Monitoring Respiratory Mechanics During Multiplex Ventilation

Daoud, Ehab

doi:10.4187/respcare.08373

Cited by 4 publications

(8 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3 Pressure sensors tend to exhibit less variability amongst types due to their robust construction. 5 Those findings are in corroboration with our observations as there tended to be more variation from flow-related measurements compared to pressure. Correlation may be more It is important to note that the accuracy of the digital numeric and graphical information displayed on the ventilator CPU are dependent on many factors, starting with sensing the signal (sensors), signal transduction and conversion to digital signal, ventilator algorithms for checking, and converting the signal into digital analogue (numbers and waveforms).…”

Section: Variability Between the Four Ventilatorssupporting

confidence: 91%

“…13 Another study by Jammes showed wide variability of the respiratory variables between 5-30%. 14 According to Sandborn, 5 pressure measurements range between 3% and 5% of reading, and flow measurements range between 6% and 10% (3 standard deviations of the mean).…”

Section: Variability Between the Four Ventilatorsmentioning

confidence: 99%

“…The accuracy or lack of in any of those steps will alter the accuracy of measurements. 5 The accuracy of critical care ventilator sensors is governed by the International Organization for Standardization (ISO) chapter 80601-2-12. 15 The subclauses contained outline the acceptable standard error (maximum bias error and maximum linearity error) for VT: ± (5 +(10% of the set volume) ml and ± (3,0 +(5 % of the set pressure) cmH2O.…”

Section: Variability Between the Four Ventilatorsmentioning

confidence: 99%

“…Advancement of microelectronics has compensated to account for nonlinear data sampling which maintains an indistinguishable accuracy when compared to linear data. 5 Pressure is often measured through pressure transducers in contact with the flow of gas to the patient. 5 These transducers typically utilize a piezoresistive strain gauge that contains a malleable resistor that changes its resistance in response to a change in length.…”

Section: Introductionmentioning

confidence: 99%

“…5 Pressure is often measured through pressure transducers in contact with the flow of gas to the patient. 5 These transducers typically utilize a piezoresistive strain gauge that contains a malleable resistor that changes its resistance in response to a change in length. Wheatstone bridges are a common circuit used to take advantage of this malleable resistive feature to produce a calibrated voltage change.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Mechanical ventilator flow and pressure sensors: Does location matter?

Toma¹,

Shokry²,

Daoud³

2023

JMV

View full text Add to dashboard Cite

Introduction Accurate measurements of parameters are essential during mechanical ventilation support. These measurements are achieved through sensors that monitor flows, volumes and pressures. External and internal flow sensors are both commonly used in mechanical ventilation systems to measure gas entering and leaving the lungs. The sensors could be located outside the ventilator (external or proximal) or inside the ventilator (internal or distal), each of which have their own respective advantages and disadvantages. There are differences in the way they function and the information they provide, which can affect their accuracy and usefulness in different clinical situations. The purpose of this study was to examine the differences between two critical care ventilators utilizing external sensors to two other ventilators utilizing internal sensors. Methods A bench study using a lung simulator was conducted using three passive, single compartment models: 1) compliance of 40 ml/cmH2O, resistance of 10 cmH2O, 2) compliance of 40 ml/cmH2O, resistance of 20 cmH2O, and 3) compliance of 20 ml/cmH2O, resistance of 10 cmH2O. In each study, two different modes of ventilation, volume controlled (tidal volume 400 ml, respiratory rate 20, PEEP 5 cmH2O, inspiratory time 0.7 seconds) and pressure controlled (inspiratory pressure 15 cmH2O, respiratory rate 20, PEEP 5 cmH2O, inspiratory time 0.7 seconds) were tested. We compared the inspiratory flow, inspiratory tidal volume, peak inspiratory pressures and PEEP in four commercially available critical care ventilators. Two use external flow sensors: G5 (Hamilton Medical), Bellavista 1000e (Vyaire Medical), and two use internal flow sensors: Evita Infinity 500 (Drager), and PB 980 (Medtronic). We also compared these parameters to a mathematical model. Results There were statistically significant differences (P < 0.001) in all four measured parameters: inspiratory flow, tidal volume, PIP and PEEP between all four ventilators, and between the mathematical model and all four ventilators in both modes, in all three clinical scenarios. The post-hoc Dunn test showed significant differences between each ventilator, except for a few parameters in PIP and PEEP, but not in flow or volume. There were variable but significant differences between some of the four parameters measured from the ventilator compared to those measured from the simulator of all four ventilators in both modes. The two ventilators using external sensors had more accurate differences between the delivered and measured tidal volumes (P < 0.001) and inspiratory flow (P < 0.001), however, the other two ventilators with internal sensors had more accurate differences between the delivered and measured PIP (P < 0.001) and PEEP (P < 0.001) levels. Conclusions All four ventilators performed differently from each other and from the mathematical model. The two ventilators using external sensors had more accurate differences between the delivered and measured tidal volumes and inspiratory flow, the two ventilators with internal sensors had more accurate differences between the delivered and measured PIP and PEEP levels. Differences between the ventilators depend on multiple factors including location, type of sensor, and respiratory mechanics. Keywords: Flow sensor, Pressure sensor, PIP, PEEP, Tidal volume, Flow

