scholarly journals Accuracy of the BoMED NCCOM3 Bioimpedance Cardiac Output Monitor during Induced Hypotension: An Experimental Study in Dogs

1992 ◽  
Vol 20 (3) ◽  
pp. 326-331 ◽  
Author(s):  
J. Tibballs ◽  
M. Hochmann ◽  
A. Osborne ◽  
B. Carter
Keyword(s):  
Cardiac Output ◽  
Resting State ◽  
Cardiac Cycle ◽  
Mean Difference ◽  
The Other ◽  
Limits Of Agreement ◽  
Induced Hypotension ◽  
Electrical Bioimpedance ◽  
The Mean ◽  
Cardiac Output Monitor

Changes in thoracic electrical bioimpedance during the cardiac cycle are utilised by the BoMed NCCOM3 monitor to measure cardiac output (COTEB). The technique provides a continuous noninvasive measurement but it has not been widely accepted. To determine the accuracy of the monitor, we compared its measurement with cardiac output measured by dye dilution (COdd) during induced hypotension and recovery in 23 dogs. After calibration of the NCCOM3 monitor during a resting state in each dog [mean blood pressure 112 ± 17 (SD), mean CODD 3.22 ± 0.99 l/min], the mean difference (COTEB-CODD) between paired measurements at the nadir of hypotension (bloodpressure 55 ± 24 mmHg) was 0.29 ± 0.47 l/min whose limits of agreement (mean difference ± 2 SD) were + 111.8% and -59.1% of the mean hypotensive COdd (110 ± 0.66 l/min). Upon recovery from hypotension (mean blood pressue 102 ± 20 mmHg), the mean difference between paired measurements was -0.28 ± 0.66 l/min, whose limits of agreement were +44.1% and -67.8% of the mean CODD (2.36 ± 1.01 l/min). The mean difference between the two techniques is too variable and excessive to permit substitution of one technique for the other. These results do not support the accuracy and reliability of the BoMed NCCOM3 cardiac output monitor.

scholarly journals A three minutes supine position test reveals higher risk of spinal anesthesia induced hypotension during cesarean delivery. An observational study.

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1028 ◽  
Author(s):  
Markos Erango ◽  
Arnoldo Frigessi ◽  
Leiv Arne Rosseland
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Observational Study ◽  
Pregnant Women ◽  
Spinal Anesthesia ◽  
Cesarean Delivery ◽  
Supine Position ◽  
The Other ◽  
Induced Hypotension ◽  
The Mean

Background: Cesarean delivery is performed under spinal anesthesia, and vasodilation is the main cause for a drop in blood pressure. The compression of the aorta and inferior vena cava by the gravid uterus is of additional clinical importance. Hypotension may occur during cesarean delivery even if prophylactic infusion of phenylephrine is practiced. We have tested if a 3 minute supine observation, can identify a subset of women with decreasing systolic arterial pressure (SAP) under spinal anesthesia. Methods: We performed a prospective observational study at Oslo University Hospital on healthy pregnant women for planned cesarean delivery. Continuous measurements of calibrated invasive SAP and estimated cardiac output were recorded for 76 women in a 3 minutes measurement with the woman in the left lateral position, followed by supine position for 3 minutes. Using functional data clustering, principal component analysis and curve smoothing, to filter way noise and reduce the dimensionality of the signal, we clustered the women into separate SAP groups.   Results: We identified two significantly different groups of women during supine position; one characterized by initial drop in SAP, the other showed initial increase. After spinal anesthesia, the mean SAP curve of the women in the first group showed a drop in blood pressure, which was more rapid than for the other women. A minor difference in cardiac output was observed between the two groups of women with the mean cardiac output curve for the first group being higher. Conclusions: This work indicates that supine position affect clinically relevant cardiovascular measurements in pregnant women. A simple test may identify patients with increased risk of spinal anesthesia induced hypotension.

scholarly journals Corneal Biomechanical Parameters and Central Corneal Thickness in Glaucoma Patients, Glaucoma Suspects, and a Healthy Population

