Effects of Nasal Ventilation on Cerebral and Pulmonary Function in Orally Intubated Patients

NCT ID: NCT06438302

Last Updated: 2025-12-03

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 22 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-01-31
• Study Completion Date: 2028-02-01

Brief Summary

The passage of air through the nasal cavity generates rhythmic oscillations transmitted by the olfactory bulb to the brain, which induces cerebral activation in functional areas and is associated with better cognitive performance compared to oral breathing. Consequently, the abolition of nasal ventilation in patients intubated via the orotracheal route could have deleterious effects on brain activity. Besides the loss of olfaction, the abolition of nasal ventilation could affect brain activity and respiratory control, consequently altering regional pulmonary ventilation.

The hypothesis of the study is that nasal ventilation through the passage of humidified nasal airflow in patients intubated via the orotracheal route would be associated with modulation of cerebral electrical activity and tissue oxygenation and a modification of regional pulmonary ventilation.

Detailed Description

The effects of nasal ventilation on cerebral activity will be studied on orally intubated and sedated patients in six experimental conditions. The first condition consists of nociceptive stimulation of the left upper limb as a negative control. In three conditions, the inspired fraction of oxygen (FiO2) will remain at 21% while applying three different rates of humidified nasal air at 0L/min, 30L/min and 60L/min respectively. The last two conditions consist of applying humidified nasal air at 30L/min and 60L/min with a FiO2 of 100%. The primary objective of this study is to evaluate the effects of high-flow humidified nasal air on electroencephalogram activity (root mean square gamma frequency) in sedated, orally intubated patients. The secondary objectives of the study are to evaluate the effects of high-flow humidified nasal air on cerebral perfusion and oxygenation, gas exchange and regional pulmonary ventilation in the same patients.

Conditions

Hypoxemic Acute Respiratory Failure

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Major mechanically ventilated patients intubated orotracheally

The study population will be adult patients with acute respiratory failure who are orally intubated and sedated. These patients should be free of neurological and psychiatric diseases prior to ICU admission. The choice of this particular population is justified by its exposure to mechanical ventilation and continuous sedation, which are recognized risk factors for brain damage.

EEG activity measurement

Intervention Type: DEVICE

The nasal ventilation device (placed as part of the research) (AIRVO 2; Fisher and Paykel Healthcare, Auckland, New Zealand) will be positioned via nasal cannulas adapted to the patient's anatomy. The FiO2 will be set at 21% and the flow rate will be fixed at 0 L/min at the inclusion visit. The temperature of the humidified nasal oxygenator will be set at 31°C.

Six 30-minute experimental conditions will be performed successively: 1) 0 L/min flow, FiO2 21%, 2) 30 L/min flow, FiO2 21%, 3) 30 L/min flow, FiO2 100%, 4) 60 L/min flow, FiO2 21%, 5) 60 L/min flow, FiO2 100%, 6) Negative control.

At the end of each condition, a 10-minute thoracic electrical impedance tomography recording, a 10-minute EEG recording, a 10-minute cerebral NIRS recording and an instantaneous temporal Doppler velocity measurement will be performed. A blood gas (1.5 mL) will also be taken at the end of each condition.

Interventions

EEG activity measurement

The nasal ventilation device (placed as part of the research) (AIRVO 2; Fisher and Paykel Healthcare, Auckland, New Zealand) will be positioned via nasal cannulas adapted to the patient's anatomy. The FiO2 will be set at 21% and the flow rate will be fixed at 0 L/min at the inclusion visit. The temperature of the humidified nasal oxygenator will be set at 31°C.

Six 30-minute experimental conditions will be performed successively: 1) 0 L/min flow, FiO2 21%, 2) 30 L/min flow, FiO2 21%, 3) 30 L/min flow, FiO2 100%, 4) 60 L/min flow, FiO2 21%, 5) 60 L/min flow, FiO2 100%, 6) Negative control.

At the end of each condition, a 10-minute thoracic electrical impedance tomography recording, a 10-minute EEG recording, a 10-minute cerebral NIRS recording and an instantaneous temporal Doppler velocity measurement will be performed. A blood gas (1.5 mL) will also be taken at the end of each condition.

Intervention Type: DEVICE

Other Intervention Names

Post-intubation nasal ventilation; Additional blood samples (from care catheter 1.5 mL); Electrical impedance tomography

Eligibility Criteria

Inclusion Criteria

1. Age ≥ 18 years old

2. Hypoxemic acute respiratory failure

3. Intubation and mechanical ventilation since less than 4 days

4. PaO2/FiO2 ratio less than 200

5. RASS<-4

6. Consent obtained from next of kin

7. Patient with health insurance

Exclusion Criteria

1. Central nervous system diseases (stroke, MS, epilepsy)

2. Psychiatric illnesses (psychosis, depression) (indicated on patient's medical record)

3. Hemodynamic instability (noradrenalin>2mg/h)

4. Patient on AME

5. Patients under legal protection (guardianship/curators)

6. Pregnant or breast-feeding women

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Assistance Publique - Hôpitaux de Paris

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Service de Médecine Intensive Réanimation - Hôpital Pitié -Salpêtrière

Paris, , France

Site Status: RECRUITING

Countries

France

Central Contacts

Martin Dres

Role: CONTACT

martin.dres@aphp.fr

0142167809

Facility Contacts

Martin DRES, Pr

Role: primary

martin.dres@aphp.fr

0142167809 ext. +33

Other Identifiers

APHP240271

Identifier Type: -

Identifier Source: org_study_id