Remifentanil alters sensory neuromodulation of swallowing in healthy volunteers: quantification by a novel pressure-impedance analysis

Sensory Changes Related to Swallowing in Motor Neurone Disease

Dysphagia is common in motor neurone disease (MND) and associated with negative health and psychosocial outcomes. Although largely considered a motor disease, a growing body of evidence suggests that MND can also affect the sensory system. As intact sensation is vital for safe swallowing, and sensory changes can influence the clinical management of dysphagia in people living with MND, this review evaluated and summarised the current evidence for sensory changes related to swallowing in MND. Of 3,481 articles originally identified, 29 met the inclusion criteria. Of these, 20 studies reported sensory changes, which included laryngeal sensation, taste, gag reflex, cough reflex, tongue sensation, smell, palatal and pharyngeal sensation, silent aspiration, and undefined sensation of the swallowing mechanism. Sensory changes were either described as decreased (n = 16) or heightened (n = 4). In the remaining nine studies, sensory function was reported as unaffected. The presence of changes to sensory function related to swallowing in MND remains inconclusive, although an increasing number of studies report sensory changes in some sensory domains. Future research is needed to evaluate the prevalence of sensory changes in MND and how such changes may influence dysphagia and its management.

Normative High-Resolution Pharyngeal Manometry: Impact of Age, Size of System, and Sex on Primary Metrics and Pressure Stability

There have been many reports of normative pharyngeal swallowing pressures using high-resolution pharyngeal manometry, but there is a fair amount of between-subject variance in reported pressure parameters. The purpose of this study was to put forward normative pharyngeal high-resolution manometry measures across the lifespan and investigate the effects of age, size of system, and sex. High-resolution pharyngeal manometry was performed on 98 healthy adults (43 males) between the ages 21 and 89. Pressure duration, maxima, integral, and within-individual variability metrics were averaged over 10 swallows of 10-ml thin liquid. Multiple linear and logistic regressions with model fitting were used to examine how pharyngeal pressures relate to age, pharyngeal size, and sex. Age was associated with tongue base maximum pressure, tongue base maximum variability, and upper esophageal sphincter-integrated relaxation pressure (F3,92 = 6.69; p < 0.001; adjusted R2 = 0.15). Pharyngeal area during bolus hold was associated with velopharynx integral (F1,89 = 5.362; p = 0.02; adjusted R2 = 0.05), and there was no significant model relating pharyngeal pressures to C2-C4 length (p < 0.05). Sex differences were best described by tongue base integral and hypopharynx maximum variability (χ2 = 10.27; p = 0.006; pseudo R2 = 0.14). Normative data reveal the distribution of swallow pressure metrics which need to be accounted for when addressing dysphagia patients, the importance of pressure interactions in normal swallow, and address the relative stability of swallow metrics with normal aging.

Evidence for peripheral and central actions of codeine to dysregulate swallowing in the anesthetized cat

Systemic administration of opioids has been associated with aspiration and swallow dysfunction in humans. We speculated that systemic administration of codeine would induce dysfunctional swallowing and that this effect would have a peripheral component. Experiments were conducted in spontaneously breathing, anesthetized cats. The animals were tracheotomized and electromyogram (EMG) electrodes were placed in upper airway and chest wall respiratory muscles for recording swallow related motor activity. The animals were allocated into three groups: vagal intact (VI), cervical vagotomy (CVx), and supra-nodose ganglion vagotomy (SNGx). A dose response to intravenous codeine was performed in each animal. Swallowing was elicited by injection of 3 mL of water into the oropharynx. The number of swallows after vehicle was significantly higher in the VI group than in SNGx. Codeine had no significant effect on the number of swallows induced by water in any of the groups. However, the magnitudes of water swallow-related EMGs of the thyropharyngeus muscle were significantly increased in the VI and CVx groups by 2-4 fold in a dose-related manner. In the CVx group, the geniohyoid muscle EMG during water swallows was significantly increased. There was a significant dose-related increase in spontaneous swallowing in each group from codeine. The spontaneous swallow number at the 10 mg/kg dose of codeine was significantly larger in the CVx group than that in the SNGx group. During water-evoked swallows, intravenous codeine increased upper airway motor drive in a dose-related manner, consistent with dysregulation. The data support the existence of both central and peripheral actions of codeine on spontaneous swallowing. At the highest dose of codeine, the reduced spontaneous swallow number in the SNGx group relative to CVx is consistent with a peripheral excitatory action of codeine either on pharyngeal/laryngeal receptors or in the nodose ganglion itself. The higher number of swallows in the CVx group than the VI group supports disinhibition of this behavior by elimination of inhibitory vagal sensory afferents.

