Pharyngeal Pressure Variability During Volitional Swallowing Maneuvers

Purpose: Within-individual pharyngeal swallowing pressure variability differs among pharyngeal regions in healthy individuals and increases with age. It remains unknown if pharyngeal pressure variability is impacted by volitional swallowing tasks. We hypothesized that pressure variability would increase during volitional swallowing maneuvers and differ among pharyngeal regions depending on the type of swallowing task being performed. Method: Pharyngeal high-resolution manometry was used to record swallowing pressure data from 156 healthy participants during liquid (5 cc) or saliva swallows, and during volitional swallowing tasks including effortful swallow, Mendelsohn maneuver, Masako maneuver, or during postural adjustments. The coefficient of variation was used to determine pressure variability of velopharynx, tongue base, hypopharynx, and upper esophageal sphincter regions. Repeated-measures analysis of variance was used on log-transformed data to examine effects of pharyngeal region and swallowing tasks on swallow-to-swallow variability. Results: There was a significant main effect of task with greater pressure variability for the effortful swallow ( p = .002), Mendelsohn maneuver ( p < .001), Masako maneuver ( p = .002), and the head turn ( p = .006) compared with normal effort swallowing. There was also a significant main effect of region ( p < .01). In general, swallowing pressure variability was lower for the tongue base and upper esophageal sphincter regions than the hypopharynx. There was no significant interaction of task and region (effortful, p = .182; Mendelsohn, p = .365; Masako, p = .885; chin tuck, p = .840; head turn, p = .059; and inverted, p = .773). Conclusions: Pharyngeal swallowing pressure variability increases in healthy individuals during volitional swallowing tasks. Less stable swallow patterns may result when tasks are less automatic and greater in complexity. These findings may have relevance to swallowing motor control integrity in healthy aging and individuals with neurogenic dysphagia.

Evaluation of pharyngeal swallowing pressure using high-resolution manometry during transoral surgery for oropharyngeal cancer

BackgroundTransoral robotic surgery is frequently described, driven by the desire to offer a less morbid alternative to chemoradiation. However, the objective evaluation of post-operative function has rarely been reported. Therefore, high-resolution manometry was used in this study to evaluate the impact of changes in peri-operative swallowing function on pharyngeal pressure events.MethodsTen patients with various stages of oropharyngeal cancer underwent transoral surgery. High-resolution manometry and videofluoroscopic swallow studies were performed before surgery and two months afterwards. The following parameters were obtained: velopharyngeal and mesopharyngeal post-deglutitive upper oesophageal sphincter pressures, velo-meso-hypopharyngeal contractile integral, upper oesophageal sphincter relaxation pressure, and pharyngeal velocity.ResultsThere was no significant difference in pharyngeal pressure or contractile integral pre- versus post-operatively. However, pharyngeal velocity was significantly higher post-operatively than pre-operatively.ConclusionHigh-resolution manometry showed that transoral surgery in patients without pre-operative dysphagia preserved pharyngeal constriction. However, transoral surgery might produce scar formation in the pharynx, which could lead to narrowing of the pharynx.

CPAP combined with oral appliance therapy reduces CPAP requirements and pharyngeal pressure swings in obstructive sleep apnea

Combined CPAP and oral appliance therapy has been suggested as an alternative for incomplete responders to oral appliance therapy. We used a novel oral appliance incorporating an oral airway together with CPAP to show that pharyngeal pressure swings were normalized at reduced CPAP levels. Our findings demonstrate that using CPAP and oral appliance together may be a beneficial alternative for incomplete responders to oral appliance therapy and intolerant CPAP users due to high-pressure requirements.

Adequate Number of Swallows for Pharyngeal Pressure Measurement of a Subject using High-resolution Manometry

Introduction The number of pressure measurements that need to be recorded using high-resolution manometry (HRM) for the accurate evaluation of pharyngeal function is not well established. Objective The purpose of this study is to clarify the number of swallows required to obtain an accurate pharyngeal manometric profile of a person. Methods Forty healthy adults performed a dry swallow and bolus swallows using 3-, 5-, or 10 ml of water and underwent measurements using the Starlet HRM system. Each subject underwent 10 swallows for each of the four bolus volume conditions. Results The mean of up to seven measurements of maximum pre-swallow upper esophageal sphincter pressure with 10 ml of swallow was close to the mean of up to eight measurements in 95% of the subjects. Similarly, the rate of change of the average for the eighth and ninth measurements and the rate of change for the average of the ninth and tenth measurements were less than 5%. When the other parameters were similarly measured up to the sixth measurement, no major change in the average value was observed even if more measurements were taken. Conclusion A minimum of six measurements are required, and seven swallows are sufficient for evaluating the pharyngeal manometric profile of a single person. This number of measurements can be a useful criterion when performing HRM measurements on individual subjects.

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&lt;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.

Does the RAM Cannula Provide Continuous Positive Airway Pressure as Effectively as the Hudson Prongs in Preterm Neonates?

Objective To compare the level of continuous positive airway pressure (CPAP) delivered by the RAM cannula system (Neotech, Valencia, CA) with that delivered by a traditional CPAP nasal delivery interface (Hudson prongs; Hudson-RCI, Temecula, CA) in preterm infants with respiratory distress. Methods This was a crossover intervention study in a convenience sample of preterm infants with respiratory distress requiring treatment with CPAP. We measured the mean intraoral (pharyngeal) pressure, which approximates the applied CPAP level, using both the RAM cannula and Hudson prongs. The primary outcome was a comparison of the differences between the set CPAP levels and the measured intraoral pressures of both delivery systems. Results We analyzed data from 12 preterm infants with mean (standard deviation) birth weight of 1,225 (405) g and gestational age of 28.4 (2.1) weeks at a median postnatal age of 10 days. The mean difference (95% confidence interval) between the set CPAP level and measured intraoral pressure was −2.45 cm H2O (−3.36, −1.55) with the RAM cannula and +0.40 cm H2O (−0.30, 1.12) with Hudson prongs, p = 0.0002. Conclusion For given set CPAP pressure level in preterm infants, the RAM cannula system consistently delivers lower pharyngeal pressure (effective CPAP) levels than Hudson prongs.