Prophylactic Use of APRV Before Extubation in Morbidly Obese Patients After Cardiac Surgery.

NCT07409324 | Not Yet Recruiting DMC

• 1 other identifier: FMASU MD288/2025
• Study Type: interventional
• Target: 180
• Locations: 0 countries
• Sites: N/A

Brief Summary

Morbidly obese patients undergoing open heart surgery are at increased risk of breathing problems after removal of the breathing tube due to reduced lung function and chest wall restriction following surgery. These complications may result in poor oxygenation, respiratory failure, and prolonged ICU stay. Airway Pressure Release Ventilation (APRV) is a mechanical ventilation mode that improves lung recruitment and oxygenation. This study aims to evaluate whether the prophylactic use of APRV after ICU admission, compared with conventional lung-protective mechanical ventilation, improves oxygenation, lung function, and ICU outcomes in morbidly obese patients undergoing elective cardiac surgery. Patients will be randomly assigned to receive either APRV or conventional ventilation during postoperative mechanical ventilation, followed by standard weaning and extubation. Outcomes include oxygenation index, lung ultrasound findings, need for reintubation, and ICU clinical outcomes.

Conditions

Morbid Obesity in Cardiac Surgery Patients; Postoperative Respiratory Dysfunction; Mechanical Ventilation Strategies

Keywords

Airway Pressure Release Ventilation; Morbid Obesity; Cardiac Surgery; Postoperative Ventilation; Lung Ultrasound; Oxygenation

Outcome Measures

Primary Outcomes (1)

• Oxygenation Index (OI)

  The oxygenation index will be used as a quantitative measure of pulmonary oxygenation efficiency. It will be calculated using the formula: OI = (Mean Airway Pressure × FiO₂ × 100) / PaO₂. Changes in oxygenation index will be assessed to compare the effect of prophylactic APRV versus conventional lung-protective ventilation on pulmonary function in morbidly obese patients after elective cardiac surgery.

  o Immediately before APRV initiation o 1 hour before extubation o 1 hour post-extubation o 6 hours post extubation o 24 hours post extubation

Secondary Outcomes (7)

• Lung Ultrasound Score (LUS)

  o 1 hour before extubation o 6 hours post extubation

• PaO₂/FiO₂ Ratio

  o Immediately before APRV initiation o 1 hour before extubation o 1 hour post-extubation o 6 hours post extubation o 24 hours post extubation

• Reintubation Rate

  Within 48 hours after extubation

• Duration of Mechanical Ventilation

  From ICU admission until successful extubation, assessed up to 24 hours

• Incidence of Post-Extubation Pulmonary Complications

  Within 48 hours post-extubation

Study Arms (2)

APRV Ventilation Strategy Group

EXPERIMENTAL

Intervention Name: Airway Pressure Release Ventilation (APRV) Patients will receive airway pressure release ventilation immediately upon admission to the intensive care unit following elective cardiac surgery. APRV will be applied as the primary ventilatory mode until the patient fulfills predefined extubation readiness criteria. Prior to extubation, patients will be transitioned to continuous positive airway pressure (CPAP) with pressure support or a T-piece trial for 15-30 minutes according to ICU protocol.

Device: Airway Pressure Release Ventilation (APRV)

Conventional Lung-Protective Ventilation Group

ACTIVE COMPARATOR

Patients will receive conventional lung-protective mechanical ventilation using synchronized intermittent mandatory ventilation (SIMV) in volume-controlled mode with a tidal volume of 6-8 mL/kg of ideal body weight and high positive end-expiratory pressure upon admission to the intensive care unit. Ventilation will be continued until extubation readiness criteria are met, followed by a CPAP with pressure support or T-piece trial for 15-30 minutes prior to extubation.

Device: Conventional Lung-Protective Mechanical Ventilation

Interventions

Airway Pressure Release Ventilation (APRV) DEVICE

Patients will be ventilated using the Airway Pressure Release Ventilation (APRV) mode immediately upon ICU admission. This mode will be maintained throughout the postoperative period until the patient meets the clinical criteria for extubation. with the following standardized steps: Initial APRV Settings * P High: 20-25 cm H₂O * P Low: 0 cm H₂O * T High: 4.0-6.0 seconds * T Low: 0.5-0.8 seconds * FiO₂: Adjusted to maintain SpO₂ \>92% Note: P High may be titrated according to patient tolerance, Mean airway pressure (MAP), and plateau pressures. T Low is set to terminate expiratory flow at 50-75% to preserve lung recruitment. Weaning/Transition from APRV to Extubation Once oxygenation and ventilation criteria are met: * T High will be gradually increased (to ≥8 sec) and P High decreased (to 10-15 cm H₂O) * Then transition to CPAP/PS for 15-30 minutes Final decision for extubation will be based on successful spontaneous breathing trial (SBT) (RSBI \< 105) and clinical readiness

Also known as: APRV

APRV Ventilation Strategy Group

Conventional Lung-Protective Mechanical Ventilation DEVICE

Patients will be ventilated using the SIMV Volume-Controlled mode with lung-protective strategies: * Tidal volume: 6-8 mL/kg of Ideal Body Weight (IBW) * PEEP: Set at 8-12 cm H₂O, individualized based on oxygenation status * Respiratory rate: Adjusted to maintain normocapnia, typically starting from 12-18 breaths per minute * FiO₂: Titrated to maintain SpO₂ \> 92% * Also transition to CPAP/PS for 15-30 minutes as a transition before extubation will be applied.

Also known as: SIMV Volume-Controlled Ventilation

Conventional Lung-Protective Ventilation Group

Eligibility Criteria

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

You may qualify if:

• Adult patients aged 18-65 year of both sex.
• Morbidly obese patients (body mass index ≥ 40 kg/m² or ≥ 35 kg/m² with obesity-related comorbidities)
• Scheduled for elective cardiac surgery (CABG, valve, or combined) requiring cardiopulmonary bypass
• Planned postoperative admission to the cardiac surgical intensive care unit
• Patients eligible for mechanical ventilation with planned early extubation within 6-12 hours postoperatively
• Ability to provide written informed consent

You may not qualify if:

• Severe pulmonary disease (e.g., COPD GOLD III/IV, home oxygen therapy, and pulmonary fibrosis).
• Patients with history of previous spontaneous pneumothorax or postoperative pneumothorax.
• Intracranial hypertension or contraindication to APRV. Hemodynamically unstable on admission (MAP less than 65 mmHg) Vasopressor/inotropic score (VIS) more than 10 Requirement for postoperative extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pump (IABP).
• Inability to obtain informed consent

Sponsors & Collaborators

• Ain Shams University: lead

MeSH Terms

Conditions

Obesity, Morbid

Interventions

Continuous Positive Airway Pressure

Condition Hierarchy (Ancestors)

Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Positive-Pressure Respiration; Respiration, Artificial; Airway Management; Therapeutics; Respiratory Therapy

Study Officials

• Aya M Abbas, M.B.B.CH., M.Sc

  Ain Shams University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Aya M Abbas, M.B.B.CH., M.Sc

CONTACT

+201157115835; ayaaabbass75@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 24, 2026
• First Posted: February 13, 2026
• Study Start: February 1, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): November 1, 2026
• Last Updated: February 13, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: before 12/2026
• Access Criteria: free