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Biomedical subjects

D O Castell

Publications and source records attributed to D O Castell.

At least 127 records · Page 7Linked to original sources
PubMed1996

Esophageal sensation in spinal cord-injured patients: balloon distension and cerebral evoked potential recording.

We sought to determine the esophageal sensory function in patients with a C6 or C7 spinal cord injury. A balloon was repetitively distended 10 cm above the lower esophageal sphincter in five patients and nine normal control subjects. Sensation was reported on a scale from 0 to 2 with progressive distension to pain threshold (level 2). Cortical responses were recorded from midline scalp electrodes. Blinded determinations of quality and reproducibility of the potentials were performed. All subjects experienced sensation with esophageal balloon distension. Volumes to sensation showed a trend toward a higher sensory threshold in patients but were significant only for first sensation, not pain. In all subjects, a triphasic evoked potential response consisting of a negative-positive-negative complex was noted with distension but not with sham distension. Characteristics (amplitude, latency, reproducibility, and quality) of the evoked potentials were not different in patient and control groups. These data suggest sensory pathways from the distal esophagus are intact in patients with a C6 or C7 spinal cord injury.

Adult↗
PubMed1996

Dual site ambulatory pH monitoring: a probe across the lower esophageal sphincter does not induce gastroesophageal reflux.

BACKGROUND: Twenty-four-hour ambulatory pH studies have traditionally been performed with placement of the pH electrodes proximal to the lower esophageal sphincter (LES). More recently, simultaneous gastric and esophageal pH monitoring studies have been performed to allow the simultaneous assessment and correlation of esophageal and gastric pH. OBJECTIVES: The purpose of this study was to determine if pH probe placement across the LES increases esophageal acid exposure either in asymptomatic, healthy volunteers or in symptomatic patients with a documented history of erosive esophagitis. METHODS: Ten healthy volunteers (five female, five male; mean age 27 yr) and 13 patients with endoscopically confirmed erosive esophagitis (seven female, six male; mean age 35 yr) were randomly assigned, in cross-over fashion, into two protocols. The first protocol required placement of a dual antimony pH electrode catheter (2.1-mm outside diameter) across the LES with pH electrodes positioned 5 cm above and 10 cm below the manometrically identified LES. The second protocol required catheter placement 5 cm and 20 cm above the LES. Twenty-four-hour pH monitoring was performed on all subjects. Healthy volunteers were permitted an unrestricted diet and were studied in an out-patient setting. Symptomatic patients were assessed in an inpatient setting on a standardized diet with a refluxogenic dinner meal. RESULTS: The total number of reflux episodes, number of reflux episodes greater than 5 min, and the fraction of time that pH was less than 4 were evaluated over the total 24-h time period in the upright and supine positions. Nonparametric paired tests including a Wilcoxon signed rank test and a Robust analysis were used for statistical assessment. There was no significant increase in gastroesophageal reflux observed with placement of the pH probe across the LES either in the asymptomatic healthy volunteers or in patients with documented erosive esophagitis. Neither upright nor supine esophageal acid exposures were modified by catheter placement. CONCLUSIONS: Our study results indicate that placement of a 2.1-mm diameter pH probe across the LES does not induce reflux in asymptomatic healthy volunteers or in patients with GERD. Dual site ambulatory pH monitoring with trans-sphincteric pH catheter placement is a valid diagnostic technique that can be applied clinically when required.

Adult↗
PubMed1996

Comparison of barium radiology with esophageal pH monitoring in the diagnosis of gastroesophageal reflux disease.

OBJECTIVE: Barium radiology has recently been recommended as a screening procedure for gastroesophageal reflux disease. The aim of this study was to assess the accuracy of barium screening as a predictor of abnormal esophageal acid exposure on pH monitoring. PATIENTS AND METHODS: One hundred and twenty-five patients underwent both barium radiology and esophageal pH monitoring at the Thomas Jefferson Hospital, Philadelphia, from October 1989 through July 1991. The presence or absence of spontaneous reflux, reflux during the water-siphon test, and a hiatus hernia was recorded and assessed retrospectively. RESULTS: The proportion of patients with a positive pH test did not differ among those with spontaneous reflux (21/31, 68%) and those with no reflux, on barium study (61/94, 65%). The proportion of patients with a positive pH test did not differ among those with a hiatus hernia (35/50, 70%) and those without (47/75, 63%). This was despite significantly higher median percent total times pH < 4 among those with spontaneous reflux or a hiatus hernia (p < 0.05). The additional application of a water-siphon test induced reflux in 91% of those tested. The sensitivities of spontaneous reflux and hiatus hernia were low (26% and 43%), and specificities were only modest (77% and 65%). The addition of the water-siphon test gave a sensitivity of 92%, but the specificity was zero. CONCLUSION: A significantly greater degree of abnormal esophageal acid exposure occurs in patients who have either a hiatus hernia or spontaneous reflux, demonstrated during fluoroscopy. However, the sensitivity and specificity of barium radiology for abnormal degrees of acid reflux are insufficient for it to be worthwhile as a screening procedure.

