Pharyngeal Contractile Integral Research Articles

Characterization of pharyngeal contractile integral using pharyngeal manometry in children.

Pharyngeal contractile integral (PhCI) is the product of mean pharyngeal contractile amplitude, length, and duration, and provides a single metric for the vigor of entire pharyngeal contraction. A major limitation in children is lack of characterization of PhCI on high-resolution pharyngeal manometry. We aimed to determine and compare the values of PhCI in children with the abnormal and normal videofluoroscopic study of swallow (VFSS). Children who underwent high-resolution pharyngeal and esophageal manometry (HRPM/HREM), as well as VFSS, were divided into two groups; "normal VFSS" and "abnormal VFSS" groups. PhCI was calculated from the pharyngo-esophageal manometry analysis software (MMS, v9.5, Laborie Medical Technologies), and compared in these two groups. Of 67 children, 9 had abnormal VFSS (mean age 64 ± 50 months; 66.7% males), while 58 had normal VFSS (mean age 123 ± 55 months; 47% males). The mean PhCI in abnormal and normal VFSS groups was 82.00 ± 51.90 and 147.28 ± 53.89 mmHg.s.cm, respectively (p = 0.001). Subjects with abnormal VFSS were significantly younger than those with normal VFSS (p = 0.003). However, after adjusting for the VFSS result, age was no longer related to PhCI (p = 0.364). In subgroup analysis of children presenting with dysphagia, the mean PhCI in abnormal (9 subjects) and normal (36 subjects) VFSS groups was 82.00 ± 51.90 and 141.86 ± 50.39 mmHg.s.cm, respectively (p = 0.003). PhCI was significantly lower in children with abnormal VFSS than in those with normal VFSS. We did not find a significant impact of age on PhCI in our pediatric populations.

The Natural Swallow: Factors Affecting Subject Choice of Bolus Volume and Pharyngeal Swallow Parameters in a Self-selected Swallow.

Predetermined volumes are used extensively throughout clinical assessment of swallowing physiology, but bolus volumes selected by an individual in their natural swallow can vary greatly from those used in structured assessment. This study aims to identify factors influencing self-selected volume and how the mechanics of self-selected volume swallows differ from predetermined volume swallows. We used pharyngeal high-resolution manometry (HRM) with simultaneous videofluoroscopy to measure swallowing pressures in the velopharynx, hypopharynx, and upper esophageal sphincter (UES). Data were collected from 95 healthy adults during thin liquid swallows of 10mL and a self-selected comfortable volume. An intraclass correlation coefficient (ICC) was calculated to analyze within-subject self-selected volume reliability. Linear mixed effects regression models were used to examine the association of subject characteristics with self-selected swallow volume and of self-selected volumes on pharyngeal swallowing pressures and timing events. Mean self-selected volume was 16.66 ± 7.70mL. Increased age (p = 0.002), male sex (p = 0.021), and increased pharyngeal hold area (p = 0.007) were significantly associated with increase in self-selected bolus volume. There was good reliability between subjects' individual swallow volumes (ICC = 0.80). Velopharyngeal maximum pressure and pressure integral, tongue base duration and maximum pressure, UES pre- and post-swallow maximum pressure, and overall pharyngeal contractile integral decreased significantly with self-selected boluses. Understanding a patient's natural swallow volume, and how their natural swallow functions, will be important for designing clinical evaluations that place stress on the patient's natural swallowing mechanics in order to assess for areas of dysfunction.

Age-Related Functional Reserve Decline Is Not Seen in Pharyngeal Swallowing Pressures.

