scholarly journals The effect of body mass and sex on the accuracy of respiratory magnetometers for measurement of end-expiratory lung volumes

2016 ◽  
Vol 121 (5) ◽  
pp. 1169-1177 ◽  
Author(s):  
Joanne Avraam ◽  
Rosie Bourke ◽  
John Trinder ◽  
Christian L. Nicholas ◽  
Danny Brazzale ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Body Mass ◽  
Lung Volume ◽  
Normal Weight ◽  
Volume Changes ◽  
Obstructive Sleep ◽  
Target Volumes ◽  
Healthy Obese ◽  
Magnetometer Calibration ◽  
Calibration Techniques

Respiratory magnetometers are increasingly being used in sleep studies to measure changes in end-expiratory lung volume (EELV), including in obese obstructive sleep apnea patients. Despite this, the accuracy of magnetometers has not been confirmed in obese patients nor compared between sexes. Thus we compared spirometer-measured and magnetometer-estimated lung volume and tidal volume changes during voluntary end-expiratory lung volume changes of 1.5, 1, and 0.5 l above and 0.5 l below functional respiratory capacity in supine normal-weight [body mass index (BMI) < 25 kg/m] and healthy obese (BMI > 30 kg/m) men and women. Two different magnetometer calibration techniques proposed by Banzett et al. [Banzett RB, Mahan ST, Garner DM, Brughera A, Loring SH. J Appl Physiol (1985) 79: 2169–2176, 1995] and Sackner et al. [Sackner MA, Watson H, Belsito AS, Feinerman D, Suarez M, Gonzalez G, Bizousky F, Krieger B. J Appl Physiol (1985) 66: 410–420, 1989] were assessed. Across all groups and target volumes, magnetometers overestimated spirometer-measured EELV by ~65 ml (<0.001) with no difference between techniques (0.07). The Banzett method overestimated the spirometer EELV change in normal-weight women for all target volumes except +0.5 l, whereas no differences between mass or sex groups were observed for the Sackner technique. The variability of breath-to-breath measures of EELV was significantly higher for obese compared with nonobese subjects and was higher for the Sackner than Banzett technique. On the other hand, for tidal volume, both calibration techniques underestimated spirometer measurements (<0.001), with the underestimation being more marked for the Banzett than Sackner technique (0.03), in obese than normal weight (<0.001) and in men than in women (0.003). These results indicate that both body mass and sex affect the accuracy of respiratory magnetometers in measuring EELV and tidal volume.

Effect of changes in lung volume on respiratory system compliance in newborn infants

1989 ◽  
Vol 67 (3) ◽  
pp. 1192-1197 ◽  
Author(s):  
F. Ratjen ◽  
R. Zinman ◽  
A. R. Stark ◽  
L. E. Leszczynski ◽  
M. E. Wohl
Keyword(s):  
Tidal Volume ◽  
Respiratory System ◽  
Lung Volume ◽  
Newborn Infants ◽  
Face Mask ◽  
Flow Volume ◽  
Respiratory System Compliance ◽  
Tidal Breathing ◽  
Volume Changes ◽  
Passive Flow

Total respiratory system compliance (Crs) at volumes above the tidal volume (VT) was studied by use of the expiratory volume clamping (EVC) technique in 10 healthy sleeping unsedated newborn infants. Flow was measured with a pneumotachograph attached to a face mask and integrated to yield volume. Volume changes were confirmed by respiratory inductance plethysmography. Crs measured by EVC was compared with Crs during tidal breathing determined by the passive flow-volume (PFV) technique. Volume increases of approximately 75% VT were achieved with three to eight inspiratory efforts during expiratory occlusions. Crs above VT was consistently greater than during tidal breathing (P less than 0.0005). This increase in Crs likely reflects recruitment of lung units that are closed or atelectatic in the VT range. Within the VT range, Crs measured by PFV was compared with that obtained by the multiple-occlusion method (MO). PFV yielded greater values of Crs than MO (P less than 0.01). This may be due to braking of expiratory airflow after the release of an occlusion or nonlinearity of Crs. Thus both volume recruitment and airflow retardation may affect the measurement of Crs in unsedated newborn infants.

