The Experts below are selected from a list of 8139 Experts worldwide ranked by ideXlab platform
Craig M. Zaidman - One of the best experts on this subject based on the ideXlab platform.
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reliability of bedside ultrasound of limb and diaphragm Muscle Thickness in critically ill children
Muscle & Nerve, 2019Co-Authors: Kay W. P. Ng, Alexander R. Dietz, Ryan Johnson, Michael Shoykhet, Craig M. ZaidmanAbstract:INTRODUCTION: We evaluated the reliability of measuring Muscle Thickness with ultrasound in limbs and diaphragms of critically ill children and determined the sensitivity of these measures to quantitate Muscle atrophy over time. METHODS: An expert and trained novice sonographers prospectively measured limb and diaphragm Muscle Thickness in 33 critically ill children. RESULTS: Expert and novice intrarater and interrater reliability were similar. Intraclass correlations (ICC) and coefficients of variation (CoV) were better in limbs (ICC > 0.9; CoV 3.57%-5.40%) than in diaphragm (ICC > 0.8; CoV novice 11.88%, expert, 12.28%). Mean relative difference in all Muscles was small (1%-8%). Limits of agreement of the relative difference were smaller in limb ( 13% in limb and >38% in diaphragm Muscles. The smaller detectable change in limb Muscles is likely due to their greater Thickness. Muscle Nerve 59:88-94, 2019.
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Reliability of Bedside Ultrasound of Limb and Diaphragm Muscle Thickness in Critically-ill Children
Muscle & Nerve, 2018Co-Authors: Kay W. P. Ng, Alexander R. Dietz, Ryan Johnson, Michael Shoykhet, Craig M. ZaidmanAbstract:Introduction: We evaluated the reliability of measuring Muscle Thickness with ultrasound in limbs and diaphragms of critically-ill children and determined the sensitivity of these measures to quantify Muscle atrophy over time.
Andrew D Bersten - One of the best experts on this subject based on the ideXlab platform.
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diaphragm and peripheral Muscle Thickness on ultrasound intra rater reliability and variability of a methodology using non standard recumbent positions
Respirology, 2011Co-Authors: Claire E Baldwin, Jenny Davida Paratz, Andrew D BerstenAbstract:Background and objective: Reliable measurement of diaphragm and peripheral Muscle Thickness, using diagnostic ultrasound, has only been validated in the erect posture. However, in many clinical populations, including critically ill patients, the erect posture presents logistic difficulties. This study aimed to validate ultrasound measurement of diaphragm and peripheral Muscle Thickness in the recumbent position. Methods: An observational methodology of repeated but blind ultrasound and anthropometric measurements was applied, to assess inta-rater reliability. Thirteen healthy volunteers (aged 20-73 years) participated. A pneumotachograph was used to target lung volume, as diaphragm Thickness was measured from ultrasound at end-expiration, and both 25% and 50% of inspiratory capacity, while semi-recumbent. The Thicknesses of the mid-upper arm, mid-forearm and mid-thigh musculature were also measured bilaterally while supine. Results: Diaphragm Thickness could be reliably measured at end-expiration (intra-class correlation coefficient (ICC) = 0.990, 95% confidence interval: 0.918-0.998), 25% of inspiratory capacity (ICC = 0.959 (0.870-0.988)) and 50% of inspiratory capacity (ICC = 0.994 (0.980-0.998)). Peripheral Muscle Thickness measurements were also reliable (ICC = 0.998-1.0). Supine anthropometric measurements of limb segment lengths and girths were highly reproducible. Conclusions: This ultrasound technique has good reliability in recumbent positions, making it useful for application to clinical populations when the erect posture is not practical. Recumbent postures may affect the reliability of diaphragm and peripheral Muscle Thickness measured with ultrasound. While usually performed erect, patients may not tolerate this posture. We demonstrated that recumbent positions can be used to reliably measure diaphragm and peripheral Muscle Thickness, and that imaging sites can be accurately located supine.
Kay W. P. Ng - One of the best experts on this subject based on the ideXlab platform.
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reliability of bedside ultrasound of limb and diaphragm Muscle Thickness in critically ill children
Muscle & Nerve, 2019Co-Authors: Kay W. P. Ng, Alexander R. Dietz, Ryan Johnson, Michael Shoykhet, Craig M. ZaidmanAbstract:INTRODUCTION: We evaluated the reliability of measuring Muscle Thickness with ultrasound in limbs and diaphragms of critically ill children and determined the sensitivity of these measures to quantitate Muscle atrophy over time. METHODS: An expert and trained novice sonographers prospectively measured limb and diaphragm Muscle Thickness in 33 critically ill children. RESULTS: Expert and novice intrarater and interrater reliability were similar. Intraclass correlations (ICC) and coefficients of variation (CoV) were better in limbs (ICC > 0.9; CoV 3.57%-5.40%) than in diaphragm (ICC > 0.8; CoV novice 11.88%, expert, 12.28%). Mean relative difference in all Muscles was small (1%-8%). Limits of agreement of the relative difference were smaller in limb ( 13% in limb and >38% in diaphragm Muscles. The smaller detectable change in limb Muscles is likely due to their greater Thickness. Muscle Nerve 59:88-94, 2019.
