An interventional study of Volume Support Mode Mechanical Ventilation and Assist Control Mode Mechanical Ventilation in Mechanical Ventilation Complication, sponsored by University of Chicago. Recruiting at 2 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-13.
Sponsored by University of Chicago · Not applicable, Interventional, and Treatment
The objective of the study is to determine how controlled mode ventilation and support mode ventilation impact ventilator-free days and diaphragmatic atrophy.
Ventilator-induced diaphragmatic dysfunction (VIDD) is characterized by diaphragmatic atrophy and weakness leading to an inability to liberate from the ventilator. Patients with VIDD have increased intensive care unit and hospital length of stay, higher reintubation rates, and need for tracheostomy. There are two commonly used modes of ventilation in the ICU - controlled and support mode ventilation. Conventional practice is to initiate mechanical ventilation with controlled mode followed by a support mode to facilitate weaning and eventual extubation. However, this approach may induce irreversible diaphragmatic atrophy. Observational studies suggest that controlled ventilation is associated with higher rates of diaphragmatic atrophy than support modes of ventilation. Diaphragmatic atrophy occurs within the first 24 hours of mechanical ventilation. To date, it remains unknown whether early initiation of support mode ventilation prevents VIDD and its associated complications in comparison to controlled mode ventilation.
The investigators hypothesize that by initiating subjects on support mode ventilation, an associated increase in ventilator-free days will be seen in comparison to subjects on controlled mode ventilation. Subjects on support mode ventilation will have less diaphragmatic atrophy and weakness than subjects on controlled mode ventilation. To investigate this hypothesis,investigators are conducting a phase III randomized trial examining the effects of volume support mode versus assist control mode ventilation on ventilator-free days and rate of diaphragm atrophy.
enrolled subjects requiring mechanical ventilation will be randomized to either volume support mode or assist control mode within 24 hours of mechanical ventilation initiation. Diaphragm thickness will be measured by ultrasound daily and subsequently diaphragm atrophy rate will be calculated in each arm. The operator acquiring ultrasound images will be blinded to the ventilator mode that the subject was randomized to. Subjects in the study will follow standard ICU sedation awakening trials and spontaneous breathing trials. The medical team in charge of the subject will determine when the subject will be liberated from the ventilator.
There will be up to a 24 hour period from initiation of standard, non-study mechanical ventilation during which the subject can be consented and enrolled. This will allow the research team time to contact the subject and/or family in order to obtain informed consent. Once randomized, all subjects will be initiated on study mode of ventilation. The medical team will direct other aspects of care.
The phase III trial will be powered to determine if there is a statistically significant difference in rate of diaphragm atrophy and ventilator-free days between volume support mode and assist control mode.
933 studies on the registry are indexed under Delirium; 190 are open to participants now.
This study's planned enrollment of 468 is above the median of 112 across 550 interventional studies indexed under Delirium.
Browse Delirium studies →University of Chicago is the lead sponsor of 924 studies on the registry; 185 are open to participants now.
Of its 103 completed or terminated interventional studies of FDA-regulated products, 72 (70%) have results posted.
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subjects > 18 years of age that have been intubated and mechanically ventilated for \< 36 hours at the time of screening will be eligible for enrollment
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Volume support mode ventilation is a spontaneous mode where a target goal volume is set on the ventilator. This ventilatory strategy is dependent on patients spontaneously breathing and triggering (or activating) the ventilator to support the breath. The ventilator adjusts the amount of pressure support to deliver with each breath (i.e. if the patient's tidal volume is greater than the set target volume, then the ventilator will decrease the amount of pressure support in the subsequent breath to try to achieve the goal volume and vice versa). The respiratory rate is not set in this mode of ventilation and is dependent on the patient. For patients randomized to this mode, the goal tidal volume will be set at 6 cc/kg of ideal body weight (IBW).
Other: Volume Support Mode Mechanical Ventilation
In assist control mode ventilation, the machine is programmed to deliver a set tidal volume and set respiratory rate. Patients can breathe over the set respiratory rate, but the volume of breath that they receive is fixed and delivered by the ventilator. For patients randomized to this mode, the tidal volume will be set at 6 cc/kg of ideal body weight (IBW).
Other: Assist Control Mode Mechanical Ventilation
This is a spontaneous mode of mechanical ventilation that depends on the patient's efforts. A target volume (6 cc/kg of IBW), PEEP and FiO2 are set by the medical team, and the ventilator varies the inspiratory pressure support with each breath to achieve the target volume. The respiratory rate is fully dependent on the patient. Sedation while on mechanical ventilation will be set at a goal RASS of 0 to -2.
This is a controlled mode of mechanical ventilation that is independent of patient's efforts. A tidal volume (6 cc/kg of IBW), respiratory rate, PEEP and FiO2 are set by the medical team. Sedation while on mechanical ventilation will be set at a goal RASS of 0 to -2.
Ventilator-Free Days
A Phase III Primary Outcome; Defined as days alive and free from mechanical ventilation at day 28
Time frame: 28 days
Rate of Diaphragm Atrophy
Defined as percentage decline in diaphragm thickness per day
Time frame: Through study completion, an average of 28 days
Noninvasive Measurements of Diaphragm Inspiratory Strength 3.+ 9+ Noninvasive Measurements of Diaphragm Function
negative inspiratory force (nif)--measured unit cm H2O
Time frame: Through study completion, an average of 28 days
Noninvasive Measurements of Diaphragm Expiratory Strength
positive expiratory force (pef)--measured unit cm H2O
Time frame: Through study completion, an average of 28 days
Diaphragm Thickening Fraction
(diaphragm thickness at end expiration - diaphragm thickness at end inspiration)/diaphragm thickness at end expiration; measured by ultrasound
Time frame: Through study completion, an average of 28 days
Duration of Mechanical Ventilation
Days on mechanical ventilation
Time frame: 28 days
Frequency of Ventilator-Related Complications
Including the Following: -reintubation * tracheostomy * mechanical ventilation \> 14 days * patients with delirium
Time frame: Through study completion, an average of 28 days
Readmission to ICU During Same Hospital Admission
Bivariate outcome regarding readmission to ICU--"Yes or No"
Time frame: Through study completion, an average of 28 days
Death in ICU
Death that occurs while in the ICU
Time frame: 90 days
Death in Hospital
Death that occurs while in the Hospital
Time frame: 90 days
Discharge Destination
i.e. home, long term assisted care, skilled nursing facility, death
Time frame: 90 days
Mortality
measured at 28 days, 90 days, and 1 year
Time frame: 1 month, 3 months, and 12 months
Started Mar 2019 (actual). Primary completion is estimated for May 2027, 98 months after the start.
Of 219 non-industry interventional studies with no phase under Delirium, half reached primary completion within 26 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 45. This study's planned 98 months is above that.
Counting every sponsor, half of 222 studies reached it within 26 months; a quarter within 12 and three quarters within 45.
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