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Biomedical subjects

Donald O Castell

Publications and source records attributed to Donald O Castell.

At least 37 records · Page 2Linked to original sources
PubMed2005

Multichannel intraluminal impedance: general principles and technical issues.

Multichannel intraluminal impedance (MII) is a new technology that allows detection of bolus movement without the use of external radiation or radiolabeled substances. The principles of MII are based on changes in resistance to alternating electrical current (impedance) induced by the presence of various boluses within the esophagus. The timing of changes in multiple impedance-measuring segments in the esophagus allows determination of the direction of bolus movement. Combined MII and manometry (MII-EM) provides simultaneous information on intraesophageal pressures and bolus transit, offers the ability to monitor all types of reflux, and allows the detection of the physical (liquid, gas, or mixed) and chemical (acid, nonacid) characteristics of the gastroesophageal refluxate.

Electric Impedance↗
PubMed2005

Physiologic model of oropharyngeal swallowing revisited.

OBJECTIVE: The purposes of this investigation were to determine whether the temporal onsets of swallow events segment into oral and pharyngeal phases, to test the interdependence of temporal onsets of swallow events, and to determine the influence of age on total swallow duration. STUDY DESIGN AND SETTING: The onsets of swallowing and respiratory measures were studied in 76 healthy normal individuals. RESULTS: Confirmatory factor analysis revealed a 2-factor solution but did not support the hypothesized 2-phase structure (ie, oral and pharyngeal). Two of the onsets, apnea onset and apnea offset, formed a single factor that explained 12.6% of the variation among the 11 onset times. The other 9 onsets formed a second factor that explained 66.4% of the variation. Age accounted for modest variation in total swallow duration. CONCLUSIONS: The two factors, oropharyngeal and respiratory, explained 79% of the variation among the 11 onset times. SIGNIFICANCE: This finding speaks to the overlap between the initiation of oral and pharyngeal components of swallowing in adults and highlights the artificiality of separating the swallowing continuum into isolated phases.

Adult↗
PubMed2005

Nighttime reflux is primarily an early event.

GOALS: Our clinical impression gleaned from reading large numbers of ambulatory pH studies is that recumbent reflux episodes mostly occur in the early part of the nighttime period. In this study, we propose to test this hypothesis. STUDY: A total of 201 consecutive pH studies performed in our laboratory between November 2001 and October 2002 were analyzed. Population characteristics: 75 males and 126 females; mean age, 50.4 yrs (range, 16-88 years). Reflux was defined by a drop in pH to less than 4. Abnormal total recumbent reflux was defined as >1.2% time pH < 4. For patients with abnormal recumbent reflux, the recumbent period was divided into two halves and the reflux time in each period was calculated. In all patients, ingestion of a meal within 2 hours of retiring was also identified. RESULTS: A total of 59 patients had abnormal recumbent reflux: 24 males and 35 females; mean age, 48.9 years. In patients with abnormal recumbent reflux, acid reflux was significantly more frequent in the first half of the recumbent period compared with the second half (median, 6.3%; vs. 0.3%, respectively; P < 0.001; Wilcoxon signed rank test, two-tailed analysis). Those patients (N = 118) having had a meal within 2 hours of retiring were 2.46 times more likely to develop recumbent reflux than those whose last meal was more than 2 hours earlier (N = 83). CONCLUSION: These results support our hypothesis that nighttime reflux occurs primarily during the first half of the recumbent period. In addition, they reinforce the concept of maintaining control of early nighttime reflux and the importance of counseling patients with nocturnal symptoms against late meals and snacks.

Adolescent↗
PubMed2005

Updated guidelines for the diagnosis and treatment of gastroesophageal reflux disease.

