Variability in quantitative outcomes of instrumental swallowing assessments in adults: a scoping review. / Variabilidade dos desfechos quantitativos nas avaliações instrumentais da deglutição em adultos: uma revisão de escopo.

PURPOSE: To map scientific evidence on the variability of quantitative parameters extracted by instrumental swallowing assessment tests in adults, using the coefficient of variation. RESEARCH STRATEGIES: The methodological procedures recommended by the Joanna Briggs Institute and the extension for scoping reviews of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA-ScR) were followed. SELECTION CRITERIA: The search was carried out in the Pubmed/Medline, Lilacs, Cochrane Library, Embase, Web of Science, Scopus and CINAHL databases, as well as in Google Scholar to consult the gray literature. DATA ANALYSIS: Two blind and independent reviewers screened the articles by title and abstract. Subsequently, the articles were read in full and selected according to the eligibility criteria. Data were extracted according to a standardized instrument. RESULTS: 363 studies were found, 13 of which were eligible. Most studies had a sample size of less than 30 participants and were made up of healthy individuals. The instrumental exams used were diverse: videofluoroscopy, electrical impedance tomography, laryngeal sensors, high-resolution manometry and surface electromyography. The studies searched for intra-individual variability and the coefficient of variation ranged from low to high variability, as the instruments, parameters and collection procedures were very heterogeneous and non-standardized. CONCLUSION: Intra-individual variability of the quantitative outcomes of instrumental swallowing assessments in adults ranged from low to high according to the exam, outcome, presence or absence of underlying disease, consistency and volume of the bolus.

OBJETIVO: Mapear as evidências científicas sobre a variabilidade dos parâmetros quantitativos extraídos por exames instrumentais de avaliação da deglutição em adultos, mediante o coeficiente de variação. ESTRATÉGIA DE PESQUISA: Foram seguidos os procedimentos metodológicos recomendados pelo Joanna Briggs Institute e a extensão para revisões de escopo do Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA-ScR). CRITÉRIOS DE SELEçÃO: A busca foi realizada nas bases de dados Pubmed/Medline, Lilacs, Cochrane Library, Embase, Web of Science, Scopus e CINAHL, assim como no Google Scholar para consultar a literatura cinzenta. ANÁLISE DOS DADOS: Dois revisores cegos e independentes fizeram o rastreamento dos artigos por título e resumo. Posteriormente, os artigos foram lidos na íntegra e selecionados de acordo com os critérios de elegibilidade. Os dados foram extraídos de acordo com um instrumento padronizado. RESULTADOS: Foram encontrados 363 estudos, sendo 13 elegíveis. A maioria dos estudos teve amostra menor que 30 participantes e foi composta por indivíduos saudáveis. Os exames instrumentais utilizados foram diversos: videofluoroscopia, tomografia de impedância elétrica, sensores laríngeos, manometria de alta resolução e eletromiografia de superfície. Os estudos investigaram principalmente a variabilidade intraindividual e os valores do coeficiente de variação oscilaram entre baixa e alta variabilidade, pois os instrumentos, parâmetros e procedimentos de coleta foram heterogêneos e não padronizados. CONCLUSÃO: A variabilidade intraindividual dos parâmetros quantitativos da deglutição obtidos por meio de exames instrumentais em adultos oscila entre baixa e alta conforme o exame, parâmetro testado, presença ou não de doença de base, consistência e volume do bolo alimentar.

Comparison of the Kron technique and digital manometry for measuring intra-abdominal pressure in emergency department patients diagnosed with ileus.

BACKGROUND: Numerous measurement techniques for intra-abdominal pressure have been explored, with the Kron Technique established as the gold standard. Despite its prominence, the search for alternative methods persists due to its lengthy application time, the requirement for additional equipment, and overall impracticality. This study investigated a quicker, more accessible method for effective intra-abdominal pressure measurement in the emergency department. It aimed to compare intra-abdominal pressure measurements in patients diagnosed with ileus using a digital manometer and the Kron Technique. METHODS: Conducted from October 2022 to February 2023, this single-center, prospective, single-blind method comparison study involved patients diagnosed with ileus at a tertiary emergency department. Intra-abdominal pressure was measured using both the Kron Technique and a digital manometer by separate practitioners blinded to the study results. RESULTS: The study included 30 patients. No statistically significant difference was observed in the intra-abdominal pressure measurements between the two methods (p<0.237). A very strong correlation existed between the two methods (Spearman's Rho = 0.998). Bland-Altman analysis showed a bias value of 0.091 mmHg for the digital manometer, with upper and lower agreement limits of -0.825 and 1.007 mmHg, respectively. The measurement time was significantly shorter with the digital manometer than with the Kron Technique (15 vs. 390.5 seconds; p<0.001). CONCLUSION: We believe that the intra-abdominal pressure measurement technique using a digital manometer is a method that can be effectively employed by healthcare professionals in emergency departments. This technique offers ease of use, requires minimal equipment, provides rapid results, and delivers reliable measurement values compared to the Kron Technique.