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Reliability of Bedside Ultrasound of Limb and Diaphragm Muscle Thickness in Critically-ill Children
Muscle & Nerve, 2018Co-Authors: Kay W. P. Ng, Alexander R. Dietz, Ryan Johnson, Michael Shoykhet, Craig M. ZaidmanAbstract:Introduction: We evaluated the reliability of measuring Muscle Thickness with ultrasound in limbs and diaphragms of critically-ill children and determined the sensitivity of these measures to quantify Muscle atrophy over time.
Claire E Baldwin - One of the best experts on this subject based on the ideXlab platform.
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diaphragm and peripheral Muscle Thickness on ultrasound intra rater reliability and variability of a methodology using non standard recumbent positions
Respirology, 2011Co-Authors: Claire E Baldwin, Jenny Davida Paratz, Andrew D BerstenAbstract:Background and objective: Reliable measurement of diaphragm and peripheral Muscle Thickness, using diagnostic ultrasound, has only been validated in the erect posture. However, in many clinical populations, including critically ill patients, the erect posture presents logistic difficulties. This study aimed to validate ultrasound measurement of diaphragm and peripheral Muscle Thickness in the recumbent position. Methods: An observational methodology of repeated but blind ultrasound and anthropometric measurements was applied, to assess inta-rater reliability. Thirteen healthy volunteers (aged 20-73 years) participated. A pneumotachograph was used to target lung volume, as diaphragm Thickness was measured from ultrasound at end-expiration, and both 25% and 50% of inspiratory capacity, while semi-recumbent. The Thicknesses of the mid-upper arm, mid-forearm and mid-thigh musculature were also measured bilaterally while supine. Results: Diaphragm Thickness could be reliably measured at end-expiration (intra-class correlation coefficient (ICC) = 0.990, 95% confidence interval: 0.918-0.998), 25% of inspiratory capacity (ICC = 0.959 (0.870-0.988)) and 50% of inspiratory capacity (ICC = 0.994 (0.980-0.998)). Peripheral Muscle Thickness measurements were also reliable (ICC = 0.998-1.0). Supine anthropometric measurements of limb segment lengths and girths were highly reproducible. Conclusions: This ultrasound technique has good reliability in recumbent positions, making it useful for application to clinical populations when the erect posture is not practical. Recumbent postures may affect the reliability of diaphragm and peripheral Muscle Thickness measured with ultrasound. While usually performed erect, patients may not tolerate this posture. We demonstrated that recumbent positions can be used to reliably measure diaphragm and peripheral Muscle Thickness, and that imaging sites can be accurately located supine.
Ravinder K Mittal - One of the best experts on this subject based on the ideXlab platform.
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prevalence of increased esophageal Muscle Thickness in patients with esophageal symptoms
The American Journal of Gastroenterology, 2007Co-Authors: Ibrahim Dogan, James L Puckett, Bikram S Padda, Ravinder K MittalAbstract:BACKGROUND: Patients with achalasia, diffuse esophageal spasm (DES), and nutcracker esophagus have a thicker muscularis propria than normal subjects. The goal of our study was to determine the prevalence of increased Muscle Thickness in a group of unselected patients referred to the esophageal function laboratory for evaluation of the symptoms. METHODS: We studied 40 normal subjects and 94 consecutive patients. Manometry and ultrasound images were recorded concurrently, using a special custom-built catheter. Esophageal Muscle Thickness and Muscle cross-sectional area were measured at 2 and 10 cm above the lower esophageal sphincter (LES). Patients were assigned manometric diagnosis and determination was made if they had increased Muscle Thickness and Muscle cross-sectional area. RESULTS: Nearly all patients with well-defined spastic motor disorders, i.e., achalasia, DES, and nutcracker esophagus, revealed (a) an increase in the Muscle Thickness/cross-sectional area, (b) increase in esophageal Muscle Thickness/cross-sectional area was also seen, albeit at a lower prevalence rate, in patients with less well-characterized manometric abnormalities, i.e., hypertensive LES, impaired LES relaxation, and ineffective esophageal motility, and (c) 24% of patients with esophageal symptoms but normal manometry were also found to have an increase in Muscle Thickness/cross-sectional area. Dysphagia was more likely, and heartburn less likely in patients with increased Muscle Thickness, but there were no differences in chest pain and regurgitation symptoms between the groups. CONCLUSION: We describe, for the first time, increased Muscle Thickness in patients with esophageal symptoms and normal manometry. We suggest that increased esophageal Muscle Thickness is likely to be an important marker of esophageal motor dysfunction.
