A comparison of methods used to quantify the work of breathing during exercise

2021 ◽  
Author(s):  
Troy James Cross ◽  
Elizabeth A. Gideon ◽  
Sarah J. Morris ◽  
Catherine L. Coriell ◽  
Colin D. Hubbard ◽  
...  
Keyword(s):  
Gold Standard ◽  
Respiratory Mechanics ◽  
Work Of Breathing ◽  
Specific Method ◽  
Campbell Diagram ◽  
Volitional Exhaustion ◽  
Volume Integration ◽  
Graded Exercise ◽  
Systematic Pattern ◽  
No Gold Standard

The mechanical work of breathing (Wb) is an insightful tool used to assess respiratory mechanics during exercise. There are several different methods used to calculate the Wb, however - each approach having its own distinct advantages/disadvantages. To date, a comprehensive assessment of the differences in the components of Wb between these methods is lacking. We therefore sought to compare the values of Wb during graded exercise as determined via the 4 most popular methods: (i) pressure-volume integration; (ii) the Hedstrand diagram; (iii) the Otis diagram; and the (iv) modified Campbell diagram. Forty-two participants (30 ± 15 years; 16 women) performed graded cycling to volitional exhaustion. Oesophageal pressure-volume loops were obtained throughout exercise. These data were used to calculate the total Wb and, where possible, its subcomponents of inspiratory and expiratory, resistive and elastic Wb, using each of the 4 methods. Our results demonstrate that the components of Wb were indeed different between methods across the minute ventilations engendered by graded exercise (P < 0.05). Importantly, however, no systematic pattern in these differences could be observed. Our findings indicate that the values of Wb obtained during exercise are uniquely determined by the specific method chosen to compute its value - no two methods yield identical results. Because there is currently no "gold-standard" for measuring the Wb, it is emphasized that future investigators be cognizant of the limitations incurred by their chosen method, such that observations made by others may be interpreted with greater context, and transparency.

The effect of estimating chest wall compliance on the work of breathing during exercise as determined via the modified Campbell diagram

2020 ◽  
Author(s):  
Elizabeth A. Gideon ◽  
Troy J. Cross ◽  
Catherine L. Coriell ◽  
Joseph W. Duke
Keyword(s):  
Chest Wall ◽  
Work Of Breathing ◽  
Cycle Ergometer ◽  
Campbell Diagram ◽  
Chest Wall Compliance ◽  
A Value ◽  
Graded Exercise ◽  
Prior Literature ◽  
Wall Compliance

The modified Campbell diagram provides one of the most comprehensive assessments of the work of breathing (Wb) during exercise, wherein the resistive and elastic work of inspiration and expiration are quantified. Importantly, a necessary step in constructing the modified Campbell diagram is to obtain a value for chest wall compliance (CCW). To date, it remains unknown whether estimating or directly measuring CCW impacts on the Wb as determined by the modified Campbell diagram. Therefore, the purpose of this study was to evaluate whether the components of the Wb differ when the modified Campbell diagram is constructed using an estimated versus measured value of CCW. Forty-two participants (n = 26 men, 16 women) performed graded exercise to volitional exhaustion on a cycle ergometer. CCW was measured directly at rest via quasi-static relaxation. Estimated values of CCW were taken from prior literature. The measured value of CCW was greater than that obtained via estimation (214 ± 52 mL∙cmH2O-1 vs. 189 ± 18 mL∙cmH2O-1, p < 0.05). At modest to high minute ventilations (i.e., 50-200 L∙min-1), the inspiratory elastic Wb was greater, and expiratory resistive Wb was lower, when modified Campbell diagrams were constructed using estimated compared with measured values of CCW (p < 0.05). These differences were however small, and never exceeded ±5%. Thus, although our findings demonstrate that estimating CCW has a measurable impact on the determination of the Wb, its effect appears relatively small within a cohort of healthy adults during graded exercise.

