June A. Castell

Esophageal Manometry in 95 Healthy Adult Volunteers Variability of Pressures with Age and Frequency of "Abnormal" Contractions

Although esophageal manometry is widely used in clinical practice, the normal range of esophageal contraction parameters is poorly defined. Therefore, 95 healthy volunteers (mean age: 43 years; range 22–79 years) were studied with a low-compliance infusion system and 4.5-mm-diameter catheter. All subjects were given 10 wet swallows (5 cc H2O) and 38 subjects also were given 10 dry swallows. Results: Amplitude, but not duration, was greater (P<0.05) after wet compared to dry swallows. Both distal mean contractile amplitude and duration of wet swallows significantly increased with age and peaked in the fifties. Double-peaked waves frequently occurred after both wet (11.3%) and dry (18.1%) swallows, but triple-peaked waves were rare (<1%). Nonperistaltic contractions were more common (P<0.001) after dry compared to wet swallows (18.1% vs 4.1%). This difference resulted from frequent simultaneous contractions after dry swallows (12.6% vs 0.4%). Conclusions: (1) Distal esophageal contractile amplitude and duration after wet swallows increases with age. (2) Triple-peaked waves and wet-swallow-induced simultaneous contractions should suggest an esophageal motility disorder. Double-peaked waves are a common variant of normal. (3) Dry swallows have little use in the current evaluation of esophageal peristalsis.

Ineffective Esophageal Motility (IEM) (The Primary Finding in Patients with Nonspecific Esophageal Motility Disorder)

Nonspecific esophageal motility disorder (NEMD)is a vague category used to include patients with poorlydefined esophageal contraction abnormalities. Thecriteria include “ineffective” contractionwaves, ie, peristaltic waves that are either of lowamplitude or are not transmitted. The aim of this studywas to identify the prevalence of ineffective esophagealmotility (IEM) found during manometry testing and to evaluate esophageal acid exposure andesophageal acid clearance (EAC) in patients with IEMcompared to those with other motility findings. Weanalyzed esophageal manometric tracings from 600consecutive patients undergoing manometry in our laboratoryfollowing a specific protocol from April 1992 throughOctober 1994 to identify the frequency of ineffectivecontractions and the percentages of other motility abnormalities present in patients meetingcriteria for NEMD. Comparison of acid exposure and EACwas made with 150 patients who also had both esophagealmanometry and pH-metry over the same time period. Sixty-one of 600 patients (10%) met thediagnostic criteria for NEMD. Sixty of 61 (98% ) ofthese patients had IEM, defined by at least 30%ineffective contractions out of 10 wet swallows.Thirty-five of these patients also underwent ambulatoryesophageal pH monitoring. Patients with IEM demonstratedsignificant increases in both recumbent medianpercentage of time of pH 4 (4.5%) and median distal EAC (4.2 min/episode) compared to those with normalmotility (0.2%, 1 min/episode), diffuse esophageal spasm(0%, 0.6 min/episode), hypertensive LES (0%, 1.8min/episode), and nutcracker esophagus (0.4% 1.6 min/episode). Recumbent acid exposure inIEM did not differ significantly from that in patientswith systemic scleroderma (SSc) for either variable(5.4%, 4.2 min/episode). We propose that IEM is a more appropriate term and should replace NEMD,giving it a more specific manometric identity. IEMpatients demonstrate a distinctive recumbent refluxpattern, similar to that seen in patients with SSc. This finding indicates that there is anassociation between IEM and recumbent GER. Whether IEMis the cause or the effect of increased esophageal acidexposure remains to be determined.

Pharyngeal and Upper Esophageal Sphincter Manometry in the Evaluation of Dysphagia

The use of esophageal manometry seems to be increasing, but the utility of pharyngeal and upper esophageal sphincter (UES) manometry is not widely recognized. This article is intended to clarify this subject. Initially, we review the anatomy and physiology of this area. Most studies indicate that the manometry of the UES and pharynx provides useful information primarily in patients that have symptoms of oropharyngeal dysfunction. Oropharyngeal dysphagia has high morbidity, mortality, and cost. It occurs in one third of all stroke patients and is common in the chronic care setting; up to 60% of nursing home occupants have feeding difficulties, of whom a substantial portion have dysphagia. For patients with oropharyngeal dysphagia, as for those with esophageal dysphagia, barium swallow study and manometry are complimentary. Their combined use permits us to enhance the understanding of the pathophysiologic process that causes the patient’s symptoms. Abnormalities have been noted in a variety of diseases, such as Parkinson’s disease, oculopharyngeal muscular dystrophy, achalasia, and scleroderma. Thus, it is possible to determine the primary pathology that is causing the patient’s dysphagia by analyzing the manometry results. Pharyngeal and UES manometry also has a value in evaluating patients who are candidates for myotomy or dilatation, as it can help identify patients with a prospective good outcome.

