Association of lipid-laden alveolar macrophages and gastroesophageal reflux in children

Lipid-laden alveolar macrophages (LLAM): a useful marker of silent aspiration in children

At present there is no test available which identifies children suffering from silent aspiration due to gastroesophageal reflux (GER). The purpose of this study was to determine whether lipid-laden alveolar macrophage (LLAM) scoring is a useful method to arrive at the diagnosis. We evaluated bronchoalveolar lavage fluid (BALF) from 68 children aged 6 months to 14 years (median 3.75 years) for the presence of lipid-laden alveolar macrophages. We compared children with chronic chest disease (CCD) and GER to healthy surgical controls without known lung disease, and to children with recurrent pneumonia without GER. By grading the amount of intracellular Sudan Red-positive material, we determined a semiquantitative lipid-laden macrophage (LLAM) score for each patient. Patients with chronic chest disease suspected to be caused by silent aspiration secondary to GER had a significantly higher LLAM score (median, 117; range, 10-956) than children with recurrent pneumonia due to other reasons (median, 29; range, 5-127; P < 0.01) and healthy controls (median, 37; range, 5-188; P < 0.01). We believe that simply observing lipid-laden macrophages is nonspecific, but quantitation of these cells is a useful method for diagnosing silent aspiration in children, especially when the score exceeds 200.

Lipid-laden macrophages in bronchoalveolar lavage fluid as a marker for pulmonary aspiration

An increased lipid content in alveolar macrophages of bronchoalveolar lavage (BAL) fluid is thought to be a useful indicator for recurrent pulmonary aspiration. To assess whether pulmonary diseases unrelated to aspiration can raise the lipid content in alveolar macrophages, we evaluated Oil-Red-O-stained smears of BAL fluid in 18 children aged 3-15 years undergoing elective surgery for nonpulmonary illnesses under general anesthesia and in 18 children aged 1-16 years who had pulmonary diseases without clinical evidence of aspiration (pneumonia, exogenous allergic alveolitis, or cystic fibrosis). A semiquantitative lipid-laden macrophage (LLM) index was determined for each patient. LLM indices in children without pulmonary disease were higher than those published for healthy adults. In children with pulmonary diseases but without evidence of aspiration, a significantly higher LLM index was observed compared to controls. The LLM indices of children with pulmonary diseases were similar to those published by other authors for children with pulmonary aspiration. We conclude that an elevated LLM index in alveolar macrophages of BAL can be found in a variety of pulmonary diseases in which there is no clinical evidence of aspiration and is therefore unlikely to be a specific parameter for silent pulmonary aspiration.

Role of gastroesophageal reflux in pediatric upper airway disorders

Gastroesophageal reflux (GER) into the laryngopharynx causes or contributes significantly to a variety of upper respiratory problems in children. The pH probe, laryngeal examinations, and broncholveolar lavage results for children with subglottic stenosis, recurrent croup, apnea, chronic cough, laryngomalacia, recurrent choanal stenosis, vocal fold nodules, and chronic sinusitis/otitis/bronchitis were reviewed in an effort to quantify the role of GER in each of these disorders. This review suggests that GER plays a causative role in subglottic stenosis, recurrent croup, apnea, and chronic cough. It is an important inflammatory cofactor in laryngomalacia and possibly in true vocal cord nodules and problematic recurrent choanal stenosis. GER is also an important inflammatory cofactor in chronic sinusitis/otitis/bronchitis but may be the result of chronic illness in the older patients.

Primary tracheomalacia and gastroesophageal reflux in infants with cough

Cough is an uncommon sign in infants. Cough may result from the presence of abnormal secretions in the airway or abnormalities of the central airways that affect the infant's ability to clear normal secretions. Tracheomalacia (TM) and gastroesophageal reflux (GER) can both cause cough in infants. Four infants whose cough began in the newborn period were diagnosed with TM and GER. Symptoms of central airway obstruction (homophonous wheeze or tracheal cough) suggested the diagnoses. In three patients, the diagnosis was made by barium esophagraphy and airway fluoroscopy. The infants responded to conservative and medical therapy for GER and to nebulized bronchodilators. Tracheomalacia and GER cause cough in infants that begins in the newborn period. The diagnosis can often be made with studies available to the primary care provider, and the conditions are often responsive to medical management.