Adolescent↗
PubMed1996

Persistent acid secretion during omeprazole therapy: a study of gastric acid profiles in patients demonstrating failure of omeprazole therapy.

OBJECTIVE: To identify patients with gastroesophageal reflux disease (GERD) who, despite omeprazole 20 mg b.i.d., demonstrate continued abnormal gastric acid secretion. METHODS: Eighty-eight patients with GERD completed ambulatory gastric and esophageal pH monitoring for persistent symptoms on omeprazole 20 mg b.i.d.. Seventeen (19%) demonstrated abnormal gastric acid secretion (percentage time gastric pH < 4 > 50%). The 17 omeprazole failures (OF) were compared with: 1) 19 randomly selected patients with GERD (also studied on omeprazole 20 mg b.i.d. and 2) 19 normal volunteers studied on both placebo and omeprazole 20 mg b.i.d.. Total time intragastric pH < 4, 24-hr gastric pH frequency distribution, and 15-min median pH values for the 6-h period after the evening omeprazole dose were compared. RESULTS: Both the 24-hr frequency distribution for gastric pH and the 15-min median gastric pH profile for patients with GERD and volunteers on omeprazole 20 mg b.i.d. were almost identical. By contrast, gastric pH studies from the OF group receiving omeprazole 20 mg b.i.d. most closely resembled those of the normal subjects receiving placebo, with respect to these variables. Gastric pH monitoring in seven of the 17 OF patients while on omeprazole 80 mg/day demonstrated a significant decrease in the median percentage time gastric pH remained below 4 (32.8% on 80 mg/day vs 74.3% on 40 mg/day; p < 0.02). CONCLUSION: There are individuals whose intragastric acidity persists despite conventional doses of omeprazole. Although the underlying mechanism remains unclear, the majority (six of seven) (87%) demonstrated improved gastric acid control when placed on high dose omeprazole, indicating that this is often a dose-dependent phenomenon.

Anti-Ulcer Agents↗
PubMed1996

Optimal dosing of omeprazole 40 mg daily: effects on gastric and esophageal pH and serum gastrin in healthy controls.

BACKGROUND: Little is known about the best regimen of omeprazole 40 mg/day for suppressing gastric acid and distal esophageal acid exposure. In addition, the relationship between the level of serum gastrin and gastric pH and this therapy is still uncertain. METHODS: Nineteen healthy male volunteers (mean age 25 yr) had a baseline fasting serum gastrin and 24-h ambulatory combined distal esophageal and gastric pH monitoring. Subjects underwent a 7-day course of each of three specific regimens of omeprazole 40 mg (20 mg b.i.d., 40 mg qAM, 40 mg qPM) with repeat pH and gastrin on day 6. Meals and activity patterns were constant for each subject during the test series. Medications were taken before meals. RESULTS: All dosing regimens caused significant (p < 0.01) acid reduction compared with baseline in both the stomach and the distal esophagus. There was no significant difference in the amount of acid exposure (time pH < 4) among the three dosing regimens in the esophagus and between qAM and qAM dosing in the stomach. However, b.i.d. dosing gave better (p < 0.05) gastric acid suppression compared with single daily dosing in 15 of 19 subjects. When the baseline was compared with all regimens of omeprazole 40 mg, there was a significant difference with both the serum gastrin (p < 0.01) and the percentage time gastric pH was < 4 (p < 0.01). The correlation between change in serum gastrin and change in percentage time gastric pH was < 4 was poor (r = 0.26). CONCLUSIONS: Divided dosing of omeprazole 20 mg b.i.d. provides superior gastric acid suppression to either once a day regimen of omeprazole 40 mg in most individuals. Serum gastrin levels do not correspond well to gastric pH, necessitating the use of gastric pH monitoring to accurately determine the response to gastric acid suppression.

