Progressive Pressure Support Reduction as Inspiratory Muscle Endurance Training in Mechanically Ventilated Patients

NCT07689110 | Not Yet Recruiting DMC

• 1 other identifier: INSPIRA-RCT-2026-HACunqueiro
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

Mechanical ventilation causes rapid diaphragm muscle atrophy, detectable within 18 hours of ventilator support, which is a major contributor to weaning failure and prolonged ICU stay. This randomized controlled trial tests whether a physiotherapist-guided inspiratory endurance training program - achieved by progressively reducing pressure support (PS) levels on the ventilator - can preserve or improve inspiratory muscle strength and diaphragm structure in critically ill adults on mechanical ventilation, compared to standard ICU care. Participants will be randomly assigned to one of two groups. The intervention group will receive twice-daily training sessions (weekdays only) in which the physiotherapist gradually reduces PS by up to 50% of the baseline level, causing the patient to breathe with greater muscular effort - equivalent to progressive endurance exercise for the diaphragm. The control group will receive standard weaning care as directed by the attending intensivist. The primary outcome is maximal inspiratory pressure (PImax) at day 7. Secondary outcomes include diaphragm thickening fraction measured by ultrasound, time to successful extubation, weaning success rate, and mortality. All measurements are performed by the ICU physician (blinded to group allocation) using airway occlusion maneuvers recorded on the ventilator and diaphragm ultrasound, following a standardized protocol.

Conditions

Respiratory Muscle Weakness; Physiotherapy; Endurance Training; Mechanical Ventilation Weaning

Outcome Measures

Primary Outcomes (1)

• Maximal Inspiratory Pressure (PImax)

  Measured by manual airway occlusion at end-expiration with pressure curve recorded on the ventilator. Standardized verbal instruction given to the patient. Best of 3 valid maneuvers recorded. Performed by the ICU physician blinded to group allocation.

  Day 7 from randomization

Secondary Outcomes (11)

• Diaphragm Thickening Fraction (DTF)

  Days 0, 3, 7 and 14 from randomization

• P0.1 (Airway Occlusion Pressure at 100ms

  Baseline and days 3, 7 and 14; and at start, mid and end of each training session (intervention group)

• Time to Successful Extubation

  From randomization until extubation, up to 14 days

• Weaning Success Rate

  Days 7 and 14 from randomization

• Sustained Pressure Support Reduction

  days 1, 3, 5 and 7 from randomization

Study Arms (2)

Inspiratory Resistance Training (IRT-PS)

EXPERIMENTAL

Physiotherapist-guided inspiratory endurance training by progressive pressure support reduction (25-50% of baseline PS), 1-3 sets of 5-15 minutes, twice daily on weekdays, for up to 14 days or until extubation. Target: Borg CR10 score 3-5. P0.1 monitored continuously; sessions stopped if P0.1 \> 4 cmH2O sustained \> 2 minutes.

Behavioral: Progressive Pressure Support Reduction (IRT-PS)

Standard Care (Usual Care)

ACTIVE COMPARATOR

Conventional weaning as directed by the attending intensivist, without a structured inspiratory muscle training program. Conventional physiotherapy (early mobilization, chest physiotherapy) is permitted in both groups.

Other: Standard ICU Care

Interventions

Progressive Pressure Support Reduction (IRT-PS) BEHAVIORAL

Progressive reduction of pressure support (PS) during ventilator-assisted breathing, performed by a physiotherapist twice daily (weekdays only). Sessions consist of 1-3 sets of 5-15 minutes with 2-minute rest intervals at baseline PS. PS is reduced by 25% initially up to a maximum of 50% of baseline (minimum 5 cmH2O) for PS ≥10 cmH2O; by 1-2 cmH2O for PS 5-9 cmH2O; and by 1 cmH2O down to 0 cmH2O for PS \<5 cmH2O. Target perceived exertion: Borg CR10 3-5. P0.1 monitored continuously; session stopped if P0.1 \>4 cmH2O sustained \>2 minutes (Goligher et al. criteria). Safety stop criteria: RR \>35 rpm, SpO2 \<90%, HR \>120 bpm.

Inspiratory Resistance Training (IRT-PS)

Standard ICU Care OTHER

Conventional weaning managed by the attending intensivist according to standard clinical practice, without a structured inspiratory muscle training protocol. Conventional physiotherapy (early mobilization, chest physiotherapy) permitted in both groups.

Standard Care (Usual Care)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 18 years
• Admitted to ICU with invasive mechanical ventilation for more than 48 hours at the time of randomization
• Expected to remain intubated for at least 24 additional hours, at the discretion of the attending intensivist
• Active pressure support ventilation (PSV) mode with PS level ≥ 5 cmH2O
• Richmond Agitation-Sedation Scale (RASS) score between -1 and +1
• Arterial pH ≥ 7.35 and serum lactate ≤ 2.0 mmol/L
• Peripheral oxygen saturation (SpO2) ≥ 90% with current FiO2
• Informed consent obtained from patient or legal representative

You may not qualify if:

• Neurological condition affecting central respiratory control (high cervical spinal cord injury, ALS, myasthenia gravis, active Guillain-Barré syndrome)
• Restriction on head-of-bed elevation to ≥ 30 degrees
• Decision to limit therapeutic effort (LET) or life expectancy \< 48 hours
• Active hemodynamic instability (requirement for ≥ 2 vasopressors or vasopressor adjustment within the last 6 hours)
• Multiple rib fractures or undrained pneumothorax
• Simultaneous participation in another interventional clinical trial

Sponsors & Collaborators

• University of Santiago de Compostela: lead

Study Sites (1)

Hospital Álvaro Cunqueiro

Vigo, Spain

Location

Central Study Contacts

Ricardo Miguel Rodrigues-Gomes

CONTACT

+34618060702; ric.mr.gomes@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Asociate Profesor

Study Record Dates

• First Submitted: May 23, 2026
• First Posted: July 8, 2026
• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): March 30, 2028
• Last Updated: July 8, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

ES (1)