Gastroesophageal reflux in infants and children

Gastroesophageal reflux is a common pediatric complaint and a frequent reason for pediatric patients to be referred to a gastroenterologist. The pathophysiology and clinical manifestations of this disorder differ according to patient age. The diagnosis is suggested by the history and can be confirmed by a pH probe. In the appropriate clinical setting, anatomic obstruction may need to be ruled out by contrast study. Endoscopy is used to assess associated complications, including esophagitis, esophageal strictures, Barrett's transformation, and failure to thrive. Other complications are controversial, including pulmonary disease, apnea, and sudden infant death syndrome. Treatment depends on the severity of disease. Conservative therapy includes behavorial modifications, prokinetic agents, and H2 antagonists. Proton pump inhibitors are generally reserved for refractory esophagitis. Surgical treatment may be necessary for gastroesophageal reflux resistant to medical management or for severe complications. Gastroesophageal reflux beyond infancy tends to be chronic; therefore, lifelong behavioral modifications or repeated courses of medical therapy may be necessary. An algorithm for the suggested diagnostic approach to gastroesophageal reflux is presented herein.

Gastroesophageal reflux and asthma

The medical literature has been deluged with articles on the relation between gastroesophageal reflux (GER) and asthma. In an effort to piece together the complex puzzle, investigators from all disciplines have gathered their patients with wheezing and heartburn and studied the epidemiology, the possible cause or effect mechanisms and the therapeutic response to GER treatment. Indeed, since humans first began to hunker down and work together to discuss interesting observations, the world has begun to breathe easier. Epidemiological evidence for a GER/asthma association suggests that about three-fourths of asthmatics, independent of the use of bronchodilators, have acid GER, increased frequency of reflux episodes, or heartburn; and 40% have reflux esophagitis. Physiological studies suggest that 2 separate mechanisms are involved in the GER/asthma relationship: (1) a vagally mediated pathway and (2) microaspiration. In any given patient, however, there is no acceptable diagnostic method available to confirm the presence or absence of GER-induced asthma. Clinical trials, using antireflux medical therapy and antireflux surgery have begun to provide some clues about GER-related pulmonary symptoms. The trials of medical therapy using acid suppressing drugs (e.g. histamine-2 receptor antagonists) have ranged from no benefit to modest improvement of only nocturnal asthma symptoms. Studies with proton-pump inhibitors are underway. In uncontrolled surgical studies, antireflux surgery has resulted in partial or complete remission of asthma symptoms in a large proportion of patients. Despite the uncontrolled nature of these studies, many patients have had dramatic subjective improvement in pulmonary symptoms. It appears for now that clinical trials are the only available means to assess whether medical or surgical treatment of GER in patients with both GER and asthma improves the symptoms of asthma and decreases the need for pulmonary medications. One conclusion is certain: We no longer can ignore the important co-existent nature of these 2 afflictions.

Immunohistochemical detection of human milk components aspirated in lungs of an infant

We examined an autopsy case of an infant whose cause of death was suspected to be asphyxia due to human breast milk aspiration. In order to demonstrate aspirated milk in the lungs, we conducted immunohistochemical staining using eight antibodies against the components of human milk. Seven of the eight antibodies reacted positively with the substances suspected to be aspirated milk. We concluded that immunohistochemical staining with these antibodies is useful to demonstrate human milk aspiration and provide some keys for detecting the causes of unexpected infant deaths.