Purpose Functional reserve represents the difference between an individual's ability to produce a maximum output function and the ability to perform a functional task. Several studies have documented an age-related decrease in functional reserve with oral tongue pressure generation. Whether this pattern is seen in pharyngeal swallowing pressures is unknown. The aim of this study was to investigate pharyngeal functional reserve using high-resolution manometry during normal-effort and effortful swallows. Method Pharyngeal high-resolution manometry was performed on 38 younger healthy individuals (≤ 40 years) and 18 older healthy individuals (≥ 60 years) during normal-effort and effortful water swallows. Pressure metrics included maximum pressure in the velopharynx, tongue base, and hypopharynx, as well as pharyngeal contractile integral and minimum pressure in the upper esophageal sphincter (UES). Repeated-measures analysis of variance was used to determine the effects of swallow task, age, and pharyngeal region on pressure generation. Results Maximum pharyngeal pressures and pharyngeal contractile integral were significantly increased during the effortful swallows compared to normal-effort swallows (p < .001), but there were no interactions between task and age in pharyngeal pressures. In the UES, minimum pressures were significantly elevated in older individuals during effortful swallows compared to normal-effort swallows (p = .007) but did not follow a pattern consistent with reduced functional reserve. Conclusions Healthy individuals increase pharyngeal driving pressures during effortful swallows, without an age-related reduction in the magnitude of pressure increase. Thus, this study did not find evidence for an age-related reduction in pharyngeal functional reserve. The preserved ability to increase pharyngeal pressures during effortful swallowing in aging may support the use of behavioral swallowing interventions in older individuals without neuromuscular conditions. Supplemental Material https://doi.org/10.23641/asha.16606709.

Effect of Capsaicinoids on Neurophysiological, Biochemical, and Mechanical Parameters of Swallowing Function

Oropharyngeal dysphagia is prevalent in age-related neurological disorders presenting with impaired efficacy and safety of swallowing due to a loss of muscle force and sensory deficits. Stimulating the oropharynx with capsaicin that mediates Substance P release is an emerging pharmacological treatment option which needs further scientific evidence. Our aim was to comprehensively evaluate the effect of capsaicin on biochemical, neurophysiological, and biomechanical parameters of swallowing function. In a randomized study on healthy individuals, the impact of orally administered capsaicinoids at different dosages and application durations in comparison to non-carbonated water was evaluated. Time course and magnitude of salivary Substance P increase were monitored. Magnetoencephalography was used to detect cortical swallowing network alterations. Modifications in swallowing biomechanics were measured applying high-resolution pharyngeal manometry. Capsaicinoids at 10 μmol/L improved swallowing efficacy as seen by a significant increase of pharyngeal contractile integral and upper esophageal sphincter activation and relaxation times in manometry. Significant improvement of precision in a challenging swallow task accompanied by a reduction in swallowing-related submental electromyographic power was observed with capsaicinoids preconditioning at 10 μmol/L over 5 min, but not with continuous stimulation. The cortical activation pattern remained unchanged after any intervention. A significant increase of salivary Substance P was not detected with 10 μmol/L but with 50 μmol/L and lasted for 15 min after application. Capsaicinoids mediate dose-dependent Substance P release and positively alter swallowing biomechanics in healthy subjects. The results provide supportive evidence for the value of natural capsaicinoids to improve swallowing function.

Effect of Tongue-Hold Swallow on Pharyngeal Contractile Properties in Healthy Individuals

Tongue-hold swallow (THS) is a swallow exercise in which an individual swallows saliva while holding the anterior portion of the tongue between the front teeth. The effect of THS on pharyngeal contractile vigor is still unclear. The purpose of this study was to quantify THS using high-resolution manometry with a contractile integral analysis. Twenty-two healthy participants performed three different saliva swallow tasks: normal swallow, weak THS (in which the tongue was protruded 1 cm outside the upper incisors), and strong THS (in which the tongue was protruded 2 cm outside the upper incisors). The participants repeated each task twice randomly. Pharyngeal and upper esophageal sphincter metrics, including the pharyngeal contractile integral, were analyzed. Both weak and strong THS enhanced the velopharyngeal contractile integral and peak pressure compared with normal swallow (P < 0.01). THS also prolonged mesopharyngeal contraction (P < 0.01). Holding the tongue anteriorly during swallow requires significant biomechanical changes to pharyngeal contractile properties at the superior and middle pharyngeal constrictor levels; thus, it may serve as a resistance exercise for the muscles that are involved in bolus propulsion.

Pharyngeal Swallowing Pressures in Patients with Radiation-Associated Dysphagia.