Clinical Validation of Carotid-Femoral Pulse Wave Velocity Measurement Using a Multi-Beam Laser Vibrometer: The CARDIS Study.

BACKGROUND: Carotid-femoral pulse wave velocity (cfPWV) is the gold standard for noninvasive arterial stiffness assessment, an independent predictor of cardiovascular disease, and a potential parameter to guide therapy. However, cfPWV is not routinely measured in clinical practice due to the unavailability of a low-cost, operator-friendly, and independent device. The current study validated a novel laser Doppler vibrometry (LDV)-based measurement of cfPWV against the reference technique. METHODS: In 100 (50 men) hypertensive patients, cfPWV was measured using applanation tonometry (Sphygmocor) and the novel LDV device. This device has 2 handpieces with 6 laser beams each that simultaneously measure vibrations from the skin surface at carotid and femoral sites. Pulse wave velocity is calculated using ECG for the identification of cardiac cycles. An ECG-independent method was also devised. Cardiovascular risk score was calculated for patients between 40 and 75 years old using the WHO risk scoring chart. RESULTS: LDV-based cfPWV correlated significantly with tonometry (r=0.86, P<0.0001 ECG-dependent [cfPWVLDV_ECG] and r=0.80, P<0.001 ECG-independent [cfPWVLDV_w/oECG] methods). Bland-Altman analysis showed nonsignificant bias (0.65 m/s) and acceptable SD (1.27 m/s) between methods. Intraobserver coefficient of variance for LDV was 4.7% (95% CI, 3.0%-5.5%), and interobserver coefficient of variance was 5.87%. CfPWV correlated significantly with CVD risk (r=0.64, P<0.001; r=0.41, P=0.003; and r=0.37, P=0.006 for tonometry, LDV-with, and LDV-without ECG, respectively). CONCLUSIONS: The study demonstrates clinical validity of the LDV device. The LDV provides a simple, noninvasive, operator-independent method to measure cfPWV for assessing arterial stiffness, comparable to the standard existing techniques. REGISTRATION: URL: https://clinicaltrials.gov/study/NCT03446430; Unique identifier: NCT03446430.

Criterion (Concurrent) Validity and Clinical Utility of the Tongueometer Device.

PURPOSE: Tongue manometry (i.e., tongue pressure measurement) is a commonly used assessment for patients with suspected oral-motor involvement in swallowing disorders. Availability of lingual manometry has changed in recent years, with the introduction of the Tongueometer device being a more affordable tongue manometry system. The purpose of this study was to test concurrent (criterion) validity of the Tongueometer compared to the current standard reference device, the Iowa Oral Performance Instrument (IOPI). METHOD: Adults without dysphagia were recruited for participation in this study. Standard lingual measurements (swallowing-related pressures, maximum isometric pressure [MIP], and maximum isometric endurance) were recorded, with the bulb anteriorly placed, with both devices, in a randomized order. The Bland-Altman method was used to determine concurrent (criterion) validity of these measurements compared to the clinical standard IOPI device. A recently available suggested corrective value by Curtis et al. (2023) was also applied, with comparisons made between devices both with and without the Curtis correction. RESULTS: The final sample included 70 adult participants aged 20-89 years (Mage = 52.3 years). Measures with the Tongueometer device were significantly lower when compared with the same measures taken using the IOPI (p < .01) for all measures including MIP, endurance, and swallow pressures. The correction suggested by Curtis and colleagues did not ameliorate these differences. CONCLUSIONS: The Tongueometer lingual measurements were consistently lower compared to the IOPI. Clinical use of values taken with the Tongueometer device should be compared to normative data published for each specific device. Available features of each device (e.g., display, bulb texture, technology/application) should be considered when selecting which device to use with an individual patient.

A comparison of function lumen imaging probe measurements of anal sphincter function in fecal incontinence.