A systematic evaluation of mechanisms in chronic cough

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

The diagnostic value of bronchoalveolar lavage in immunocompetent children with chronic diffuse pulmonary infiltrates

We have investigated the diagnostic value of (BAL) in 29 immunocompetent children (ages 1 month to 18 years) with chronic diffuse pulmonary infiltrates on chest radiograph who presented for evaluation over a 3-year period. The median age at the time of the BAL was 20 months with a range of 1-210 months. Positive results (1) diagnostic of a primary disorder; (2) consistent with a diagnosis; or (3) diagnostic of a secondary disorder, were obtained in 20/29 patients (13 with a single positive BAL finding and 7 with more than one finding). BAL was diagnostic of a primary disorder in only 5 patients (17%) with aspiration detected in 3 and infection in 2. The differential diagnosis was narrowed in 15 patients by the presence of lymphocytosis, neutrophilia, or eosinophilia. A secondary disorder was uncovered in 8 patients. Negative results were obtained in 9 additional patients. We conclude that BAL provided useful information in children with chronic diffuse infiltrates, but its ability to determine the primary cause was limited.

Simultaneous tracheal and oesophageal pH monitoring during mechanical ventilation

OBJECTIVE

To simultaneously record tracheal and oesophageal pH in mechanically ventilated children to determine: (1) the feasibility and safety of the method; (2) the incidence of gastro-oesophageal reflux (GOR) and pulmonary contamination; and (3) their associated risk factors.

DESIGN

Prospective study.

SETTING

Paediatric intensive care unit in a university hospital.

PATIENTS

Twenty mechanically ventilated children (mean age 6.7 years) who met the following inclusion criteria: endotracheal tube with an internal diameter of 4 mm or more (cuffed or uncuffed), mechanical ventilation for an acute disease, no treatment with antiacids, prokinetics, or H2-receptor blockers, and no nasogastric or orogastric tube.

METHODS

The tracheal antimony pH probe was positioned 1 cm below the distal end of the endotracheal tube. The oesophageal antimony pH probe was positioned at the lower third of the oesophagus. pH was recorded on a double channel recorder and analysed with EsopHogram 5.01 software and by examination of the trace. The following definitions were used: GOR index, percentage of time pH < 4; pathological GOR, GOR index > 4.8%; tracheal reflux, fall in tracheal pH < 4, 4.5, or 5, or a decrease of one unit from baseline, in both cases preceded by an episode of GOR. The results were analysed statistically by Fisher's exact and the Kruskal-Wallis test.

RESULTS

The procedure was well tolerated and the median duration of analysable recording was 6 hours (range 5-22.6). Pathological GOR was observed in eight (40%) children. GOR was more frequent with an uncuffed endotracheal tube than with a cuffed one (p = 0.01). Tracheal reflux (pH < 4) was observed in four children (20%) without clinical evidence of pulmonary aspiration. Episodes of tracheal reflux were associated with a GOR index > 10% (p < 0.01) and were more frequent with a maximal inspiratory pressure of < 25 cm H2O (p = 0.03), but were not related to the indication for mechanical ventilation, whether the endotracheal tube was cuffed or not, age, or drug treatment.

CONCLUSIONS

Simultaneous tracheal and oesophageal pH monitoring was feasible in the setting of this study. Tracheal reflux can occur without pathological GOR, and GOR may occur without tracheal reflux. Further prospective studies in larger groups of patients are now justified.

Flexible fibre-optic bronchoscopy in the management of lung complications in cystic fibrosis

Flexible fibre-optic bronchoscopy was performed under sedation in 24 children with cystic fibrosis. In eight cases bronchoscopy was carried out as a therapeutic procedure. Most children were subjectively improved, but objective evidence of change was minimal. Useful information was obtained in 9/16 children who underwent the procedure for diagnostic purposes. Information included sensitive identification of organisms responsible for lower respiratory symptoms in non-expectorating cases and identification of unsuspected gastro-oesophageal reflux.

Diagnostic procedures of GER in childhood lung disease

Respiratory diseases are frequently related to gastroesophageal reflux (GER). In the absence of classic symptoms like vomiting, silent GER can only be ruled out by further studies. Esophageal pH monitoring of long duration (18 to 24 hr) is now recommended as the technique of choice in infants and children with atypical presentation of GER. Mechanisms of GER pathway are complex and may provoke chronic pneumonia or wheezing; pH monitoring cannot be considered an "all or nothing" exam. Several esophageal pH profiles have been described in various respiratory diseases.

