Ventilator Settings for Mechanical Ventilation

(SEVERE Trial)

Overseen By Irene Telias

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Unity Health Toronto

Must not be taking: Neuromuscular blockers

Disqualifiers: Severe neurological disorders, lung transplant, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

30 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications. However, if you are using continuous neuromuscular blocking agents, you cannot participate in the study.

What data supports the effectiveness of the treatment involving changes in ventilator settings for mechanical ventilation?

Research suggests that adjusting ventilator settings like tidal volume and respiratory rate can help prevent lung injury and improve breathing in patients on mechanical ventilation. Studies have shown that using patient-specific settings based on lung mechanics can prevent alveolar collapse and injury, indicating the potential effectiveness of this treatment. ^{1 2 3 4 5}

Is mechanical ventilation generally safe for humans?

Mechanical ventilation is generally safe when used with protective settings, but it can cause lung injury if not properly managed. Safety measures like monitoring and adjusting ventilator settings based on individual patient needs can help reduce risks. ^{6 7 8 9 10}

How is the treatment of adjusting ventilator settings for mechanical ventilation different from other treatments?

This treatment is unique because it involves adjusting the ventilator's respiratory rate and tidal volume (the amount of air delivered to the lungs with each breath) to match the patient's specific lung mechanics and condition, which can help prevent lung injury and improve breathing efficiency. Unlike standard treatments, it requires continuous monitoring and personalized adjustments to optimize lung protection and function. ^{1 3 6 11 12}

What is the purpose of this trial?

Background: Reverse triggering (RT) is a frequent phenomenon observed in sedated patients under a mechanical ventilation mode called assist-control ventilation. RT is when the ventilator would trigger the patient's respiratory effort instead of the correct order of the patient's respiratory effort triggering the ventilator. Reverse triggering can have negative consequences (loss of protective lung ventilation, and causing double breaths - with the ventilator giving two consecutive breaths and not allowing the patient to exhale) but also offer some protective effects (avoid diaphragm disuse atrophy). The balance of its negative vs positive effects depends on its frequency and magnitude of its associated respiratory effort. Respiratory entrainment is the most often referred mechanism involving a change in patient's rate of breathing effort from that of patient's intrinsic rate to the rate of mechanical insufflation. The specific ventilatory settings associated with or responsible for RT remains unknown. Aims: To assess in mechanically ventilated critically ill patients the influence of the set respiratory rate (RR) and tidal volume (Vt) on the presence/development of RT and to describe the pattern of respiratory muscle activity during Reverse Triggering (RT). Methods. 30 adult patients (15 in each group), sedated and under assist-controlled ventilation will be included. Ventilator settings will be modified to modulate the frequency and magnitude of reverse triggering. Initially, with the ventilator on a mode called volume control, which means the ventilator controls the amount of air (tidal volume) and the number of breaths the patients gets every minute (respiratory rate \[RR\]). The tidal volume will be set at the current standard clinical practice setting (6 ml/kg of predicted body weight). The presence of an intrinsic respiratory rate will be assessed with an end-expiratory occlusion maneuver. Next, the number of breaths the ventilator gives per minute (RR) will be changed from 6 breaths less to 6 breaths more, in steps of 2 breaths every minute. The protocol will be repeated again changing the amount of air the patients gets (tidal volume) from 4, 5, 7 and 8 ml/kg. Continuous recordings of airway pressure, flow, esophageal pressure, electrical activity of the diaphragm, main accessory muscles and frontal electroencephalography will be obtained during the protocol and baseline clinical and physiological characteristics and outcomes will be recorded. A validated software will be used to detect RT and measure the intensity and timing of each muscle electrical activity and the magnitude of the inspiratory effort during RT.

Research Team

Laurent Brochard

Principal Investigator

Unity Health Toronto - St. Michael's Hospital

Eligibility Criteria

This trial is for adult patients who are critically ill and require mechanical ventilation in a mode called assist-control. Participants must be sedated and able to undergo changes in ventilator settings without risk. Specific criteria about health status or other conditions aren't provided, but typically, patients with unstable conditions would be excluded.

Inclusion Criteria

I have been under sedation for at least 6 hours.

Patients intubated for more than 12 hours

With a sedation-agitation score ≤ 4

Exclusion Criteria

History of previous lung transplant

Severe metabolic acidosis (pH < 7.25) at the time of study procedure

History of primary severe neurological disorders

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Ventilator Setting Adjustment

Ventilator settings are adjusted to assess the influence on reverse triggering and respiratory muscle activity.