Dysphagia associated with radiotherapy for head and neck cancer is complex and can be difficult to treat. Videofluoroscopic swallow studies (VFSS) are the current gold-standard instrumented swallow assessment. High-resolution manometry (HRM) is an additional approach that provides objective measurements of swallowing-related pressures in the pharynx and esophagus. This can provide functional information on the pressure gradients underlying bolus propulsion, and is relevant for this patient population, where radiation-related fibrosis can lead to weakness and impaired pressure generation. The purpose of this preliminary study was to describe pharyngeal swallowing pressures in patients with radiation-associated dysphagia (RAD) and late radiation-associated dysphagia (LRAD) using HRM. RAD occurs during and immediately following treatment, whereas LRAD is a more recently described phenomenon in which the patient experiences an onset of dysphagia at least 5years post-treatment. We performed a retrospective analysis of pharyngeal swallowing pressures from 21 patients with RAD or LRAD and 21 healthy sex/age-matched controls. Patients with RAD or LRAD exhibited decreased swallowing pressure durations throughout the pharynx (p ≤ 0.002), as well as decreased hypopharynx maximum pressure (p = 0.003) and pharyngeal contractile integral ( p < 0.0001). Understanding how pharyngeal pressure generation is altered in patients with a history of radiotherapy can help clinicians form more precise treatment plans.

Impact of Sensory Stimulation on Pharyngo-esophageal Swallowing Biomechanics in Adults with Dysphagia: A High-Resolution Manometry Study.

Evidence supporting sensory stimulation of swallowing is based mostly on videofluoroscopy and provides little insight into changes to swallowing physiology. In this study, the impact of sensory stimulation on pharyngo-esophageal swallowing biomechanics was investigated in adults with dysphagia using pharyngeal high-resolution manometry. Fifteen adults (8 males; 45-86years) with mixed etiology dysphagia were consecutively recruited over a three-month period. PHRM equipment with a 4.2mm pressure catheter was used. The protocol included duplicate 10ml neutral, sour, cold, and carbonated liquid swallows in randomized order. Semi-automated analysis was completed using an online portal ( www.swallowgateway.com ). Data from 98/120 swallows were analyzed. During the pharyngeal phase, mean pharyngeal contractile integral (PhCI) increased significantly with cold (p = 0.03), sour (p = 0.00), and carbonation (p = 0.02). Mean velopharyngeal contractile integral (VCI) (p = 0.01) and mesopharyngeal contractile integral (MCI) (p = 0.04) both increased significantly with carbonation. Mean hypopharyngeal contractile integral (HPCI) was not significantly altered by sensory stimulation. Regarding UES opening, UES relaxation time (UESRT) increased significantly with cold (p = 0.032), carbonation (p = 0.032), and sour (p = 0.027). Extent of UES opening as measured by IRP reduced significantly with cold stimulation (9.34 to 5.17mmHg) (p = 0.032). No significant changes were observed to UES basal pressure or UES peak pressure with sensory stimulation. Sensory stimulation induced biomechanical changes to pharyngeal contraction vigor, UES relaxation time and extent of UES opening during swallowing in adults with dysphagia. This study contributes evidence to support sensory stimulation as a dysphagia intervention. Further combined pressure impedance studies in homogeneous clinical populations are ongoing.

AGE-RELATED FUNCTIONAL RESERVE DECLINE IS NOT SEEN IN PHARYNGEAL SWALLOWING PRESSURES

Age-related decline in functional reserve has been described in tongue strength: tongue pressure during swallowing does not change with age, but maximal-effort isometric tongue pressure decreases with age. Healthy persons show a slight increase in pharyngeal swallowing pressure with age, but it is unknown if there is a similar decline in functional reserve. Fifty-six healthy adults (n=38 60 years) underwent pharyngeal high-resolution manometry during effortful and normal-effort thin liquid swallows. Repeated measures ANOVAs were performed on maximum pressures, pharyngeal contractile integral (PCI), pharyngeal pressure gradients, and upper esophageal sphincter minimum pressures. We hypothesized that older individuals would generate a less-robust pressure increase with effortful swallowing than younger individuals. Maximum pressures, PCI, and gradients increase during effortful swallowing (p<0.001), but there was no interaction effect with age, suggesting a lack of age-related functional reserve decline. Older individuals had greater UES minimum pressures than younger individuals in the effortful swallowing task (p=0.03), which may stem from reduced muscular compliance in this area. These findings do not align with those reported in tongue pressures, suggesting that muscle properties and pressure generation may be fundamentally different between the pharynx and the oral tongue. Alternatively, the effortful swallowing task may not elicit maximum contractility of the pharyngeal musculature. The preserved ability to increase pharyngeal pressure during effortful swallowing may support the use of the effortful swallow exercise in older adults with swallowing disorders.

High-Resolution Pharyngeal Manometry and Impedance: Protocols and Metrics-Recommendations of a High-Resolution Pharyngeal Manometry International Working Group.