Regulation of frequency and depth of breathing during expiratory threshold loading in cats

1975 ◽  
Vol 38 (5) ◽  
pp. 869-874 ◽  
Author(s):  
M. M. Grunstein ◽  
I. Wyszogrodski ◽  
J. Milic-Emili
Keyword(s):  
Tidal Volume ◽  
Lung Volume ◽  
The Other ◽  
Spontaneous Ventilation ◽  
Volume Changes ◽  
Phasic Component ◽  
Stretch Receptors ◽  
Pulmonary Stretch Receptors ◽  
The Absolute ◽  
Spontaneously Breathing

In six spontaneously breathing anesthetized cats, intermittently subjected to inspiratory elastic loads, we have studied the relationships between tidal volume (VT) and the durations of inspiration (Ti) and breath duration (Ttot) obtained during spontaneous ventilation from resting lung volume (FRCc) and from elevated end-expiratory levels. The latter was elevated by submerging the expiratory breathing line into a column of water, representing the addition of an expiratory threshold load (ETL). The VT vs. Ti relationships obtained at different end-expiratory levels were similar, indicating that during ETL the vagal mechanism regulating Ti responds only to lung volume changes above the new end-expiratory level and is independent of the absolute end-expiratory lung volume. Single vagal fiber recordings suggest that this effect on Ti control may be explained on the basis of adaptation occurring at the level of the pulmonary stretch receptors. The control of Ttot, on the other hand, was found to depend both on the Ti of the preceding breath (phasic component) and on a separate vagal mechanism specifically affecting the duration of expiration (Te) in response to changes in the absolute end-expiratory lung volume. The latter mechanism is functionally inoperative at FRCc.

scholarly journals Obesity phenotypes and their adipocyte dysfunction among the attendants at outpatient department

2018 ◽  
Vol 11 (2) ◽  
pp. 112
Author(s):  
Sabikun Naher ◽  
M. Mozammel Hoque ◽  
Hasan Imam
Keyword(s):  
Metabolic Syndrome ◽  
Body Mass Index ◽  
Body Mass ◽  
Normal Weight ◽  
Outpatient Department ◽  
Adiponectin Concentration ◽  
Purposive Sampling ◽  
Metabolically Obese Normal Weight ◽  
Healthy Obese ◽  
Apparently Healthy

<p>The present study was aimed to find out the frequency of obesity phenotypes and to correlate adipocyte dysfunction with different obesity phenotypes. A total of 1,507 apparently healthy adults attending the outpatient department were grouped into three based on body mass index which were then further categorized into six groups according to metabolically unhealthy or healthy phenotypes by the presence or absence of metabolic syndrome. Of them, metabolically obese normal weight, overweight, healthy obese and unhealthy obese groups were included as obesity phenotypes. Then by purposive sampling, leptin and adiponectin concentration of 184 subjects with different phenotypes were measured to find out the adipocyte dysfunction. Metabolically obese overweight followed by metabolically unhealthy obese were more prevalent i,e.,  24.9% and 19.5%. All obesity phenotypes except metabolically obese normal weight were significantly documented with adipocyte dysfunction (p&lt;0.05).</p>

Effects of aging on sensation of respiratory force and displacement

1983 ◽  
Vol 55 (5) ◽  
pp. 1433-1440 ◽  
Author(s):  
M. Tack ◽  
M. D. Altose ◽  
N. S. Cherniack
Keyword(s):  
Tidal Volume ◽  
Lung Volume ◽  
Young Group ◽  
Magnitude Production ◽  
Volume Changes ◽  
Older Subjects ◽  
Young Subjects ◽  
Function Relationship ◽  
Effects Of Aging ◽  
Force Scaling

