinin A. Combined, these 3 mechanisms may lead to an increase in vagal efferent impulses that can cause or augment airway hyperresponsiveness. Studies indicate that there is an increase in airway responsiveness in asthma patients who have documented GER. Further, based on the reported number of reflux episodes occurring during 24-hour pH monitoring, airway hyperresponsiveness to methacholine challenge tends to increase as GER worsens.

Exhaled breath condensates: a potential novel technique for detecting aspiration

There is an urgent need for diagnostic procedures that can detect aspiration of oral and gastrointestinal (GI) secretions into the respiratory tract. Current approaches are limited by poor sensitivity and specificity. These techniques include (1) adding indicators to feedings; (2) recovery of lipid-filled macrophages in respiratory secretions; (3) measurement of changes in the pH of the upper GI and respiratory tracts; (4) endoscopic visualization of reflux events; and (5) measurement of increased glucose concentrations in respiratory secretions. Ideally, specific markers from various sites in the oral and GI tracts might be discovered in respiratory secretions, but conventional bronchoalveolar lavage for sampling respiratory secretions is not practical and involves some risk. Noninvasive measurements of indicators in the exhaled breath condensates could be used to detect aspiration, but a number of theoretical and practical aspects of such studies must be considered before this approach can be applied to the problem of aspiration.

Improvement of respiratory symptoms following laparoscopic Nissen fundoplication

BACKGROUND

Laparoscopic fundoplication has become the standard of care for the management of symptomatic gastro-oesophageal reflux disease (GORD). Although atypical and respiratory symptoms are frequently described in standard texts in association with reflux, the response of respiratory symptoms to management of GORD has not been extensively studied.

METHODS

Herein is reported a prospective series of 29 patients who presented with predominantly respiratory symptoms. Typical and respiratory symptoms were graded according to a standard scale. All patients had preoperative investigations confirming GORD. These patients were treated by a laparoscopic Nissen fundoplication and followed up for a minimum of 14 months (range: 14-48 months). Patients were contacted and interviewed by an independent observer.

RESULTS

Conversion to open surgery was necessary in three patients. There were four significant complications. Ultimately control of typical reflux symptoms was achieved in 88%. Cough was completely relieved in 81% and improved in a further 13%. Wheeze and nocturnal bronchospasm was completely relieved in 50% and improved in the balance. Dysphagia remains a significant problem, with only 42% of patients completely free of trouble.

CONCLUSIONS

Overall the respiratory symptoms were improved in the majority of patients, with cough responding somewhat better than wheeze. Appropriate patient selection remains the greatest challenge when a patient with cough or wheeze that is considered to be due to GORD is referred for surgery.

Aspiration-related illnesses: definitions and diagnosis

BACKGROUND

Aspiration is a leading cause of morbidity and mortality. It is the most common cause of pneumonia and one of the most serious adverse effects of enteral nutrition support. It is important to use standardized terminology to define and discuss aspiration-related illnesses.

METHODS

Review of the medical literature and extraction of definitions and descriptions of aspiration-related illnesses.

RESULTS

Definitions, clinical features, diagnosis, and treatment of common aspiration-related illnesses are discussed.

CONCLUSIONS

Precisely defined terminology of aspiration-related illnesses adds consistency to this area of medicine and simplifies analysis and comparison of clinical studies.

Gastroesophageal reflux and obstructive sleep apnea

OBJECTIVE

To determine the extent to which gastroesophageal reflux (GER)-initiated laryngeal chemoreflexes contribute to obstructive sleep apnea (OSA).

METHODS

Prospective, nonrandomized clinical trial of an antireflux treatment protocol as a means of reducing the severity of OSA. Population consisted of 10 males aged 20 to 64 years with confirmed OSA (by overnight polysomnography) and GER (by ambulatory pH probe monitoring). Patients were treated with omeprazole and standard antireflux protocol for 30 days and pre- and posttreatment polysomnography variables were compared.

RESULTS

Mean apnea index declined 31% (45-31, P = .04); mean respiratory disturbance index declined 25% (62-46, P = .06). Three patients (30%) are "treatment responders" as defined by traditional OSA treatment definitions.

CONCLUSIONS

These results suggest a potential relationship between OSA and GER, the treatment of which may be an effective adjunctive in those with both disorders. Treatment of GER may significantly impact OSA in select individuals.