Guidelines for the diagnosis and treatment of gastroesophageal reflux disease (GERD) were published in 1995 and updated in 1999. These and other guidelines undergo periodic review. Advances continue to be made in the area of GERD, leading us to review and revise previous guideline statements. GERD is defined as symptoms or mucosal damage produced by the abnormal reflux of gastric contents into the esophagus. These guidelines were developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee, and approved by the Board of Trustees. Diagnostic guidelines address empiric therapy and the use of endoscopy, ambulatory reflux monitoring, and esophageal manometry in GERD. Treatment guidelines address the role of lifestyle changes, patient directed (OTC) therapy, acid suppression, promotility therapy, maintenance therapy, antireflux surgery, and endoscopic therapy in GERD. Finally, there is a discussion of the rare patient with refractory GERD and a list of areas in need of additional study.

Anti-Ulcer Agents↗
PubMed2005

Non-acid gastroesophageal reflux: documenting its relationship to symptoms using multichannel intraluminal impedance (MII).

Multichannel intraluminal impedance (MII) is a new technique for evaluating esophageal function and gastroesophageal reflux. This technique depends on changes in resistance to alternating current between two metal electrodes produced by the presence of liquid or gas bolus inside the esophageal lumen. Combined multichannel intraluminal impedance and manometry (MII-EM) provides simultaneous information on intraluminal pressure changes and bolus movement whereas combined multichannel intraluminal impedance and pH (MII-pH) allows detection of gastroesophageal reflux (GER) episodes irrespective of their pH values (i.e. acid and non-acid reflux). Combined MII-pH testing presents a new paradigm for reflux testing. In MII-pH studies reflux events are no longer primarily detected by pH. Refluxate presence, distribution and clearing is primarily detected by MII and simply characterized as acid or non-acid based on pH change and as liquid, gas or mixed based on MII. MII determines refluxate clearance time while pH measures acid clearance time. MII-pH shows promise to become an important clinical tool, particularly to assess GER in the postprandial period and in patients with persistent symptoms on acid suppression therapy.

Adult↗
PubMed2004

Nocturnal acid breakthrough - approach to management.

Nocturnal acid breakthrough is defined as the presence of intragastric pH < 4 during the overnight period for at least 60 continuous minutes in patients taking a proton-pump inhibitor (PPI). Nocturnal acid breakthrough occurs in more than 70% of Helicobacter pylori-negative patients on PPI therapy and has clinical consequences in particular in patients with complicated gastroesophageal reflux disease (GERD), Barrett's esophagus, and esophageal motility abnormalities. The clinical importance of nocturnal acid breakthrough and the benefit of adding histamine-2 receptor antagonists (H2RAs) to PPI therapy have been debated ever since these concepts were introduced. In our experience, the addition of bedtime H2RAs is clinically effective in controlling nocturnal acid breakthrough and GERD symptoms.

Circadian Rhythm↗
PubMed2004

Clarification of the esophageal function defect in patients with manometric ineffective esophageal motility: studies using combined impedance-manometry.

BACKGROUND & AIMS: Combined multichannel intraluminal impedance (MII) and manometry (MII-EM) recently became available as an esophageal function test. Initial studies in healthy volunteers have shown that a proportion of ineffective contractions actually have complete bolus transit. The aim of our study is to evaluate esophageal bolus transit in patients with manometric patterns of ineffective esophageal motility (IEM). METHODS: All patients referred for esophageal function testing during a 9-month period underwent combined MII-EM studies, including 10 liquid and 10 viscous swallows. IEM is defined as >or=30% liquid swallows with contraction amplitude <30 mm Hg in the distal esophagus. Diagnosis of esophageal transit abnormalities is defined as abnormal bolus transit if >or=30% of liquid and >or=40% of viscous swallows had incomplete bolus transit. RESULTS: Seventy patients (35 women; mean age, 54 yr; range, 17-86 yr) with a manometric diagnosis of IEM were identified of a total of 350 combined MII-EM studies. In these patients, 68% of liquid and 59% of viscous swallows showed normal bolus transit, and almost one third of patients received an overall diagnosis of normal bolus transit for both liquid and viscous swallows. CONCLUSIONS: Our experience with combined MII-EM in patients with a manometric diagnosis of IEM confirms the suspicion that "effectiveness" should only be determined by using a test of esophageal function. Furthermore, we believe our results support a conclusion that a higher level of esophageal diagnostic information is best obtained by combined MII-EM. Future outcome studies should establish its value in patients with nonobstructive dysphagia and in prefundoplication assessment.