Swallowing biomechanics in tracheostomised critically ill patients compared to age- and gender-matched healthy controls

Objective

The mechanistic effects of a tracheostomy on swallowing are unclear. Pharyngeal high-resolution manometry with impedance (P-HRM-I) is a novel swallow assessment tool providing quantifiable metrics. This study aimed to characterise swallowing biomechanics in tracheostomised critically ill (non-neurological) patients.

Design

Cohort study.

Setting

Australian tertiary hospital intensive care unit.

Participants

Tracheostomised adults, planned for decannulation.

Main outcome measures

Swallowing assessment using P-HRM-I, compared to healthy age- and gender-matched controls.

Results

In this tracheostomised cohort (n = 10), the Swallow Risk Index, a global measure of swallow function, was significantly elevated (p < 0.001). At the upper oesophageal sphincter (UOS), hypopharyngeal intrabolus pressure and UOS integrated relaxation pressure were significantly elevated (control 0.65 mmHg [-1.02, 2.33] v tracheostomy 13.7 mmHg [10.4, 16.9], P < 0.001; control -4.28 mmHg [-5.87, 2.69] v tracheostomy 12.2 mmHg [8.83, 15.6], P < 0.001, respectively). Furthermore, UOS opening extent and relaxation time were reduced (control 4.83 mS [4.60, 5.07] v tracheostomy 4.33 mS [3.97, 4.69], P = 0.002; control 0.52 s [0.49, 0.55] v tracheostomy 0.41 s [0.37, 0.45], P < 0.001, respectively). Total pharyngeal contractility (PhCI) measuring pharyngeal pressure generation was significantly elevated (control 199.5 mmHg cm.s [177.4, 221.6] v tracheostomy 326.5 mmHg cm.s [253.3, 399.7]; P = 0.001).

Conclusion

In a critically ill tracheostomised cohort, UOS dysfunction was the prevalent biomechanical feature, with elevated pharyngeal pressures. Pharyngeal weakness is not contributing to dysphagia in this cohort. Instead, elevated pharyngeal pressures may represent a compensatory mechanism to overcome the UOS dysfunction. Further studies to extend these findings may inform the development of timely and targeted rehabilitation.

Evaluation of oropharyngeal deglutitive pressure dynamics in patients with Parkinson's disease

In Parkinson's disease (PD), oropharyngeal dysphagia is common and clinically relevant. The neurophysiology of dysphagia in PD is complex and incompletely understood. The aim of the study was to determine the changes in oropharyngeal deglutitive pressure dynamics in PD and to correlate these with clinical characteristics including dysphagia and PD severity. In prospective consecutive series of 64 patients with PD [mean age: 66.9 ± 8.3 (SD)], we evaluated dysphagia severity clinically as well as with Sydney Swallow Questionnaire (SSQ) and Swallow Quality-of-Life Questionnaire (SWAL-QOL). PD severity was assessed with Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS). We used high-resolution pharyngeal impedance manometry (HRPIM) to objectively evaluate swallow function and compared data from 23 age-matched healthy controls [mean age 62.3 ± 9.1 (SD)]. Metrics assessed were upper esophageal sphincter (UES), integrated relaxation pressure (IRP), relaxation time (RT), maximum opening (MaxAdm), and pharyngeal intrabolus pressure (IBP) and pharyngeal contractility (PhCI). Mean MDS-UPDRS score was positively associated with dysphagia severity on SSQ and SWAL-QOL. HRPIM in PD compared with controls showed impaired UES relaxation parameters, with shorter RT, and elevated IRP and IBP. MaxAdm was not affected. The overall pharyngeal contractility was significantly higher in PD. Only the IBP and IRP were associated with PD severity and only IBP was significantly associated with dysphagia severity. UES dysfunction leading to increased flow resistance is common in patients with PD and correlates with dysphagia severity. Increased flow resistance may suggest impaired UES relaxation and/or impaired neuromodulation to bolus volume.NEW & NOTEWORTHY In Parkinson's disease, objective assessment of swallow function with high-resolution impedance manometry identifies upper esophageal sphincter dysfunction leading to increased flow resistance.