Hospitalization with respiratory disease following hiatal hernia and reflux esophagitis in a prospective, population-based study

PURPOSE

Hiatal hernia and reflux esophagitis have been associated with respiratory manifestations, though the temporal sequence of this relationship is uncertain. This study examined prospectively the relationship of hiatal hernia and reflux esophagitis with respiratory outcomes in a representative sample of the United States population.

METHODS

6928 participants in the first National Health and Nutrition Examination Survey, a population-based sample initially examined in 1971-1975, who were hospitalized during follow-up through 1992-1993 composed the study population. The relationship between hiatal hernia and reflux esophagitis hospitalization and a subsequent hospitalization with respiratory outcomes was measured in persons free of respiratory disease at baseline and at first hospitalization.

RESULTS

Multivariable survival analysis showed higher rates of hospitalization with any respiratory diagnosis [rate ratio (RR) = 1.4, 95% confidence interval (CI) 1.2-1.7] in persons with preceding hiatal hernia or reflux esophagitis hospitalization. Individually, rate ratios of pharyngitis (RR = 5.6, CI 2.0-15.7), tonsillitis (RR = 8.0, CI 2.5-25.8), bronchitis (RR = 1.8, CI 1.2-2.7), pneumonia (RR = 1.3, CI 1.0-1.7), emphysema (RR = 2.9, CI 1.5-5.5), asthma (RR = 2.1, CI 1.1-4.2), bronchiectasis (RR = 6.2, CI 1.1-34.3), and empyema or abscess (RR = 7.4, CI 1.3-42.3) were all higher following hiatal hernia and reflux esophagitis. Rate ratios were similar when reflux esophagitis and hiatal hernia were examined separately.

CONCLUSIONS

A prior hiatal hernia or reflux esophagitis hospitalization increased risk of respiratory disease hospitalization.

Gastroesophageal reflux disease. Control of symptoms, prevention of complications

GERD is a common disease that has a significant impact on patients' quality of life. Many surveys have shown that up to 60% of the population suffers from GERD at some time. Heartburn and acid regurgitation are the classic symptoms, but manifestations are variable. Of the several extraesophageal manifestations of GERD, reflux-induced asthma may be the most important. Complications of GERD include peptic strictures of the esophagus and Barrett's metaplasia. Clinical diagnosis of GERD can be confirmed by response to antisecretory therapy. A high-dose trial of a PPI is becoming an accepted diagnostic technique for uncomplicated mild or moderate GERD. Endoscopic examination and ambulatory esophageal pH monitoring still have a role in the evaluation of severe GERD or when other diseases are suspected. Lifestyle changes rarely are beneficial, and antisecretory therapy remains the mainstay of GERD treatment. PPIs have been shown to be more effective than H2 blockers. Antireflux surgery is indicated in some patients. Healing of esophagitis can take up to 8 weeks; failure to control symptoms necessitates the use of higher drug doses. Failure to control symptoms with high-dose PPI treatment raises the likelihood of other causes.

Supraesophageal complications of gastroesophageal reflux

Supraesophageal complications of GERD have become more commonly recognized or suspected by physicians. However, the direct association between these complications and GERD has often been difficult, if not impossible, to establish. Furthermore, the majority of patients with suspected supraesophageal complications of GERD do not have either the characteristic symptoms of heartburn and regurgitation or the definitive findings of esophageal inflammation, which would help reinforce the suspicion of a connection between the supraesophageal complications and GERD. Frequent acid reflux has been shown in patients with various bron-chopulmonary, laryngopharyngeal, or oral cavity disorders. GERD is one of the most common gastrointestinal complaints in the population. It is possible that the supraesophageal problems and acid reflux are mutually independent disorders that occur in the same person. The suspected mechanisms of GERD-related supraesophageal complications appear to be directed through two pathways: by a vagal reflex between the esophagus and tracheobronchial tree triggered by acid reflux or by microaspiration that causes contact damage to mucosal surfaces. The most useful diagnostic modality available to the clinician to aid in the diagnosis of supraesophageal GERD complications is the ambulatory pH recording technique. However, the sensitivity and specificity of this test for recording esophageal or pharyngeal acid reflux events has been critically challenged. Despite the many clinical studies that support the theory that GER has a role in suspected supraesophageal complications, only 1 long-term prospective controlled study of a large group of patients with asthma has shown the positive effects of the elimination of acid reflux. With the focus now on "outcomes medicine," there is a serious need for appropriately designed, controlled studies to answer the many questions surrounding a cause-and-effect association between acid reflux and supraesophageal disorders. Because of the lack of convincing proof between acid reflux and suspected supraesophageal complications, the physician must resort to an intent-to-treat strategy as both a primary therapy and a diagnostic trial. High-dose PPI therapy for prolonged periods is the recognized conservative therapy. Operative therapy (i.e., fundoplication operation) is the procedure of choice when overt regurgitation occurs or when medical therapy, although successful, is not practical for long periods. Controlled, well-designed clinical trials and more sophisticated techniques to measure and quantify acid reflux are crucial in the future to help determine which patients with suspected supraesophageal complications actually have acid reflux as a primary cause. The medical community needs to be alerted to the possibility of an association between GERD and supra-esophageal complications so that patients with a GERD-related complication will be recognized and effectively treated.

