Morphologic Changes in the Upper Airway of Children during Awakening from Propofol Administration

Background The purpose of this study was to determine the morphologic changes that occur in the upper airway of children during awakening from propofol sedation. Methods Children undergoing magnetic resonance imaging of the head underwent additional scans of the upper airway during deep sedation with propofol; this was repeated on awakening. Axial views were obtained at the most posterior sites of the pharynx at the levels of the soft palate and tongue. Measurements were then obtained of the anterior-posterior (A-P) diameter, transverse diameter, and cross-sectional areas at these levels. Results Data were obtained on 16 children, aged 10 months to 7 yr. In both sedated and awakening states, most children had the smallest cross-sectional area of the pharynx at the level of the soft palate. During the sedated state, at the soft palate level, the transverse diameter was most narrow in 11 children, the A-P diameter was most narrow in 1 child, and they were equal in 2 children. During the sedated state, at the level of the tongue, the transverse diameter was most narrow in 9 children, the A-P diameter was most narrow in 5 children, and they were equal in 2 children. During awakening, at the soft palate level, the transverse diameter was most narrow in none of the children, the A-P diameter was most narrow in 13 children, and they were equal in 1 child. At the level of the tongue, the transverse diameter was most narrow in 4 children, and the A-P diameter was most narrow in 12 children. During awakening, the A-P diameter of the pharynx at the level of the soft palate decreased in 12 children, increased in 1 child, and remained the same in 1 child. (P < 0.001). The transverse diameter increased in 11 children, decreased in 1 child, and remained the same in 2 children (P = 0.001). The cross-sectional area at the level of the soft palate increased in 4 children, decreased in 8 children, and stayed the same in 2 children (P = 0.5). During awakening, the A-P diameter of the pharynx at the level of the tongue decreased in 11 children, increased in 4 children, and remained the same in 1 child. (P = 0.01). The transverse diameter increased in 11 children and decreased in 5 children (P = 0.07). The cross-sectional area at the level of the tongue increased in 7 children, decreased in 7 children, and stayed the same in 2 children (P = 0.9). Conclusions The dimensions of the upper airways of children change shape significantly on awakening from propofol sedation. When sedated, the upper airway is oblong shaped, with the A-P diameter larger than the transverse diameter. On awakening, the shape of the upper airway in most children changed such that the transverse diameter was larger. Cross-sectional areas between sedated and awakening states were unchanged. These changes may reflect the differential effects of propofol on upper airway musculature during awakening.

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A Simple Endoscopic Technique for Measuring the Cross-Sectional Area of the Upper Airway in a Rabbit Model

Annals of Otology Rhinology & Laryngology ◽

10.1177/0003489418759361 ◽

2018 ◽

Vol 127 (4) ◽

pp. 275-281 ◽

Cited By ~ 3

Author(s):

Paul R. Wistermayer ◽

Wesley R. McIlwain ◽

Nicholas Ieronimakis ◽

Derek J. Rogers

Keyword(s):

Rabbit Model ◽

Upper Airway ◽

Cross Sectional Area ◽

Endoscopic Technique ◽

Sectional Area ◽

Cross Sectional ◽

The Cross

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Effect of Increasing Depth of Propofol Anesthesia on Upper Airway Configuration in Children

Anesthesiology ◽

10.1097/00000542-200309000-00014 ◽

2003 ◽

Vol 99 (3) ◽

pp. 596-602 ◽

Cited By ~ 66

Author(s):

Russell G. Evans ◽

Mark W. Crawford ◽

Michael D. Noseworthy ◽

Shi-Joon Yoo

Keyword(s):

Confidence Interval ◽

Soft Palate ◽

Upper Airway ◽

Magnetic Resonance Images ◽

Cross Sectional Area ◽

Depth Of Anesthesia ◽

Sectional Area ◽

Cross Sectional ◽

Airway Narrowing ◽

Pharyngeal Airway

Background The upper airway tends to be obstructed during anesthesia in spontaneously breathing patients. The purpose of the current study was to determine the effect of increasing depth of propofol anesthesia on airway size and configuration in children. Methods Magnetic resonance images of the upper airway were obtained in 15 children, aged 2-6 yr. Cross-sectional area, anteroposterior dimension, and transverse dimension were measured at the level of the soft palate, dorsum of the tongue, and tip of the epiglottis. Images were obtained during infusion of propofol at a rate of 50-80 microg.kg-1.min-1 and after increasing the depth of anesthesia by administering a bolus dose of propofol and increasing the infusion rate to 240 microg.kg-1.min-1. Results Overall, the cross-sectional area of the entire pharyngeal airway decreased with increasing depth of anesthesia. The reduction in cross-sectional area was greatest at the level of the epiglottis (24.5 mm2, 95% confidence interval = 16.9-32.2 mm2; P < 0.0001), intermediate at the level of the tongue (19.3 mm2, 95% confidence interval = 9.2-29.3 mm2; P < 0.0001), and least at the level of the soft palate (12.6 mm2, 95% confidence interval = 2.7-22.6 mm2; P < 0.005) in expiration and resulted predominantly from a reduction in anteroposterior dimension. The airway cross-sectional area decreased further in inspiration at the level of the epiglottis. The narrowest portion of the airway resided at the level of the soft palate or epiglottis in the majority of children. Conclusion Increasing depth of propofol anesthesia in children is associated with upper airway narrowing that occurs throughout the entire upper airway and is most pronounced in the hypopharynx at the level of the epiglottis.