BACKGROUND: The functional lumen imaging probe (FLIP) is a test of anal sphincter distensibility under evaluation by specialist centers. Two measurement protocols termed "stepwise" and "ramp" are used, risking a lack of standardization. This study aims to compare the performance of these protocols to establish if there are differences between them. METHODS: Patients with fecal incontinence were recruited and underwent measurement with both protocols at a tertiary pelvic floor referral unit. Differences in minimum diameter, FLIP bag pressure, and distensibility index (DI) at rest and during squeeze were calculated at various FLIP bag volumes. KEY RESULTS: Twenty patients (19 female, mean age 61 [range: 38-78]) were included. The resting minimum diameter at 30 and 40 mL bag volumes were less in the stepwise protocol (mean bias: -0.55 mm and -1.18 mm, p < 0.05) along with the DI at the same bag volumes (mean bias: -0.37 mm2/mmHg and -0.55 mm2/mmHg, p < 0.05). There was also a trend towards greater bag pressures at 30 mL (mean bias: +2.08 mmHg, p = 0.114) and 40 mL (mean bias: +2.81 mmHg, p = 0.129) volumes in the stepwise protocol. There were no differences between protocols in measurements of minimum diameter, maximum bag pressure, or DI during voluntary squeeze (p > 0.05). CONCLUSION AND INFERENCES: There are differences between the two commonly described FLIP measurement protocols at rest, although there are no differences in the assessment of squeeze function. Consensus agreement is required to agree the most appropriate FLIP measurement protocol in assessing anal sphincter function.

Clinical validation of the VIPUN™ gastric monitoring system versus manometry for the evaluation of gastric motility.

BACKGROUND: Gastrointestinal dysmotility is frequently suspected in patients with gastroparesis, functional dyspepsia, and ileus, and in the intensive care unit. Monitoring of gastric motility in clinical practice remains challenging. A novel technology was developed to meet the medical need for a widely available bedside tool to monitor gastric motility continuously. The VIPUN™ Gastric Monitoring System (GMS) comprises a nasogastric feeding tube with intragastric balloon to allow for measuring gastric contractions. AIMS: To compare the performance of the VIPUN GMS versus a reference technique (manometry). METHODS: In this validation study in healthy subjects, the investigational catheter and a solid-state manometry catheter were placed in the stomach concomitantly. Motility was recorded for 2.5 h: 2 h in a fasting state, followed by a 400-kcal liquid meal, and monitoring of the fed state for the remaining half hour. The performance of both systems was compared by automated recognition and manual identification of the contractile activity. Data are presented as mean (standard deviation). KEY RESULTS: The analysis set comprised 13 healthy subjects (6 women, age: 27.5 (8.1) years, BMI: 22.2 (2.46) kg/m2). Automatically-recognized contractility was strongly correlated between the two techniques (endpoint: contraction duration; Spearman ρ = 0.96, p < 0.001). A correlation was also observed between the number of individual contractions identified by expert gastroenterologists on both technologies independently (ρ = 0.71, p = .007) and between the contractions identified by the experts and by the GMS software (ρ = 0.87, p = 0.001). No serious or unanticipated adverse events occurred. CONCLUSIONS & INFERENCES: The observed strong correlations with the gold standard, manometry, validate the performance of the VIPUN GMS as a gastric monitoring system.

Concordance Analysis of the Pressure Chamber and Tubomanometer According to Estève for the Determination of Eustachian Tube Opening Pressure.

INTRODUCTION: For the diagnosis of Eustachian tube dysfunction (ETD), clinical procedures such as tympanometry, micro-otoscopy, and maneuvers according to Toynbee and Valsalva only allow an indirect assessment for the moment. With a prevalence of up to 5%, the selection of patients with ETD and its subtypes is clinically relevant. Dynamic methods of Eustachian tube function assessment include a hypo/hyperbaric pressure chamber and Estève's tubomanometer (TMM). One method of assessing ETD is the evaluation of Eustachian tube opening pressure (ETOP). MATERIAL AND METHODS: We performed a concordance analysis between pressure chamber and TMM to determine ETOP. For this purpose, we analyzed the measurements of both methods from 28 healthy subjects using Bland-Altman plots, regression according to Passing-Bablok and Lin's concordance correlations coefficient. The maximum tolerated clinical deviation of measured values was set at 10%. RESULTS: A maximum of 53 measurements of ETOP between pressure chamber and TMM were compared. Mean ETOP for TMM was 28.7 hPa, passive opening was 32 hPa, Toynbee maneuver was 28.4 hPa, and Valsalva maneuver was 54.6 hPa. Concordance analysis revealed following results: passive opening versus TMM: Bland-Altman mean difference 3.3 hPa, limits of agreement ±31.8 hPa; Passing-Bablok regression y = 0.67 x + 9.36; Lin's rccc = 0.18. Toynbee versus TMM: Bland-Altman mean difference 0.7 hPa, limits of agreement ±35.8 hPa; Passing-Bablok regression y = 0.47x + 14.03; Lin's rccc = 0.14. Valsalva versus TMM: Bland-Altman mean difference 24.2 hPa, limits of agreement ±117.5 hPa; Passing-Bablok regression y = 0.17x + 25.12; Lin's rccc = 0.18. CONCLUSION: Estève's tubomanometer and pressure chamber measurements of ETOP are not concordant. The two methods cannot be interchanged without reservation.