Adolescent↗
PubMed2004

Rumination documented by using combined multichannel intraluminal impedance and manometry.

According to the Rome criteria, rumination is considered to be an esophageal functional disorder. Because documentation of rumination is difficult, it has been suggested that rumination is a clinical diagnosis. Even though a clinical diagnosis of rumination can be based only on history, this conclusion often leaves both the patient and the physician dissatisfied. In this article we describe the case of a 26-year-old man referred for evaluation of persistent regurgitation. By using combined multichannel intraluminal impedance and manometry we were able to document the sequence of events leading to regurgitation. These include an increase in intra-abdominal pressure identified in the pressure transducer located in the stomach, which initiates the reflux event identified by both impedance changes as well as common cavity phenomenon, followed by peristaltic fore contractions, which clear the intraesophageal content, a pattern highly suggestive for rumination. The opportunity to review these documented changes visually helps to make the patient aware of the functional aspects of the condition, avoiding unwarranted therapies and providing the opportunity to reinforce behavioral modifications.

Adolescent↗
PubMed2004

Are 10 wet swallows an appropriate sample of esophageal motility? Yes and no.

BACKGROUND: Traditionally 10 wet swallows are used to assess esophageal motility. Given this relative small number of swallows concerns have been raised whether the abnormal findings based on 10 wet swallows would persist with another set of 10 wet swallows. PURPOSE: To evaluate whether 10 wet swallows during esophageal manometry is an adequate sampling of esophageal motility. METHODS: Over a 4-month-period 100 consecutive patients (excluding patients with achalasia) were given 20 liquid (5 ml each) swallows. The standard manometry technique in our laboratory was performed using 10 wet swallows with pressure transducers placed 4 cm and 9 cm above the lower esophageal sphincter (LES). The diagnosis was based on the initial 10 swallows. The additional 10 swallows were blinded and separately analyzed, then compared with the initial swallows for each patient. RESULTS: Of the 100 studies (64 women; mean age 51; range 21-85), 91 had a consistent diagnosis for both pairs of 10 swallows. The number of abnormal swallows (ineffective or simultaneous) differed between the 2 sets of 10 swallows in 9 patients, but, when the first 10 were analyzed vs. all 20 swallows only 2 patients had discordant diagnoses. There was an excellent agreement between the 1st and 2nd set of 10 swallows (kappa = 0.846) and between the first 10 and all 20 swallows (kappa = 0.965). CONCLUSIONS: Ten wet swallows are sufficient for making a manometric diagnosis, because additional swallows are likely to change the diagnosis in only 2% of patients.

Adult↗
PubMed2004

Nocturnal acid breakthrough: pH, drugs and bugs.

Nocturnal acid breakthrough (NAB) was defined by Peghini et al. in 1998 as the presence of at least 60 continuous minutes of intragastric pH < 4 during the overnight period (22:00-06:00 h) in patients taking a proton pump inhibitor (PPI) twice-daily before meals. NAB was shown to occur in more than 70% of patients on PPI therapy but can be decreased or eliminated by adding a histamine-2 receptor antagonist (H2RA) at bedtime. Helicobacter pylori status influences intragastric acid control on PPI therapy: H. pylori-positive patients having better gastric acid control compared with their H. pylori-negative counterparts. Recent data indicate that NAB might not occur in H. pylori-positive subjects on twice-daily PPI, suggesting there is no need for combined PPI twice-daily and H2RA therapy to control night-time gastric acid secretion in these individuals. The clinical importance of NAB has been debated ever since this concept was introduced. The importance of NAB in healthy subjects and asymptomatic, uncomplicated gastro-oesophageal reflux disease patients on PPI therapy may be low, but ignoring it in patients with poor oesophageal motility and Barrett's oesophagus may result in suboptimal treatment. Further studies are warranted to investigate whether leaving H. pylori to 'assist'acid suppression obtained by PPI twice-daily, adding bedtime H2RAs after successful H. pylori eradication or other approaches to eliminate NAB results in better clinical outcomes.