Applying High-Resolution Impedance Manometry for Detecting Swallowing Change in Anterior Cervical Spine Surgery Patients

Background

Objectively detecting perioperative swallowing changes is essential for differentiating the reporting of subjective trouble sensations in patients undergoing anterior cervical spine surgery (ACSS). Swallowing indicates the transmission of fluid boluses from the pharynx (velopharynx, oropharynx, and hypopharynx) through the upper esophageal sphincter (UES). Abnormal swallowing can reveal fluid accumulation at the pharynx, which increased the aspiration risk. However, objective evidence is limited. High-resolution impedance manometry (HRIM) was applied for an objective swallowing evaluation for a more detailed analysis. We aimed to elucidate whether HRIM can be used to detect perioperative swallowing changes in patients undergoing ACSS.

Methods

Fourteen patients undergoing elective ACSS underwent HRIM with the Dysphagia Short Questionnaire (DSQ, score: 0–18) preoperatively (PreOP), on postoperative at day 1 (POD1), and postoperative at day seven (POD7). We calculated hypopharyngeal and UES variables, including hypopharyngeal mean peak pressure (PeakP) and UES peak pressure, representing their contractility (normal range of PeakP, 69–280 mmHg; peak pressure, 149–548 mmHg). The velopharynx-to-tongue base contractile (VTI) was also calculated (normal range, 300–700 mmHg.s.cm), indicating contractility. The swallowing risk index (SRI) from HRIM combined with four hypopharyngeal parameters, including PeakP, represents the global swallowing function (normal range, 0–11). A higher SRI value indicated higher aspiration.

Results

SRI was significantly higher on POD1 (10.88 ± 5.69) than PreOP (6.06 ± 3.71) and POD7 (8.99 ± 4.64). In all patients, PeakP was significantly lower on POD1 (61.8 ± 18.0 mmHg) than PreOP (84.9 ±34.7 mmHg) and on POD7 (75.3 ± 23.4 mmHg). The UES peak pressure was significantly lower on POD1 (80.4 ± 30.0 mmHg) than PreOP (112.9 ± 49.3 mmHg) and on POD7 (105.6 ± 59.1 mmHg). Other variables, including VTI, did not change significantly among the three time points. DSQ scores were 1.36, 3.43, and 2.36 at PreOP, POD1, and POD7 respectively.

Conclusions

With similar trends in DSQ and SRI, swallowing was significantly decreased on POD1 because of decreased hypopharyngeal and UES contractility but recovered to the preoperative state on POD7 after ACSS. Applying HRIM is superior to DSQ in detecting mechanisms and monitoring the recovery from swallowing dysfunction.

Clinical Trial Registration

The study was registered at ClinicalTrials.gov (NCT03891940).

Effects of remifentanil on pharyngeal swallowing and esophageal motility: no impact of different bolus volumes and partial antagonism by methylnaltrexone