Adult↗
PubMed1996

Changes in overnight fasting intragastric pH show poor correlation with duodenogastric bile reflux in normal subjects.

BACKGROUND: Spontaneous rises in intragastric pH are a common phenomenon in patients and normal subjects who undergo prolonged ambulatory pH monitoring; however, controversy exists over their etiology. Some investigators have postulated that these events are secondary to duodenogastric bile reflux (DGBR), and others have implicated increased salivation or increased esophageal bicarbonate production. The advent of a fiberoptic system that reliably identifies the presence of bilirubin has made it feasible to qualitatively detect DGBR. We used this technology along with simultaneous ambulatory intragastric pH monitoring to evaluate the relationship between DGBR and rises in intragastric pH in normal subjects. METHODS: We studied five normal subjects for a 15-h overnight period with simultaneous intragastric pH and bilirubin monitoring. The probes were sutured together so that the pH electrode lay adjacent to the fiberoptic bilirubin sensor, then passed transnasally into the fundus of the stomach. Subjects were fasted for the entire study. Data were obtained by plotting all intragastric pH values (recorded every 4 s) and their corresponding intragastric bilirubin absorbance units (recorded every 8 s) at 5-min intervals from the beginning to the end of the study for each of the five subjects (n = 903). RESULTS: Regression analysis of the data showed poor correlation (r = 0.26) between intragastric pH and intragastric bilirubin absorbance. CONCLUSION: Rises in intragastric pH do not predict the presence of bile in normal subjects. In addition, DGBR usually does not cause alkaline shifts of intragastric pH. Although further studies are needed to fully elucidate the etiology of spontaneous rises in intragastric pH, we believe that the measurement of "alkaline reflux" with ambulatory intragastric pH monitoring alone is an outdated technique and that the Bilitec 2000 should become the standard technique for the detection of intraluminal bile.

Adult↗
PubMed1996

Pulmonary symptoms associated with gastroesophageal reflux: use of ambulatory pH monitoring to diagnose and to direct therapy.

BACKGROUND: We studied 54 patients with chronic persistent cough or asthma suspected to be due to reflux using distal and proximal pH monitoring. Therapy for reflux was determined by the referring physician and included H2 blockers (51%), omeprazole (36%), surgery (10%), and lifestyle modifications only (3%). On follow-up evaluation, the effect of anti-reflux therapy on pulmonary symptoms (PS) was scored as excellent, good, fair, no change, or worsening symptoms. RESULTS: Forty-two of the 54 patients (78%) had abnormal reflux. Of these, 28 patients (67%) had abnormal proximal acid exposure. Seventy-one percent of reflux patients achieved good to excellent response in PS from anti-reflux therapy. The response was not significantly different between patients with proximal reflux and those with only distal reflux. None of the patients without documented reflux who nevertheless received anti-reflux therapy had a response, even when fair improvement was included as a response. Seventeen percent of patients whose pulmonary symptoms responded to anti-reflux therapy would not have been recognized as having abnormal reflux if proximal pH monitoring had not been done. CONCLUSIONS: The percentage of patients (78%) with pulmonary symptoms having abnormal reflux is consistent with prior studies. Documenting abnormal gastroesophageal reflux helps direct appropriate therapy, and proximal pH monitoring may identify patients with pulmonary symptoms who respond to anti-reflux therapy.

Anti-Ulcer Agents↗
PubMed1996

Sensitization of esophageal mucosa by prior acid infusion: effect of decreasing intervals between infusions.

OBJECTIVE: To determine the effect of decreasing time intervals between acid exposures on the sensitivity of the esophageal mucosa. METHODS: Ten healthy subjects with no history of gastroesophageal reflux disease who were symptomatic during a modified Bernstein acid infusion test were recruited for the study. Hydrochloric acid solutions of pH 3, 2, and 1 were sequentially tested. The weakest pH solution that was perceived by the patient was used for the study. The same duration of acid infusions (9 ml/min for 5 min) were made but with decreasing time intervals between each subsequent acid infusion (30-0 min). Esophageal sensation during each of the infusions, the amount of distilled water required to raise intraesophageal pH > 4, and the duration of residual heartburn after pH > 4 were recorded. RESULTS: Seven of the 10 subjects (70%) were Bernstein-positive to pH 3, two to pH 2, and only one to pH 1 solution. The median time to initial heartburn was significantly reduced only between the initial infusion and the first subsequent acid exposure 30 min later (165 vs 51.5 s, p < 0.009). Subsequent reductions in the time interval between infusions did not significantly reduce the perception threshold. The water required to clear the esophagus to pH > 4 and time required for the residual esophageal sensation to disappear were not significantly altered throughout the study. CONCLUSIONS: These data suggest that some episodes of reflux may be felt sooner and perhaps more severely despite similar levels of acid burden in the esophagus when sensitization by a prior reflux episode occurs.