Aspiration complicating bronchopulmonary dysplasia

The purpose of this study was to study the relationship of aspiration with ongoing respiratory difficulties in infants with bronchopulmonary dysplasia (BPD). Twelve infants with BPD were identified out of 314 children who had flexible bronchoscopy between 1987 and 1990; 11 of 12 had bronchoalveolar lavage (BAL). The lipid index (LI) was used to quantify the degree of lipid-laden macrophages in the BAL fluid as a marker of aspiration. The age range at the time of bronchoscopy was 3 months to 5 years. The LI was considered positive in 6 of 11 subjects. A pH probe study was done on seven subjects with concordant findings in five. Other findings included dynamic or structural airway abnormalities in 10 of the 12 subjects. These data suggest that aspiration frequently is associated with BPD in addition to the previously recognized dynamic and structural airway problems. The predisposition to gastroesophageal reflux and laryngeal injury probably accounts for the increased aspiration risk in children with BPD.

Usefulness of miniature flexible fiberoptic bronchoscopy in children

A miniature flexible fiberoptic bronchoscope (FFB) (Olympus BF-N20) (2.2 mm diameter) was applied to 53 children (20 female subjects) ranging in age from 3 months to 15 years (mean, 4.19 years). Most common indications for bronchoscopy included stridor or weak cry and persistent wheezing or cough unresponsive to inhaled bronchodilators, chest physiotherapy, steroids, and antimicrobial agents. There were no complications. In 38 children (71.6 percent) it was diagnostically useful, particularly for the investigations of upper airway obstruction (66 percent). In 22 children (41.5 percent) it provided guidance for surgical interventions. The instrument was particularly useful during its application in infants with severe upper airway obstruction who otherwise would require open rigid-tube bronchoscopy in the operating room. It was of limited value when excessive bronchial secretions obstructed the view of the working field for which a bronchoscope with a built-in suction channel was needed. It is concluded that this miniature FFB is a useful diagnostic tool in infants and children particularly for obstructed upper airways but has limited applications in children with peripheral airway disease. The 2.2-mm bronchoscope may have its greatest advantage in preterm neonates and intubated infants, where the small glottic or endotracheal tube size renders the 3.5-mm bronchoscope useless.

Sudden infant death syndrome prevention and an understanding of selected clinical issues

The etiology and prevention of sudden infant death syndrome (SIDS) are among the more frustrating topics in pediatrics. This article addresses several clinically relevant issues, including the relationships between apnea and SIDS, the nature of the "terminal event," effectiveness of home monitoring, the role of gastroesophageal reflux in apparent life-threatening events, and the association between the prone sleeping position and SIDS. This article is intended to provide the clinician with an awareness of the issues and the scientific basis needed to understand their contribution to SIDS.

Pediatric airway manifestations of gastroesophageal reflux

Gastroesophageal reflux (GER) in children may be classified as physiologic or pathologic, depending on its degree and consequences. There are many head and neck complications of GER in pediatric patients, but most numerous are the airway manifestations, including stridor, recurrent croup, exacerbation of subglottic stenosis, laryngeal irritation with or without laryngospasm, chronic cough, and obstructive apnea. Diagnosis may be difficult unless there is a high index of suspicion for GER and awareness of the concept of "silent" GER. We present the common pediatric airway manifestations of GER, illustrated by case reports, and provide a paradigm to assist in the diagnosis and management of children with airway compromise associated with GER.