Remifentanil impairs swallowing, and disturbed accommodation to bolus volume may be one of the underlying causes. It is not fully understood whether remifentanil-induced swallowing dysfunction is mediated by peripheral or central mechanisms. So, this study aimed to investigate if remifentanil-induced swallowing dysfunction is dependent on the bolus volume and whether the effect of remifentanil could be counteracted by methylnaltrexone, a peripherally acting opioid antagonist. Nineteen healthy volunteers were included in this double-blinded, randomized, placebo-controlled, crossover study. Study participants received target-controlled remifentanil infusions and placebo infusions in a randomized order. Methylnaltrexone was administered by intravenous injection of doses of 0.3 mg/kg. Recordings of pressure and impedance data were acquired using a combined manometry and impedance solid-state catheter. Data were analyzed from three series of bolus swallows, baseline, during study medication exposure, and 15 min after methylnaltrexone. Remifentanil induced significant effects on multiple pharyngeal and esophageal function parameters. No significant differences in remifentanil-induced swallowing dysfunction related to different bolus volumes were found. Pharyngeal effects of remifentanil were not significantly counteracted by methylnaltrexone, whereas on the distal esophageal level, effects on distension pressures were counteracted. Changes in pharyngeal and esophageal pressure flow variables were consistent with previous results on remifentanil-induced swallowing dysfunction and uniform across all bolus volumes. The effects of remifentanil on the pharyngeal level and on the proximal esophagus appear to be predominantly centrally mediated, whereas the effects of remifentanil on the distal esophagus may be mediated by both central and peripheral mechanisms.NEW & NOTEWORTHY In this randomized controlled trial, we used the "Swallow Gateway" online platform to analyze the effects of remifentanil on pharyngeal and esophageal swallowing. It is not fully understood whether remifentanil-induced swallowing dysfunction is mediated by peripheral or central mechanisms. By using methylnaltrexone, we demonstrated that effects of remifentanil on pharyngeal swallowing were predominantly centrally mediated, whereas its effects on the distal esophagus may be mediated by both central and peripheral mechanisms.

Diagnosis and treatment of neurogenic dysphagia - S1 guideline of the German Society of Neurology

Introduction

Neurogenic dysphagia defines swallowing disorders caused by diseases of the central and peripheral nervous system, neuromuscular transmission, or muscles. Neurogenic dysphagia is one of the most common and at the same time most dangerous symptoms of many neurological diseases. Its most important sequelae include aspiration pneumonia, malnutrition and dehydration, and affected patients more often require long-term care and are exposed to an increased mortality. Based on a systematic pubmed research of related original papers, review articles, international guidelines and surveys about the diagnostics and treatment of neurogenic dysphagia, a consensus process was initiated, which included dysphagia experts from 27 medical societies.

Recommendations

This guideline consists of 53 recommendations covering in its first part the whole diagnostic spectrum from the dysphagia specific medical history, initial dysphagia screening and clinical assessment, to more refined instrumental procedures, such as flexible endoscopic evaluation of swallowing, the videofluoroscopic swallowing study and high-resolution manometry. In addition, specific clinical scenarios are captured, among others the management of patients with nasogastric and tracheotomy tubes. The second part of this guideline is dedicated to the treatment of neurogenic dysphagia. Apart from dietary interventions and behavioral swallowing treatment, interventions to improve oral hygiene, pharmacological treatment options, different modalities of neurostimulation as well as minimally invasive and surgical therapies are dealt with.

Conclusions

The diagnosis and treatment of neurogenic dysphagia is challenging and requires a joined effort of different medical professions. While the evidence supporting the implementation of dysphagia screening is rather convincing, further trials are needed to improve the quality of evidence for more refined methods of dysphagia diagnostics and, in particular, the different treatment options of neurogenic dysphagia. The present article is an abridged and translated version of the guideline recently published online (https://www.awmf.org/uploads/tx_szleitlinien/030-111l_Neurogene-Dysphagie_2020-05.pdf).

Codeine induces increased resistance at the esophagogastric junction but has no effect on motility and bolus flow in the pharynx and upper esophageal sphincter in healthy volunteers: A randomized, double-blind, placebo-controlled, cross-over trial

BACKGROUND

Chronic opioid use can induce esophageal dysfunction with symptoms resembling achalasia and a manometric pattern of esophagogastric junction-outflow obstruction (EGJ-OO). However, the effect of opioids in acute setting on pharyngeal function and esophageal body contractility has not been investigated.

METHODS

After positioning the high-resolution impedance manometry (HRiM) catheter, codeine (60 mg) or placebo (glucose syrup) was infused intragastrically. Forty-five minutes post-infusion, participants received liquid, semi-solid, and solid boluses to assess esophageal and pharyngeal function. HRiM analysis was performed adhering to the Chicago classification v3.0. (CC v3.0). Pressure flow analysis (PFA) for the esophageal body and the pharynx was performed using the SwallowGateway™ online platform.

