Pharyngeal flow interval: a novel impedance-based parameter correlating with aspiration

Clinical effects of oral motor intervention combined with non-nutritive sucking on oral feeding in preterm infants with dysphagia

OBJECTIVE

To explore the effectiveness of oral motor intervention combined with non-nutritive sucking in treating premature infants with dysphagia.

METHODS

Sixty preterm infants admitted to the neonatal intensive care unit of the present study's hospital were selected and randomly divided into the control and intervention groups. The control group was given non-nutritive sucking intervention alone, while the intervention group was given oral motor intervention combined with non-nutritive sucking. The oral motor ability, milk sucking amount and sucking rate, feeding efficiency and outcomes, and the occurrence of adverse reactions were measured and compared.

RESULTS

Compared to first-day interventions, preterm infant oral feeding readiness assessment scale-Chinese version (PIOFRAS-CV) scores of the two groups significantly increased after 14 days of intervention, and this score was higher in the intervention group compared to the control group. Similarly, after 14 days of intervention, the intervention group's milk sucking rate and amount were significantly higher than the control group. Also, after the intervention, the intervention group's total oral feeding weeks were considerably lower, while the feeding efficiency and body weight were significantly higher than the control group. Moreover, the overall adverse reaction rate in the intervention group was lower than that in the control group.

CONCLUSIONS

Oral motor intervention combined with non-nutritive sucking can significantly improve the oral motor ability of premature newborns, promote the process of oral feeding, improve the outcome of oral feeding, and reduce the occurrence of adverse effects. The combined intervention seems to have a beneficial effect on oral feeding proficiency in preterm infants.

Identifying Aspiration Among Infants in Neonatal Intensive Care Units Through Occupational Therapy Feeding Evaluations

IMPORTANCE

When a neonate's sucking, swallowing, and breathing are disorganized, oropharyngeal aspiration often occurs and results in illness, developmental problems, and even death. Occupational therapists who work in the neonatal intensive care unit (NICU) need to identify neonates who are at risk for aspirating so they can provide appropriate treatment.

OBJECTIVE

To ascertain whether client factors and performance skills of infants ages 0-6 mo during occupational therapy feeding evaluations are related to results of videofluoroscopic swallowing studies (VFSSs).

DESIGN

Retrospective chart reviews.

SETTING

187-bed NICU in a nonprofit teaching hospital.

PARTICIPANTS

A purposive sample of 334 infants ages 0-6 mo, ≥33 wk gestational age at birth, admitted to a Level II, III, or IV NICU as defined by the American Academy of Pediatrics.

OUTCOMES AND MEASURES

Neonates were administered a feeding evaluation by an occupational therapist and a VFSS by a speech-language pathologist, which yielded information about client factors and performance skills.

RESULTS

Signs and symptoms of aspiration on the evaluations were significantly associated with VFSS results. Of 310 patients, 79 had silent aspiration. Of 55 infants who demonstrated no aspiration symptoms during the feeding evaluation, 45% demonstrated aspiration symptoms on the VFSS, and 55% aspirated on the VFSS but demonstrated no symptoms of aspiration.

CONCLUSIONS AND RELEVANCE

Aspiration among infants occurs inconsistently and depends on client factors, contexts, and environments. Occupational therapists are encouraged to assess an infant's feeding over several sessions to obtain a more accurate picture of the infant's feeding status.

WHAT THIS ARTICLE ADDS

This study provides information that helps occupational therapists identify infants at risk for aspiration and make optimal recommendations regarding safe feeding practices and appropriate referrals for a VFSS. Making appropriate referrals for VFSS is also important in preventing unnecessary exposure to radiation for preterm infants.

Esophageal pH-impedance monitoring in children: position paper on indications, methodology and interpretation by the SIGENP working group

Multichannel intraluminal impedance pH (MII-pH) monitoring currently represents the gold standard diagnostic technique for the detection of gastro-esophageal reflux (GER), since it allows to quantify and characterize all reflux events and their possible relation with symptoms. Over the last ten years, thanks to its strengths and along with the publication of several clinical studies, its worldwide use has gradually increased, particularly in infants and children. Nevertheless, factors such as the limited pediatric reference values and limited therapeutic options still weaken its current clinical impact. Through an up-to-date review of the available scientific evidence, our aim was to produce a position paper on behalf of the working group on neurogastroenterology and acid-related disorders of the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) on MII-pH monitoring technique, indications and interpretation in pediatric age, in order to standardise its use and to help clinicians in the diagnostic approach to children with GER symptoms.