Adult↗
PubMed1996

Efficacy and safety of lansoprazole in the treatment of erosive reflux esophagitis. The Lansoprazole Group.

OBJECTIVES: This study was designed to compare lansoprazole 30 mg, lansoprazole 15 mg, omeprazole 20 mg, and placebo in the treatment of erosive reflux esophagitis. METHODS: In a double-blind, multicenter study, 1284 patients with endoscopically diagnosed erosive reflux esophagitis were randomized to received lansoprazole 30 mg (n = 422), lansoprazole 15 mg (n = 218), omeprazole 20 mg (n = 431), or placebo (n = 213) once daily for 8 wk. At 2, 4, 6, and 8 wk, healing was evaluated endoscopically. Patients kept daily diaries of symptoms. RESULTS: Healing rates at 2, 4, 6, and 8 wk were 65.3%, 83.3%, 89.4%, and 90.0%, respectively, for lansoprazole 30 mg; 56.3%, 74.6%, 80.3%, and 78.8% for lansoprazole 15 mg; 60.9%, 82.0%, 89.7%, and 90.7% for omeprazole 20 mg; and 23.9%, 32.8%, 36.6%, and 40.0% for placebo (all active treatments higher than placebo, p < 0.001). Healing rates with lansoprazole 30 mg were significantly higher than with lansoprazole 15 mg at all time points (p < 0.05). Healing rates with omeprazole 20 mg were significantly higher than with lansoprazole 15 mg at 4, 6, and 8 wk and were similar to those with lansoprazole 30 mg. Based on patient diaries, lansoprazole 30 mg produced better symptomatic relief than lansoprazole 15 mg or omeprazole 20 mg, primarily early in the treatment course. CONCLUSIONS: Both lansoprazole 30 mg and omeprazole 20 mg were more effective than lansoprazole 15 mg in esophageal mucosal healing. Compared with omeprazole 20 mg, lansoprazole 30 mg was as safe, was similarly effective with respect to esophageal healing, and provided superior symptomatic relief, primarily early in treatment. Lansoprazole 30 mg provided greater symptomatic relief than lansoprazole 15 mg.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

Prolonged ambulatory pH monitoring in patients with persistent gastroesophageal reflux disease symptoms: testing while on therapy identifies the need for more aggressive anti-reflux therapy.

UNLABELLED: Patients with gastroesophageal reflux disease (GERD) who remain symptomatic despite receiving a moderate dose of a proton pump inhibitor need accurate assessment to determine who will respond to high doses of the drug or even need surgery. AIM: To determine if prolonged ambulatory pH monitoring performed in patients with persistent symptoms potentially due to GERD while on therapy could predict which patients are likely to benefit from more aggressive anti-reflux therapy. METHODS: Ambulatory pH studies were reviewed for 45 patients with continuing reflux-type symptoms while on 20 mg omeprazole b.i.d. Patients were separated by typical symptoms (heartburn) versus atypical symptoms (chest pain, asthma, hoarseness, cough, throat burning) and for degree of symptom association with episodes of reflux during pH monitoring (symptom index). Control of esophageal acid exposure by omeprazole was defined as distal esophageal pH < 4 < 1.6% total time. RESULTS: Of these 45 patients, 14 (31%) had acid reflux that was not controlled by omeprazole 20 mg b.i.d. Thirty-six patients had atypical symptoms of GERD, and 10 of these patients had poorly controlled reflux. Of these 10 patients, only one patient responded to omeprazole 20 mg q.i.d. In the other nine patients, omeprazole at the higher dose controlled the reflux (documented by pH monitor), but symptoms persisted with poor association to reflux. Thus, only one out of 36 patients with atypical symptoms had subsequent improvement in symptoms. Nine patients had persistent, typical GERD symptoms, and five of these patients had poorly controlled GER. The three patients with good symptom correlation and poorly controlled reflux all responded to increased omeprazole whereas the two with poor symptom association did not. One patient with good control of reflux but good correlation of the remaining reflux to persistent symptoms also responded symptomatically to 80 mg of omeprazole. CONCLUSION: By assessing symptom correlation to reflux episodes and control of reflux by therapy, ambulatory pH monitoring performed in patients with persistent symptoms potentially due to reflux while on therapy gives valuable information concerning further treatment strategies.