KEY RESULTS

Nineteen healthy volunteers (HV) [5 male; age 38.3] were included. After codeine administration, higher integrated relaxation pressure 4 s values resulted in significantly reduced deglutitive EGJ relaxation and distal latency was significantly shorter. Distal contractility was similar in both conditions. Bolus flow resistance at the EGJ and distention pressures increased significantly after codeine infusion. Based on CC v3.0, acute infusion of codeine induced EGJ-OO in six HV (p = 0.0003 vs. placebo). Codeine administration induced no significant alterations in any of the pharyngeal PFA metrics.

CONCLUSIONS & INFERENCES

In HV, acute administration of codeine increased bolus resistance at the EGJ secondary to induced incomplete EGJ relaxation leading to major motility disorders in a subset of subjects including EGJ-OO. However, an acute single dose of codeine did not affect motility or bolus flow in pharynx and UES. ClinicalTrials.gov number, NCT03784105.

Characterizing the proximal esophageal segment in patients with symptoms of esophageal dysmotility

BACKGROUND

Proximal esophageal striated muscle contractility may be abnormal in patients with esophageal symptoms, but is not assessed in the Chicago Classification (CC) v3.0. We aimed to (a) determine the prevalence of abnormal proximal esophageal contractility in patients with esophageal symptoms; (b) compare proximal esophageal contractility in patients with different esophageal motility disorders; (c) assess the association of abnormal proximal esophageal contractility with esophageal symptoms.

METHODS

Patients undergoing high-resolution esophageal manometry (HREM) from 7/2019 to 11/2019 and healthy volunteers (HVs) were studied. Measurements of the proximal esophageal segment included the vigor of contractility of the proximal esophagus (proximal contractile integral/PCI). Patients rated gastrointestinal symptoms' severity.

KEY RESULTS

HREM was performed on 221 patients (63.8% females, mean age 57.1 ± 1.1 years) and 19 HVs. Mean PCI in HVs was 299.5 ± 30.6 (95% CI 32.3-566.7 mm Hg^. s^. cm). Of all patients, 61 (27.6%) had abnormal PCI. HVs and patients with different esophageal motility disorders had significantly different PCI (P < .01). Type 1 achalasia patients had weaker PCI than patients with absent contractility (P = .02). Patients with abnormal PCI had more severe dysphagia (P = .02), nausea (P = .03), vomiting (P = .03), and lower bolus clearance (P < .01) than patients with normal PCI.

CONCLUSIONS AND INFERENCES

Abnormal PCI was found in a fourth of patients with esophageal symptoms. PCI may be useful to distinguish some esophageal motility disorders. Patients with abnormal PCI had a higher severity of some upper gastrointestinal symptoms than patients with normal PCI. Assessing the proximal esophageal segment on HREM may be useful in characterizing patients with esophageal 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.

High-resolution manometry: what about the pharynx?

PURPOSE OF REVIEW

High-resolution pharyngeal manometry (HRPM) is a well tolerated, catheter-based, method for recording the pressures and bolus flow generated by the pharyngeal muscles during swallowing. Despite a body of published evidence and a critical mass of investigators in the field, there is a lack of consensus surrounding what biomechanical phenomena to measure. The purpose of this review is to provide some insights into the information on swallowing physiology that can be gathered using HRPM.

RECENT FINDINGS

HRPM literature has focused on measuring biomechanical phenomena that may be relevant to measure in relation to dysphagia research. This review focuses on the measurement of pharyngeal luminal occlusive forces, intrabolus distension pressure, bolus presence and bolus flow timing as key features of pharyngeal swallowing that require measurement and allow for derivation of the Swallow Risk Index, a global measure of swallow function indicative of swallowing functional reserve.

SUMMARY

HRPM allows objective derivation of measures of swallow function that may have value for diagnosis and research in relation to swallowing disorders. HRPM has demonstrated clinical applicability in specific patient populations and offers unique advantages that compliment current assessment methods.