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.

Derivation and measurement consistency of a novel biofluid dynamics measure of deglutitive bolus-driving function-pharyngeal swallowing power

BACKGROUND

The primary function of the pharyngeal swallowing mechanism is to drive ingested materials into the esophagus. Currently, a definitive measure of pharyngeal bolus-driving function that accounts for bolus movement remains lacking. The primary objectives of this study were to describe the derivation of a novel biofluid dynamics measure of deglutition-that is, pharyngeal swallowing power (PSP)-and to demonstrate the consistency of PSP in normal swallowing.

METHODS

The pharyngeal swallowing mechanism was conceptualized as a hydraulic power system with the upper esophageal sphincter (UES) as a conduit. PSP was calculated as the product of bolus pressure and flow across the UES. Thirty-four young healthy subjects swallowed materials consisting of two bolus volumes (10, 20 mL) and four bolus viscosities (thin liquid, nectar-thick liquid, honey-thick liquid, pudding). High-resolution impedance manometry was used for data collection. The consistency of PSP across specific bolus conditions was evaluated using standardized Cronbach's coefficient alpha.

KEY RESULTS

Standardized Cronbach's coefficient alphas in specific bolus conditions ranged between 0.85 and 0.93. Fisher weighted mean Cronbach's coefficient alphas for swallow trials across bolus volumes and across bolus viscosities ranged from 0.86 to 0.90. Fisher weighted mean Cronbach's coefficient alpha for overall consistency of PSP across all swallow trials was 0.88.

CONCLUSIONS AND INFERENCES

PSP estimates the output power of the pharyngeal bolus-driving mechanism during deglutition. PSP's high consistency indicates that it can be a useful biofluid dynamics measure of pharyngeal bolus-driving function. Current results also demonstrate that consistency in pharyngeal bolus propulsion is an important physiological target for the pharyngeal swallowing mechanism.

Effects of remifentanil on pharyngeal swallowing: A double blind randomised cross-over study in healthy volunteers

BACKGROUND

Exposure to remifentanil increases the incidence of pulmonary aspiration in healthy volunteers. This effect may be explained by impairment of airway defence mechanisms and/or altered swallowing function. Pressure-flow analysis is a technique that allows objective assessment of swallowing based on pressure-impedance patterns recorded during bolus swallowing.

OBJECTIVES

The aim of this study was to use pressure-flow analysis to quantify the effect of remifentanil on healthy pharyngeal swallowing and to compare these effects with morphine.

DESIGN

A double-blind, randomised, cross-over study.

SETTING

A tertiary care teaching hospital.

VOLUNTEERS

Eleven young volunteers (mean age, 23 years) and seven older volunteers (mean age, 73 years).

INTERVENTIONS

Volunteers were studied twice and received either a target-controlled remifentanil infusion (target concentrations: young, 3 ng ml; old, 2 ng ml) or a bolus injection of morphine (dose: young, 0.1 mg kg; old, 0.07 mg kg). Pharyngeal pressure and impedance were recorded with an indwelling catheter while swallowing 10 boluses of liquid during each measuring phase. Variables defining swallowing function were calculated and compared to determine drug effects.

MAIN OUTCOME MEASURES

Pharyngeal pressure-flow variables following remifentanil exposure.

RESULTS

Changes produced by remifentanil in the measured variables were consistent with greater dysfunction of swallowing. Both the strength of the pharyngeal contractions and pharyngeal bolus propulsion were reduced, whereas flow resistance was increased. The swallow risk index, a global index of swallowing dysfunction, increased overall. At the experimental doses tested, morphine produced similar, but less extensive effects on swallowing.

CONCLUSION

Remifentanil induced dysfunction of the pharyngeal swallowing mechanism. This may contribute to an increased risk of aspiration.

TRIAL REGISTRATION

NCT01924234 (www.clinicaltrials.gov).