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Comparison Between Mathematical and Software Calculation Methods for the Measurement of the Cross-sectional Area in Upper Airway Imaging

Cureus ◽

10.7759/cureus.6106 ◽

2019 ◽

Author(s):

Yousef Aljathlany ◽

Kholoud Alamari ◽

Abdullah Aljasser ◽

Abdullah Alhelali ◽

Manal Bukhari ◽

...

Keyword(s):

Upper Airway ◽

Cross Sectional Area ◽

Sectional Area ◽

Calculation Methods ◽

Cross Sectional ◽

The Cross

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Impact of positive end expiratory pressure on left internal jugular vein size

Journal of Kathmandu Medical College ◽

10.3126/jkmc.v7i1.20623 ◽

2018 ◽

Vol 7 (1) ◽

pp. 12-17

Author(s):

Mona Sharma ◽

Babu Raja Shrestha ◽

Sushila Lama Moktan ◽

Manan Karki

Keyword(s):

Internal Jugular Vein ◽

Jugular Vein ◽

Cross Sectional Area ◽

P Value ◽

Transverse Diameter ◽

Sectional Area ◽

Left Internal Jugular Vein ◽

Positive End Expiratory Pressure ◽

Cross Sectional ◽

The Cross

Background: Increasing the cross sectional area (CSA) of the left internal jugular vein facilitates cannulation and decreases complications. But, the literature is sparse regarding the methods to increase the cross sectional area of the left internal jugular vein.Objective: To assess the changes that occur in cross sectional area of left internal jugular vein after application of different levels of positive end expiratory pressure and compare the findings with right internal jugular vein.Methodology: Sixty-four patients were included. Antero posterior diameter, transverse diameter and cross sectional area of left and right internal jugular vein was measured using two-dimensional ultrasound before the induction of anesthesia and after intubation at positive end expiratory pressure of 0, 5, 10 and 15 cm H2O. Result: The increase in positive end expiratory pressure was associated with increase in cross sectional area, anteroposterior and transverse diameter of left internal jugular vein. At 10 cmH2 Opositive end expiratory pressure, left internal jugular vein cross sectional area increased significantly by 22.8% that is 1.34±0.53cm2(P value< 0.05). The right internal jugular vein is significantly larger than left at baseline and at all levels of studied positive end expiratory pressure. The percentage increase of cross sectional area for both internal jugular veins was similar.Conclusion: The left internal jugular vein cross sectional area increment has direct relationship with increment of positive end expiratory levels at studied points. However, above 10 cm H2O of positive end expiratory pressure, there was only non significant increase (P value > 0.05).

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A retrospective study: does upper airway morphology differ between non-positional and positional obstructive sleep apnea?

PeerJ ◽

10.7717/peerj.3918 ◽

2017 ◽

Vol 5 ◽

pp. e3918 ◽

Cited By ~ 1

Author(s):

Xiao Jiao ◽

Jianyin Zou ◽

Suru Liu ◽

Jian Guan ◽

Hongliang Yi ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Retrospective Study ◽

Sleep Apnea ◽

Soft Palate ◽

Upper Airway ◽

Cross Sectional Area ◽

Sectional Area ◽

Cross Sectional ◽

Obstructive Sleep ◽

Airway Morphology

Objective The objective of this study was to explore the differences in upper airway morphology between positional (POSA) and non-positional (NPOSA) obstructive sleep apnea. Methods This retrospective study enrolled 75 patients (45 NPOSA and 30 POSA) who underwent polysomnography (PSG) and computed tomography (CT). The differences in, and relationships of, the PSG values and CT data between POSA and NPOSA were analyzed. Results Significant (p < 0.05) differences between the two groups were found in the apnea/hypopnea index (AHI), lateral-AHI (L-AHI), soft palate length (SPL), cross-sectional palatopharyngeal area, and the coronal diameter (CD) of the palatopharyngeal area at the narrowest part of the glossopharynx, which were all higher in POSA, except for SPL, AHI, and L-AHI. L-AHI was correlated with the cross-sectional area (r = − 0.306, p = 0.008) and CD (r = − 0.398, p < 0.001) of the palatopharyngeal area, the cross-sectional area (r = − 0.241, p = 0.038) and CD (r = − 0.297, p = 0.010) of the narrowest level of the glossopharynx, the CD of the glossopharynx (r = 0.284, p = 0.013), body mass index (BMI, r = 0.273, p = 0.018), SPL (r = 0.284, p = 0.014), and vallecula-tip of tongue (r = 0.250, p = 0.030). The SPL and CD at the narrowest part of the glossopharynx were included in the simplified screening model. Conclusions In NPOSA, the CD of the upper airway was smaller, and the soft palate was longer, than in POSA. These differences may play significant roles in explaining the main differences between NPOSA and POSA.