2021 ◽  
Vol 10 (12) ◽  
pp. 2637
Author(s):  
Mª. Ángeles del Buey-Sayas ◽  
Elena Lanchares-Sancho ◽  
Pilar Campins-Falcó ◽  
María Dolores Pinazo-Durán ◽  
Cristina Peris-Martínez
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Mean Difference ◽  
The Other ◽  
Control Group ◽  
Healthy Population ◽  
Diagnostic Categories ◽  
Significant Difference ◽  
Biomechanical Parameters ◽  
The Mean

Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group.

scholarly journals Evaluation of Inter-System Variability in Liver Stiffness Measurements

2018 ◽  
Vol 40 (01) ◽  
pp. 64-75 ◽  
Author(s):  
Giovanna Ferraioli ◽  
Annalisa De Silvestri ◽  
Raffaella Lissandrin ◽  
Laura Maiocchi ◽  
Carmine Tinelli ◽  
...  
Keyword(s):  
Shear Wave ◽  
Liver Stiffness ◽  
Shear Wave Elastography ◽  
Mean Difference ◽  
Observer Agreement ◽  
Concordance Correlation ◽  
Limits Of Agreement ◽  
Inter Observer Variability ◽  
System Variability ◽  
The Mean

Abstract Aim The primary aim of this study was to determine the inter-system variability of liver stiffness measurements (LSMs) in patients with varying degrees of liver stiffness. The secondary aim was to determine the inter-observer variability of measurements. Materials and Methods 21 individuals affected by chronic hepatitis C and 5 healthy individuals were prospectively enrolled. The assessment of LSMs was performed using six ultrasound (US) systems, four of which with point shear wave elastography (p-SWE) and two with 2 D shear wave elastography (2D-SWE) systems. The Fibroscan (Echosens, France) was used as the reference standard. Four observers performed the measurements in pairs (A-B, C-D). The agreement between different observers or methods was calculated using Lin’s concordance correlation coefficient. The Bland-Altman limits of agreement (LOA) were calculated as well. Results There was agreement above 0.80 for all pairs of systems. The mean difference between the values of the systems with 2D-SWE technique was 1.54 kPa, whereas the maximum mean difference between the values of three out of four systems with the pSWE technique was 0.79 kPa. The intra-patient concordance for all systems was 0.89 (95 % CI: 0.83 – 0.94). Inter-observer agreement was 0.96 (95 % CI: 0.94 – 0.98) for the pair of observers A-B and 0.93 (95 % CI: 0.89 – 0.96) for the pair of observers C-D. Conclusion The results of this study show that the agreement between LSMs performed with different US systems is good to excellent and the overall inter-observer agreement in “ideal conditions” is above 0.90 in expert hands.

Biochemical Aspects and Clinical Perspectives of Continuous Urea Monitoring in Plasma Ultrafiltrate: Preliminary Results of a Multicenter Study

1995 ◽  
Vol 18 (9) ◽  
pp. 544-547 ◽  
Author(s):  
G. Colasanti ◽  
G. Arrigo ◽  
A. Santoro ◽  
S. Mandolfo ◽  
C. Tetta ◽  
...  
Keyword(s):  
Laboratory Method ◽  
Mean Difference ◽  
Limits Of Agreement ◽  
Laboratory Plasma ◽  
Plasma Urea ◽  
Urea Kinetics ◽  
On Line ◽  
The Mean ◽  
Plasma Urea Concentration

We tested a new biosensor for urea monitoring in the ultrafiltrate during PFD in a group of 5 hemodialyzed stable patients. The inspection of the UF-urea profile reflects the dynamical changes of the plasma urea concentration during diffusive dialysis and allows the fitting of the main mathematical models of urea kinetics. The biosensor efficiency was 98.4% on average (SD: 1.5%) at Uf fluxes varying from 45 to 55 ml/min (mean: 51 ml/min; SD: 3.2) and at Uf-urea concentrations varying from 23 to 165 mg/dl. The mean difference between Uf-urea determined by the laboratory method and Uf-urea assayed by the biosensor was -1.07 mg/dl and the 95% confidence interval ranged from -2.01 to 0.13 mg/dl. The mean difference between laboratory plasma urea and Uf-urea from the biosensor was on average -1.9 mg/dl and the estimated limits of agreement with a confidence of 95% were -3.16 and 0.64 mg/dl. Comparison between kinetic models and experimental profiles of plasma urea decrease, evaluations of recirculation and post-dialytic rebound, the role of Kt/V on-line during dialysis were the preliminary clinical applications of this biosensor.