European Society for Paediatric Gastroenterology, Hepatology and Nutrition Guidelines for the Evaluation and Treatment of Gastrointestinal and Nutritional Complications in Children With Neurological Impairment

OBJECTIVES

Feeding difficulties are frequent in children with neurological impairments and can be associated with undernutrition, growth failure, micronutrients deficiencies, osteopenia, and nutritional comorbidities. Gastrointestinal problems including gastroesophageal reflux disease, constipation, and dysphagia are also frequent in this population and affect quality of life and nutritional status. There is currently a lack of a systematic approach to the care of these patients. With this report, European Society of Gastroenterology, Hepatology and Nutrition aims to develop uniform guidelines for the management of the gastroenterological and nutritional problems in children with neurological impairment.

METHODS

Thirty-one clinical questions addressing the diagnosis, treatment, and prognosis of common gastrointestinal and nutritional problems in neurological impaired children were formulated. Questions aimed to assess the nutritional management including nutritional status, identifying undernutrition, monitoring nutritional status, and defining nutritional requirements; to classify gastrointestinal issues including oropharyngeal dysfunctions, motor and sensory function, gastroesophageal reflux disease, and constipation; to evaluate the indications for nutritional rehabilitation including enteral feeding and percutaneous gastrostomy/jejunostomy; to define indications for surgical interventions (eg, Nissen Fundoplication, esophagogastric disconnection); and finally to consider ethical issues related to digestive and nutritional problems in the severely neurologically impaired children. A systematic literature search was performed from 1980 to October 2015 using MEDLINE. The approach of the Grading of Recommendations Assessment, Development, and Evaluation was applied to evaluate the outcomes. During 2 consensus meetings, all recommendations were discussed and finalized. The group members voted on each recommendation using the nominal voting technique. Expert opinion was applied to support the recommendations where no randomized controlled trials were available.

Pediatric feeding and swallowing rehabilitation: An overview

Children with neurological disabilities frequently have problems with feeding and swallowing. Such problems have a significant impact on the health and well-being of these children and their families. The primary aims in the rehabilitation of pediatric feeding and swallowing disorders are focused on supporting growth, nutrition and hydration, the development of feeding activities, and ensuring safe swallowing with the aim of preventing choking and aspiration pneumonia. Pediatric feeding and swallowing disorders can be divided into four groups: transient, developmental, chronic or progressive.This article provides an overview of the available literature about the rehabilitation of feeding and swallowing disorders in infants and children. Principles of motor control, motor learning and neuroplasticity are discussed for the four groups of children with feeding and swallowing disorders.

Failed Deglutitive Upper Esophageal Sphincter Relaxation Is a Risk Factor for Aspiration in Stroke Patients with Oropharyngeal Dysphagia

Background/Aims

We attempted to examine the relationship between abnormal findings on high-resolution manometry (HRM) and videofluoroscopic swallowing study (VFSS) of the pharynx and upper esophageal sphincter (UES), and to identify the risk factors for aspiration.

Methods

We performed VFSS and HRM on the same day in 36 ischemic stroke patients (mean age, 67.5 years) with dysphagia. Pressure (basal, median intra bolus, and nadir), relaxation time interval of the UES, and mesopharyngeal and hypopharyngeal contractility (as a contractile integral) were examined using HRM. The parameters of VFSS were vallecular residue, pyriform sinus residue, vallecular overflow, penetration, and aspiration. The association between the parameters of VFSS and HRM was analyzed by the Student’s t test.

Results

Three (8.3%) and 4 (11.1%) stroke patients with dysphagia had pyriform sinus residue and vallecular sinus residue, respectively, and 5 (13.8%) patients showed aspiration. Mesopharyngeal and hypopharyngeal contractile integrals in patients with residue in the pyriform sinus were significantly lower than those in patients without residue in the pyriform sinus (P < 0.05). Relaxation time intervals in patients with aspiration were significantly shorter than those in patients without aspiration (P < 0.05), and multivariate regression analysis revealed a shorter relaxation time interval as the main risk factor for aspiration (OR, 0.03; 95% CI, 0.01–0.65; P < 0.05).

Conclusions

Manometric measurements of the pharynx and UES were well correlated with abnormal findings in the VFSS, and a shorter relaxation time interval of the UES during deglutition is an important parameter for the development of aspiration.