Integrated Relaxation Pressure and Its Diagnostic Ability May Vary According to the Conditions Used for HREM Recording.

Integrated Residual Pressure (IRP) measured under conditions alternative to supine single swallows may provide clinically useful information regarding EGJ relaxation. This study aimed to compare IRP values obtained under different situations and explore their potential clinical utility. We analyzed and compared the values of IRP obtained from healthy volunteers and patients with suspected achalasia during supine single swallows (Ssup-IRP), sitting single swallows (Ssit-IRP), supine multiple rapid swallows (Msup-IRP), and sitting multiple rapid swallows (Msit-IRP). We analyzed the HREM recordings of 40 healthy volunteers and 53 patients with suspected achalasia. The four metrics were significantly different from each other in healthy volunteers (Ssup-IRP > Msup-IRP > Ssit-IRP > Msit-IRP) and their corresponding 95th percentiles were substantially distinct (Ssup-IRP: 25.3 mmHg, Ssit-IRP: 20.9 mmHg, Msup-IRP: 15.9 mmHg, and Msit-IRP: 11.9 mm Hg, respectively). Complete agreement among the four metrics in predicting abnormal IRP was found in 39 of the 47 patients with suspected achalasia who completed the protocol. Optimal cutoffs derived from ROC curve analysis demonstrated ≥ 0.95 specificities for detection of impaired EGJ relaxation among patients with suspected achalasia. Among the eight patients with suspected achalasia with normal Ssup-IRP, five demonstrated abnormal Msit-IRP and four abnormal Ssit-IRP. Significant differences of IRP exist depending on the measurement situation, indicating that correct interpretation of IRP values requires specific cutoffs for each situation.The sensitivities of Ssit-IRP and Msit-IRP in detecting defective EGJ relaxation appear to be slightly higher than that of Ssup-IRP.

Manometric parameters, when measured with the 3-dimensional high-definition anorectal manometry probe, poorly predict prolonged balloon expulsion time.

BACKGROUND: There are little data evaluating the performance of the 3-dimensional high-definition anorectal manometry (3D-HDAM) system in the diagnosis of dyssynergic defecation. Physical properties of the thicker, rigid, 3D-HDAM probe may have implications on the measurements of anorectal pressures. AIM: Our aim was to compare 3D-HDAM to balloon expulsion test and magnetic resonance (MR) defecography. METHODS: Consecutive constipated patients referred for anorectal function testing at the Calgary Gut Motility Centre (Calgary, Canada) between 2014 and 2019 were assessed. All patients underwent anorectal manometry with the 3D-HDAM probe, and a subset underwent BET or MR defecography. Anorectal manometric variables were compared between patients who had normal and abnormal BET. RESULTS: Over the study period, 81 patients underwent both 3D-HDAM and BET for symptoms of constipation. 52 patients expelled the balloon within 3 minutes. Patients with abnormal BET had significantly lower rectoanal pressure differential (RAPD) (-61 vs. -31 mmHg for normal BET, p = 0.03) and defecation index (0.29 vs. 0.56, p = 0.03). On logistic regression analysis, RAPD (OR: 0.99, 95% CI: 0.97-0.99, p = 0.03) remained a negative predictor of abnormal BET. On ROC analysis, RAPD had an AUC of 0.65. There was good agreement between dyssynergic patterns on 3D-HDAM and defecographic evidence of dyssynergia (sensitivity 80%, specificity 90%, PLR 9, NLR 0.22, accuracy 85%). CONCLUSIONS: Manometric parameters, when measured with the 3D-HDAM probe, poorly predict prolonged balloon expulsion time. RAPD remains the best predictor of prolonged balloon expulsion time. The 3D-HDAM probe may not be the ideal tool to diagnose functional defecatory disorders.

Translating Fecobionics Into a Technique That Addresses Clinical Needs for Objective Perineal Descent Measurements.