Development of Blue-Yellow and Red-Green Discriminations in Infants during the First Year of Life

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 235-235
Author(s):  
L I Leushina ◽  
V M Bondarko ◽  
A A Nevskaya
Keyword(s):  
Healthy Subjects ◽  
Risk Group ◽  
Emotional Reaction ◽  
Mean Difference ◽  
The Other ◽  
First Year ◽  
Colour Discrimination ◽  
The Subject ◽  
The Mean ◽  
First Year Of Life

Colour discrimination was investigated in infants aged 4 – 14 months. 250 healthy subjects and 80 subjects with slight defects in basic visual functions (the risk group) participated. A coloured toy was moved in front of the subject and disappeared behind a screen, reappearing after 2 – 3 s at the other side. Sometimes when the toy was hidden, the experimenter replaced it with another one that differed only in colour: yellow was replaced by blue or vice versa (Y/B switch), or red by green or vice versa (R/G switch). The form and size of the toy remained constant. The emotional reaction of surprise showed whether the infant discriminated these colour pairs. The brightness of the stimuli was slightly varied make sure that the infant reacted to the change in colour rather than brightness. About 75% of healthy 4 – 5-month-olds showed good expressive reactions to the Y/B switch, and practically all children did so at 7 – 8 months. The discrimination of red and green develops more slowly: only at 12 months did practically all children show good reactions to the R/G switch. In all children, Y/B discrimination preceded R/G discrimination. The mean difference between the numbers of children discriminating these two pairs was 7.6%. The infants of the risk group were as good as their healthy age-mates in Y/B discrimination, but performed significantly less well on R/G: the mean difference between the numbers discriminating the former but not the latter was 17.0%. Possible reasons for the retardation of chromatic discrimination in the risk group are discussed.

Convergent validation of a questionnaire to assess the mode and frequency of commuting to and from school

2017 ◽  
Vol 45 (6) ◽  
pp. 612-620 ◽  
Author(s):  
Palma Chillón ◽  
Manuel Herrador-Colmenero ◽  
Jairo H. Migueles ◽  
Verónica Cabanas-Sánchez ◽  
Jorge R. Fernández-Santos ◽  
...  
Keyword(s):  
Physical Activity ◽  
Convergent Validity ◽  
Vigorous Physical Activity ◽  
Mean Difference ◽  
Activity Levels ◽  
Limits Of Agreement ◽  
Google Maps ◽  
Journey Time ◽  
The Mean ◽  
Convergent Validation

Aims: The purposes of this research were to study the convergent validity of the Mode and Frequency of Commuting To and From School Questionnaire using objectively assessed steps and time spent in different physical activity intensities and to compare the self-reported versus objective journey time in Spanish youths. Methods: Three hundred and eighty-nine Spanish youth aged 7–19 years were asked to complete the questionnaire and wore an accelerometer for five days. The objective commuting distance and time from home to school were estimated using Google MapsTM. Results: There were significant differences between passive and walking participants on step numbers, sedentary time and physical activity levels (except for vigorous physical activity in children). For children, a mean difference of −4.03 minutes between objective measured and self-reported journey time was found (95% limits of agreement were 13.55 and −21.60 minutes). For adolescents, the mean difference was −1.39 minutes (95% limits of agreement were 15.23 and −18.02 minutes). Conclusions: The findings indicated that the Mode of Commuting To and From School Questionnaire showed a convergent validity to assess this behaviour in Spanish youths. Self-reported journey time for walking is comparable to Google MapsTM in adolescents but not in children.

scholarly journals Resting energy expenditure measured longitudinally following hip fracture compared to predictive equations: is an injury adjustment required?