On the robustness of latent class models for diagnostic testing with no gold standard

2021 ◽  
Author(s):  
Matthew R. Schofield ◽  
Michael J. Maze ◽  
John A. Crump ◽  
Matthew P. Rubach ◽  
Renee Galloway ◽  
...  
Keyword(s):  
Gold Standard ◽  
Latent Class ◽  
Diagnostic Testing ◽  
Latent Class Models ◽  
No Gold Standard ◽  
Class Models

Rejoinder to “On the robustness of latent class models for diagnostic testing with no gold standard”

2021 ◽  
Vol 40 (22) ◽  
pp. 4770-4771
Author(s):  
Matthew R. Schofield ◽  
Michael J. Maze ◽  
John A. Crump ◽  
Matthew P. Rubach ◽  
Renee L. Galloway ◽  
...  
Keyword(s):  
Gold Standard ◽  
Latent Class ◽  
Diagnostic Testing ◽  
Latent Class Models ◽  
No Gold Standard ◽  
Class Models

scholarly journals LVNC – A review

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Lisa Brandon ◽  
◽  
Brian Kerr ◽  
Ken McDonald ◽  
◽  
...  
Keyword(s):  
Heart Failure ◽  
Congenital Heart Disease ◽  
Heart Disease ◽  
Gold Standard ◽  
Congenital Heart ◽  
Imaging Techniques ◽  
Disease Modifying Therapies ◽  
Increased Risk ◽  
Disease Modifying ◽  
No Gold Standard

LVNC is a relatively new clinical entity, with a significant increase in awareness and diagnosis in recent years. Currently the aetiology and pathogenesis of LVNC remains uncertain, alongside prevalence, however the diagnosis of LVNC appears to be increasing with improving imaging techniques. For educational purposes involving a rare clinical condition, we present the case of a 52 year old gentleman who was diagnosed with LV non compaction via ECHO and CMR. Interestingly it was noted two of his children had congenital heart disease, one daughter had Tetralogy of Fallot, and a second daughter had both an ASD and VSD. Challenges facing LVNC involve difficulty of diagnosis with no gold standard yet available, uncertainty of benefit with standard disease modifying therapies for HF-REF, and apparent increased risk of arrhythmias suggesting early ICD placement may be warranted for patients. Keywords: Hr-Ref; heart failure; lv non compaction; arrhythmias; lcd Risk.

scholarly journals Therapeutic difficulties in vesicorectal fistula treatment using several techniques in one center

2021 ◽  
Author(s):  
Maciej Przudzik ◽  
Maria Derkaczew ◽  
Robert Hofman ◽  
Marek Roslan
Keyword(s):  
Radical Cystectomy ◽  
Gold Standard ◽  
Ileal Conduit ◽  
Surgical Techniques ◽  
Anterior Rectal Resection ◽  
Surgical Methods ◽  
The Mean ◽  
Fistula Treatment ◽  
No Gold Standard ◽  
Radiotherapy Treatment

Introduction: Vesicorectal fistula (VRF) is a rare but devastating condition that may develop after surgery or radiotherapy. Many surgical methods to treat VRF have been described, but there is still no gold standard of VRF treatment. Aim: The aim of the study is to present our experience in the treatment of VRFs and analyze different surgical techniques applied in our center retrospectively. Material and methods: From June 2016 to June 2020, 7 patients (5 males and 2 females) aged 59–73 years (average 67.3 years) were treated for VRF in our center. The primary causes of VRFs were complications after laparoscopic radical prostatectomy (LRP), sigmoidectomy, laparotomy with removal of the tumour of the vaginal stump and anterior rectal resection and colostomy, Hartmann’s operation due to rectosigmoid carcinoma, radiotherapy, treatment of cervical cancer and transurethral resection of bladder tumor (TURBT). The patients were treated with one of the following methods: transvesical laparoscopic single-site surgery (T-LESS), transanal minimally invasive surgery (TAMIS), transurethral fulguration and radical cystectomy with the Bricker’s ileal conduit. Results and discussion: Five patients underwent T-LESS, 2 TAMIS, 1 transurethral fulguration and 1 radical cystectomy with the Bricker’s ileal conduit. The mean postoperative hospital stay was 4 days (range 2–8 days). The mean operative time was 139 minutes (range 100–285 minutes). Only 1 patient had a recurrence of a fistula. Conclusions: Surgical management of VRFs is obligatory to prevent possible complications. Currently, there is no gold standard for treatment of VRFs. Therefore, this condition requires further investigation.

scholarly journals The Influence of Filters on EEG-ERP Testing: Analysis of Motor Cortex in Healthy Subjects

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7711
Author(s):  
Ilona Karpiel ◽  
Zofia Kurasz ◽  
Rafał Kurasz ◽  
Klaudia Duch
Keyword(s):  
Gold Standard ◽  
Healthy Subjects ◽  
Data Interpretation ◽  
Eeg Signal ◽  
Sensorimotor Area ◽  
Eeg Data ◽  
Reduction Methods ◽  
Characteristic Values ◽  
No Gold Standard ◽  
Correct Data