INTRODUCTION: Perineal descent is a phenomenon associated with anorectal dysfunction. It is diagnosed by defecography but subjected to manual measurements on the images/videos and interobserver bias. Fecobionics is a simulated feces for assessing important physiological parameters during defecation. Here, we translate Fecobionics into a new method for estimation of perineal descent based on electronic signals from the embedded inertial measurement units (IMUs). METHODS: A displacement measurement method by a combined zero-velocity update and gravity compensation algorithm from IMUs was developed. The method was verified in a robot model, which mimicked perineal descent motion. RESULTS: The method correlated well with the reference (R = 0.9789) and had a deviation from the peak displacement (range 0.25-2.5 cm) of -0.04 ± 0.498 cm. The method was further validated in 5 human experiments with comparison to the benchmark defecography technology (R = 0.79). DISCUSSION: The proposed technology is objective, i.e., electronic measurements rather than by fluoroscopy or MRI. The development may impact clinical practice by providing a resource-saving and objective technology for diagnosing perineal descent in the many patients suffering from anorectal disorders. The technology may also be used in colon experiments with Fecobionics and for other gastrointestinal devices containing IMUs such as ingestible capsules like the Smartpill.

Characterization of Patients With Obstructed Defecation and Slow Transit Constipation With a Simulated Stool.

INTRODUCTION: Defecatory disorders including obstructed defecation (OD) are currently diagnosed using specialized investigations including anorectal manometry and the balloon expulsion test. Recently, we developed a simulated stool named Fecobionics that provides a novel type of pressure measurements and analysis. The aim was to study OD phenotypes compared with slow transit constipation (STC) patients and normal subjects (NS). METHODS: Fecobionics expulsion parameters were assessed in an interventional study design. The Fecobionics device contained pressure sensors at the front, rear, and inside a bag. All constipation patients had colon transit study, defecography, anorectal manometry, and balloon expulsion test performed. The Fecobionics bag was distended in the rectum until desire-to-defecate in 26 OD compared with 8 STC patients and 10 NS. Rear-front pressures (preload-afterload parameters) and defecation indices (DIs) were compared between groups. RESULTS: The Wexner constipation scoring system score was 13.8 ± 0.9 and 14.6 ± 1.5 in the OD and STC patients (P > 0.5). The median desire-to-defecate volume was 80 (quartiles 56-80), 60 (54-80), and 45 (23-60) mL in OD, STC, and NS, respectively (P < 0.01). The median expulsion duration was 37 (quartiles 15-120), 6 (3-11), and 11 (8-11) seconds for the 3 groups (P < 0.03). Fecobionics rear-front pressure diagrams demonstrated clockwise loops with distinct phenotype differences between OD and the other groups. Most DIs differed between OD and the other groups, especially those based on the anal afterload reflecting the nature of OD constipation. Several OD subtypes were identified. DISCUSSION: Fecobionics obtained novel pressure phenotypes in OD patients. DIs showed pronounced differences between groups. Larger studies are needed on OD subtyping.

Pressure measurement characteristics of a micro-transducer and balloon catheters.

Respiratory pressure responses to cervical magnetic stimulation are important measurements in monitoring the mechanical function of the respiratory muscles. Pressures can be measured using balloon catheters or a catheter containing integrated micro-transducers. However, no research has provided a comprehensive analysis of their pressure measurement characteristics. Accordingly, the aim of this study was to provide a comparative analysis of these characteristics in two separate experiments: (1) in vitro with a reference pressure transducer following a controlled pressurization; and (2) in vivo following cervical magnetic stimulations. In vitro the micro-transducer catheter recorded pressure amplitudes and areas which were in closer agreement to the reference pressure transducer than the balloon catheter. In vivo there was a main effect for stimulation power and catheter for esophageal (Pes ), gastric (Pga ), and transdiaphragmatic (Pdi ) pressure amplitudes (p < 0.001) with the micro-transducer catheter recording larger pressure amplitudes. There was a main effect of stimulation power (p < 0.001) and no main effect of catheter for esophageal (p = 0.481), gastric (p = 0.923), and transdiaphragmatic (p = 0.964) pressure areas. At 100% stimulator power agreement between catheters for Pdi amplitude (bias =6.9 cmH2 O and LOA -0.61 to 14.27 cmH2 O) and pressure areas (bias = -0.05 cmH2 O·s and LOA -1.22 to 1.11 cmH2 O·s) were assessed. At 100% stimulator power, and compared to the balloon catheters, the micro-transducer catheter displayed a shorter 10-90% rise time, contraction time, latency, and half-relaxation time, alongside greater maximal rates of change in pressure for esophageal, gastric, and transdiaphragmatic pressure amplitudes (p < 0.05). These results suggest that caution is warranted if comparing pressure amplitude results utilizing different catheter systems, or if micro-transducers are used in clinical settings while applying balloon catheter-derived normative values. However, pressure areas could be used as an alternative point of comparison between catheter systems.