Coexisting endogenous lipoid pneumonia, cholesterol granulomas, and pulmonary alveolar proteinosis in a pediatric population: a clinical, radiographic, and pathologic correlation

Benign pulmonary diseases that have been associated with the accumulation of endogenous lipids within the alveoli, bronchioles, and interstitial tissues include endogenous lipoid pneumonia (ELP), pulmonary alveolar proteinosis (PAP), pulmonary interstitial and intra-alveolar cholesterol granulomas (PICG), various xanthomatous lesions, and malakoplakia. In ELP, fat-filled finely vacuolated macrophages fill the alveoli. In PAP, the aveoli become filled with cholesterol and periodic acid-Schiff (PAS)-positive acellular debris. In PICG, cholesterol esters are released from degenerating macrophages and, as organization occurs, the cholesterol is deposited in the form of acicular clefts within the interstitium. These morphologically distinct presentations of endogenous lipid deposition within the lung have long been thought to represent unique disease processes but several authors now postulate a possible relationship between these entities. We report here on the clinical, radiographic, and morphologic findings in eight pediatric patients with diverse primary disease processes who were subsequently found to have varying and often coexisting degrees of ELP, PAP, and PICG.

The otolaryngologic manifestations of gastroesophageal reflux disease (GERD): a clinical investigation of 225 patients using ambulatory 24-hour pH monitoring and an experimental investigation of the role of acid and pepsin in the development of laryngeal injury

Occult (silent) gastroesophageal reflux disease (GER, GERD) is believed to be an important etiologic factor in the development of many inflammatory and neoplastic disorders of the upper aerodigestive tract. In order ot test this hypothesis, a human study and an animal study were performed. The human study consisted primarily of applying a new diagnostic technique (double-probe pH monitoring) to a population of otolaryngology patients with GERD to determine the incidence of overt and occult GERD. The animal study consisted of experiments to evaluate the potential damaging effects of intermittent GER on the larynx. Two hundred twenty-five consecutive patients with otolaryngologic disorders having suspected GERD evaluated from 1985 through 1988 are reported. Ambulatory 24-hour intraesophageal pH monitoring was performed in 197; of those, 81% underwent double-probe pH monitoring, with the second pH probe being placed in the hypopharynx at the laryngeal inlet. Seventy percent of the patients also underwent barium esophagography with videofluoroscopy. The patient population was divided into seven diagnostic subgroups: carcinoma of the larynx (n = 31), laryngeal and tracheal stenosis (n = 33), reflux laryngitis (n = 61), globus pharyngeus (n = 27), dysphagia (n = 25), chronic cough (n = 30), and a group with miscellaneous disorders (n = 18). The most common symptoms were hoarseness (71%), cough (51%), globus (47%), and throat clearing (42%). Only 43% of the patients had gastrointestinal symptoms (heartburn or acid regurgitation). Thus, by traditional symptomatology, GER was occult or silent in the majority of the study population. Twenty-eight patients (12%) refused or could not tolerate pH monitoring. Of the patients undergoing diagnostic pH monitoring, 62% had abnormal esophageal pH studies, and 30% demonstrated reflux into the pharynx. The results of diagnostic pH monitoring for each of the subgroups were as follows (percentage with abnormal studies): carcinoma (71%), stenosis (78%), reflux laryngitis (60%), globus (58%), dysphagia (45%), chronic cough (52%), and miscellaneous (13%). The highest yield of abnormal pharyngeal reflux was in the carcinoma group and the stenosis group (58% and 56%, respectively). By comparison, the diagnostic barium esophagogram with videofluoroscopy was frequently negative. The results were as follows: esophagitis (18%), reflux (9%), esophageal dysmotility (12%), and stricture (3%). All of the study patients were treated with antireflux therapy. Follow-up was available on 68% of the patients and the mean follow-up period was 11.6 +/- 12.7 months.(ABSTRACT TRUNCATED AT 400 WORDS)

Nonsurgical management of the infant with gastroesophageal reflux and respiratory problems

Gastroesophageal reflux (GER), which is associated with respiratory problems such as choking, aspiration, apnea, and chronic respiratory disorders, is a source of significant concern to parents and health care providers. An understanding of the physiologic basis for the association between GER and these disorders enables the nurse practitioner (NP) to act as case manager for these patients. Knowledge of diagnostic procedures and components of management such as positional therapy, feeding techniques, pharmacologic therapy, home monitoring, and social support strategies enables the NP to collaborate effectively with other members of the health care team in providing nonsurgical treatment for these infants.