The raw EEG signal is always contaminated with many different artifacts, such as muscle movements (electromyographic artifacts), eye blinking (electrooculographic artifacts) or power line disturbances. All artifacts must be removed for correct data interpretation. However, various noise reduction methods significantly influence the final shape of the EEG signal and thus its characteristic values, latency and amplitude. There are several types of filters to eliminate noise early in the processing of EEG data. However, there is no gold standard for their use. This article aims to verify and compare the influence of four various filters (FIR, IIR, FFT, NOTCH) on the latency and amplitude of the EEG signal. By presenting a comparison of selected filters, the authors intend to raise awareness among researchers as regards the effects of known filters on latency and amplitude in a selected area—the sensorimotor area.

Reproducibility of the Rotor 2INpower Crankset for Monitoring Cycling Power Output: A Comprehensive Analysis in Different Real-Context Situations

2021 ◽  
pp. 1-6
Author(s):  
Víctor Rodríguez-Rielves ◽  
Alejandro Martínez-Cava ◽  
Ángel Buendía-Romero ◽  
José Ramón Lillo-Beviá ◽  
Javier Courel-Ibáñez ◽  
...  
Keyword(s):  
Exercise Test ◽  
Standard Error ◽  
Power Output ◽  
Gold Standard ◽  
Graded Exercise Test ◽  
Wide Range ◽  
Graded Exercise ◽  
Standard Error Of Measurement ◽  
Acceptable Agreement ◽  
Error Of Measurement

Purpose: To examine the reproducibility (intradevice and interdevice agreement) of the Rotor 2INpower device under a wide range of cycling conditions. Methods: Twelve highly trained male cyclists and triathletes completed 5 cycling tests, including graded exercise tests at different cadences (70–100 rpm), workloads (100–650 W), pedaling positions (seated and standing), and vibration conditions (20–40 Hz) and an 8-second maximal sprint (>1000 W). An intradevice analysis included a comparison between the power output registered by 3 units of Rotor 2INpower, whereas the power output provided by each one of these units and the gold-standard SRM crankset were compared for the interdevice analysis. Among others, statistical calculations included the standard error of measurement, expressed in absolute (in watts) and relative terms as the coefficient of variation (CV). Results: Except for the graded exercise test seated at 100 rpm/100 W (CV = 10.2%), the intradevice analysis showed an acceptable magnitude of error (CV ≤ 6.9%, standard error of measurement ≤ 12.3 W) between the 3 Rotor 2INpower. Similarly, these 3 units showed an acceptable agreement with the gold standard in all graded exercise test situations (CV ≤ 4.0%, standard error of measurement ≤ 13.1 W). On the other hand, both the intradevice and interdevice agreements proved to be slightly reduced under high cadences (intradevice: CV ≤ 10.2%; interdevice: CV ≤ 4.0%) and vibration (intradevice: CV ≤ 4.0%; interdevice: CV ≤ 3.6%), as well as during standing pedaling (intradevice: CV ≤ 4.1%; interdevice: CV ≤ 2.5%). Although within the limits of an acceptable agreement, measurement errors increased during the sprint tests (CV ≤ 7.4%). Conclusions: Based on these results, the Rotor 2INpower could be considered a reproducible tool to monitor power output in most cycling situations.

The Role of Average Health Status

2016 ◽  
pp. 884-899
Author(s):  
Jordan Panayotov
Keyword(s):  
Health Status ◽  
Population Health ◽  
Gold Standard ◽  
Health Impact ◽  
Local Context ◽  
Policy Options ◽  
The Matrix ◽  
The Right ◽  
No Gold Standard ◽  
Average Health

Economic, social and environmental policies, programs and projects have impact on health. Health in All Policies (HiAP) aims to improve population health by taking into account these impacts. HiAP needs appropriate tools for assessing impacts on population health. When making choices between policy options, decision-makers rely on predictions from Health Impact Assessment. Currently there is no gold standard for establishing and assessing validity of predictions. This paper distinguishes between two levels of causal pathways regarding health impacts – specific and conditional, and proposes the Average Health Status – Health Inequalities Matrix as gold standard. The Matrix facilitates making the right choices at any level and local context, thus is useful for researchers, policy-makers and practitioners for designing, analysing and evaluating all kinds of policies. By allowing quick, reliable and inexpensive appraisal of different policy options the matrix makes feasible taking into account the impacts on population health and paves the way for institutionalizing of HiAP.

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