Utility of a new automated diagnostic program in high-resolution esophageal manometry.

BACKGROUND: A new automated diagnostic program for high-resolution esophageal manometry (HREM) has been developed. This diagnostic program could detect locations of landmarks and could make final diagnoses automatically. However, the accuracy of the program is not known. The aim of this study was to evaluate the accuracy of the automated diagnostic program for HREM. METHODS: A total of 445 studies were enrolled. An HREM system (Starlet®) was used, and esophageal motility was diagnosed using the Chicago classification v3.0. First, the locations of the upper esophageal sphincter, transition zone, lower esophageal sphincter, esophago-gastric junction, crural diaphragm and stomach were determined, and each swallow was checked manually. Then, the parameters of the Chicago classification were calculated using an analytic program of the Starlet, and diagnoses were made by three experts. Second, all study raw data were analyzed again by the automated diagnostic program. Diagnoses made by the program were compared to those made by experts to evaluate the accuracy of the diagnoses. RESULTS: The new diagnostic program could identify the landmarks of each swallow, calculate the parameters and make a final diagnosis within 10 s. The diagnoses made by the automated diagnostic program were not matched to those made by experts in only 10 studies, and the overall accuracy of the new automated diagnostic program thus reached 97.8% (435/445). CONCLUSIONS: The new automated diagnostic program for HREM is clinically useful in terms of high diagnostic accuracy and time-saving.

Gastric accumulation of enteral nutrition reduces pressure changes induced by phasic contractility in an isovolumetric intragastric balloon.

BACKGROUND: An isovolumetric intragastric balloon to continuously measure gastric phasic contractility was recently developed by us. We aimed to investigate the readout of this technique in relation to gastric content and gastric emptying. METHODS: In this crossover investigation, the VIPUNTM Gastric Monitoring System, which comprises a double lumen nasogastric feeding tube with integrated intragastric balloon, was used to assess phasic gastric contractility by interpretation of the pressure in an isovolumetric balloon in 10 healthy subjects. Balloon pressure was recorded in fasted state, during a 2-hour intragastric nutrient infusion (1 kcal/ml at 25, 75, or 250 ml/h) and 4 hours post-infusion, and quantified as Gastric Balloon Motility Index (GBMI), ranging from 0 (no contractility) to 1 (maximal contractility). Gastric accumulation was quantified with magnetic resonance imaging and gastric emptying with a13 C-breath test. Results are expressed as mean(SD). KEY RESULTS: GBMI was significantly lower during infusion at 250 ml/h compared to baseline (0.13(0.05) versus 0.46(0.12)) and compared to infusion at 25 (0.54(0.21)) and 75 ml/h (0.43(0.20)), all P < 0.005. Gastric content volume was larger after infusion at 250 versus 75 ml/h (P < 0.001). Half-emptying time and accumulation were both negatively correlated with postprandial contractility. Postprandial GBMI was significantly lower when GCV>0 ml compared to when the stomach was empty. CONCLUSIONS AND INFERENCES: Enteral nutrition dose-dependently decreased the contractility readout. This decrease was linked to gastric accumulation of enteral nutrition.

Comparison of the iCare, Tono-Pen, non-contact airpuff, and Goldmann applanation tonometers in eyes with corneal edema after penetrating keratoplasty.