The psychophysical technique of magnitude production was used to evaluate the sensation of inspiratory force and inspired volume in young and older subjects. Inspiratory force was generated during a static inspiratory maneuver against a closed airway. The exponent of the power function relationship between airway pressure and sensation intensity during force scaling was not significantly different between young and older subjects. In contrast, the exponents for the magnitude production of inspired volume were significantly greater in the older compared with the young group. We also assessed the effects of age on the relative importance of force and displacement signals on the sensation of inspired volume. Subjects attempted to reproduce a control tidal volume while breathing against a series of inspiratory resistive and elastic loads. In both groups error in tidal volume reproduction increased progressively as the severity of the load increased. During moderate and severe loading the error in the older subjects was significantly greater than in the young group. Correspondingly, the peak inspiratory airway pressures at tidal volume reproduction against these loads were significantly smaller in the older compared with the young subjects. The results suggest that in older subjects cues related to respiratory muscle force are more important than volume in the sensation of lung volume changes. In young subjects the sensation of lung volume changes is based to a greater degree on signals of volume or displacement.

scholarly journals The influence of end-expiratory lung volume on measurements of pharyngeal collapsibility

2010 ◽  
Vol 108 (2) ◽  
pp. 445-451 ◽  
Author(s):  
Robert L. Owens ◽  
Atul Malhotra ◽  
Danny J. Eckert ◽  
David P. White ◽  
Amy S. Jordan
Keyword(s):  
Lung Volume ◽  
Airway Pressure ◽  
Upper Airway ◽  
Similar Amount ◽  
Volume Changes ◽  
Pressure Drops ◽  
Control Subjects ◽  
Obstructive Sleep ◽  
Upper Airway Collapsibility ◽  
And Control

Changes in end-expiratory lung volume (EELV) affect upper airway stability. The passive pharyngeal critical pressure (Pcrit), a measure of upper airway collapsibility, is determined using airway pressure drops. The EELV change during these drops has not been quantified and may differ between obese obstructive sleep apnea (OSA) patients and controls. Continuous positive airway pressure (CPAP)-treated OSA patients and controls were instrumented with an epiglottic catheter, magnetometers (to measure change in EELV), and a nasal mask/pneumotachograph. Subjects slept supine in a head-out plastic chamber in which the extrathoracic pressure could be lowered (to raise EELV) while on nasal CPAP. The magnitude of EELV change during Pcrit measurement (sudden reductions of CPAP for 3–5 breaths each minute) was assessed at baseline and with EELV increased ∼500 ml. Fifteen OSA patients and 7 controls were studied. EELV change during Pcrit measurement was rapid and pressure dependent, but similar in OSA and control subjects (74 ± 36 and 59 ± 24 ml/cmH2O respectively, P = 0.33). Increased lung volume (mean +521 ml) decreased Pcrit by a similar amount in OSA and control subjects (−3.1 ± 1.7 vs. −3.9 ± 1.9 cmH2O, P = 0.31). Important lung volume changes occur during passive Pcrit measurement. However, on average, there is no difference in lung volume change for a given CPAP change between obese OSA subjects and controls. Changes in lung volume alter Pcrit substantially. This work supports a role for lung volume in the pathogenesis of OSA, and lung volume changes should be a consideration during assessment of pharyngeal mechanics.

EFFECT OF BODY MASS INDEX ON PEAK EXPIRATORY FLOW RATE

2019 ◽  
Vol 3 (9) ◽  
Author(s):  
K. Subramanyam ◽  
Dr. P. Subhash Babu
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Peak Expiratory Flow ◽  
Flow Rate ◽  
Peak Expiratory Flow Rate ◽  
Normal Weight ◽  
The Body ◽  
Health Care Centre ◽  
Expiratory Flow ◽  
Group B

Obesity has become one of the major health issues in India. WHO defines obesity as “A condition with excessive fat accumulation in the body to the extent that the health and wellbeing are adversely affected”. Obesity results from a complex interaction of genetic, behavioral, environmental and socioeconomic factors causing an imbalance in energy production and expenditure. Peak expiratory flow rate is the maximum rate of airflow that can be generated during forced expiratory manoeuvre starting from total lung capacity. The simplicity of the method is its main advantage. It is measured by using a standard Wright Peak Flow Meter or mini Wright Meter. The aim of the study is to see the effect of body mass index on Peak Expiratory Flow Rate values in young adults. The place of a study was done tertiary health care centre, in India for the period of 6 months. Study was performed on 80 subjects age group 20 -30 years, categorised as normal weight BMI =18.5 -24.99 kg/m2 and overweight BMI =25-29.99 kg/m2. There were 40 normal weight BMI (Group A) and 40 over weight BMI (Group B). BMI affects PEFR. Increase in BMI decreases PEFR. Early identification of risk individuals prior to the onset of disease is imperative in our developing country. Keywords: BMI, PEFR.