Circadian Rhythm↗
PubMed2004

Profile of GERD in the adult population of a northeast urban community.

STUDY: An observational, cross-sectional, epidemiology study of the characteristics of GERD in a large northeast urban population was performed using a self-responding 84-question survey. Four-hundred and ten surveys were completed from a population sample with demographics comparable to those of the 1990 US Census data. RESULTS: No differences in heartburn frequency (monthly) were found between white or black, male or female respondents. Heartburn was significantly (P = 0.01) less common in those over age 60 (36.9%) than in young (47.7%) or middle-age (57.3%) respondents. Impact of heartburn on social activities was less (P = 0.002) in the over 60 group (4.9%) compared with the young (19.3%) or middle-age (20.0%) groups. Although 49.8% of respondents were familiar to the term GERD, few were aware that swallowing difficulty (17.3%), asthma (9.3%) or hoarseness (11.5%) were possible symptoms and similar numbers considered stroke (33.2%) and cancer (31.7%) to be complications of GERD. CONCLUSIONS: Frequency of GERD symptoms in the United States is unaffected by gender or race but is lower in the elderly.

Adult↗
PubMed2004

Diagnosis of laryngopharyngeal reflux.

PURPOSE OF REVIEW: Laryngopharyngeal reflux is of great interest to otolaryngologists, speech and language therapists, and gastroenterologists. This is a brief review of recent publications in the diagnosis of laryngopharyngeal reflux. RECENT FINDINGS: Otolaryngologic signs and symptoms can be found in 4 to 10% of patients with gastroesophageal reflux and those presenting for ear, nose, and throat evaluations. Laryngeal signs are not pathognomonic for laryngopharyngeal reflux because many of these signs can be found in healthy volunteers. A combination of signs and symptoms should be sought before suspecting this diagnosis. Most investigators consider pH monitoring the best currently available instrument to diagnose gastroesophageal reflux, even though it is not considered to be 100% sensitive and specific. Studies in normal volunteers indicate that a minimal number of reflux episodes reach the hypopharynx. The correlation between laryngeal signs and symptoms and pH-documented reflux is less than perfect, whereas the combination of pH testing and signs and symptoms is better in detecting patients with a favorable response to acid-suppressing therapy. Using an empiric trial of high-dose proton pump inhibitors over a prolonged period of time to diagnose laryngopharyngeal reflux is supported mainly by uncontrolled studies. To date, double-blind, placebo-controlled studies suggest that empiric trials of proton pump inhibitors may not have high accuracy for the diagnosis of laryngopharyngeal reflux. SUMMARY: Multidisciplinary trials are needed to establish the optimal combination of sign and symptom scores, reflux monitoring results, and empiric treatment trials for the most accurate diagnosis of laryngopharyngeal reflux.

Antacids↗
PubMed2004

Combined multichannel intraluminal impedance and manometry clarifies esophageal function abnormalities: study in 350 patients.

BACKGROUND: Combined multichannel intraluminal impedance and esophageal manometry (MII-EM) is a technique that uses an FDA-approved device allowing simultaneous evaluation of bolus transit (MII) in relation to pressure changes (EM). METHODS: During a 9-month period, beginning from July 2002 through March 2003, we prospectively performed combined MII-EM on all patients referred for esophageal function testing. Each patient received 10 liquid and 10 viscous swallows. Manometric findings were reported based on criteria described by Spechler and Castell for liquid swallows. MII findings were reported as having normal bolus transit if >/=80% (8/10) of liquid and >/=70% (7/10) of viscous swallows had complete bolus transit. RESULTS: Three-hundred fifty studies were evaluated from patients with a variety of symptoms having the following manometric diagnoses: normal manometry (125), achalasia (24), scleroderma (4), ineffective esophageal motility (IEM) (71), distal esophageal spasm (DES) (33), nutcracker esophagus (30), hypertensive lower esophageal sphincter (LES) (25), hypotensive LES (5), and poorly relaxing LES (33). None of the patients with achalasia and scleroderma had normal bolus transit. Fifty-one percent of patients with IEM and 55% of patients with DES had normal bolus transit while almost all (more than 95%) patients with normal esophageal manometry, nutcracker esophagus, poorly relaxing LES, hypertensive LES, and hypotensive LES had normal bolus transit. Dysphagia occurred most often in patients with incomplete bolus transit on MII testing. CONCLUSION: Esophageal body pressures primarily determine bolus transit with isolated LES abnormalities appearing to have little effect on esophageal function. MII clarifies functional abnormalities in patients with abnormal manometric studies.