BACKGROUND: To compare the utility of the iCare, Tono-Pen, and non-contact airpuff (NCT) tonometers with the Goldmann applanation tonometer (GAT) for measuring intraocular pressure (IOP) in patients with corneal edema after penetrating keratoplasty (PKP) and to assess the effects of central corneal thickness (CCT) and corneal curvature (CC) on IOP measurements. METHODS: Thirty-two eyes of 27 patients with corneal edema after PKP due to corneal abnormalities and 43 control eyes of 30 patients with normal corneas were recruited. Before IOP measurements, all patients underwent a baseline examination, including auto-refraction, keratometry, slit lamp biomicroscopy, and CCT measurement. IOP was measured using the devices in the same order: first the NCT, followed by the iCare, Tono-Pen, and GAT. The differences between the iCare, Tono-Pen, NCT, and GAT were calculated with repeated-measures analysis of variance. The Bland-Altman method was used to assess the agreement between the iCare, Tono-Pen, and NCT versus the GAT. The influences of CCT and CC on IOP measurement were evaluated by correlation analysis using Pearson's correlation coefficient. RESULTS: Mean IOP measurements were significantly higher with the NCT and Tono-Pen than with the GAT in the PKP and control groups. When compared with GAT, iCare showed significantly higher IOP readings in the control group, but the IOP readings did not differ between the iCare and GAT in the PKP group. Poor agreement was noted between the NCT and GAT in both groups. The Tono-Pen showed clinically acceptable agreement with GAT in control eyes and poor agreement in PKP eyes. The agreement between the iCare and GAT appeared to be clinically acceptable in both groups. Correlation analysis of the results from control eyes showed that the IOP measurements with the GAT and NCT were weakly related to CCT and moderately correlated with CC. The iCare IOP readings were weakly correlated with CCT and CC. CONCLUSION: In the PKP group, the NCT and Tono-Pen significantly overestimated IOP, whereas the iCare IOP readings were similar to those obtained using the GAT. Poor agreement was noted between the NCT and GAT as well as between the Tono-Pen and GAT, but the iCare showed clinically acceptable agreement with GAT. In normal corneas, the GAT, NCT, and iCare were affected by CCT and CC. The iCare tonometer was less affected by corneal edema than were the NCT and the Tono-Pen. The iCare appears to be a useful device for IOP measurement in eyes with corneal edema after PKP.

Evaluation of the effect of disposable tonometer cover brand on performance of Tono-Pen Vet in canine eyes.

PRIMARY OBJECTIVE: To evaluate the effect of latex tip cover manufacturer on accuracy and repeatability of Tono-Pen Vet™ in canine eyes. ANIMAL STUDIED: Twelve enucleated globes from six dogs. PROCEDURES: The anterior chamber was cannulated and connected to a calibrated manometer. Intraocular pressure (IOP) measurements were obtained using the Tono-Pen Vet and TONOVET Plus at manometric IOP ranging from 5 to 80 mmHg. At each IOP, the Tono-Pen Vet was used with a new Ocu-Film™ latex tip cover (the only manufacturer-approved brand of cover) followed by a new Softips™ latex tip cover. For comparison, the TONOVET Plus was also used at each IOP with a new disposable rebound probe. Measured IOP values were analyzed by linear regression and intraclass correlation coefficient (ICC). RESULTS: Tono-Pen Vet accuracy was unaffected by tip cover manufacturer or by frequent change in cover. Using ICC analysis, repeatability of measurements using either tonometer was good to excellent at physiologic IOP levels but variably decreased with both devices at supraphysiologic IOP. CONCLUSIONS: Neither tip cover manufacturer nor frequent changes in tip cover adversely affect Tono-Pen Vet accuracy. Measurement repeatability with Tono-Pen Vet and TONOVET Plus is widely variable at supraphysiologic IOP. Therefore, minor changes in IOP >25 mmHg should not be used to make clinical decisions without considering this variability.

VALIDATION OF A NEW WATER-PERFUSED HIGH-RESOLUTION MANOMETRY SYSTEM.

BACKGROUND: Water-perfused high resolution manometry system. High-resolution manometry is more costly but clinically superior to conventional manometry. Water-perfused systems may decrease costs, but it is unclear if they are as reliable as solid-state systems, and reference values are interchangeable. AIM: To validate normal values for a new water-perfusion high-resolution manometry system. METHODS: Normative values for a 24-sensors water perfused high-resolution manometry system were validated by studying 225 individuals who underwent high resolution manometry for clinical complaints. Patients were divided in four groups: group 1 - gastroesophageal reflux disease; group 2 - achalasia; group 3 - systemic diseases with possible esophageal manifestation; and group 4 - dysphagia. RESULTS: In group 1, a hypotonic lower esophageal sphincter was found in 49% of individuals with positive 24 h pH monitoring, and in 28% in pH-negative individuals. In groups 2 and 3, aperistalsis was found in all individuals. In group 4, only one patient (14%) had normal high-resolution manometry. CONCLUSIONS: The normal values determined for this low-cost water-perfused HRM system with unique peristaltic pump and helicoidal sensor distribution are discriminatory of most abnormalities of esophageal motility seen in clinical practice.

Biofeedback Training Improves Swallowing in a Unique Case of Upper Esophageal Sphincter Hypotonicity.