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Relationship between esophageal Muscle Thickness and intraluminal pressure in patients with esophageal spasm
American Journal of Physiology-gastrointestinal and Liver Physiology, 2002Co-Authors: Nonko Pehlivanov, Ghassan S. Kassab, Cheryl Beaumont, Ravinder K MittalAbstract:We previously showed, in normal subjects, a positive correlation between the esophageal contraction amplitude and peak Muscle Thickness. The goal of this study was to determine the relationship between esophageal Muscle Thickness and contraction amplitude in patients with high-amplitude peristaltic and simultaneous contractions. Eleven patients with high-amplitude peristaltic contractions, 8 with diffuse esophageal spasm (DES), 7 with nonspecific (NS) motor disorder of the esophagus, and 10 normal subjects were studied using simultaneous pressure and ultrasound imaging. Pressure was recorded by manometry and ultrasound imaging with a high-frequency ultrasound probe catheter. Recordings were performed in the lower esophageal sphincter (LES) and at 2, 4, 6, 8, and 10 cm above the LES during resting state and swallow-induced contractions. Baseline esophageal Muscle was thicker in the distal, compared with the proximal esophagus both in normal subjects and patient groups. Patients with DES and nutcracker esophagus (NC) have a higher baseline Muscle Thickness compared with normal and NS patients. Correlation between the peak pressure and the peak Muscle Thickness was weaker in patients with NC and DES compared with normal subjects and patients with NS. Whereas normal subjects have good correlation between delta (difference between peak and baseline) Muscle Thickness and peak pressures, this relationship was absent in patients with NC and DES. Increase in contraction amplitude in patients with NC and DES was associated with an increase in baseline Thickness of esophageal muscularis propria. Increase in baseline Thickness was specific to patients with spastic motor disorders and was not seen in patients with NS.
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Relationship between esophageal Muscle Thickness and intraluminal pressure: an ultrasonographic study
American Journal of Physiology-gastrointestinal and Liver Physiology, 2001Co-Authors: Nonko Pehlivanov, James L Puckett, Ghassan S. Kassab, Ravinder K MittalAbstract:A number of studies show a close temporal relationship between the rate of change in Muscle Thickness as detected by high-frequency intraluminal ultrasonography (HFIUS) and intraluminal pressure measured by manometry. There is a marked variability in esophageal contraction amplitude from one swallow to another at a given level in the esophagus and along the length of the esophagus. Furthermore, peristaltic pressures are higher in the distal compared with the proximal esophagus. The goal of this study was to evaluate the relationship between the baseline and peak Muscle Thickness and the contraction amplitude during swallow-induced contractions along the length of the esophagus. Fifteen normal subjects were studied using simultaneous esophageal pressures and HFIUS or HFIUS alone. Recordings were made during baseline and standardized swallows in the lower esophageal sphincter (LES) and at 2, 4, 6, 8, and 10 cm above the LES. HFIUS images were digitized, and esophageal Muscle Thickness and peak contraction amplitudes were measured. In the resting state, Muscle Thickness is higher in the LES compared with the rest of the esophagus. Baseline Muscle Thickness is also significantly higher at 2 cm vs. 10 cm above the LES. In a given subject and among different subjects, there is a good relationship between peak Muscle Thickness and peak peristaltic pressures (r = 0.55) at all sites along the length of the esophagus. The positive correlation between pressure and Muscle Thickness implies that the mean circumferential wall stress is fairly uniform from one swallow to another, irrespective of the contraction amplitude.
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Asymmetry of lower esophageal sphincter pressure: is it related to the Muscle Thickness or its shape?
American Journal of Physiology-gastrointestinal and Liver Physiology, 1997Co-Authors: V. K. Parashar, Ravinder K MittalAbstract:Lower esophageal sphincter (LES) pressure shows axial and circumferential asymmetry, the reasons for which are not clear. Our aim was to determine whether the Muscle Thickness and shape of the LES were the reasons for the axial and circumferential asymmetry in the LES pressure. High-frequency, catheter-based intraluminal ultrasonography was performed to obtain images of the human LES and esophagus. Station pull-through manometry was performed to record the axial and circumferential asymmetry of LES pressure. Circular and longitudinal Muscle were thicker in the LES compared with in the esophagus. There was a close correlation between the axial asymmetry in LES pressure and circular Muscle Thickness. The Thickness of LES Muscle increased and decreased with an increase and decrease in the LES pressure, respectively. The circumferential asymmetry in resting LES pressure was related to the noncircular shape of the LES. A swallow-induced LES relaxation was followed by its contraction. During the contraction phase, the LES and esophagus showed relative symmetry in pressure and shape. We conclude that the axial asymmetry of LES pressure is explained by its Muscle Thickness. On the other hand, circumferential asymmetry is related to the noncircular shape of the LES.