Gastroesophageal reflux disease in asthma: effects of medical and surgical antireflux therapy on asthma control

OBJECTIVE

To critique the English-language reports describing the effects of medical and surgical antireflux therapy on respiratory symptoms and function in patients with asthma.

METHODS

The Medline computerized database (1959-1999) was searched, and all publications relating to both asthma and gastroesophageal reflux disease were retrieved.

RESULTS

Seven of nine trials of histamine-receptor antagonists showed a treatment-related improvement in asthma symptoms, with half of the patients benefiting. Only one study identified a beneficial effect on objective measures of pulmonary function. Three of six trials of proton pump inhibitors documented improvement in asthma symptoms with treatment; benefit was seen in 25% of patients. Half of the studies reported improvement in pulmonary function, but the effect occurred in fewer than 15% of patients. In the one study that used optimal antisecretory therapy, asthma symptoms were improved in 67% of patients and pulmonary function was improved in 20%. Combined data from 5 pediatric and 14 adult studies of anti-reflux surgery indicated that almost 90% of children and 70% of adults had improvement in respiratory symptoms, with approximately one third experiencing improvements in objective measures of pulmonary function.

CONCLUSIONS

Fundoplication has been consistently shown to ameliorate reflux-induced asthma; results are superior to the published results of antisecretory therapy. Optimal medical therapy may offer similar results, but large studies providing support for this assertion are lacking.

Airway reactivity following repeated milk aspiration in rabbits

Asthma and gastroesophageal reflux (GER) are commonly associated disorders. Microaspiration is one possible link between these processes. The purpose of this study was to assess methacholine reactivity following repeated small-volume aspiration such as may occur with GER. This was also correlated with airway cytology. Five weekly intratracheal instillations of either milk (N = 8) or saline sham controls (N = 7) in volumes of 0.25 mL/kg were performed in anesthetized rabbits. Transpulmonary pressure, flow, tidal volume, central airways resistance, and dynamic lung compliance were measured in anesthetized and paralyzed animals at baseline, after 2 and 5 weeks of instillation, and 3 weeks after the last instillation. Doubling concentrations of methacholine were given until a 50% or greater increase in resistance occurred (PC50R). Bronchial washings for cytological evaluation were performed after the physiologic measurements and before each instillation. There were no significant differences in airway reactivity between baseline and all subsequent observation points within each of the two groups. However, methacholine responsiveness was significantly higher in the milk group before the final instillation (PC50R = 5.84 vs. 12.97 mg/mL, P = 0.03) and at recovery (PC50R = 6.40 vs. 10.56 mg/mL, P = 0.047) when compared to saline controls. This was associated with a higher neutrophil percentage (P = 0.01) at 5 weeks, and eosinophil percentage (P = 0.05) at recovery in the bronchial wash specimens from the milk group. These results show that repeated small-volume aspiration of milk in rabbits causes persistent inflammation and is associated with greater airway reactivity when compared to sham controls. This inflammation was accompanied by either increased neutrophils or eosinophils in bronchial lavage specimens. These findings lend support to a possible role of microaspiration in association with increased airway reactivity in patients with GER.

Esophagopharyngeal acid regurgitation: dual pH monitoring criteria for its detection and insights into mechanisms

BACKGROUND & AIMS

A valid technique for the detection of esophagopharyngeal acid regurgitation would be valuable to evaluate suspected reflux-related otolaryngologic and respiratory disorders. The aim of this study was to derive pH criteria that optimally define esophagopharyngeal acid regurgitation and to examine patterns of regurgitation.