A systematic review of current methodology of high resolution pharyngeal manometry with and without impedance

PURPOSE

This systematic review appraises and summaries methodology documented in studies using high resolution pharyngeal manometry (HRM) with and without impedance technology (HRIM) in adult populations.

METHODS

Four electronic databases CINAHL, EMBASE, MEDLINE, and Cochrane Library were searched up to, and including March 2017. Studies reporting pharyngeal HRM/HRIM for swallowing and/or phonatory assessment, published in peer-reviewed journals in English, German, or Spanish were assessed for the inclusion criteria. Of the selected studies, methodological aspects of data acquisition and analysis were extracted. Publications were graded based on their level of evidence and quality of methodological aspects was assessed.

RESULTS

Sixty-two articles were identified eligible, from which 50 studies reported the use of HRM and 12 studies used HRIM. Of all included manuscripts, the majority utilized the ManoScan™ system (64.5%), a catheter diameter of 4.2 mm was most prevalently documented (30.6%). Most publications reported the application of topical anesthesia (53.2%). For data analysis in studies using HRM, software intrinsic to the recording system was reported most frequently (56%). A minority of the studies using HRM provided data about measurement reliability (10%). This is higher for studies using HRIM (50%).

CONCLUSIONS

Considerable methodological variability exists regarding data acquisition and analysis in published studies using HRM/HRIM. Lacking reports of methodology make study replications difficult and reduce the comparability across studies. More data regarding the impact of individual methodological aspects on study outcomes are further required for the development of methodological recommendations.

The critical importance of pharyngeal contractile forces on the validity of intrabolus pressure as a predictor of impaired pharyngo-esophageal junction compliance

INTRODUCTION

Restrictive defects of the pharyngo-esophageal junction (PEJ) are common in both structural and neurological disorders and are amenable to therapies aiming to reduce outflow resistance. Intrabolus pressure (IBP) acquired with high-resolution manometry and impedance (HRMI) is an indicator of resistance and a marker of reduced PEJ compliance. Constraints and limitations of IBP as well as the optimal IBP parameter remain undefined.

AIMS

To determine: (i) the impact of peak pharyngeal pressure (PeakP) on the diagnostic accuracy of IBP for the detection of a restrictive defect at the PEJ and (ii) the optimal IBP parameter for this purpose.

METHODS

In 52 dysphagic patients previously treated for head and neck cancer. Five candidate IBP measures and PeakP were obtained with HRMI, as well as a presence of a stricture determined by a mucosal tear after endoscopic dilatation. Predictive values of IBP measures were evaluated by receiver operating characteristic (ROC) analysis for all patients and reiterated as patients with lowest PeakP were progressively removed from the cohort.

RESULTS

All IBP parameters had fair to good accuracy at predicting strictures. Intrabolus pressure measured at a discrete point of maximum admittance 1 cm above the maximal excursion of the upper esophageal sphincter had highest sensitivity (0.76) and specificity (0.78). When PeakP was at least 57 mm Hg both sensitivity and specificity improved to 0.9.

CONCLUSIONS

Pharyngeal propulsive force has substantial impact on the accuracy of IBP as a predictor of a PEJ stricture. When PeakP is ≥57 mm Hg, an elevated IBP is highly predictive of a restrictive defect at the PEJ.

Pathophysiology of swallowing following oropharyngeal surgery for obstructive sleep apnea syndrome

BACKGROUND

Uvulopalatopharyngoplasty (UPPP) and coblation channeling of the tongue (CCT) are oropharyngeal surgeries used to treat obstructive sleep apnea syndrome. The extent to which UPPP and CCT affect pharyngeal swallow has not been determined. We therefore conducted a novel case series study employing high-resolution impedance manometry (HRIM) to quantify the swallowing-related biomechanics following UPPP and/or CCT surgery.

METHODS

Twelve patients who underwent UPPP+CCT or CCT only were assessed an average 2.5 years postsurgery. Swallow function data were compared with ten healthy controls. All patients completed the Sydney swallow questionnaire (SSQ). Pharyngeal pressure-flow analysis of HRIM recordings captured key distension, contractility and pressure-flow timing swallow parameters testing 5, 10, and 20 mL volumes of thin and thick fluid consistencies.

