ARDS (Acute Respiratory Distress Syndrome)Phase 2COBRANCT07567768
Continuous vs Bolus Neuromuscular Blockade Regimens in Moderate to Severe Hypoxemic Respiratory Failure and ARDS (COBRA)
A Phase 2 study testing Neuromuscular Blocking Agent - Bolus Dosing and Neuromuscular Blocking Agent - Continuous Infusion in people with ARDS (Acute Respiratory Distress Syndrome), run by University of Calgary.
Trial summary
Current clinical guidelines, such as those from the Surviving Sepsis Campaign and ARDSNet, recommend short-term NMBA use for patients with moderate to severe ARDS who exhibit persistent ventilator dyssynchrony or high plateau pressures despite deep sedation . Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- ARDS (Acute Respiratory Distress Syndrome)
- What is being tested?
- Neuromuscular Blocking Agent - Bolus Dosing and Neuromuscular Blocking Agent - Continuous Infusion
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2027to 1 Jan 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥18 years
- Mechanically ventilated and on a controlled ventilation mode
- Diagnosis of moderate to severe ARDS (PaO₂/FiO₂ ≤150 mmHg on PEEP ≥5 cm H₂O)
- Bilateral pulmonary infiltrates consistent with ARDS
- Randomized within 24 hours of meeting ARDS criteria
Who cannot join
- Pregnancy
- Known allergy or contraindication to rocuronium
- Neuromuscular disorders (e.g., myasthenia gravis, Guillain-Barré syndrome)
- Brain death or decision for withdrawal of life-sustaining therapy
- Enrollment in a conflicting interventional trial
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: The Effect of Continuous vs Bolus Neuromuscular Blockade Regimens for Patients With Moderate to Severe Hypoxemic Respiratory Failure and ARDS (COBRA): A Pilot Randomized Controlled Trial
Current clinical guidelines, such as those from the Surviving Sepsis Campaign and ARDSNet, recommend short-term NMBA use for patients with moderate to severe ARDS who exhibit persistent ventilator dyssynchrony or high plateau pressures despite deep sedation . However, they do not provide clear recommendations regarding the mode of administration. As a result, clinicians are left to extrapolate from limited or indirect evidence, which may lead to practice variation, uncertainty, and suboptimal care.
This pilot randomized controlled trial is designed to directly address this critical gap by comparing intermittent bolus administration versus continuous infusion of NMBAs in a pragmatic, real-world ICU setting. The study will assess feasibility metrics necessary to plan a definitive trial and generate preliminary clinical data on safety and effectiveness. By clarifying the comparative benefits and risks of each approach, the results may influence practice guidelines, reduce variation in care, and improve patient outcomes and reduce practice variation.patient outcomes, optimize resource use, and inform future guidelines on the management of moderate to severe ARDS.
Read the detailed description
Study Title: The Effect of Continuous vs Bolus Neuromuscular Blockade for Patients with Moderate to Severe HRF and ARDS: A Pilot Randomized Controlled Trial
Background:
Acute Respiratory Distress Syndrome (ARDS) affects ~10% of ICU patients and carries high morbidity and mortality. Neuromuscular blockade agents (NMBAs), especially cisatracurium, have historically been administered via continuous infusion to improve oxygenation and reduce ventilator-induced lung injury. However, recent evidence (e.g., ROSE trial) questions this approach, and emerging guidelines suggest intermittent bolus dosing may offer similar benefits with fewer adverse effects. There is a lack of direct comparative data, creating uncertainty in clinical practice.
Hypothesis \& Objectives:
The study hypothesizes that a multicenter RCT comparing intermittent bolus vs continuous NMBA infusion in ARDS is feasible and that bolus dosing may show trends toward improved outcomes (e.g., ventilator-free days, fewer adverse events).
Primary objective: Assess feasibility of a definitive trial. Feasibility aims: 1. Recruitment rate (target ≥75%) 2. Protocol adherence (≥85%) 3. Data completeness (≥95%) 4. Safety monitoring of adverse events.
Secondary (exploratory) objectives: Compare 28-day ventilator-free days (VFDs), mortality, ICU/hospital length of stay, and ICU-acquired weakness.
Methods: This is a multicenter, prospective, pilot RCT in Alberta ICUs. 100 adult patients with moderate to severe ARDS will be randomized within 24 hours of diagnosis to either: 1. Intermittent bolus NMBA dosing OR 2. Continuous NMBA infusion (up to 48 hours). Both arms will receive lung-protective ventilation and guideline-based sedation.
Analysis: Feasibility outcomes will be described with 95% confidence intervals. Exploratory clinical outcomes will follow intention-to-treat principles using regression models. Results will inform design and sample size for a full-scale trial.