1 day

Continuous monitoring during hospital stay

Continuous Monitoring

Continuous recording of ventilator waveforms and EEG to investigate intrinsic respiratory rate and brain activity.

24 hours

Continuous monitoring during hospital stay

Follow-up

Participants are monitored for safety and effectiveness after ventilator adjustments.

1-2 weeks

Treatment Details

Interventions

• Changes in the ventilator respiratory rate and tidal volume

Trial Overview The study is testing how different ventilator settings (respiratory rate and tidal volume) affect the occurrence of reverse triggering—a condition where the ventilator initiates breaths instead of the patient—and its impact on respiratory muscle activity.

Participant Groups

Group I: Patients under mechanical ventilation Experimental Treatment 1 Intervention

Patients intubated for more than 12 hours, on assist-control ventilation, not triggering the ventilator with or without reverse triggering, exposed to sedation for at least 6 hours, with a sedation-agitation score ≤ 4.

Who Is Running the Clinical Trial?

Unity Health Toronto

Lead Sponsor

Trials

572

Recruited

470,000+

Findings from Research

In a study involving 44 anesthetized rabbits, using a higher positive end-expiratory pressure (PEEP at 12 cm H2O) and a shorter inspiratory time (0.45 seconds) significantly improved gas exchange and lung compliance, suggesting these settings may help prevent ventilator-induced lung injury.

As lung injury developed, the study observed an increase in tidal volume and a change in the airway pressure waveform, indicating that monitoring these parameters could be important in managing ventilator settings to minimize lung damage.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of ventilatory pattern on experimental lung injury caused by high airway pressure. Simonson, DA., Adams, AB., Wright, LA., et al.[2019]

In a study of 243 mechanically ventilated patients, adaptive support ventilation (ASV) adjusted tidal volume (VT) and respiratory rate (RR) based on the patient's lung condition, delivering higher VT and lower RR for COPD patients compared to those with ALI/ARDS.

For patients who actively triggered the ventilator, ASV did not show significant differences in VT-RR combinations across various lung conditions, indicating a potential uniformity in support for these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Automatic selection of breathing pattern using adaptive support ventilation. Arnal, JM., Wysocki, M., Nafati, C., et al.[2022]

In a study of 60 mechanically ventilated patients, using an intratracheal catheter to set tidal volume (TV) and positive end-expiratory pressure (PEEP) resulted in significantly better PEEP levels and improved PaO2/FiO2 ratios by day 7 compared to conventional methods.

The findings suggest that monitoring respiratory mechanics with an intratracheal catheter provides more accurate ventilator settings, which may help prevent alveolar collapse and injury in intensive care unit patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Study of Tidal Volume and Positive End-Expiratory Pressure on Alveolar Recruitment Using Spiro Dynamics in Mechanically Ventilated Patients. Saxena, S., Tripathi, M., Kumar, V., et al.[2022]

In a study of 51,689 adult patients receiving mechanical ventilation across 274 California hospitals, higher hospital ventilation volumes were associated with increased odds of in-hospital death and tracheostomy procedures, suggesting worse outcomes at high-volume centers.

Interestingly, patients at high-volume hospitals had lower odds of 30-day readmission after discharge, indicating a complex relationship between hospital volume and patient outcomes that warrants further investigation into care processes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Hospital Mechanical Ventilation Volume and Patient Outcomes: Too Much of a Good Thing? Mehta, AB., Walkey, AJ., Curran-Everett, D., et al.[2020]

A study involving 159 patients in an intensive care unit showed that using predicted body weight based on knee height led to a significant reduction in tidal volume delivered during mechanical ventilation, from 8.97 mL/kg to 7.49 mL/kg, which is important for lung protection.

The intervention, which included education and feedback, resulted in sustained adherence to the new tidal volume guidelines for 12 months, highlighting the effectiveness of this approach in improving mechanical ventilation practices.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Lung protection: an intervention for tidal volume reduction in a teaching intensive care unit. Briva, A., Gaiero, C.[2022]

Using protective ventilator settings, including reduced tidal volumes and appropriate positive end-expiratory pressure, is crucial for managing patients with acute respiratory distress syndrome (ARDS) to minimize lung injury.

Current evidence supports the importance of preserving spontaneous breathing for at least 48 hours after ARDS onset, highlighting the need for individualized ventilatory strategies based on the patient's condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Ventilation in acute respiratory distress. Lung-protective strategies]. Bruells, CS., Rossaint, R., Dembinski, R.[2021]

An electronic algorithm was developed to monitor ventilator settings in real-time, alerting healthcare providers to potentially harmful settings, which was tested on 1,159 patients in intensive care units.