Oropharyngeal dysphagia: manifestations and diagnosis

Swallowing disorders (dysphagia) have been recognized by the WHO as a medical disability associated with increased morbidity, mortality and costs of care. With increasing survival rates and ageing of the population, swallowing disorders and their role in causing pulmonary and nutritional pathologies are becoming exceedingly important. Over the past two decades, the study of oropharyngeal dysphagia has been approached from various disciplines with considerable progress in understanding its pathophysiology. This Review describes the most frequent manifestations of oropharyngeal dysphagia and the clinical as well as instrumental techniques that are available to diagnose patients with dysphagia. However, the clinical value of these diagnostic tests and their sensitivity to predict outcomes is limited. Despite considerable clinical research efforts, conventional diagnostic methods for oropharyngeal dysphagia have limited proven accuracy in predicting aspiration and respiratory disease. We contend that incorporation of measurable objective assessments into clinical diagnosis is needed and might be key in developing novel therapeutic strategies.

High-resolution impedance manometry measurement of bolus flow time in achalasia and its correlation with dysphagia

BACKGROUND

We assessed whether a high-resolution impedance manometry (HRIM) metric, bolus flow time (BFT) across the esophagogastric junction (EGJ), was abnormal in achalasia patients subtyped by the Chicago Classification and compared BFT to other HRM metrics.

METHODS

HRIM studies were performed in 60 achalasia patients (14 type I, 36 type II and 10 type III) and 15 healthy controls. Studies were analyzed with a MATLAB program to calculate BFT using a virtual HRIM sleeve. Integrated relaxation pressure (IRP) and basal end-expiratory EGJ pressure were also calculated. The relationship between BFT and dysphagia symptom scores was assessed using the impaction dysphagia questionnaire (IDQ).

KEY RESULTS

Median BFT was significantly lower in achalasia patients (0.5 s, range 0.0-3.5 s) compared to controls (3.5 s, range 2.0-5.0 s; p < 0.05). BFT was significantly lower in types I and II than in type III achalasia in both the supine and upright positions (p < 0.0001). BFT was the only HRIM metric significantly associated with IDQ score in both the supine (R(2)  = 0.20, p = 0.0046) and upright positions (R(2)  = 0.27, p = 0.0002).

CONCLUSIONS & INFERENCES

BFT was significantly reduced in all subtypes of achalasia and complementary to the IRP as a diagnostic discriminant in equivocal achalasia cases. Additionally, BFT had a more robust correlation with dysphagia severity compared to other metrics of EGJ function.

Development of Suck and Swallow Mechanisms in Infants

Preterm infants' hospital discharge is often delayed due to their inability to feed by mouth safely and competently. No evidence-based supported guidelines are currently available for health-care professionals caring for these infants. Available interventions advocating benefits are not readily acknowledged for lack of rigorous documentation inasmuch as any improvements may ensue from infants' normal maturation. Through research, a growing understanding of the development of nutritive sucking skills has emerged, shedding light on how and why infants may encounter oral feeding difficulties due to the immaturity of specific physiologic functions. Unfortunately, this knowledge has yet to be translated to the clinical practice to improve the diagnoses of oral feeding problems through the development of relevant assessment tools and to enhance infants' oral feeding skills through the development of efficacious preventive and therapeutic interventions. This review focuses on the maturation of the various physiologic functions implicated in the transport of a bolus from the oral cavity to the stomach. Although infants' readiness for oral feeding is deemed attained when suck, swallow, and respiration are coordinated, we do not have a clear definition of what coordination implies. We have learned that each of these functions encompasses a number of elements that mature at different times and rates. Consequently, it would appear that the proper functioning of sucking, the swallow processing, and respiration need to occur at two levels: first, the elements within each function must reach an appropriate functional maturation that can work in synchrony with each other to generate an appropriate suck, swallow process, and respiration; and second, the elements of all these distinct functions, in turn, must be able to do the same at an integrative level to ensure the safe and efficient transport of a bolus from the mouth to the stomach.

Pediatric Dysphagia: Physiology, Assessment, and Management

Infancy and childhood represent a time of unparalleled physical growth and cognitive development. In order for infants and children to reach their linear and neurological growth potential, they must be able to reliably and safely consume sufficient energy and nutrients. Swallowing difficulties (dysphagia) in pediatric populations can have a detrimental effect on dietary intake and, thus, growth and development. As a result, it is imperative to accurately identify and appropriately manage dysphagia in pediatric populations. This article provides an overview of dysphagia in children, as well as common causes of childhood swallowing difficulties, populations at risk for pediatric dysphagia, techniques used to assess swallowing in pediatric patients, and the current treatment options available for infants and children with dysphagia.