METHODS

In 19 healthy controls and 15 patients with suspected regurgitation, dual or quadruple pH sensors were used to monitor pharyngeal and esophageal pH. For each combination of the 2 variables, DeltapH and nadir pH, proportions of pH decreases that occurred during or independent of esophageal acidification were calculated to determine the likelihood that an individual pharyngeal pH decrease was a candidate regurgitation event or a definite artifact.

RESULTS

Overall, 92% of pharyngeal pH decreases of 1-2 pH units and 66% of pH decreases of this magnitude reaching a nadir pH of <4 were artifactual. Optimal criteria defining a pharyngeal acid regurgitation event were a pH decrease that occurred during esophageal acidification, had a DeltapH of >2 units, and reached a nadir of <4 units in less than 30 seconds. Regurgitation occurred more frequently in subjects in an upright (32 of 35) than in a supine (3 of 35 events; P </= 0.0001) position and was more frequently abrupt (synchronous with esophageal acidification) than delayed (P </= 0.05).

CONCLUSIONS

Accepted criteria for gastroesophageal reflux are not applicable to the detection of esophagopharyngeal acid regurgitation, and most regurgitation occurs abruptly and in upright position.

Relationship between asthma and gastro-oesophageal reflux: significance of endoscopic grade of reflux oesophagitis in adult asthmatics

BACKGROUND

The association between asthma and gastro-oesophageal reflux disease (GERD) is well known. The aim of this study was to elucidate the causal relationship between reflux oesophagitis (RE) and asthma.

METHODS

Seventy-two adult asthmatics were examined regarding their GERD symptoms, and each underwent an endoscopic examination. According to the Los Angeles classification, we divided the patients into three groups: group 1 (n= 52), no mucosal break; group 2 (n= 15), RE corresponding to grades A or B; group 3 (n = 5), RE corresponding to grades C or D. The asthmatics in groups 2 and 3 received anti-reflux treatment for their GERD for 8 weeks. Their morning and evening peak expiratory flow rates (PEFR), daily variability of the PEFR and daily use of an inhalation bronchodilator were compared before and after this treatment.

RESULTS

The percentage of severe asthma and postprandial exacerbation of asthma in group 3 were significantly higher than those in the other two groups. In contrast, the number of eosinophiles and the serum level of immunoglobulin E in group 3 were significantly lower than those in the other two groups. After the antireflux treatment, significant improvements of both PEFR and daily use of the inhalation bronchodilator were observed only in group 3.

CONCLUSIONS

The endoscopic severity of RE is associated with the characteristics of adult asthmatics and the treatment of severe RE improved the asthmatics' condition.

Results of the gastroesophageal reflux assessment in wheezy children

Gastroesophageal reflux (GER) is implicated in the pathogenesis of respiratory symptoms in childhood. It should be taken into account especially in the differential diagnosis of children presenting with wheezing. Although, oesophageal pH monitorization has been reported to be the best technique in the evaluation of GER, radionuclide studies have also been shown to be very sensitive recently. In this study, 82 children presenting with recurrent wheezing (n = 74) and/or vomiting (n = 28) (mean age 17.4 months; range 3-48 months) were evaluated. GER scintigraphy was performed to determine the frequency of GER. GER was determined in 18 of the 82 cases (21.9%). The GER was found in 21.1% of children with recurrent wheezing and in 16.6% of children suffering from recurrent vomiting. GER scintigraphy should be kept in mind in the evaluation of children with the complaint of recurrent wheezing since it is a noninvasive and easily applicable method.

Respiratory complications of gastrointestinal diseases

Further advances in the ability to diagnose GER disease by use of ambulatory pH monitoring have unveiled a host of extraesophageal manifestations of GERD. These include pulmonary symptoms of asthma, recurrent pneumonia, cough or bronchitis, and infant apnea. Many of these symptoms may be the sole presentations of GER in these patients. It is important that the clinician is aware of these atypical presentations of GERD. The expanding use of ambulatory pH monitoring is helping to clarify the underlying pathophysiology of these disorders as well as to improve the ability to diagnose the atypical manifestations of GERD.

Diagnosis and treatment of gastroesophageal reflux in children and adolescents with severe asthma

BACKGROUND

The ability of gastroesophageal reflux disease to provoke asthma is controversial. Recent reports have suggested that reflux to the proximal esophagus may be especially likely to aggravate asthma, but the prevalence of proximal reflux in children and adolescents is poorly documented. It is also unclear how sensitive and specific the commonly used tests of reflux, barium swallow, and scintiscan are compared with pH probe studies in young patients. There is limited information on the effectiveness of the combination of H2 blockers and prokinetic agents in controlling reflux in children.