2005 ◽  
Vol 94 (6) ◽  
pp. 976-982 ◽  
Author(s):  
Michelle D. Miller ◽  
Lynne A. Daniels ◽  
Elaine Bannerman ◽  
Maria Crotty
Keyword(s):  
Hip Fracture ◽  
Energy Expenditure ◽  
Total Energy ◽  
Physiological Stress ◽  
Resting Energy Expenditure ◽  
Mean Difference ◽  
Limits Of Agreement ◽  
Predictive Equations ◽  
The Mean ◽  
Resting Energy

The present study measuring resting energy expenditure (REE; kJ/d) longitudinally using indirect calorimetry in six elderly women aged ≥70 years following surgery for hip fracture, describes changes over time (days 10, 42 and 84 post-injury) and compares measured values to those calculated from routinely applied predictive equations. REE was compared to REE predicted using the Harris Benedict and Schofield equations, with and without accounting for the theoretical increase in energy expenditure of 35 % secondary to physiological stress of injury and surgery. Mean (95 % CI) measured REE (kJ/d) was 4704 (4354, 5054), 4090 (3719, 4461) and 4145 (3908, 4382) for days 10, 42 and 84, respectively. A time effect was observed for measured REE,P=0·003. Without adjusting for stress the mean difference and 95 % limits of agreement for measured and predicted REE (kJ/kg per d) for the Harris Benedict equation were 1 (−9, 12), 10 (2, 18) and 9 (1, 17) for days 10, 42 and 84, respectively. The mean difference and 95 % limits of agreement for measured and predicted REE (kJ/kg per d) for the Schofield equation without adjusting for stress were 8 (−3, 19), 16 (6, 26) and 16 (10, 22) for days 10, 42 and 84, respectively. After adjusting for stress, REE predicted from the Harris Benedict or Schofield equations overestimated measured REE by between 38 and 69 %. Energy expenditure following fracture is poorly understood. Our data suggest REE was relatively elevated early in recovery but declined during the first 6 weeks. Using the Harris Benedict or Schofield equations adjusted for stress may lead to overestimation of REE in the clinical setting. Further work is required to evaluate total energy expenditure before recommendations can be made to alter current practice for calculating theoretical total energy requirements of hip fracture patients.

Inter- and intra-operator variability associated with extracapsular suture tensioning

2012 ◽  
Vol 25 (06) ◽  
pp. 472-477 ◽  
Author(s):  
E. A. Buffa ◽  
A. M. Marchevsky ◽  
J. Heller ◽  
A. P. Moores ◽  
M. Farrell ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Cruciate Ligament ◽  
Mean Difference ◽  
Marked Variation ◽  
Limits Of Agreement ◽  
Cranial Cruciate Ligament ◽  
Suture Tension ◽  
Clinical Consequences ◽  
The Mean ◽  
The Difference

SummaryObjectives: To determine inter- and intra- operator variability associated with extracapsular suture tensioning as performed during lateral fabello-tibial suture placement.Study design: Ex vivo study.Methods: Fifteen Greyhound cadaveric pelvic limbs were prepared by cutting the cranial cruciate ligament and placing an extracapsular fabello-tibial suture. On two occasions, three surgeons tensioned the extracapsular suture of each stifle. Stifles were returned to 135 degrees of flexion and the suture tension was measured using a commercially available suture tensioner with inbuilt tensiometer.Statistical analysis: Intra-operator and inter-operator agreement were assessed using the limits of agreement method. A linear mixed effects model was specified to assess the effect of operator, repeated estimates and stifle order on tension applied.Results: The mean difference within the three operators ranged from 0 to 14.7N. With 95% limits of agreement, on most occasions for all three operators, the difference was between –31.7 and 41.0 N. The mean difference between the three operators ranged from 6.0 to 30.7 N. With 95% limits of agreement, on most occasions the difference between operators was between –25.6 and 62.5 N.Clinical significance: Marked variation exists in the tension applied during fabello- tibial suture application, both within and between surgeons. This variation may lead to inconsistent clinical outcomes. Further studies are required to determine the clinical consequences of this marked variation in extracapsular suture tensioning.