Clinical and videofluoroscopic diagnosis of dysphagia in chronic encephalopathy of childhood

OBJECTIVE

To evaluate the contribution of deglutition videofluoroscopy in the clinical diagnosis of dysphagia in chronic encephalopathy of childhood.

MATERIALS AND METHODS

The study sample consisted of 93 children diagnosed with chronic encephalopathy, in the age range between two and five years, selected by convenience among patients referred to the authors' institution by speech therapists, neurologists and gastroenterologists in the period from March 2010 to September 2011. The data collection was made at two different moments, by different investigators who were blind to each other.

RESULTS

The method presented low sensitivity for detecting aspiration with puree consistency (p = 0.04). Specificity and negative predictive value were high for clinical diagnosis of dysphagia with puree consistency.

CONCLUSION

In the present study, the value for sensitivity in the clinical diagnosis of dysphagia demonstrates that this diagnostic procedure may not detect any change in the swallowing process regardless of the food consistency used during the investigation. Thus, the addition of the videofluoroscopic method can significantly contribute to the diagnosis of dysphagia.

Pressure flow analysis in the assessment of preswallow pharyngeal bolus presence in Dysphagia

Objectives. Preswallow pharyngeal bolus presence is evident in patients with oropharyngeal dysphagia. Pressure flow analysis (PFA) using high resolution manometry with impedance (HRMI) with AIMplot software is a method for objective interpretation of pharyngeal and upper esophageal sphincter (UES) pressures and bolus flow patterns during swallowing. This study aimed to observe alterations in PFA metrics in the event of preswallow pharyngeal bolus presence as seen on videofluoroscopy (VFSS). Methods. Swallows from 40 broad dysphagia patients and 8 controls were recorded with a HRMI catheter during simultaneous VFSS. Evidence of bolus presence and level reached prior to pharyngeal swallow onset was recorded. AIMPlot software derived automated PFA functional metrics. Results. Patients with bolus movement to the pyriform sinuses had a higher SRI, indicating greater swallow dysfunction. Amongst individual metrics, TNadImp to PeakP was shorter and flow interval longer in patient groups compared to controls. A higher pharyngeal mean impedance and UES mean impedance differentiated the two patient groups. Conclusions. This pilot study identifies specific altered PFA metrics in patients demonstrating preswallow pharyngeal bolus presence to the pyriform sinuses. PFA metrics may be used to guide diagnosis and treatment of patients with oropharyngeal dysphagia and track changes in swallow function over time.

Impedance as an adjunct to manometric testing to investigate symptoms of dysphagia: What it has failed to do and what it may tell us in the future

Dysphagia is a common reason for referral for investigations of oesophageal motility. Impedance measurement has now been incorporated into commercially available diagnostic manometry systems for more than a decade. This innovation, which offered the ability to record patterns of bolus transport without the need for simultaneous radiology, has for the most part failed to live up to expectations, offering few additional diagnostic insights. This review examines the potential pitfalls related to how impedance patterns are currently analysed and introduces and discusses the new concept of pressure-flow analysis integrating pressure and impedance measurements to derive new metrics linked to the pressures occurring within and around the bolus as it is being transported.

Automatische Impedantie Manometrie (AIM): objectieve diagnostiek van oro-faryngale dysfagie

AUTOMATED IMPEDANCE MANOMETRY (AIM): OBJECTIVE DIAGNOSIS OF OROPHARYNGEAL DYSPHAGIA: This review article aims to demonstrate the clinical potential of Automated Impedance Manometry (AIM) as a new, non-radiological technique for screening and diagnosis of oro-pharyngeal dysphagia. An integrated - rather than separate - analysis of pressure and impedance patterns generated in the pharynx when swallowing a food bolus, can be a useful complement to the radiological investigations considered as gold standard today. Major advantages are the objective nature of this technique and the fully automated calculation of various swallow parameters. A global measure of swallowing function can be derived (a Swallow Risk Index, SRI) and is related to (the severity of) the risk of aspiration and the presence of pharyngeal post-swallow residue. It was shown that aspiration on videofluoroscopy was accurately detected by using AIM with a sensitivity of 0.88 and a specificity of 0.96. AIM analysis can be performed quickly and is reliable in the hands of different end users. Various parameters are sufficiently sensitive to detect changes in bolus consistency and - as was recently found - are influenced by swallowing manoeuvers. Furthermore, different patterns of deviant swallow parameters can be found in different patient populations. Whether this observation can provide specific diagnoses and - as a consequence - more targeted treatments is currently under investigation.