Body Mass Index Impact on Disease Activity, Clinical and Sonographic Remission Rates in Patients with Rheumatoid Arthritis

2019 ◽  
Vol 15 (3) ◽  
pp. 215-223
Author(s):  
Tanya Sapundzhieva ◽  
Rositsa Karalilova ◽  
Anastas Batalov
Keyword(s):  
Rheumatoid Arthritis ◽  
Body Mass Index ◽  
Disease Activity ◽  
Body Mass ◽  
Normal Weight ◽  
Clinical Disease ◽  
Clinical Disease Activity ◽  
Das 28 ◽  
Remission Rates ◽  
Activity Indices

Aim: To investigate the impact of body mass index (BMI) on clinical disease activity indices and clinical and sonographic remission rates in patients with rheumatoid arthritis (RA). Patients and Methods: Sixty-three patients with RA were categorized according to BMI score into three groups: normal (BMI<25), overweight (BMI 25-30) and obese (BMI≥30). Thirty-three of them were treated with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), and 30 with biologic DMARDs (bDMARDs). Patients underwent clinical and laboratory assessment and musculoskeletal ultrasound examination (MSUS) at baseline and at 6 months after initiation of therapy. We evaluated the rate of clinical and sonographic remission (defined as Power Doppler score (PD) = 0) and its correlation with BMI score. Results: In the csDMARDs group, 60% of the normal weight patients reached DAS28 remission; 33.3% of the overweight; and 0% of the obese patients. In the bDMARDs group, the percentage of remission was as follows: 60% in the normal weight subgroup, 33.3% in the overweight; and 15.8% in the obese. Within the csDMARDs treatment group, two significant correlations were found: BMI score–DAS 28 at 6th month, rs = .372, p = .033; BMI score–DAS 28 categories, rs = .447, p = .014. Within the bDMARDs group, three significant correlations were identified: BMI score–PDUS at sixth month, rs = .506, p =.004; BMI score–DAS 28, rs = .511, p = .004; BMI score–DAS 28 categories, rs = .592, p = .001. Sonographic remission rates at 6 months were significantly higher in the normal BMI category in both treatment groups. Conclusion: BMI influences the treatment response, clinical disease activity indices and the rates of clinical and sonographic remission in patients with RA. Obesity and overweight are associated with lower remission rates regardless of the type of treatment.

scholarly journals BASAN index (Body mass index, Age, Sex, Arterial hypertension and Neck circumference) predicts severe apnoea in adults living at high altitude

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e044228
Author(s):  
Henry Oliveros ◽  
Rafael Lobelo ◽  
Luis Fernando Giraldo-Cadavid ◽  
Alirio Bastidas ◽  
Constanza Ballesteros ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Arterial Hypertension ◽  
High Altitude ◽  
Body Mass ◽  
Sleep Apnoea ◽  
Neck Circumference ◽  
Binary Logistic Regression Model ◽  
Cross Sectional ◽  
Derivation Cohort ◽  
Obstructive Sleep