High-resolution manometry has traditionally been utilized in gastroenterology diagnostic clinical and research applications. Recently, it is also finding new and important applications in speech pathology and laryngology practices. A High-Resolution Pharyngeal Manometry International Working Group was formed as a grass roots effort to establish a consensus on methodology, protocol, and outcome metrics for high-resolution pharyngeal manometry (HRPM) with consideration of impedance as an adjunct modality. The Working Group undertook three tasks (1) survey what experts were currently doing in their clinical and/or research practice; (2) perform a review of the literature underpinning the value of particular HRPM metrics for understanding swallowing physiology and pathophysiology; and (3) establish a core outcomes set of HRPM metrics via a Delphi consensus process. Expert survey results were used to create a recommended HRPM protocol addressing system configuration, catheter insertion, and bolus administration. Ninety two articles were included in the final literature review resulting in categorization of 22 HRPM-impedance metrics into three classes: pharyngeal lumen occlusive pressures, hypopharyngeal intrabolus pressures, and upper esophageal sphincter (UES) function. A stable Delphi consensus was achieved for 8 HRPM-Impedance metrics: pharyngeal contractile integral (CI), velopharyngeal CI, hypopharyngeal CI, hypopharyngeal pressure at nadir impedance, UES integrated relaxation pressure, relaxation time, and maximum admittance. While some important unanswered questions remain, our work represents the first step in standardization of high-resolution pharyngeal manometry acquisition, measurement, and reporting. This could potentially inform future proposals for an HRPM-based classification system specifically for pharyngeal swallowing disorders.

Pharyngeal Swallowing During Wake and Sleep.

Sleep is associated with stages of relative cortical quiescence, enabling evaluation of swallowing under periods of reduced consciousness and, hence, absent volition. The aim of this study was to measure and characterize changes in the characteristics of pharyngeal swallows during sleep and wake using high-resolution manometry (HRM). Pharyngeal swallows were recorded with a ManoScan™ HRM in wake-upright, wake-supine, and sleep conditions in 20 healthy participants (mean 27years; range 21-52). Velopharyngeal and hypopharyngeal segments were analysed separately. Contractile integral, mean peak pressure, inverse velocity of superior-to-inferior pharyngeal pressure, and time to first maximum pressure were analysed with custom-designed software. The supine-wake condition was compared to both upright-wake and sleep conditions using linear mixed effects models. No significant differences were found between supine-wake and upright-wake conditions on any measures. The mean peak pharyngeal pressure was lower during sleep than during the supine-wake condition for both the velopharynx (- 60mmHg, standard error [SE] = 11, p < 0.001) and hypopharynx (- 59mmHg, SE = 9, p = 0.001), as was the pharyngeal inverse velocity (- 12ms/cm, SE = 4, p = 0.012) for the hypopharyngeal segment and the pharyngeal contractile integral (- 32mmHg scm, SE = 6, p < 0.001). No significant differences were found in time to the first pharyngeal maximum pressure. This study used HRM to characterize and compare pharyngeal pressures during swallowing in both wake and sleep conditions. No differences were found between upright and supine awake conditions, a finding important to pharyngeal manometric measures made during supine positioning, such as in fMRI. Higher pressures and longer time-related measures of volitional pharyngeal swallowing when awake indicate that cortical input plays an important role in modulation of pharyngeal swallowing.

Length Normalisation for Pharyngeal and Distal Contractile Integrals: Is It Necessary?

Introduction: High-resolution pharyngeal manometry (HRPM) is instrumental in evaluation of the intraluminal pressure in the pharynx, thus can be utilized in guiding therapy. The pharyngeal contractile integral (PhCI) is a HRPM metric assessing “vigor” of the pharyngeal contraction, and is analogous to the distal contractile integral (DCI) of the esophagus. Pharyngeal and esophageal length can vary from person to person and may confound PhCI and DCI measurements, so we decided to investigate this further. Methods: To compare normalized (nPhCI) and (nDCI) versus non-normalized PhCI and DCI using pharyngeal and esophageal length measurementsRetrospective study including 100 people underwent HRM excluding those with total absence of peristalsis. nDCI was calculated by dividing average DCI to their esophageal length which was defined by HRM as the distance between inferior border of UES to the upper of the LES. nPhCI was calculated by dividing average PhCI to its pharyngeal length. Pharyngeal length was measured radiographically from anterior superior edge of C1 vertebra to the anterior inferior edge of C5. Results: Results are summarized in table 1 and 2. nPhCI was tightly correlated with the original average PhCI, suggesting that pharyngeal length is fairly constant over the range of observed PhCI (r=0.95, p<0.001) (figure 1A). nDCI was also tightly correlated with the original average DCI value (r=0.99, p<0.001) (figure 1B). Conclusion: Data suggests that “normalization” for pharyngeal and esophageal lengths are not necessary when completing HRM. PhCI may a useful indicator of the severity of pharyngeal swallowing impairment. HRPM has the potential to be a valuable adjunct testing procedure in the evaluation and treatment of dysphagic individuals. 384_A Figure 1 No Caption available.384_B Figure 2 No Caption available.384_C Figure 3 No Caption available.