Pharyngeal transit in patients with chronic progressive external ophthalmoplegia

PURPOSE

A common presentation of mitochondrial myopathies is chronic progressive external ophthalmoplegia (CPEO). Dysphagia is a complaint in about 50% of cases.

METHOD

This investigation evaluated pharyngeal transit in patients with CPEO. Videofluoroscopic swallowing evaluation was performed with paste, liquid and solid boluses in 14 patients with CPEO and in 16 normal volunteers.

RESULT

There was no difference between patients and volunteers in the duration of pharyngeal swallowing events with the liquid bolus. Compared to control participants, patients with CPEO had significantly shorter duration of pharyngeal transit for paste and solid boluses, of pharyngeal clearance for paste bolus, and of upper oesophageal sphincter transit for paste and solid boluses. Spontaneous multiple swallows and effortful swallows were performed by patients but not by the volunteers.

CONCLUSION

It was concluded that patients with CPEO have shorter pharyngeal transit duration of paste and solid boluses than normal volunteers, which may be a consequence of a spontaneous smaller bolus volume in each swallow and/or effortful swallows.

Objective assessment of swallow function in children with suspected aspiration using pharyngeal automated impedance manometry

OBJECTIVES

The purpose of the present study was to apply a new method, pharyngeal automated impedance manometry (AIM), as an objective assessment tool of swallow function relevant to aspiration, in a cohort of paediatric patients with dysphagia.

METHODS

We studied 20 children (mean age 6 years [5 months to 13.4 years]) referred for videofluoroscopy to assess aspiration risk with simultaneous manometry-impedance. Fluoroscopic evidence of aspiration was scored using a validated aspiration-penetration score. Pressure-flow profiles were analysed using AIM analysis measuring peak pressure, pressure at nadir impedance, time from nadir impedance to peak pressure, and flow interval. These variables were combined into a swallow risk index (SRI).

RESULTS

Six of 20 children presented with deglutitive aspiration during videofluoroscopic assessment of swallowing. Of 58 liquid swallows analysed, in 9 aspiration was observed. Multiple logistic regression identified longer flow interval (P < 0.05), higher SRI (P < 0.05) and increased pressure in the upper oesophageal sphincter during maximal bolus flow (P < 0.05) to be the dominant risk variables predictive of aspiration in children. Each of these nonradiologically derived pressure-flow variables correlated with higher aspiration scores on videofluoroscopy (P < 0.01).

CONCLUSIONS

We present novel, preliminary findings in children with deglutitive aspiration, suggesting that pharyngeal AIM can detect alterations in pressure-flow characteristics of swallowing that predispose to aspiration risk.

Swallowing dysfunction in healthy older people using pharyngeal pressure-flow analysis

BACKGROUND

Age-related loss of swallowing efficiency may occur for multiple reasons. Objective assessment of individual dysfunctions is difficult and may not clearly differentiate these from normal. Pharyngeal pressure-flow analysis is a novel technique that allows quantification of swallow dysfunction predisposing to aspiration risk based on a swallow risk index (SRI). In this study, we examined the effect of ageing on swallow function.

METHODS

Studies were performed in 68 healthy subjects aged 20-91 years (mean 59 years; 29 male), asymptomatic for oropharyngeal disease. Swallowing of liquid and viscous boluses was recorded with a pressure-impedance catheter. Indices of swallow function including the SRI, postswallow residues, upper esophageal sphincter opening and bolus transit time were derived using purpose designed software.

KEY RESULTS

Swallow function worsened with increasing age with a significant decline after 80 years. Higher SRI correlated with increasing age (r = 0.257, p < 0.05 for liquids and r = 0.361, p < 0.005 viscous bolus). Subjects over 80 years were overrepresented amongst those with an SRI considered diagnostically relevant (SRI > 15). In addition, upper esophageal sphincter opening was reduced and postswallow residues increased in older subjects.

CONCLUSIONS & INFERENCES

Pharyngeal pressure-flow analysis reveals multiple functional abnormalities in older individuals. The higher SRI levels seen in asymptomatic elders possibly reflect a loss of functional reserve with ageing. Automated impedance manometry analysis of swallow function may allow the risk of developing disordered swallowing to be quantified numerically.

