scholarly journals Patient–Ventilator Interaction Testing Using the Electromechanical Lung Simulator xPULM™ during V/A-C and PSV Ventilation Mode

2021 ◽  
Vol 11 (9) ◽  
pp. 3745
Author(s):  
Richard Pasteka ◽  
Joao Pedro Santos da Costa ◽  
Nelson Barros ◽  
Radim Kolar ◽  
Mathias Forjan
Keyword(s):  
Spontaneous Breathing ◽  
Pressure Support ◽  
Peak Inspiratory Pressure ◽  
Mechanical Ventilator ◽  
Lung Simulator ◽  
Alternative Approach ◽  
Interaction Testing ◽  
Flow Pressure ◽  
Triggering Events ◽  
Test Patient

During mechanical ventilation, a disparity between flow, pressure and volume demands of the patient and the assistance delivered by the mechanical ventilator often occurs. This paper introduces an alternative approach of simulating and evaluating patient–ventilator interactions with high fidelity using the electromechanical lung simulator xPULM™. The xPULM™ approximates respiratory activities of a patient during alternating phases of spontaneous breathing and apnea intervals while connected to a mechanical ventilator. Focusing on different triggering events, volume assist-control (V/A-C) and pressure support ventilation (PSV) modes were chosen to test patient–ventilator interactions. In V/A-C mode, a double-triggering was detected every third breathing cycle, leading to an asynchrony index of 16.67%, which is classified as severe. This asynchrony causes a significant increase of peak inspiratory pressure (7.96 ± 6.38 vs. 11.09 ± 0.49 cmH2O, p < 0.01)) and peak expiratory flow (−25.57 ± 8.93 vs. 32.90 ± 0.54 L/min, p < 0.01) when compared to synchronous phases of the breathing simulation. Additionally, events of premature cycling were observed during PSV mode. In this mode, the peak delivered volume during simulated spontaneous breathing phases increased significantly (917.09 ± 45.74 vs. 468.40 ± 31.79 mL, p < 0.01) compared to apnea phases. Various dynamic clinical situations can be approximated using this approach and thereby could help to identify undesired patient–ventilation interactions in the future. Rapidly manufactured ventilator systems could also be tested using this approach.

scholarly journals Patient-Ventilator Interaction Testing Using the Electro- mechanical Lung Simulator xPULM™during V/A-C and PSV Ventilation Mode

2021 ◽  
Author(s):  
Richard Pasteka ◽  
Joao Pedro Santos da Costa ◽  
Nelson Barros ◽  
Radim Kolar ◽  
Mathias Forjan
Keyword(s):  
Spontaneous Breathing ◽  
Peak Inspiratory Pressure ◽  
Mechanical Ventilator ◽  
Mechanical Lung ◽  
Lung Simulator ◽  
Alternative Approach ◽  
Ventilation Modes ◽  
Interaction Testing ◽  
Ventilator Performance ◽  
Major Increase

During mechanical ventilation, a disparity between flow, pressure or volume demands of the patient and the assistance delivered by the mechanical ventilator often occurs. Asynchrony effect and ventilator performance are frequently studied from ICU datasets or using commercially available lung simulators and test lungs. This paper introduces an alternative approach of simulating and evaluating patient-ventilator interactions with high fidelity using the electro-mechanical lung simulator xPULM&trade; under selected conditions. The xPULM&trade; approximates respiratory activities of a patient during alternating phases of spontaneous breathing and apnoea intervals while connected to a mechanical ventilator. Focusing on different triggering events, volume assist-controlled (V/A-C) and pressure support ventilation (PSV) modes were chosen to test patient-ventilator interactions. In V/A-C mode a double-triggering was detected every third breathing cycle leading to an asynchrony index of 16.67%, being classified as severe. This asynchrony causes a major increase of Peak Inspiratory Pressure PIP = 12.80 &plusmn; 1.39 cmH2O and Peak Expiratory Flow PEF = -18.33 &plusmn; 1.13 L/min when compared to synchronous phases of the breathing simulation. Additionally, events of premature cycling were observed during PSV mode. In this mode, the peak delivered volume during simulated spontaneous breathing phases almost doubles compared to apnoea phases. The presented approach demonstrates the possibility of simulating and evaluating disparities in fundamental ventilation characteristics caused by double-triggering and premature cycling under V/A-C and PSV ventilation modes. Various dynamic clinical situations can be approximated and could help to identify undesired patient-ventilation interactions in the future. Rapidly manufactured ventilator systems could also be tested using this approach.

Respiratory phase locking during mechanical ventilation in anesthetized human subjects

1986 ◽  
Vol 250 (5) ◽  
pp. R902-R909 ◽  
Author(s):  
C. Graves ◽  
L. Glass ◽  
D. Laporta ◽  
R. Meloche ◽  
A. Grassino
Keyword(s):  
Spontaneous Breathing ◽  
Breathing Pattern ◽  
Human Subjects ◽  
Phase Locking ◽  
Phase Relationship ◽  
Mechanical Ventilator ◽  
Lung Inflation ◽  
Fixed Phase ◽  
Simple Phase ◽  
Ventilator Settings

The coupling patterns between the rhythm of a mechanical ventilator and the rhythm of spontaneous breathing were studied in enflurane-anesthetized adult human subjects. The spontaneous breathing pattern was altered in response to different frequencies and amplitudes of forced lung inflations. A 1:1 phase locking (the frequency of the mechanical ventilator is matched by the frequency of spontaneous breathing with a fixed phase between the 2 rhythms) was observed in a range of up to +/- 40% of some of the subject's spontaneous breathing frequencies. During 1:1 phase locking, there were marked changes in the expiratory duration as measured from the electromyogram of the diaphragm. The phase relationship between onset of inflation and onset of inspiration depended on the frequency and amplitude of mechanical inflation. At ventilator settings that did not give 1:1 phase locking, other simple phase-locked patterns, such as 1:2 and 2:1, or irregular non-phase-locked patterns were observed. Reflexes arising from lung inflation, which may underlie the entrainment, are discussed in the context of these results.