OBJECTIVE

There were three objectives in this study: (1) to determine the prevalence of both proximal and distal gastroesophageal reflux in asthmatic children and adolescents; (2) to determine the sensitivity, specificity, positive and negative predictive values of barium swallow and scintiscan studies; and (3) to determine the effectiveness of standard antireflux pharmacotherapy.

METHODS

A 24-hour, 2-channel pH probe study was carried out in 79 asthmatic children aged 2 to 17 years. The prevalence of abnormal proximal and distal gastroesophageal reflux was calculated from the findings. In 63 of these patients, barium swallow and Technetium99 scintiscan were carried out and the findings used to calculate the sensitivity, specificity, positive and negative predictive value of these studies relative to pH probe. In 11 subjects a follow-up, 24-hour pH probe was carried out after at least 3 weeks of therapy with an H2 blocker and prokinetic agent to determine the efficacy of therapy.

RESULTS

There was abnormal proximal esophageal reflux in 64.5% of subjects and abnormal distal reflux in 73.4%. The sensitivity, specificity, positive and negative predictive values of barium swallow were 46.1%, 83.3%, 82% and 51%, respectively. Those of scintiscan were 15%, 72.7%, 50% and 32%, respectively. Of 11 subjects studied by repeat pH probe, 10 had persistent abnormal reflux.

CONCLUSION

Abnormal reflux into the proximal esophagus occurs in the majority of asthmatic children with difficult-to-control disease. The barium swallow and scintiscan compare poorly with pH probe in diagnosing reflux. Treatment of reflux with recommended does of H2 blockers and prokinetic agents has a high failure rate, and follow-up studies are essential.

Does medical antireflux therapy improve asthma in asthmatics with gastroesophageal reflux?: a critical review of the literature

OBJECTIVE

Identify and critically review the peer-reviewed, English-language studies of the effects of medical antireflux therapy in asthmatics with gastroesophageal reflux (GER).

DESIGN

Using the 1966 to 1996 MEDLINE database, asthma was combined with GER to identify all studies of the effects of medical antireflux therapy on asthma control. The articles' bibliographies were also reviewed. Studies were graded according to Sackett's criteria and grouped by levels of evidence.

RESULTS

A total of 242 citations were found; 171 were published in English. Twelve studies of the effects of medical antireflux therapy on asthma control, with a total of 326 treated patients, were identified. Eight studies were placebo-controlled, three were open studies, and one used an untreated control. Eight studies treated 20 or fewer patients. Reflux symptoms either did not improve or the effects of antireflux therapy on them were not reported in four studies. The combined data from the controlled medical antireflux studies showed that: (1) asthma symptoms improved in 69% of the subjects; (2) asthma medication use was reduced in 62% of the subjects; (3) evening peak expiratory flow (PEF), but not PEF at other times, improved in 26% of the subjects; and (4) spirometry did not improve in any of the placebo-controlled antireflux studies.

CONCLUSIONS

Analysis of the combined data suggests that medical antireflux therapy improves asthma symptoms, may reduce asthma medication use, but has minimal or no effect on lung function.

Omeprazole improves peak expiratory flow rate and quality of life in asthmatics with gastroesophageal reflux

OBJECTIVE

The aim of this study was to determine if omeprazole improves pulmonary function and quality of life in asthmatics with gastroesophageal reflux.

METHODS

This was a double blind, randomized, placebo-controlled cross-over trial. After a 4-wk lead-in period, nine patients with documented asthma and gastroesophageal reflux, were prescribed either omeprazole 20 mg, daily or placebo for 8 wk and then crossed over to the alternate treatment. Outcome measurements included: forced expiratory volume at 1 s (FEV1), peak expiratory flow rate (PEFR), and responses on the Asthma Quality of Life Questionnaire, a validated disease specific measure of functional status.

RESULTS

After omeprazole treatment, compared with placebo, patients had higher mean morning and evening PEFR, mean absolute difference (95% CI): morning: 37.8 L/min. (10.9-64.6), evening: 31.2 (3.2-59.2). Omeprazole treatment led to higher mean overall scores on the Asthma Quality of Life Questionnaire, and on the subdomains of activity limitation, symptoms, and emotions (p = 0.039, 0.049, 0.024, 0.040). A trend toward higher FEV1 (mean: 15.6% difference) with omeprazole failed to reach statistical significance (p > 0.2).