scholarly journals Comparison of Two Techniques of Superior Vena Cava Flow Measurement in Preterm Infants With Birth Weight <1,250 g in the Transitional Period—Prospective Observational Cohort Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Jan Miletin ◽  
Zbynek Stranak ◽  
Niamh Ó Catháin ◽  
Jan Janota ◽  
Jana Semberova
Keyword(s):  
Birth Weight ◽  
Flow Measurement ◽  
Superior Vena ◽  
Vena Cava ◽  
Observational Cohort Study ◽  
Mean Difference ◽  
Prospective Observational Cohort Study ◽  
Limits Of Agreement ◽  
Observational Cohort ◽  
The Mean

Objectives: Superior Vena Cava (SVC) flow in neonates measured by the standard approach has been validated by different groups around the world. The modified SVC flow measurement technique was recently suggested. The aim of our study was to evaluate standard and modified technique of echocardiography SVC flow measurement in a cohort of extremely preterm neonates in the immediate postnatal period.Methods: Prospective, observational cohort study in a level III neonatal center. Infants with birth weight &lt;1,250 g were eligible for enrolment. SVC flow was measured by echocardiography using standard and modified methods at 6, 18 and 36 h of age. Our primary outcome was equivalency (using raw bounds of −20 to +20 mL/kg/min difference between the paired measurements), agreement and correlation between standard and modified methods of the SVC flow measurements.Results: Thirty-nine infants were enrolled. The mean gestational age of the cohort was 27.4 (SD 2.1) weeks of postmenstrual age, the mean birth weight was 0.95 kg (SD 0.2). The measurements at 6 and 36 h of age were equivalent as defined in the design of the study (p = 0.003 and p = 0.004 respectively; raw bounds −20 to +20 mL/kg/min). At 6 h of age the mean difference (bias) between the measurements was −0.8 mL/kg/min with 95% limits of agreement −65.0 to 63.4 mL/kg/min. At 18 h of age, the mean difference (bias) between the measurements was +9.5 mL/kg/min, with 95% limits of agreement −79.6 to 98.7 mL/kg/min. At 36 h of age the mean difference (bias) between the measurements was −2.2 mL/kg/min with 95% limits of agreement −73.4 to 69.1 mL/kg/min. There was a weak, but statistically significant correlation between the standard and modified method at 6 h of age (r = 0.39, p = 0.04).Conclusion: Both SVC flow echocardiography measurement techniques yielded clinically equivalent results, however due to wide limits of agreement and poor correlation they do not seem to be interchangeable.

Effect of Pure and Crossed Dextrality on Marksmanship Skill

1985 ◽  
Vol 61 (3_suppl) ◽  
pp. 1171-1174 ◽  
Author(s):  
Thomas J. Sheeran
Keyword(s):  
Mean Difference ◽  
The Other ◽  
Advanced Training ◽  
Training Camp ◽  
Right Hand ◽  
The Mean ◽  
Score Range ◽  
Training Corps ◽  
Reserve Officers Training Corps

This research examined the effects of pure and crossed dextrality on the marksmanship scores of cadets in the Reserve Officers Training Corps at their respective institutions. 34 male, right-handed (dextral) subjects (M age = 21.5 yr.) were classified on the basis of eyedness. During summer advanced training camp, subjects fired M-16A1 rifles for marksmanship qualifying scores (score range 0 to 40). Of the 34 subjects, 17 were classified as pure dextrals (right-hand, right-eye), while the other 17 were labeled crossed dextrals (right-hand, left-eye). The mean difference between the two groups was significant, suggesting that pure dextrals are better marksmen than crossed dextrals early in training. Also, the interrelation of eyedness and handedness on marksmanship scores is important but has been largely ignored.

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