Drug Administration Schedule↗
PubMed1996

Mucosal acid exposure sensitizes a subset of normal subjects to intra-oesophageal balloon distension.

OBJECT: To assess the effect of acid infusion on the response of normal subjects to progressive intra-oesophageal balloon distension (IOBD). METHODS: Twenty-one volunteers underwent slow IOBD. Subjects were asked to indicate the first perception of sensation (S1) and the onset of pain (S2), balloon volumes being recorded at both points. A 15-min infusion of 0.1 M HCl (8 ml/min) was then instilled proximal to the balloon. Subjects were designated as acid-sensitive if they reported chest pain or heartburn during the acid infusion. Thereafter S1 and S2 were assessed again in the same manner. RESULTS: Nine subjects were acid-sensitive, 12 were acid-insensitive. The subgroup of 12 acid-insensitive subjects had an increase of pain threshold after acid infusion (P < 0.05), whereas the nine acid-sensitive subjects showed a decrease of pain threshold after acid infusion (P < 0.05). No change of the threshold for sensation occurred in either of these groups after acid infusion. CONCLUSION: Individuals showing mucosal acid sensitivity have a lower threshold for mechanoreceptor stimulation after acid exposure.

Adult↗
PubMed1995

Guidelines for the diagnosis and treatment of gastroesophageal reflux disease. Practice Parameters Committee of the American College of Gastroenterology.

Gastroesophageal reflux disease (GERD) is a common disorder that affects all segments of the population. These guidelines have been prepared to suggest the preferable, but not only, approaches to the management of a patient with GERD. The physician must be free to choose the course best suited to the individual patient. The world literature was reviewed and the guidelines were developed under the auspices of the American College of Gastroenterology, and approved by other gastroenterology societies. Diagnostic recommendations include the following: (1) general approach to GERD, including empiric therapy, (2) appropriate mucosal evaluation (ie, endoscopy and radiology), (3) use of pH and provocative testing, and (4) indications for manometric evaluation. Therapeutic recommendations include the following: (1) general approach to therapy including lifestyle changes, (2) use of acid suppression, (3) use of promotility drugs, (4) maintenance treatment of GERD, and (5) indications for antireflux surgery.

Gastroesophageal Reflux↗
PubMed1995

The rationale for continuous maintenance treatment of reflux esophagitis.

Reflux esophagitis is a chronic process associated with frequent episodes of relapse in many patients. In addition, the disease may be progressive in at least some patients. Erosion of the esophageal mucosa precedes the development of some of the complications of the condition. There is accumulating evidence that continuous treatment of patients with erosive esophagitis effectively maintains symptomatic remission and absence of esophageal erosions. Whether such treatment will prevent the development of complications has not yet been demonstrated. We investigated a number of questions concerning the natural history and complications of erosive esophagitis and the need for maintenance treatment for patients with severe manifestations of disease as well as the impact of continuous maintenance treatment on the natural history of reflux esophagitis and its complications.

Chronic Disease↗
PubMed1995

Manometric characteristics of the pharynx, upper esophageal sphincter, esophagus, and lower esophageal sphincter in patients with oculopharyngeal muscular dystrophy.

Improved techniques in esophageal manometry have made this test an attractive option for investigating pharyngeal or esophageal disorders in patients with dysphagia. We studied esophageal as well as upper esophageal sphincter/pharyngeal (UES/P) pressure dynamics in 11 patients with an established diagnosis of oculopharyngeal muscular dystrophy with modern solid-state manometric techniques and then compared manometric and clinical findings. Esophageal manometric abnormalities were found in 10/11 patients, with the most common being simultaneous contractions and incomplete lower esophageal relaxation. 9/11 patients showed abnormal UES/P manometrics, with the most common abnormalities found in the pharynx. The presence of manometric abnormalities closely paralleled clinical assessment of degree of disease severity. Modern manometric techniques offer an opportunity for a quantitative assessment of swallow abnormalities.

Aged↗