Management of Post-operative Respiratory Failure by Using NIV and High Velocity Nasal Insufflation (HVNI)

Assiut University

Status: Not yet enrolling

Conditions: Respiratory Failure Without Hypercapnia; Respiratory Failure With Hypercapnia; Postoperative Respiratory Complication

Treatments: Device: Vapotherm; Device: BIPAP

Study type: Interventional

Funder types: Other

Identifiers

NCT06988111

375690

Details and patient eligibility

About

Postoperative respiratory failure (PORF) remains a critical driver of morbidity, mortality, and incremental care costs in surgical populations. Traditional escalation often involves invasive mechanical ventilation, which is associated with ventilator-associated pneumonia (VAP), prolonged intensive care unit (ICU) stays, and increased resource burden.

Full description

Noninvasive ventilation (NIV) and high-flow nasal cannula (HFNC) have both been shown to improve oxygen levels effectively and reduce the need for reintubation in various patient groups. However, head-to-head data in patients with obstructive or restrictive pulmonary function (PORF) are scarce.

This protocol employs a robust and scalable design to generate high-quality evidence, empower perioperative stakeholders, and optimize patient-centric respiratory strategies. We hypothesize that NIV will reduce 72-hour reintubation rates compared to HFNC, translating into shorter ICU stays and lower costs.

Methodology & Operational Workflow

• Screening & Consent Identify eligible patients in the post-anesthesia care unit (PACU) or ICU. Obtain informed consent from the patient or legal surrogate.
• Baseline Assessment The baseline assessment includes demographics, comorbidities, and surgical data, as well as baseline arterial blood gases (ABG), vital signs, and comfort scores.
• Randomization & Initiation Allocate via a secure web-based randomization module. Initiate assigned respiratory support within 30 minutes of notification.
• Monitoring & Data Collection The patient is receiving continuous pulse oximetry and respiratory rate monitoring.

ABGs and fraction of inspired oxygen (FIO2) at 1 hour, 6 hours, and 24 hours. Comfort scores every six hours. Record interface-related adverse events.

• Escalation Criteria The patient exhibits persistent partial arterial oxygen pressure/fraction of inspired oxygen ratio (PaO2/FiO2) levels of less than 100, even at maximal settings.

Hemodynamic instability occurs due to the use of new-onset vasopressors. Deterioration leading to invasive ventilation → classified as "reintubation."

• Weaning Protocol. Transition to standard oxygen therapy when the flow or pressure is minimal.
• Follow-Up & Discharge Track ICU length of stay (LOS), hospital LOS, and ventilation-free days (VFD). Keep a record of the 30-day survival rate and any readmissions.
• Statistical Analysis Plan Primary Endpoint: Compare reintubation rates using a χ² test; report the risk difference and 95% confidence interval.
• Missing Data: Multiple imputation for datasets with ≤ 5% missing data; sensitivity analysis for worst-case scenarios.
• Interim Analysis: After 50% enrollment, the Data Safety and Monitoring Board (DSMB) reviews efficacy and futility, using O'Brien-Fleming boundaries.

Enrollment: 180 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age above 18 years
• within 48 hours after major surgery
• PAO2/FIO2 less than 200
• Signs of respiratory distress and respiratory rate (RR) more than 25 cycles/minute

Exclusion criteria

• Age below 18 years
• Pregnant ladies
• Orofacial trauma or burns
• Active Gastrointestinal bleeding

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

---

180 participants in 2 patient groups

Non-invasive Ventilation group

Experimental group

Description:

NIV Arm * Device: Bi-level positive airway pressure (BiPAP) via oronasal mask. * Initial settings: inspiratory positive airway pressure (IPAP) 10 cmH₂O, expiratory positive airway pressure (EPAP) 5 cmH₂O, and fraction of inspired oxygen (FiO₂) titrated to oxygen saturation (SpO₂) ≥ 92%. * Weaning: Decrement IPAP/EPAP by 2 cmH₂O every four hours as tolerated.

Treatment:

Device: BIPAP

High Velocity Nasal Cannula (HVNC) group

Experimental group

Description:

HVNC Arm * Device: Heated, humidified high-flow nasal cannula (HFNC) system. * Initial flow: 50 L/min, fraction of inspired oxygen (FiO₂) titrated to SpO₂ ≥ 92%. * Weaning: Reduce flow by 10 L/min every 4 h as tolerated.

Treatment:

Device: Vapotherm