Adolescent↗
PubMed2004

The influence of rapid food intake on postprandial reflux: studies in healthy volunteers.

BACKGROUND: The postprandial increase of gastroesophageal reflux (GER) results largely from an increase in the rate of transient lower esophageal sphincter relaxations (TLESRs). Gastric distension is believed to be the most important contributing factor. The aim of this study was to determine the impact of rapid food intake on GER in healthy volunteers using combined multichannel intraluminal impedance and pH (MII-pH) testing to record both acid and nonacid reflux. Our hypothesis was that rapid food intake overstresses the gastric pressure-volume response and contributes to increased postprandial GER. METHODS: Twenty healthy volunteers were included in the study. On two separate days the participants were asked to eat the same standard meal within 5 or 30 min in random order. Acid and nonacid reflux episodes were recorded over a 2-h postprandial period. RESULTS: Intake of a standard meal within 5 min was associated with more reflux episodes (median = 14) than an intake within 30 min (median = 10, p= 0.021). The increase was confined to the first postprandial hour and was caused predominantly by an increase of nonacid reflux. During the entire 2-h postprandial period, 469 reflux episodes were noted in the 40 studies. During the first postprandial hour 45% (135/303) of reflux events were nonacid as opposed to 22% (37/166) noted during the second hour (p < 0.0001). CONCLUSION: Since rapid food intake produces more GER in healthy volunteers, studies in GERD patients are warranted to evaluate if eating slowly may represent another "life-style modification" aimed at reducing GER.

Adult↗
PubMed2003

Use of multichannel intraluminal impedance to document proximal esophageal and pharyngeal nonacidic reflux episodes.

Recent studies in adults and children suggest that combined multichannel intraluminal impedance and pH measurement (MII-pH) has the potential to become the new "gold standard" for gastroesophageal reflux testing. In combined MII-pH, reflux is detected by changes in resistance to alternating current induced by the presence of intraluminal materials with different conductivities, and is characterized as acid or nonacid reflux based on concomitant pH measurements. Proximal distribution and duration of nonacid reflux events, predominantly in postprandial periods and during acid-suppressive therapy, can now be quantified. The ability to associate symptoms with nonacid reflux events will help guide therapy in select groups of patients, such as patients with ongoing symptoms on acid-suppressive therapy as well as in the pediatric population.

Electric Impedance↗
PubMed2003

Are manometric parameters of the upper esophageal sphincter and pharynx affected by age and gender?

The effects of age and gender on the upper esophageal sphincter's (UES) and pharyngeal manometric parameters were investigated in 84 healthy subjects (45 men, 39 women, mean age = 44 years, range = 18-91). Manometric recordings were performed with solid-state circumferential transducers. Subjects older than 60 years (n = 23) showed a significant lower UES resting pressure. In addition, during water swallows they had a higher UES residual pressure, shorter UES relaxation interval and UES relaxation duration, and a decreased UES relaxation rate. Furthermore, pharyngeal contraction had significant higher amplitude and longer duration in subjects older than 60 years during water swallows. Some of these findings were also observed during cookie and pudding swallows. Women had a higher UES resting pressure and a longer UES relaxation interval than men. The observed changes with increasing age indicate loss of basal tone and decreased compliance of the UES. Increased pharyngeal contraction amplitude and its prolonged duration in the elderly might be compensatory to this. These physiologic effects of age and gender on UES and pharyngeal parameters should be taken into account during analysis of manometric studies.

Adolescent↗