Defining pharyngeal contractile integral during high-resolution manometry in neonates: a neuromotor marker of pharyngeal vigor.

BACKGROUNDPharyngeal contractility is critical for safe bolus propulsion. Pharyngeal contractile vigor can be measured by Pharyngeal Contractile Integral (PhCI): product of mean pharyngeal contractile amplitude, length, and duration. We characterized PhCI in neonates and examined the hypothesis that PhCI differs with mode of stimulation.METHODSNineteen neonates born at 38.6(34-41) weeks gestation were evaluated at 42.9 (40.4-44.0) weeks postmenstrual age using high resolution manometry (HRM). PhCI was calculated using: a) Conventional, and b) Automated Swallow Detection algorithm (ASDA) methods. Contractility metrics of all pharyngeal regions were examined using mixed statistical models during spontaneous and adaptive state (pharyngeal and oral stimulus) swallowing.RESULTSPhCI of oral stimuli swallows were distinct from pharyngeal stimuli and spontaneous swallows (P<0.05). Correlation between conventional and ASDA methods was high (P < 0.001). PhCI increased with swallows for pharyngeal stimulation (P <0.05) but remained stable for swallows with oral stimulation. PhCI differed between proximal and distal pharynx (P < 0.001).CONCLUSIONSPhCI is a novel reliable metric capable of distinguishing 1) proximal and distal pharyngeal activity, 2) effects of oral and pharyngeal stimulation, and 3) effects of prolonged stimulation. Changes in pharyngeal contractility with maturation, disease, and therapies can be examined with PhCI.

Characterization of pharyngeal peristaltic pressure variability during volitional swallowing in healthy individuals.

Recent technological advances incorporated in high resolution manometry have justifiably heightened interest in manometric evaluation of the pharynx. Despite this interest, from both physiologic and clinical perspective there remain a number of unanswered questions regarding the magnitude of variability of pharyngeal pressure phenomena. Therefore, the aim of the present study was to characterize in healthy individuals the inter-subject and recording-site specific variability of pharyngeal peristaltic pressure phenomena. We studied 32 healthy subjects (age: 21-83years,20 under 35years) during dry,5 and 10mL water swallows ×3. Pharyngeal peristaltic pressures were recorded using a high resolution (HR) manometric system and a catheter assembly with 36 circumferential sensors spaced at 1cm intervals positioned trans-nasally to traverse the pharynx, UES and proximal esophagus. Both site-specific pressure data and the Pharyngeal contractile integral (PhCI) showed wide dispersion ranging between values under 50mm Hg to over 300mm Hg and 100-600mm Hg/cm/s,respectively. There was also wide range of dispersion of data for both the standard deviations and the coefficient of variation for all sites (P=.001). The coefficient of variation for PhCI ranged between 0.02 and 0.25 representing data dispersion of 2-25 percent of the mean among subjects (P=.001). Position, age and volume of swallowed fluid did not influence the magnitude of variability. Deglutitive Pharyngeal peristalsis generates pressures with significant degree of site-related and inter-subject variability. This variability is not influenced by age, position and volume of swallowed fluid.