After implementing the alert system, the average exposure to potentially injurious ventilation settings significantly decreased from 40.6 hours to 26.9 hours, indicating improved safety in ventilator care.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Limiting ventilator-induced lung injury through individual electronic medical record surveillance. Herasevich, V., Tsapenko, M., Kojicic, M., et al.[2010]

A systematic review of 16 studies identified that use errors in mechanical ventilators are often caused by usability issues and the variability in user interfaces across different devices, which can lead to confusion among medical staff.

To reduce these errors, the review suggests that manufacturers should standardize user interface content and implement design recommendations, which could enhance safety and improve risk management in ventilator use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Causes of use errors in ventilation devices - Systematic review. Coldewey, B., Diruf, A., Röhrig, R., et al.[2021]

Mechanical ventilation can cause lung injury in patients with ARDS due to factors like pressure settings and duration of use, leading to conditions such as volutrauma and atelectrauma.

Current strategies using a tidal volume of 6 ml/kg can reduce but not completely prevent these injuries, highlighting the need for improved monitoring and innovative technologies to optimize ventilator settings in real-time.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Lung protective ventilation - pathophysiology and diagnostics]. Uhlig, S., Frerichs, I.[2020]

A study over two months involving 248 initial assessments (G1) and 250 follow-up assessments (G2) of patients on mechanical ventilation showed significant improvements in the accuracy of ventilation parameters and alarm settings after implementing corrective measures.

The corrective measures led to a generalized reduction in errors across all monitored parameters, indicating that these strategies can enhance patient safety and should be integrated into quality control programs for mechanical ventilation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Control of respiratory monitoring in the critical patient]. Subirana, M., Pascual, S., Jover, C., et al.[2016]

Mechanical ventilation is crucial for patients with acute respiratory failure (ARF), and its application is guided by hemogasanalysis, hemodynamics, and X-ray findings.

The study emphasizes the importance of understanding mechanical measures and their impact on ventilatory strategies to optimize patient outcomes during mechanical ventilation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Traditional artificial ventilation. General principles]. Ranieri, VM.[2006]

Nurses can effectively adjust mechanical ventilator settings by using data from various monitoring tools like ABG, pulse oximetry, and capnography, which helps in correcting ventilation and oxygenation issues.

Applying scientific principles consistently in these adjustments not only enhances nursing assessments and interventions but also helps prevent unnecessary discomfort and costs for patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The art and science of mechanical ventilator adjustments. Dettenmeier, PA., Johnson, TM.[2004]

References

1. United States pubmed.ncbi.nlm.nih.gov

Effects of ventilatory pattern on experimental lung injury caused by high airway pressure. [2019]

2. United States pubmed.ncbi.nlm.nih.gov

Automatic selection of breathing pattern using adaptive support ventilation. [2022]

3. India pubmed.ncbi.nlm.nih.gov

Study of Tidal Volume and Positive End-Expiratory Pressure on Alveolar Recruitment Using Spiro Dynamics in Mechanically Ventilated Patients. [2022]

4. United States pubmed.ncbi.nlm.nih.gov

Hospital Mechanical Ventilation Volume and Patient Outcomes: Too Much of a Good Thing? [2020]

5. Brazil pubmed.ncbi.nlm.nih.gov

Lung protection: an intervention for tidal volume reduction in a teaching intensive care unit. [2022]

6. Germany pubmed.ncbi.nlm.nih.gov

[Ventilation in acute respiratory distress. Lung-protective strategies]. [2021]

7. United States pubmed.ncbi.nlm.nih.gov

Limiting ventilator-induced lung injury through individual electronic medical record surveillance. [2010]

8. England pubmed.ncbi.nlm.nih.gov

Causes of use errors in ventilation devices - Systematic review. [2021]

9. Germany pubmed.ncbi.nlm.nih.gov

[Lung protective ventilation - pathophysiology and diagnostics]. [2020]

10. Spain pubmed.ncbi.nlm.nih.gov

[Control of respiratory monitoring in the critical patient]. [2016]

11. Italy pubmed.ncbi.nlm.nih.gov

[Traditional artificial ventilation. General principles]. [2006]

12. United States pubmed.ncbi.nlm.nih.gov

The art and science of mechanical ventilator adjustments. [2004]