Evaluation of esophageal motor function in clinical practice

Esophageal motor function is highly coordinated between central and enteric nervous systems and the esophageal musculature, which consists of proximal skeletal and distal smooth muscle in three functional regions, the upper and lower esophageal sphincters, and the esophageal body. While upper endoscopy is useful in evaluating for structural disorders of the esophagus, barium esophagography, radionuclide transit studies, and esophageal intraluminal impedance evaluate esophageal transit and partially assess motor function. However, esophageal manometry is the test of choice for the evaluation of esophageal motor function. In recent years, high-resolution manometry (HRM) has streamlined the process of acquisition and display of esophageal pressure data, while uncovering hitherto unrecognized esophageal physiologic mechanisms and pathophysiologic patterns. New algorithms have been devised for analysis and reporting of esophageal pressure topography from HRM. The clinical value of HRM extends to the pediatric population, and complements preoperative evaluation prior to foregut surgery. Provocative maneuvers during HRM may add to the assessment of esophageal motor function. The addition of impedance to HRM provides bolus transit data, but impact on clinical management remains unclear. Emerging techniques such as 3-D HRM and impedance planimetry show promise in the assessment of esophageal sphincter function and esophageal biomechanics.

Artificial neural network classification of pharyngeal high-resolution manometry with impedance data

OBJECTIVES/HYPOTHESIS

To use classification algorithms to classify swallows as safe, penetration, or aspiration based on measurements obtained from pharyngeal high-resolution manometry (HRM) with impedance.

STUDY DESIGN

Case series evaluating new method of data analysis.

METHODS

Multilayer perceptron, an artificial neural network (ANN), was evaluated for its ability to classify swallows as safe, penetration, or aspiration. Data were collected from 25 disordered subjects swallowing 5- or 10-mL boluses. Following extraction of relevant parameters, a subset of the data was used to train the models, and the remaining swallows were then independently classified by the ANN.

RESULTS

A classification accuracy of 89.4 ± 2.4% was achieved when including all parameters. Including only manometry-related parameters yielded a classification accuracy of 85.0 ± 6.0%, whereas including only impedance-related parameters yielded a classification accuracy of 76.0 ± 4.9%. Receiver operating characteristic analysis yielded areas under the curve of 0.8912 for safe, 0.8187 for aspiration, and 0.8014 for penetration.

CONCLUSIONS

Classification models show high accuracy in classifying swallows from dysphagic patients as safe or unsafe. HRM-impedance with ANN represents one method that could be used clinically to screen for patients at risk for penetration or aspiration.

Reproducibility and agreement of pharyngeal automated impedance manometry with videofluoroscopy

BACKGROUND & AIMS

Automated impedance manometry analysis (AIM) measures swallow function variables that define bolus timing, intrabolus pressure, contractile vigor, and bolus presence; these are combined to derive a swallow risk index (SRI) that is correlated with pharyngeal dysfunction and aspiration. We assessed intra-rater and inter-rater reproducibility of AIM analysis-derived variables; the diagnostic accuracy of AIM-based criteria for detecting aspiration was determined by using expertly scored videofluoroscopy as the standard.

METHODS

Data on 50 bolus swallows of 10 mL each were randomly selected from a database of swallows that were simultaneously recorded with impedance, manometry, and videofluoroscopy. Data were divided into 5 subgroups of 10 swallows for analysis: 10 dysphagic liquid, 10 dysphagic liquid with aspiration, 10 dysphagic semisolid, 10 control liquid, and 10 control semisolid. Repeat analyses were performed by 10 observers with varying levels of expertise in manometry by using purpose-designed software (AIMplot). Swallow videos were scored by 4 experts by using the penetration-aspiration scale (PAS) score. Reproducibility of calculation of swallow function variables and the SRI and PAS was assessed by using intraclass correlation coefficient (ICC). The majority consensus of expert PAS scores was used to dichotomously define aspiration (consensus PAS >3). Observer analyses were compared by Cohen κ statistical analysis.

RESULTS

The intra-rater and inter-rater reproducibility of swallow function variables was high (SRI mean intra-rater ICC, 0.97 and mean inter-rater ICC, 0.91). SRI >15-20 was optimal for detecting the presence of aspiration during liquid bolus swallows with an almost perfect agreement with expert scoring of videofluoroscopy (κ > 0.8).

CONCLUSIONS

AIM analysis has high intra-rater and inter-rater reproducibility, and among observers of varying expertise, SRI predicts the presence of aspiration.