Pharyngeal peristaltic pressure variability, operational range, and functional reserve

The present understanding of pharyngeal motor function remains incomplete. Among the remaining gaps of knowledge in this regard is the magnitude of variability of pharyngeal peristaltic pressure amplitude. Although variability can pose difficulty in interpretation of manometric findings, its magnitude can inform the operational range and reserve of the pharyngeal contractile function. We aimed to define the intra- and intersubject and intersession variability of select pharyngeal manometric parameters and, using this information, determine the number of swallow repetitions for acquiring reliable pharyngeal manometric data. We recorded pharyngeal peristalsis in 10 healthy subjects (age: 50 ± 25 yr, 5 women) by high-resolution manometry during two separate sessions of 20 sequences of 0.5-ml water swallows. Two-way ANOVA showed significant variation in the mean peak peristaltic pressure value across sites (P < 0.0001) as well as within the data at each site (P < 0.0001). Similarly, the pharyngeal contractile integral exhibited significant inter- (P = 0.003) and intrasubject (P < 0.001) variability. The Shapiro-Wilk normality test showed mixed results, in that some sites showed normally distributed data, whereas others did not. A robust Monte Carlo simulation showed that the nominal sample size was different for various tested metrics. For a power of 0.8, commonly accepted as an adequate threshold for acceptable statistical power, the optimal sample size for various peristaltic parameters ranged between 3 and 15. There is significant intra- and intersubject variability in site-specific and integrated parameters of pharyngeal peristalsis. The observed variance indicates a significant operational range and reserve in pharyngeal contractile function while necessitating parameter-specific sample size for reliable results.NEW & NOTEWORTHY Intra- and intersubject variability are significant and different at various sites within the contractile pharynx. In addition, significant swallow-to-swallow and subject-to-subject variability exists in pharyngeal contractile integral. The range of intrasubject variability indicates the existence of broad operational range and reserve. Lastly, our variability studies informed Monte Carlo and power analyses, yielding estimates of sample size that would ensure accurate representation of pressure metric variability.

Effects of laryngeal restriction on pharyngeal peristalsis and biomechanics: Clinical implications.

To date, rehabilitative exercises aimed at strengthening the pharyngeal muscles have not been developed due to the inability to successfully overload and fatigue these muscles during their contraction, a necessary requirement for strength training. The purpose of this study was to test the hypothesis that applying resistance against anterosuperior movement of the hyolaryngeal complex will overload the pharyngeal muscles and by repetitive swallowing will result in their fatigue manifested by a reduction in pharyngeal peristaltic amplitude. Studies were done in two groups. In group 1 studies 15 healthy subjects (age: 42 ± 14 yr, 11 females) were studied to determine whether imposing resistance to swallowing using a handmade device can affect the swallow-induced hyolaryngeal excursion and related upper esophageal sphincter (UES) opening. In group 2, an additional 15 healthy subjects (age 56 ± 25 yr, 7 females) were studied to determine whether imposing resistance to the anterosuperior excursion of the hyolaryngeal complex induces fatigue manifested as reduction in pharyngeal contractile pressure during repeated swallowing. Analysis of the video recordings showed significant decrease in maximum deglutitive superior laryngeal excursion and UES opening diameter (P < 0.01) due to resistive load. Consecutive swallows against the resistive load showed significant decrease in pharyngeal contractile integral (PhCI) values (P < 0.01). Correlation analysis showed a significant negative correlation between PhCI and successive swallows, suggesting "fatigue" (P < 0.001). In conclusion, repeated swallows against a resistive load induced by restricting the anterosuperior excursion of the larynx safely induces fatigue in pharyngeal peristalsis and thus has the potential to strengthen the pharyngeal contractile function.

Tu1454 Inter-Rater Agreement for Analysis of Pharyngeal High Resolution Manometry Parameters