Laryngomalacia in children

Two hundred three (68 percent) of 297 children with laryngomalacia had associated respiratory disorders by flexible fiberoptic bronchoscopy (FFB). Associated disorders included congenital respiratory anomalies, a variety of anatomic obstructions of the upper and lower airways, and aspiration disorders. Mean age for isolated laryngomalacia (type 1) was 11.5 weeks (range, 5 weeks to 4 months) while children with laryngomalacia and associated respiratory disorders (type 2) had a mean age of 9.06 years (range, 6 weeks to 18 years). We conclude the following: (1) complete evaluation of the pediatric airways (bronchoscopy) is recommended in every symptomatic child with diagnosis of laryngomalacia confirmed by laryngoscopy; (2) type 1 laryngomalacia was more common in early infancy while type 2 laryngomalacia was associated with older age; (3) although type 2 laryngomalacia is the most common endoscopic diagnosis in our experience, the majority of cases were associated with lower airway dysfunction.

Does mechanical ventilation precipitate gastro-oesophageal reflux during enteral feeding?

The influence of intermittent positive pressure ventilation on gastro-oesophageal reflux in preterm infants is not known. In many neonatal units, however, concern that ventilation may increase gastro-oesophageal reflux (and therefore aspiration) leads to avoidance of enteral feeding during ventilation. We have therefore performed a crossover study of gastrooesophageal reflux by monitoring lower oesophageal pH in a group of nine enterally fed, very low birthweight infants both during assisted ventilation and normal breathing. All infants had less reflux during intermittent positive pressure ventilation (mean (SEM) reflux index 2.3 (0.6%)) than during normal breathing (mean (SEM) reflux index 6.1 (1.1%)). Assisted ventilation was associated with a significant reduction in the gastro-oesophageal pressure gradient, an effect which may be related to the use of positive and end expiratory pressure during ventilation. These data show that fear of gastro-oesophageal reflux should not preclude the use of enteral feeding in preterm infants receiving ventilation.

Lipid aspiration pneumonia due to gastroesophageal reflux. A complication of nasogastric lipid feedings

The development of lipid aspiration pneumonia after chronic nasopharyngeal installation of mineral oil was first described in 1925 by Laughlin. Since that time this entity has been well recognized and numerous substances have been identified or implicated as the aspirated material. The classic radiographic appearance of severe chronic lipid aspiration pneumonia has been described as consisting of intense perihilar infiltrates. However, the radiographic findings are more often non-specific and usually consist of varying degrees of diffuse interstitial infiltrates that tend to be more prominent in the perihilar regions and the right lung. We are reporting a case of biopsy-proven lipid aspiration pneumonia in an infant with known gastro-esophageal reflux (GER) who had medium-chain triglyceride oil administered via nasogastric tube. Serial roentgenograms demonstrated a changing pulmonary pattern from diffuse bilateral interstitial infiltrates initially to a diffuse alveolar pattern at the time of the lung biopsy. Modern medicine has developed new methods for providing nourishment to sick newborns and infants to improve their nutritional status and help them to grow. One such method involves the administration of medium-chain triglycerides (MCT oil) into the GI tract via a nasogastric or nasoenteral tube. The purpose of this report is to describe a significant complication of this method of providing nutrition to an infant with gastroesophageal reflux (GER) and the diagnostic dilemma it presented.

Gastroesophageal reflux: update on pathogenesis and diagnosis

The study of GER has been hindered by the lack of a good animal model and by the presence of some reflux in all normal individuals. By the painstaking process of studying normal infants, children, and adults, it is becoming evident that abnormalities of acid clearance, especially in the recumbent position (or during sleep), may be critical to an understanding of this disorder. As more is learned about the conditions surrounding "normal" reflux, it will be possible to refine the techniques of diagnosis and thereby identify the abnormal with more security.