Radial and longitudinal asymmetry of human pharyngeal pressures during swallowing

Radial asymmetry of upper esophageal sphincter resting pressure has been previously described; however, neither radial nor longitudinal asymmetry of pharyngeal pressures has been demonstrated. The authors used a specially designed intraluminal transducer catheter (Konigsberg; Konigsberg Instruments, Pasadena, CA) with four solid-state transducers separated by 3 cm and oriented circumferentially at 90 degrees intervals to measure pharyngeal pressures. Two wet swallows at each 1-cm interval along the length of the pharynx were measured in 12 normal volunteers (10 male, 2 female; mean age, 38 years). Pressure data were collected on-line by an Apple IIe microcomputer (Apple Computer Inc., Cupertino, CA) at 100 Hz and analyzed for both radial and longitudinal asymmetry. Significant (P less than 0.05) longitudinal asymmetry was shown in all positions except right lateral. Radial asymmetry was present for the first 4 cm only, with anterior and posterior pressures significantly (P less than 0.05) higher than lateral pressures. It was concluded that pharyngeal pressure responses show both axial and longitudinal asymmetry in the distal pharynx. Awareness of transducer position and orientation is essential in the evaluation of pharyngeal pressures.

Effects of body position and bolus consistency on the manometric parameters and coordination of the upper esophageal sphincter and pharynx

The development of a solid-state intraluminal sphincter transducer has alleviated many of the problems associated with manometric studies of the upper esophageal sphincter (UES) and pharynx (P). We used this technology to study the effect of position (upright vs. supine) on resting UES pressures and the pressure dynamics of the UES/P complex during both wet and dry swallows in 11 normal volunteers and the effects of foods of different consistencies on the UES/P swallow dynamics in 10 normal volunteers. The UES/P coordination parameters were defined as the 15 time intervals that can be measured between any 2 of 6 pertinent points: the beginning, peak, and end of the pharyngeal contraction and the beginning, nadir, and end of the UES relaxation. Data from both the circumferential transducer used to measure sphincter pressures and a standard microtransducer used to measure pharyngeal pressures were collected on-line by an Apple IIe microcomputer and analyzed by programs written in our laboratory. Significant changes in swallow coordination were measured between upright and supine swallows of the same bolus size, between wet and dry swallows in the same position, and among foods of varying consistencies. Resting UES pressure was unchanged by position and pharyngeal contraction pressure was unchanged by bolus size or consistency.

Comparison of effects of upright versus supine body position and liquid versus solid bolus on esophageal pressures in normal humans

New studies monitoring ambulatory esophageal pressures during food ingestion often compare results to normal values obtained from supine liquid swallows. We compared distal esophageal peristaltic and lower esophageal sphincter (LES) pressures in 15 normal subjects during six liquid swallows in the upright and supine positions, and six solid (small marshmallow) swallows in upright position. LES pressures were significantly ( P <0.05) higher supine than upright but no differences were noted in LES pressure, relaxation, and duration of relaxation between upright solid and liquid swallows. Distal peristaltic wave velocities were faster upright than supine. Peristaltic wave amplitudes, durations, and DP/DT were significantly (P <0.05) greater in supine than in upright position. Atypical wave forms, defined as nontransmitted, simultaneous, and simultaneous/repetitive, increased in the upright position compared to supine (P <0.01), and during solid vs liquid swallows (P <0.05). These results indicate that body position substantially affects normal distal esophageal peristalsis and LES pressure and that “abnormal” wave forms occur more frequently during swallowing solids than liquids in the upright position. Conclusions regarding “abnormal” motility over prolonged periods and during food ingestion in patients should be tempered by these findings.

Hypertensive lower esophageal sphincter: what does it mean?