Introduction: Pharyngeal manometry using high resolution technology is a developing field that is being advocated for evaluation of dysphagic symptoms that are not explained by a conclusive or objective finding on routine evaluation such as radiography. Fundamental to the success of this approach, automated analysis techniques not withstanding, is the reliability and reproducibility of the measurements performed by the clinicians. Our aim was to determine the inter-rater reliability for measurements of deglutitive pharyngeal peristaltic pressure wave characteristics such as peak peristaltic amplitude, pharyngeal contractile integral (PCI), nadir upper esophageal sphincter (UES) deglutitive pressure and intrabolus pressure (IBP). Methods: We studied 11 healthy individuals (age 56±25 years, 6F) by high resolution manometry using a catheter with 36 recording sites spaced at 1 cm intervals that recorded from the entire pharyngeal contractile zone, UES and proximal esophagus. Each volunteer swallowed 0.5 ml of room temperature water 40 times with 20 seconds intervals between swallows. Three raters (one seasoned, two with recent training) each independently analyzed a total of 3080 pressure signatures, 440 pharyngeal contractile integrals and 440 intra-bolus pressures. Measured parameters included peak peristaltic wave pressures at specific manometric locations 2, 3, 4, 5, 6, 7, and 8 cm above the upper margin of the UES high pressure zone, as well as PCI, nadir UES deglutitive pressure and IBP. Inter-rater agreement was evaluated using Bland-Altman intra-class correlation coefficient (ICC) analysis. Results: As seen in the table, agreement among the three raters all for all manometric locations was highly significant (p<0.001) with sites p2 and p3 (2 and 3cm above the upper margin of the UES) having the lowest levels of agreement. Furthermore, metrics with a single value for each swallow like PCI and UES nadir pressure also showed highly significant agreement whereas IBP measurements did not. A graphical depiction of intra-rater agreement is shown in the figure for PCI as a representative parameter. Conclusion: Analysis of pharyngeal pressure parameters by individuals with proper training is reproducible as evidenced by high level of agreement between the results obtained independently by three different raters. Supported in part by EOPH grant and PPG. Supported in part by R01DK025731 and P01DK068051

841 Variability of Pharyngeal Peristaltic Pressure Parameters Measured by High Resolution Manometry (HRM); A Study of Over 900 Pressure Signatures

Introduction: With the many alluring features of HRM including superior spatial resolution and rapid recording frequency, interest in manometric evaluation of the pharynx during swallowing has been renewed. However, crucial information about the physiologic variability of pharyngeal peristaltic pressure wave parameters is scarce. These data are vital for developing normative data and correct interpretation of pharyngeal manometry results. The aims of the present study were to determine: 1) the variability of pharyngeal peristaltic pressure wave amplitude and duration between swallows at various distances from the upper esophageal sphincter (UES) and 2) Pharyngeal Contractile Integral(PCI),hypo-pharyngeal intra-bolus pressure(IBP) and nadir UES pressure(N-UESP) for a range of swallowed volumes. Methods: We studied seven healthy individuals (age:51±25 years, 6F) in upright head neutral position using a high resolution manometry catheter with 36 recording sites positioned trans-nasally such that pressure was recorded from the entire pharynx, UES and proximal esophagus. In each subject, we tested three repetitions each of dry and room temperature 0.5,5 and 10ml water at 20-30second intervals. Statistical analysis included ANOVA, Kruskal-Wallis Testing, Bartlett's Test of variance, Conover's Squared Rank Test of Variance and the coefficient of variation. Results: Spatial variation of the peak peristaltic pressure wave amplitude showed significant difference in variance across locations 2, 3, 4, 5, 6, 7 and 8cm above the upper margin of the UES high pressure zone (umUESHPZ) for dry(p=0.043), 0.5 (p=0.006) and 5ml (p=0.049)swallows (table). There was significant variability in the peak amplitude between swallows at all sites as seen by the standard deviation bars in the figure (representative example for 5ml swallows). The smallest degree of variability across sites was seen at p6 (6 cm above the umUESHPZ) shown in the figure as circles representing the coefficients of variation. Variance due to volume effects also showed significant differences; however, these difference in variance were confined only to sites 3 (p=0.015), 4 (p=0.020) and 6 (p=0.022) cm above the umUESHPZ. In contrast, PCI and IBP showed similar variability for the tested swallow volumes. Conclusions: 1) Parameters of pharyngeal peristaltic pressure wave vary significantly from one swallow to the other for dry and water swallows,2) this variability is significantly different for different locations across the pharynx. 3) these findings should be taken into account for defining normative data and using pharyngeal manometry for clinical purposes. Supported in part by R01DK025731 and P01DK068051.

842 Pediatric Gastroesophageal Reflux Disease: Acidic and Non-Acidic Gastric Juice Modulates Bronchial Epithelial IL-8 Response