ObjectivesObstructive sleep apnoea (OSA)/hypopnoea syndrome is associated with serious and major multiorgan morbidities, particularly in its most severe forms. However, no severe OSA screening instruments are available for high altitude residents that enable adequate identification and clinical prioritisation of such patients. We aimed at developing a severe OSA prediction tool based on the clinical characteristics and anthropometric measurements of a clinical referral cohort living at 2640 m.a.s.l.DesignCohort-nested cross-sectional study.SettingSleep laboratory for standard polysomnography (PSG) in Colombia.ParticipantsA predictive model was generated from 8718 participants referred to the PSG laboratory. Results were subsequently validated in a second cohort of 1898 participants.Primary outcomeTo identify clinical and anthropometric variables associated with severe OSA (>30 events/hour) and to include them in a binary logistic regression model.ResultsThe significant variables that were retained with the presence of severe OSA included Body mass index (BMI), Age, Sex, Arterial hypertension and Neck circumference (BASAN). The area under the receiver operating characteristic curvefor the BASAN index was 0.69 (95% CI: 0.68 to 0.70) in the derivation cohort and 0.67 (95% CI: 0.65 to 0.69) in the validation cohort, whereby a BASAN index ≥2 had a sensitivity of 95% and a specificity of 17% to detect severe OSA.ConclusionAn objectively based approach to screen for the presence of severe OSA, the BASAN index, exhibits favourable sensitivity characteristics that should enable its operational use as a screening tool in a Hispanic population with a clinical suspicion of OSA and living at high altitude.

scholarly journals Accuracy of Age-Based Formula to Predict the Size and Depth of Cuffed Oral Preformed Endotracheal Tubes in Children Undergoing Tonsillectomy

2021 ◽  
pp. 014556132098051
Author(s):  
Matula Tareerath ◽  
Peerachatra Mangmeesri
Keyword(s):  
Body Mass Index ◽  
Endotracheal Tube ◽  
Body Mass ◽  
Normal Weight ◽  
Overweight And Obesity ◽  
The Body ◽  
Insertion Depth ◽  
Endotracheal Tubes ◽  
Endotracheal Tube Size ◽  
Actual Size

Objectives: To retrospectively investigate the reliability of the age-based formula, year/4 + 3.5 mm in predicting size and year/2 + 12 cm in predicting insertion depth of preformed endotracheal tubes in children and correlate these data with the body mass index. Patients and Methods: Patients were classified into 4 groups according to their nutritional status: thinness, normal weight, overweight, and obesity; we then retrospectively compared the actual size of endotracheal tube and insertion depth to the predicting age-based formula and to the respective bend-to-tip distance of the used preformed tubes. Results: Altogether, 300 patients were included. The actual endotracheal tube size corresponded with the Motoyama formula (64.7%, 90% CI: 60.0-69.1), except for thin patients, where the calculated size was too large (0.5 mm). The insertion depth could be predicted within the range of the bend-to-tip distance and age-based formula in 85.0% (90% CI: 81.3-88.0) of patients. Conclusion: Prediction of the size of cuffed preformed endotracheal tubes using the formula of Motoyama was accurate in most patients, except in thin patients (body mass index < −2 SD). The insertion depth of the tubes was mostly in the range of the age-based-formula to the bend-to-tip distance.

scholarly journals Association of body mass index and maternal age with first stage duration of labour

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Louise Lundborg ◽  
Xingrong Liu ◽  
Katarina Åberg ◽  
Anna Sandström ◽  
Ellen L. Tilden ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Maternal Age ◽  
Normal Weight ◽  
The Body ◽  
Younger Women ◽  
Individualized Approach ◽  
Quantile Regression Analysis ◽  
Labour Time ◽  
Group 1

AbstractTo evaluate associations between early-pregnancy body mass index (BMI) and active first stage labour duration, accounting for possible interaction with maternal age, we conducted a cohort study of women with spontaneous onset of labour allocated to Robson group 1. Quantile regression analysis was performed to estimate first stage labour duration between BMI categories in two maternal age subgroups (more and less than 30 years). Results show that obesity (BMI > 30) among younger women (< 30 years) increased the median labour duration of first stage by 30 min compared with normal weight women (BMI < 25), and time difference estimated at the 90th quantile was more than 1 h. Active first stage labour time differences between obese and normal weight women was modified by maternal age. In conclusion: (a) obesity is associated with longer duration of first stage of labour, and (b) maternal age is an effect modifier for this association. This novel finding of an effect modification between BMI and maternal age contributes to the body of evidence that supports a more individualized approach when describing labour duration.

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