CONCLUSIONS

After taking omeprazole for 8 wk, asthmatics with GER have better PEFR and quality of life than after placebo.

Respiratory symptoms in patients with gastroesophageal reflux disease following medical therapy and following antireflux surgery

BACKGROUND

It is not known whether antireflux surgery is more effective than medical therapy to control respiratory symptoms (RS) in gastroesophageal reflux disease (GERD).

METHODS

In 21 GERD patients with RS, reflux was assessed by endoscopy, manometry, and pH monitoring. Patients had proton pump inhibitor therapy and cisapride for 6 months. After GERD relapsed following withdrawal of medical therapy, 7 patients with normal esophageal peristalsis had a laparoscopic Nissen fundoplication and 14 with impaired peristalsis a Toupet fundoplication. Respiratory symptoms were scored prior to treatment, at 6 months following medical therapy, and at 6 months after surgery.

RESULTS

Heartburn and esophagitis were effectively treated by medical and surgical therapy. Only surgery improved regurgitation. Respiratory symptoms improved in 18 patients (85.7%) following surgery and in only 3 patients (14.3%) following medical therapy (P <0.05). Esophageal peristalsis improved following the Toupet fundoplication.

CONCLUSION

Medical therapy fails to control reflux since it does not inhibit regurgitation. Surgery controls reflux and improves esophageal peristalsis, which contributes to its superiority over medical therapy in the treatment of RS associated with GERD.

Regional variability of lung inflammation in cystic fibrosis

Chest radiography in patients with cystic fibrosis (CF) frequently shows more severe changes in the upper lobes. We performed bronchoalveolar lavage (BAL) on 12 clinically stable, young adult patients with CF to determine whether inflammation varies significantly among geographically distinct areas of the lung. We found that absolute numbers of neutrophils were generally greater in BAL fluid from the upper lobe (25.7 +/- 7.9 x 10(5) neutrophils/ml [mean +/- SEM]) of the right lung than that obtained from the right lower lobe (6.8 +/- 2.8 x 10(5) neutrophils/ml; p < 0.01). The mean value of unopposed neutrophil elastase activity in upper-lobe BAL fluid (227 +/- 91 nmol peptide hydrolyzed/ml/min) was also significantly greater than that in lower-lobe BAL fluid (84 +/- 43 nmol/peptide hydrolyzed/ml/ min; p < 0.01), and similar differences were found for myeloperoxidase activity and DNA content. Neutrophil influx and unopposed neutrophil elastase for a given region correlated inversely with lung function or percentage of ideal body weight, and upper-versus lower-lobe differences were more pronounced in subjects with better preservation of lung function. Our findings suggest that regional variation in inflammation must be considered when utilizing BAL to study lower respiratory tract inflammation in CF or to monitor responses to therapeutic interventions that can potentially diminish lung inflammation. Our findings may also have implications for the study of the natural history of lung inflammation and infection in neonates, infants, and young children with CF.

Effect of aspiration of milk on mechanisms of neural control in the airways of developing rabbits

We studied the effects of recurrent aspiration of milk on neural control of airways in young developing rabbits. Beginning at 1 week of age, rabbits received 0.5 ml/kg of whole milk or sterile physiologic saline intranasally while under light methoxyflourane anesthesia 5 days a week for a period of 3 weeks. At 4 and 8 weeks of age, in vitro studies of contractile and relaxant responses of tracheal smooth muscle (TSM) segments were evaluated. To assess the neurally mediated contractile responses, frequency response curves to electrical field stimulation (EFS) were performed with results expressed in terms of frequency of EFS causing 50% of the maximal contractile response (ES50) values. In addition, the contractile responsiveness of TSM to methacholine (MCh) as reflected by the concentration causing 50% of the maximal contractile response (EC50) values was also determined to evaluate the underlying cholinergic reactivity of this segment of airway. To assess nonadrenergic noncholinergic inhibitory (NANCi) responses, experiments were performed on TSM contracted with neurokinin A in the presence of atropine, propranolol, and indomethacin. EFS was delivered to the contracted tissue at stimulation frequencies ranging from 5 to 30 Hz with results expressed as mean percent relaxation. Recurrent aspiration of milk but not saline increased EFS-induced contractile responses, as shown by significantly lower ES50 values compared with the control group: P = 0.02 and P = 0.001 at 4 and 8 weeks of age, respectively. TSM responsiveness to MCh was no different between the two groups, suggesting that alterations in prejunctional mechanisms of neural control were most likely responsible for the increased contractile response to EFS. The NANCi responses were significantly decreased by milk aspiration at both 4 and 8 weeks of age, with the abnormalities less pronounced at the later time point. These findings demonstrate that repeated aspiration of milk leads to abnormal mechanisms of neural control within airways of developing rabbits. While aspiration of milk altered both contractile and relaxant responses to EFS, the former abnormalities became more pronounced with time while the latter appeared to be resolving. These observations suggest that injury to an airway early in development does not necessarily resolve with time but may persist, with functional abnormalities becoming more pronounced even after the airway insult has ceased.