show abstract

Section: Variability Between the Four Ventilatorssupporting

confidence: 91%

Section: Variability Between the Four Ventilatorsmentioning

confidence: 99%

Section: Variability Between the Four Ventilatorsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Mechanical ventilator flow and pressure sensors: Does location matter?

Toma¹,

Shokry²,

Daoud³

2023

JMV

View full text Add to dashboard Cite

show abstract

Respiratory Monitoring During Mechanical Ventilation: The Present and the Future

Roshdy

2023

J Intensive Care Med

View full text Add to dashboard Cite

The increased application of mechanical ventilation, the recognition of its harms and the interest in individualization raised the need for an effective monitoring. An increasing number of monitoring tools and modalities were introduced over the past 2 decades with growing insight into asynchrony, lung and chest wall mechanics, respiratory effort and drive. They should be used in a complementary rather than a standalone way. A sound strategy can guide a reduction in adverse effects like ventilator-induced lung injury, ventilator-induced diaphragm dysfunction, patient-ventilator asynchrony and helps early weaning from the ventilator. However, the diversity, complexity, lack of expertise, and associated cost make formulating the appropriate monitoring strategy a challenge for clinicians. Most often, a big amount of data is fed to the clinicians making interpretation difficult. Therefore, it is fundamental for intensivists to be aware of the principle, advantages, and limits of each tool. This analytic review includes a simplified narrative of the commonly used basic and advanced respiratory monitors along with their limits and future prospective.

show abstract

Interrupter Technique Revisited: Building an Experimental Mechanical Ventilator to Assess Respiratory Mechanics in Large Animals

Zilianti,

Bashar,

Kyriakoudi

et al. 2024

Fluids

View full text Add to dashboard Cite

Large animals are increasingly used as experimental models of respiratory diseases. Precise characterization of respiratory mechanics requires dedicated equipment with specific characteristics which are difficult to find together in the same commercial device. In this work, we describe building and validation of a computer-controlled ventilator able to perform rapid airways occlusions during constant flow inflations followed by a prolonged inspiratory hold. A constant airflow is provided by a high pressure source (5 atm) connected to the breathing circuit by three proportional valves. The combined action of three 2-way valves produces the phases of the breath. During non-inspiratory breath phases, airflow is diverted to a flowmeter for precise feedback regulation of the proportional valves. A computer interface enables the user to change the breathing pattern, trigger test breaths or run predetermined breaths sequences. A respiratory system model was used to test the ability of the ventilator to correctly estimate interrupter resistance. The ventilator was able to produce a wide range of constant flows (0.1–1.6 L/s) with the selected timing. Errors in the measurement of interrupter resistance were small (1 ± 5% of the reference value). The device described reliably estimated interrupter resistance and can be useful as a measuring tool in large animal research.

show abstract

Monitoring Respiratory Mechanics During Multiplex Ventilation

Cited by 4 publications

References 2 publications

Mechanical ventilator flow and pressure sensors: Does location matter?

Mechanical ventilator flow and pressure sensors: Does location matter?

Respiratory Monitoring During Mechanical Ventilation: The Present and the Future

Interrupter Technique Revisited: Building an Experimental Mechanical Ventilator to Assess Respiratory Mechanics in Large Animals

Contact Info

Product

Resources

About