scholarly journals T-piece versus pressure-support ventilation for spontaneous breathing trials before extubation in patients at high risk of reintubation: protocol for a multicentre, randomised controlled trial (TIP-EX)

BMJ Open ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. e042619
Author(s):  
Arnaud W Thille ◽  
Rémi Coudroy ◽  
Arnaud Gacouin ◽  
Stephan Ehrmann ◽  
Damien Contou ◽  
...  
Keyword(s):  
High Risk ◽  
Randomised Controlled Trial ◽  
Pressure Support Ventilation ◽  
Spontaneous Breathing ◽  
Pressure Support ◽  
Controlled Trial ◽  
Invasive Mechanical Ventilation ◽  
Support Ventilation ◽  
Number Of Patients ◽  
Randomised Controlled

IntroductionIn intensive care unit (ICU), the decision of extubation is a critical time because mortality is particularly high in case of reintubation. To reduce that risk, guidelines recommend to systematically perform a spontaneous breathing trial (SBT) before extubation in order to mimic the postextubation physiological conditions. SBT is usually performed with a T-piece disconnecting the patient from the ventilator or with low levels of pressure-support ventilation (PSV). However, work of breathing is lower during PSV than during T-piece. Consequently, while PSV trial may hasten extubation, it may also increase the risk of reintubation. We hypothesise that, compared with T-piece, SBT performed using PSV may hasten extubation without increasing the risk of reintubation.Methods and analysisThis study is an investigator-initiated, multicentre randomised controlled trial comparing T-piece vs PSV for SBTs in patients at high risk of reintubation in ICUs. Nine hundred patients will be randomised with a 1:1 ratio in two groups according to the type of SBT. The primary outcome is the number of ventilator-free days at day 28, defined as the number of days alive and without invasive mechanical ventilation between the initial SBT (day 1) and day 28. Secondary outcomes include the number of days between the initial SBT and the first extubation attempt, weaning difficulty, the number of patients extubated after the initial SBT and not reintubated within the following 72 hours, the number of patients extubated within the 7 days following the initial SBT, the number of patients reintubated within the 7 days following extubation, in-ICU length of stay and mortality in ICU, at day 28 and at day 90.Ethics and disseminationThe study has been approved by the central ethics committee ‘Ile de France V’ (2019-A02151-56) and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.Trial registration numberNCT04227639.

Spontaneous breathing trial in T-tube negatively impact on autonomic modulation of heart rate compared with pressure support in critically ill patients

2015 ◽  
Vol 11 (4) ◽  
pp. 489-495 ◽  
Author(s):  
Adriana M. Güntzel Chiappa ◽  
Gaspar R. Chiappa ◽  
Gerson Cipriano ◽  
Ruy S. Moraes ◽  
Elton L Ferlin ◽  
...  
Keyword(s):  
Heart Rate ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Spontaneous Breathing ◽  
Pressure Support ◽  
Spontaneous Breathing Trial ◽  
Autonomic Modulation ◽  
T Tube

Spontaneous Breathing during General Anesthesia Prevents the Ventral Redistribution of Ventilation as Detected by Electrical Impedance Tomography

2012 ◽  
Vol 116 (6) ◽  
pp. 1227-1234 ◽  
Author(s):  
Oliver C. Radke ◽  
Thomas Schneider ◽  
Axel R. Heller ◽  
Thea Koch
Keyword(s):  
Laryngeal Mask Airway ◽  
General Anesthesia ◽  
Electrical Impedance Tomography ◽  
Pressure Support Ventilation ◽  
Spontaneous Breathing ◽  
Electrical Impedance ◽  
Pressure Support ◽  
Impedance Tomography ◽  
Support Ventilation ◽  
Pressure Controlled

Background Positive-pressure ventilation causes a ventral redistribution of ventilation. Spontaneous breathing during general anesthesia with a laryngeal mask airway could prevent this redistribution of ventilation. We hypothesize that, compared with pressure-controlled ventilation, spontaneous breathing and pressure support ventilation reduce the extent of the redistribution of ventilation as detected by electrical impedance tomography. Methods The study was a randomized, three-armed, observational, clinical trial without blinding. With approval from the local ethics committee, we enrolled 30 nonobese patients without severe cardiac or pulmonary comorbidities who were scheduled for elective orthopedic surgery. All of the procedures were performed under general anesthesia with a laryngeal mask airway and a standardized anesthetic regimen. The center of ventilation (primary outcome) was calculated before the induction of anesthesia (AWAKE), after the placement of the laryngeal mask airway (BEGIN), before the end of anesthesia (END), and after arrival in the postanesthesia care unit (PACU). Results The center of ventilation during anesthesia (BEGIN) was higher than baseline (AWAKE) in both the pressure-controlled and pressure support ventilation groups (pressure control: 55.0 vs. 48.3, pressure support: 54.7 vs. 48.8, respectively; multivariate analysis of covariance, P &lt; 0.01), whereas the values in the spontaneous breathing group remained at baseline levels (47.9 vs. 48.5). In the postanesthesia care unit, the center of ventilation had returned to the baseline values in all groups. No adverse events were recorded. Conclusions Both pressure-controlled ventilation and pressure support ventilation induce a redistribution of ventilation toward the ventral region, as detected by electrical impedance tomography. Spontaneous breathing prevents this redistribution.

Sign in / Sign up

Export Citation Format

Share Document