Risks \& Mitigation: Risks such as protocol non-adherence, ICU-acquired weakness, and data loss will be managed via clinician education, adherence monitoring, and real-time data checks. Safety protocols, including allowance for rescue boluses and adherence to sedation best practices, will be enforced.
Team: Led by Drs. Parhar and Doig with a multidisciplinary team of critical care and clinical trial experts, the group has a strong track record in ICU research and implementation.
Significance \& Knowledge Translation: This study addresses a critical evidence gap in ARDS care. Findings will inform future guidelines and practice by establishing whether bolus NMBA administration is a feasible, effective, and safer alternative to continuous infusion. Results will be disseminated through academic and clinical networks and will lay the groundwork for a large-scale, definitive RCT.
- Being tested
- Neuromuscular Blocking Agent - Bolus Dosing, Neuromuscular Blocking Agent - Continuous Infusion
- Keywords
- ARDS, Neuromuscular Blockade, mechanical ventilation
- Medical subject headings
- Acute Lung Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Neuromuscular Blocking Agent - Bolus DosingDrug
Also called Bolus dosing
Intermittent administration of NMBA
Neuromuscular Blocking Agent - Continuous InfusionDrug
Also called Continuous infusion
Continuous infusion of NMBA
| Study group | Role | What they receive |
|---|---|---|
| Bolus Dosing | Experimental | Bolus dosing Receives: Drug: Neuromuscular Blocking Agent - Bolus Dosing |
| Continuous Infusion | Active comparator | Continuous infusion Receives: Drug: Neuromuscular Blocking Agent - Continuous Infusion |
What is being measured
The primary outcome is the main question the study is designed to answer.
Recruitment rate among eligible patients
Recruitment rate among eligible patients
Measured: Within 48 hours of meeting ARDS criteria
Protocol adherence rate
Protocol adherence rate
Measured: for the first 28 days of mechanical ventilation
Proportion of missing baseline characteristics and outcomes
Proportion of baseline characteristics and outcomes that are missing
Measured: First 28 days of invasive ventilation post ARDS diagnosis.
Compositive Safety
rates of ICU acquired weakness, unplanned extubation, and other SAE
Measured: First 28 days of invasive ventilation post ARDS diagnosis.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 May 2026
- Study start1 Jan 2027 (estimated)
- Primary completion1 Jan 2027 (estimated)
- Study completion1 Jan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ARDS (Acute Respiratory Distress Syndrome)Studies of the same condition, open and under way.
- More trials run by University of CalgaryThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Calgary
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ken Kuljit Parhar, MD, University of Calgary
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07567768
- Sponsor's protocol ID
- REB25-1049
- Acronym
- COBRA
- Status last verified
- May 2026
- First submitted
- 13 Jun 2025
- Last updated
- 14 May 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Continuous vs Bolus Neuromuscular Blockade Regimens for Patients With Moderate to Severe Hypoxemic Respiratory Failure and ARDS (COBRA): A Pilot Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07567768
- Acronym / sponsor ID
- COBRA / REB25-1049
- Keywords
- ARDS, Neuromuscular Blockade, mechanical ventilation
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- University of CalgaryUniversity, hospital or other
- Study start
- 1 Jan 2027 (estimated)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 1 Jan 2028 (estimated)
- First posted
- 5 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Current clinical guidelines, such as those from the Surviving Sepsis Campaign and ARDSNet, recommend short-term NMBA use for patients with moderate to severe ARDS who exhibit persistent ventilator dyssynchrony or high plateau pressures despite deep sedation . However, they do not provide clear recommendations regarding the mode of administration. As a result, clinicians are left to extrapolate from limited or indirect evidence, which may lead to practice variation, uncertainty, and suboptimal care.
This pilot randomized controlled trial is designed to directly address this critical gap by comparing intermittent bolus administration versus continuous infusion of NMBAs in a pragmatic, real-world ICU setting. The study will assess feasibility metrics necessary to plan a definitive trial and generate preliminary clinical data on safety and effectiveness. By clarifying the comparative benefits and risks of each approach, the results may influence practice guidelines, reduce variation in care, and improve patient outcomes and reduce practice variation.patient outcomes, optimize resource use, and inform future guidelines on the management of moderate to severe ARDS.