Introduction: With the many alluring features of HRM including superior spatial resolution and rapid recording frequency, interest in manometric evaluation of the pharynx during swallowing has been renewed. However, crucial information about the physiologic variability of pharyngeal peristaltic pressure wave parameters is scarce. These data are vital for developing normative data and correct interpretation of pharyngeal manometry results. The aims of the present study were to determine: 1) the variability of pharyngeal peristaltic pressure wave amplitude and duration between swallows at various distances from the upper esophageal sphincter (UES) and 2) Pharyngeal Contractile Integral(PCI),hypo-pharyngeal intra-bolus pressure(IBP) and nadir UES pressure(N-UESP) for a range of swallowed volumes. Methods: We studied seven healthy individuals (age:51±25 years, 6F) in upright head neutral position using a high resolution manometry catheter with 36 recording sites positioned trans-nasally such that pressure was recorded from the entire pharynx, UES and proximal esophagus. In each subject, we tested three repetitions each of dry and room temperature 0.5,5 and 10ml water at 20-30second intervals. Statistical analysis included ANOVA, Kruskal-Wallis Testing, Bartlett's Test of variance, Conover's Squared Rank Test of Variance and the coefficient of variation. Results: Spatial variation of the peak peristaltic pressure wave amplitude showed significant difference in variance across locations 2, 3, 4, 5, 6, 7 and 8cm above the upper margin of the UES high pressure zone (umUESHPZ) for dry(p=0.043), 0.5 (p=0.006) and 5ml (p=0.049)swallows (table). There was significant variability in the peak amplitude between swallows at all sites as seen by the standard deviation bars in the figure (representative example for 5ml swallows). The smallest degree of variability across sites was seen at p6 (6 cm above the umUESHPZ) shown in the figure as circles representing the coefficients of variation. Variance due to volume effects also showed significant differences; however, these difference in variance were confined only to sites 3 (p=0.015), 4 (p=0.020) and 6 (p=0.022) cm above the umUESHPZ. In contrast, PCI and IBP showed similar variability for the tested swallow volumes. Conclusions: 1) Parameters of pharyngeal peristaltic pressure wave vary significantly from one swallow to the other for dry and water swallows,2) this variability is significantly different for different locations across the pharynx. 3) these findings should be taken into account for defining normative data and using pharyngeal manometry for clinical purposes. Supported in part by R01DK025731 and P01DK068051.

843 Association of Novel High-Resolution Impedance Manometry Parameters (HRIM) With Timed Barium Esophagram Measures and Dysphagia Symptoms in Achalasia Patients

Introduction: With the many alluring features of HRM including superior spatial resolution and rapid recording frequency, interest in manometric evaluation of the pharynx during swallowing has been renewed. However, crucial information about the physiologic variability of pharyngeal peristaltic pressure wave parameters is scarce. These data are vital for developing normative data and correct interpretation of pharyngeal manometry results. The aims of the present study were to determine: 1) the variability of pharyngeal peristaltic pressure wave amplitude and duration between swallows at various distances from the upper esophageal sphincter (UES) and 2) Pharyngeal Contractile Integral(PCI),hypo-pharyngeal intra-bolus pressure(IBP) and nadir UES pressure(N-UESP) for a range of swallowed volumes. Methods: We studied seven healthy individuals (age:51±25 years, 6F) in upright head neutral position using a high resolution manometry catheter with 36 recording sites positioned trans-nasally such that pressure was recorded from the entire pharynx, UES and proximal esophagus. In each subject, we tested three repetitions each of dry and room temperature 0.5,5 and 10ml water at 20-30second intervals. Statistical analysis included ANOVA, Kruskal-Wallis Testing, Bartlett's Test of variance, Conover's Squared Rank Test of Variance and the coefficient of variation. Results: Spatial variation of the peak peristaltic pressure wave amplitude showed significant difference in variance across locations 2, 3, 4, 5, 6, 7 and 8cm above the upper margin of the UES high pressure zone (umUESHPZ) for dry(p=0.043), 0.5 (p=0.006) and 5ml (p=0.049)swallows (table). There was significant variability in the peak amplitude between swallows at all sites as seen by the standard deviation bars in the figure (representative example for 5ml swallows). The smallest degree of variability across sites was seen at p6 (6 cm above the umUESHPZ) shown in the figure as circles representing the coefficients of variation. Variance due to volume effects also showed significant differences; however, these difference in variance were confined only to sites 3 (p=0.015), 4 (p=0.020) and 6 (p=0.022) cm above the umUESHPZ. In contrast, PCI and IBP showed similar variability for the tested swallow volumes. Conclusions: 1) Parameters of pharyngeal peristaltic pressure wave vary significantly from one swallow to the other for dry and water swallows,2) this variability is significantly different for different locations across the pharynx. 3) these findings should be taken into account for defining normative data and using pharyngeal manometry for clinical purposes. Supported in part by R01DK025731 and P01DK068051.