Pulmonary aspiration in hospitalized adults

Until recent years, pulmonary aspiration attracted remarkably little clinical investigation. Although aspiration was considered a common occurrence in hospitalized individuals, with serious and even fatal consequences, clinicians had limited scientific data to guide practice. Consequently, approaches to this problem were based largely on unsystematic observations, intuition, and tradition. Recent investigations on the subjects of aspiration have increased our understanding of patients at risk for aspiration, the value of diagnostic methods, and the efficacy of interventions to prevent or limit aspirations. Results of these studies call to question many time-honored adages and practices. Considerable uncertainty remains and more investigation is necessary before management decisions can be characterized clearly and clinical strategies defined. This review focuses on pulmonary aspiration and enteral feeding in the critically ill adult. Factors implicated in aspiration in this population are highlighted and evidence to support the application of interventions prescribed commonly is presented.

Relationship between acid neutralization capacity of saliva and gastro-oesophageal reflux

Saliva is an important factor in neutralization of oesophageal acid exposure, clinically manifested as gastrooesophageal reflux (GOR). The aim of this study is to compare the composition and the "capacity in acid neutralization" (CAN) of saliva in controls and patients suffering of GOR. We compared the composition of saliva from 56 patients who had symptoms of GOR with that of saliva from 20 healthy control subjects. After a standardized 24-hour period of pH-monitoring, 39 patients had normal pH reflux scores (normal acid score: NAc-GOR) and 17 had abnormal pH reflux scores (pathological acid score: PAc-GOR). Then, following a 10-h fast, total saliva was collected during ten minutes in all patients and in the healthy control subjects. The composition of the saliva samples was analysed and the titration curve was determined on 200 microliters aliquots by successive addition of 5 microliters volumes of 0.1 N Hcl. The GOR patients had significantly lower salivary concentrations of Na+ and of both free and bound sialic acids and had higher salivary concentrations of inorganic phosphates than the controls. These disorders were more marked in PAc-GOR patients. Initial pH was 7.43 +/- 0.43 in controls, 7.35 +/- 0.45 in NAc-GOR patients, and 6.91 +/- 0.53 in PAc-GOR patients. In the beginning of the titration curve, PAc-GOR patients were significantly different from NAc-GOR patients and from controls. Saliva of both groups of patients presented significant differences in the acidic portion of the titrations curves, at high volumes of added HCl. These data show that the composition of saliva was modified in patients with GOR disease compared to that of normal subjects. A difference in titration curves was also observed with a higher acidic buffering capacity in these GOR patients. The modifications in saliva composition suggest a role for inorganic phosophates in the acid neutralization capacity observed in GOR, perhaps linked with a adaptation to chronic acid exposure.

Airway protective mechanisms: current concepts

There are at least eight mechanisms identified that result either in volume clearance of the pharynx and esophagus (secondary peristalsis and pharyngeal swallow) or prevent entry of the gastric content into the esophagus and pharynx (LES and UES), accentuate these barriers (esophago-UES and pharyngo-UES contractile reflexes), or induce closure of the vocal cords and introitus to the trachea (esophagoglottal and pharyngoglottal reflexes). The sum effect of various combinations of these mechanisms is suggested to help prevent retrograde aspiration. In other words, airway protective mechanisms against retrograde aspiration are multifactorial and involve delicate interaction between upper GI and upper airway tracts. Although the existence of these mechanisms in normal volunteers has been documented, their function in patients with retrograde aspiration and supraesophageal complications of gastroesophageal reflux disease currently awaits investigation.