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Atrophy patterns in isolated subscapularis lesions

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04241-5 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Gernot Seppel ◽

Andreas Voss ◽

Daniel J. H. Henderson ◽

Simone Waldt ◽

Bernhard Haller ◽

...

Keyword(s):

Muscle Atrophy ◽

Area Ratio ◽

Cross Sectional Area ◽

Control Group ◽

Sectional Area ◽

Cross Sectional ◽

Subscapularis Muscle ◽

Mri Scans ◽

The Mean ◽

The Cross

Abstract Background While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. Methods Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. Results The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). Conclusion Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

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The area of eye muscle of beef cattle carcasses

Australian Journal of Experimental Agriculture ◽

10.1071/ea9630249 ◽

1963 ◽

Vol 3 (10) ◽

pp. 249

Author(s):

RM Seebeck

Keyword(s):

Beef Cattle ◽

Cross Sectional Area ◽

Carcass Weight ◽

Sectional Area ◽

Muscle Area ◽

Cross Sectional ◽

Eye Muscle ◽

Angus Cattle ◽

The Cross

Variations in the cross-sectional area of eye muscle of carcasses cut between the tenth and eleventh ribs were investigated, using 105 Hereford and 51 Angus steers aged 20 months. These cattle consisted of three groups, born in successive years. At constant carcass weight, statistically significant differences in eye muscle area were found between breeds and between years. Breed and year differences were also found in eye muscle area with width and depth of eye muscle constant, so that there are limitations to the estimation of eye muscle area from width and depth measurements. A nomograph is given for estimating eye muscle area from width and depth for Hereford and Angus cattle, when all animals are reared in the same year and environment. The use of eye muscle area as an indicator of weight of carcass muscle is discussed.

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Comparison of the Cross Sectional Area, the Loss in Volume and the Mechanical Properties of LAE442 and MgCa0.8 as Resorbable Magnesium Alloy Implants after 12 Months Implantation Duration

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.675 ◽

2010 ◽

Vol 638-642 ◽

pp. 675-680 ◽

Cited By ~ 6

Author(s):

Martina Thomann ◽

Nina von der Höh ◽

Dirk Bormann ◽

Dina Rittershaus ◽

C. Krause ◽

...

Keyword(s):

Mechanical Properties ◽

Cross Sections ◽

Degradation Process ◽

Cross Sectional Area ◽

Bending Test ◽

Sectional Area ◽

Cross Sectional ◽

Initial Strength ◽

Three Point Bending ◽

The Cross

Current research focuses on magnesium based alloys in the course of searching a resorbable osteosynthetic material which provides sufficient mechanical properties besides a good biocompatibility. Previous studies reported on a favorable biocompatibility of the alloys LAE442 and MgCa0.8. The present study compared the degradation process of cylindrical LAE442 and MgCa0.8 implants after 12 months implantation duration. Therefore, 10 extruded implants (2.5 x 25 mm, cross sectional area 4.9 mm²) of both alloys were implanted into the medullary cavity of both tibiae of rabbits for 12 months. After euthanization, the right bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical) and nine uniformly distributed cross-sections of each implant were used to determine the residual implants´ cross sectional area (Software AxioVisionRelease 4.5, Zeiss). Left implants were taken out of the bone carefully. After weighing, a three-point bending test was carried out. LAE442 implants degraded obviously slower and more homogeneously than MgCa0.8. The mean residual cross sectional area of LAE442 implants was 4.7 ± 0.07 mm². MgCa0.8 showed an area of only 2.18 ± 1.03 mm². In contrast, the loss in volume of LAE442 pins was more obvious. They lost 64 % of their initial weight. The volume of MgCa0.8 reduced clearly to 54.4 % which corresponds to the cross sectional area results. Three point bending tests revealed that LAE442 showed a loss in strength of 71.2 % while MgCa0.8 lost 85.6 % of its initial strength. All results indicated that LAE442 implants degraded slowly, probably due to the formation of a very obvious degradation layer. Degradation of MgCa0.8 implants was far advanced.

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