Detailed description
Study Title: The Effect of Continuous vs Bolus Neuromuscular Blockade for Patients with Moderate to Severe HRF and ARDS: A Pilot Randomized Controlled Trial
Background:
Acute Respiratory Distress Syndrome (ARDS) affects ~10% of ICU patients and carries high morbidity and mortality. Neuromuscular blockade agents (NMBAs), especially cisatracurium, have historically been administered via continuous infusion to improve oxygenation and reduce ventilator-induced lung injury. However, recent evidence (e.g., ROSE trial) questions this approach, and emerging guidelines suggest intermittent bolus dosing may offer similar benefits with fewer adverse effects. There is a lack of direct comparative data, creating uncertainty in clinical practice.
Hypothesis \& Objectives:
The study hypothesizes that a multicenter RCT comparing intermittent bolus vs continuous NMBA infusion in ARDS is feasible and that bolus dosing may show trends toward improved outcomes (e.g., ventilator-free days, fewer adverse events).
Primary objective: Assess feasibility of a definitive trial. Feasibility aims: 1. Recruitment rate (target ≥75%) 2. Protocol adherence (≥85%) 3. Data completeness (≥95%) 4. Safety monitoring of adverse events.
Secondary (exploratory) objectives: Compare 28-day ventilator-free days (VFDs), mortality, ICU/hospital length of stay, and ICU-acquired weakness.
Methods: This is a multicenter, prospective, pilot RCT in Alberta ICUs. 100 adult patients with moderate to severe ARDS will be randomized within 24 hours of diagnosis to either: 1. Intermittent bolus NMBA dosing OR 2. Continuous NMBA infusion (up to 48 hours). Both arms will receive lung-protective ventilation and guideline-based sedation.
Analysis: Feasibility outcomes will be described with 95% confidence intervals. Exploratory clinical outcomes will follow intention-to-treat principles using regression models. Results will inform design and sample size for a full-scale trial.
Risks \& Mitigation: Risks such as protocol non-adherence, ICU-acquired weakness, and data loss will be managed via clinician education, adherence monitoring, and real-time data checks. Safety protocols, including allowance for rescue boluses and adherence to sedation best practices, will be enforced.
Team: Led by Drs. Parhar and Doig with a multidisciplinary team of critical care and clinical trial experts, the group has a strong track record in ICU research and implementation.
Significance \& Knowledge Translation: This study addresses a critical evidence gap in ARDS care. Findings will inform future guidelines and practice by establishing whether bolus NMBA administration is a feasible, effective, and safer alternative to continuous infusion. Results will be disseminated through academic and clinical networks and will lay the groundwork for a large-scale, definitive RCT.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Bolus Dosing | Experimental | Drug: Neuromuscular Blocking Agent - Bolus DosingBolus dosing |
| Continuous Infusion | Active comparator | Drug: Neuromuscular Blocking Agent - Continuous InfusionContinuous infusion |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age ≥18 years
- Mechanically ventilated and on a controlled ventilation mode
- Diagnosis of moderate to severe ARDS (PaO₂/FiO₂ ≤150 mmHg on PEEP ≥5 cm H₂O)
- Bilateral pulmonary infiltrates consistent with ARDS
- Randomized within 24 hours of meeting ARDS criteria
Key exclusion criteria (5 listed)
- Pregnancy
- Known allergy or contraindication to rocuronium
- Neuromuscular disorders (e.g., myasthenia gravis, Guillain-Barré syndrome)
- Brain death or decision for withdrawal of life-sustaining therapy
- Enrollment in a conflicting interventional trial
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Neuromuscular Blocking Agent - Bolus DosingAlso: Bolus dosingIntermittent administration of NMBA | Drug | Bolus Dosing |
| Neuromuscular Blocking Agent - Continuous InfusionAlso: Continuous infusionContinuous infusion of NMBA | Drug | Continuous Infusion |
Primary outcome
Recruitment rate among eligible patients
Time frame: Within 48 hours of meeting ARDS criteria
Recruitment rate among eligible patients
Protocol adherence rate
Time frame: for the first 28 days of mechanical ventilation
Protocol adherence rate
Proportion of missing baseline characteristics and outcomes
Time frame: First 28 days of invasive ventilation post ARDS diagnosis.
Proportion of baseline characteristics and outcomes that are missing
Compositive Safety
Time frame: First 28 days of invasive ventilation post ARDS diagnosis.
rates of ICU acquired weakness, unplanned extubation, and other SAE
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 May 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Neuromuscular Blocking Agent - Bolus Dosing and Neuromuscular Blocking Agent - Continuous Infusion in people with ARDS (Acute Respiratory Distress Syndrome), run by University of Calgary.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 14 May 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ken Parhar, MD MSc MPH (000-000-0000, ken.parhar@albertahealthservices.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Recruitment rate among eligible patients (time frame: Within 48 hours of meeting ARDS criteria). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 May 2026.