KEY RESULTS

Postoperative patients had more dysphagia symptoms with five returning abnormal SSQ scores. Swallowing was biomechanically altered compared to controls, consistent with diminished swallowing reserve, largely driven by elevated hypopharyngeal intrabolus pressure due to a reduced capacity to open the upper esophageal sphincter to accommodate larger volumes.

CONCLUSIONS & INFERENCES

Patients who have undergone UPPP and/or CCT surgery appear to have a deficiency in normal modulation of the swallowing mechanism and a reduced swallowing functional reserve. We speculate that these changes may become relevant in later life with the onset of age-related stressors to the swallowing mechanism. This case series strikes a note of caution that further studies are needed to determine the role of preoperative swallow assessment in patients undergoing UPPP and/or CCT surgery.

Effects of remifentanil on esophageal and esophagogastric junction (EGJ) bolus transit in healthy volunteers using novel pressure-flow analysis

BACKGROUND

Remifentanil is associated with subjective dysphagia and an objective increase in aspiration risk. Studies of opioid effects have shown decreased lower esophageal sphincter relaxation. We assessed bolus transit through the esophagus and esophagogastric junction (EGJ) during remifentanil administration using objective pressure-flow analysis.

METHODS

Data from 11 healthy young participants (23±3 years, 7 M) were assessed for bolus flow through the esophagus and EGJ using high-resolution impedance manometry (Manoscan™, Sierra Scientific Instruments, Inc., LES Angeles, CA, USA) with 36 pressure and 18 impedance segments. Data were analyzed for esophageal pressure topography and pressure-flow analysis using custom Matlab analyses (Mathworks, Natick, USA). Paired t tests were performed with a P-value of < .05 regarded as significant.

KEY RESULTS

Duration of bolus flow through (remifentanil/R 3.0±0.3 vs baseline/B 5.0 ± 0.4 seconds; P < .001) and presence at the EGJ (R 5.1 ± 0.5 vs B 7.1 ± 0.5 seconds; P = .001) both decreased during remifentanil administration. Distal latency (R 5.2 ± 0.4 vs B 7.5 ± 0.2 seconds; P < .001) and distal esophageal distension-contraction latency (R 3.5 ± 0.1 vs B 4.7 ± 0.2 seconds; P < .001) were both reduced. Intrabolus pressures were increased in both the proximal (R 5.3 ± 0.9 vs B 2.6 ± 1.3 mm Hg; P = .01) and distal esophagus (R 8.6 ± 1.7 vs B 3.1 ± 0.8 mm Hg; P = .001). There was no evidence of increased esophageal bolus residue.

CONCLUSIONS AND INFERENCES

Remifentanil-induced effects were different for proximal and distal esophagus, with a reduced time for trans-sphincteric bolus flow at the EGJ, suggestive of central and peripheral μ-opioid agonism. There were no functional consequences in healthy subjects.

Diagnosis of Swallowing Disorders: How We Interpret Pharyngeal Manometry

PURPOSE OF REVIEW

We provide an overview of the clinical application of novel pharyngeal high-resolution impedance manometry (HRIM) with pressure flow analysis (PFA) in our hands with example cases.

RECENT FINDINGS

In our Centre, we base our interpretation of HRIM recordings upon a qualitative assessment of pressure-impedance waveforms during individual swallows, as well as a quantitative assessment of averaged PFA swallow function variables. We provide a description of two global swallowing efficacy measures, the swallow risk index (SRI), reflecting global swallowing dysfunction (higher SRI = greater aspiration risk) and the post-swallow impedance ratio (PSIR) detecting significant post-swallow bolus residue. We describe a further eight swallow function variables specific to the hypopharynx and upper esophageal sphincter (UES), assessing hypo-pharyngeal distension pressure, contractility, bolus presence and flow timing, and UES basal tone, relaxation, opening and contractility. Pharyngeal HRIM has now come of age, being applicable for routine clinical practice to assess the biomechanics of oropharyngeal swallowing dysfunction. In the future, it may guide treatment strategies and allow more objective longitudinal follow-up on clinical outcomes.