Hypotonicity of the upper esophageal sphincter (UES) has been reported only two times previously in the literature, with no reports of treatment options for this rarity. We present a third case of hypotonic UES found during high-resolution pharyngeal manometry. Although the patient had nearly absent resting pressures of the UES, pressures during and post-swallow were normal. It was hypothesized that the patient might be able to increase pre-swallow UES pressure using biofeedback. Using a chin up/out maneuver during manometry, the patient was able to achieve a more normal swallow pressure pattern. This case also highlights the need to complete manometry alongside other swallow imaging techniques for effective treatment planning and patient outcomes. Laryngoscope, 131:E1567-E1569, 2021.

Erythromycin stimulates phasic gastric contractility as assessed with an isovolumetric intragastric balloon pressure measurement.

BACKGROUND: A novel technique to assess gastric motility by measuring the pressure in a low-volume intragastric balloon was developed to monitor (disordered) motility. We previously showed that this technique allows measuring pharmacologically induced inhibition of motility. In this study, we assessed whether it is possible to measure pharmacologically induced stimulation of gastric motility using 200 mg erythromycin. Erythromycin is a highly effective stimulator of gastric emptying and contractility. METHODS: After an overnight fast, a nasogastric balloon catheter was introduced in healthy subjects. After inflation with 120 ml of air, the catheter was connected to a pressure sensor. Intraballoon pressure was continuously recorded for 4 h. After a baseline recording of 2 h, 200 mg erythromycin was infused intravenously over 20 min while the recording continued for 2 h. Epigastric symptoms were surveyed on 100-mm visual analogue scales. Motility was quantified from the pressure recording as a gastric balloon motility index. Wilcoxon signed-rank tests were performed. Data are shown as median (interquartile range). KEY RESULTS: Six subjects were enrolled and five completed the procedures (age: 28 (25-29) years, body mass index: 24.0 (23.8-24.5) kg m-2 ). One subject could not tolerate tube placement. Bloating, nausea, and epigastric sensation scores were 0 (0-3), 0 (0-1), and 1 (0-1) mm, respectively. Erythromycin significantly increased the motility index from 0.48 (0.41-0.51) to 0.79 (0.70-0.82) (p = 0.03). CONCLUSIONS AND INFERENCES: Gastric motility assessed via pressure measurement in a low-volume intragastric balloon is able to detect pharmacologically stimulated motility in healthy subjects, which further validates this technique.

Esophagogastric junction morphology and contractile integral on high-resolution manometry in asymptomatic healthy volunteers: An international multicenter study.

BACKGROUND: Esophagogastric junction contractile integral (EGJ-CI) and EGJ morphology are high-resolution manometry (HRM) metrics that assess EGJ barrier function. Normative data standardized across world regions and HRM manufacturers are limited. METHODS: Our aim was to determine normative EGJ metrics in a large international cohort of healthy volunteers undergoing HRM (Medtronic, Laborie, and Diversatek software) acquired from 16 countries in four world regions. EGJ-CI was calculated by the same two investigators using a distal contractile integral-like measurement across the EGJ for three respiratory cycles and corrected for respiration (mm Hg cm), using manufacturer-specific software tools. EGJ morphology was designated according to Chicago Classification v3.0. Median EGJ-CI values were calculated across age, genders, HRM systems, and regions. RESULTS: Of 484 studies (28.0 years, 56.2% F, 60.7% Medtronic studies, 26.0% Laborie, and 13.2% Diversatek), EGJ morphology was type 1 in 97.1%. Median EGJ-CI was similar between Medtronic (37.0 mm Hg cm, IQR 23.6-53.7 mm Hg cm) and Diversatek (34.9 mm Hg cm, IQR 22.1-56.1 mm Hg cm, P = 0.87), but was significantly higher using Laborie equipment (56.5 mm Hg cm, IQR 35.0-75.3 mm Hg cm, P < 0.001). 5th percentile EGJ-CI values ranged from 6.9 to 12.1 mm Hg cm. EGJ-CI values were consistent across world regions, but different between manufacturers even within the same world region (P ≤ 0.001). Within Medtronic studies, EGJ-CI and basal LESP were similar in younger and older individuals (P ≥ 0.3) but higher in women (P < 0.001). CONCLUSIONS: EGJ morphology is predominantly type 1 in healthy adults. EGJ-CI varies widely in health, with significant gender influence, but is consistent within each HRM system. Manufacturer-specific normative values should be utilized for clinical HRM interpretation.