The hypertensive lower esophageal sphincter (LES) (mean LES pressure >45 mm Hg; LES relaxation >75%; normal peristalsis) is a poorly characterized motility disorder associated with chest pain and dysphagia. Therefore, we carried out a multidisciplinary study to assess esophageal pressures and function in 15 symptomatic hypertensive LES patients (3 men, 12 women; mean age, 53 years). On-line computer analysis showed a significant (p < 0.05) increase in LES pressure (55.5 versus 14.9 mm Hg) and residual pressure (6.8 versus 1.1 mm Hg) as well as a decrease in percentage of LES relaxation (87 versus 93%) in patients compared with age-matched controls. All patients had normal peristalsis but 7 of 15 had nutcracker esophagus (mean distal amplitude, 216 mm Hg). No patient had evidence of impaired liquid transport on barium esophagram. The emptying of solids as assessed by radionuclide scans was normal in 14 of 15 patients. Of the 12 patients who completed both psychological inventories, nine had elevated scores on scales assessing anxiety and somatization. The heterogenous nature of this disorder is illustrated by a patient with a changeable narrowing in the distal esophagus associated with the transient impaction of a marshmallow. Dysphagia but not chest pain improved after pneumatic dilatation. We conclude that the hypertensive LES is a heterogenous disorder. Despite abnormal LES parameters, most patients have normal esophageal function, and frequent psychological abnormalities may contribute to their report of symptoms. A minority have abnormal esophageal transit.

Computer analysis of human esophageal peristalsis and lower esophageal sphincter pressure: II. An interactive system for on-line data collection and analysis

A computer program has been written to directly read and analyze esophageal manometric tracings on-line using low-cost off-the-shelf microcomputer hardware. The system consists of an Apple IIe microcomputer and an Interactive Microwave Inc. ADALAB Data Acquisition System with an AI13 fast A/D Multiplexer. The primary program is in BASIC with ASSEMBLY language subroutines for data collection. Data are collected through the voltage output of a Hewlett-Packard recorder at 30 points per second on four channels for lower esophageal sphincter pressures (LESP) and three channels for peristaltic waves. Computer-determined values for LESP and wave parameters showed excellent correlation with mean values as read by five individuals experienced in esophageal manometry.

Alginic acid decreases postprandial upright gastroesophageal reflux : comparison with equal-strength antacid

This study tested the hypothesis that (alginic) acid may have a preferential effect on reflux in the upright position. We evaluated the effect of a compound containing alginic acid plus antacid (extrastrength Gaviscon) versus active control antacid with equal acidneutralizing capacity on intraesophageal acid exposure following a high-fat, meal (61% fat: sausage, egg, and biscuit). In random sequence, each of the 10 volunteers received either alginic acid-antacid or control antacid immediately following and 1, 2, and 3 hr after the meal. The sequence was repeated for both test drugs in the supine and upright positions with constant pH monitoring. Alginic acid-antacid significantly decreased postprandial reflux in the upright position compared to an equal amount of antacid. This effect did not occur in the supine position. These findings support the hypothesis that alginic acid is primarily effective in the upright position and the clinical observations of the effectiveness of alginic acid on daytime reflux symptoms.

Pharyngeal/upper esophageal sphincter pressure dynamics in humans. Effects of pharmacologic agents and thermal stimulation.

Extensive physiological studies of swallowing have been carried out in laboratory animals; however, similar studies in humans have been limited by available technology. In this study we describe the use of a solid-state circumferential sphincter transducer to define manometric characteristics of the human pharynx and upper esophageal sphincter (UES). Effects of pharmacologic agents and thermal stimulation are also described. We studied nine normal volunteers on three separate days. All studies were done in the upright position and consisted of a station pull-through of the UES and six wet swallows with the sphincter transducer in the most proximal segment of the UES and a posteriorly oriented single transducer 5 cm proximal in the pharynx. Baseline studies preceded all drug studies. Effects of bethanechol were studied on day 1, cold stimulation and benzonatate on day 2, edrophonium and atropine on day 3. The UES resting pressure showed large intrasubject day-to-day variations; however, mean values did not differ. There were no effects on UES relaxation or swallow coordination with any of the pharmacologic agents, although benzonatate produced multiple pharyngeal contractions.