Acute Respiratory Failure
Conditions
Keywords
Acute respiratory failure, High flow nasal cannulae, Electroencephalogram, Near infrared spectroscopy
Brief summary
Acute hypoxemic de novo respiratory failure (AHRF) is a common cause of admission to the intensive care unit (ICU). Its main cause is community-acquired pneumonia. Prevention of intubation relies, among other things, on high-flow nasal canulae (HFNC). However, approximately 40% of patients are intubated despite HFNC. Our team has developed measurements derived from electroencephalograms (EEG) and near-infrared spectroscopy (NIRS) that enable the study of brain-ventilation interactions. To date, these tools have been studied exclusively in intubated patients. the investigators now wish to study them in non-intubated patients. The objective of this study is to investigate the relationship between the brain and lungs in adult patients admitted to the intensive care unit for acute hypoxemic respiratory failure and for whom the attending physician has decided to initiate HFNC. Before and one hour after the introduction of HFNC, electroencephalogram (EEG), near-infrared spectroscopy (NIRS), and electromyogram (EMG) of the Scalen muscles will be collected. From these recordings, the following variables will be collected: 1) The density of the gamma (30-100 Hz), beta (13-30 Hz), alpha (8-12 Hz), theta (4-8 Hz), and delta (0.5-4 Hz) frequency spectrum of the EEG in each of the following right and left cortical regions: medial region of the prefrontal cortex, anterior region of the cingulate gyrus, posterior region of the cingulate gyrus, insula, somatosensory cortex, angular gyrus, lateral prefrontal cortex, and supplementary motor area; 2) Connectivity between these regions for each frequency spectrum; 3) Pre-inspiratory potential; 4) Rieman classifier; 5) Coherence and Granger causality between each frequency spectrum and the scalene muscles EMG. These variables will be compared before and 1 hour after initiation of HFNC and between patients who will be intubated because of HFNC failure and those who will not.
Detailed description
Acute hypoxemic de novo respiratory failure (AHRF) is a common cause of admission to the intensive care unit (ICU). Its main cause is community-acquired pneumonia. Prevention of intubation relies, among other things, on high-flow nasal canulae (HFNC). However, approximately 40% of patients are intubated despite HFNC. Our team has developed measurements derived from electroencephalograms (EEG) and near-infrared spectroscopy (NIRS) that enable the study of brain-ventilation interactions. To date, these tools have been studied exclusively in intubated patients. the investigators now wish to study them in non-intubated patients. The objective of this study is to investigate the relationship between the brain and lungs in adult patients admitted to the intensive care unit for acute hypoxemic respiratory failure and for whom the attending physician has decided to initiate HFNC. Before and one hour after the introduction of HFNC, electroencephalogram (EEG), near-infrared spectroscopy (NIRS), and electromyogram (EMG) of the Scalen muscles will be collected. From these recordings, the following variables will be collected: 1) The density of the gamma (30-100 Hz), beta (13-30 Hz), alpha (8-12 Hz), theta (4-8 Hz), and delta (0.5-4 Hz) frequency spectrum of the EEG in each of the following right and left cortical regions: medial region of the prefrontal cortex, anterior region of the cingulate gyrus, posterior region of the cingulate gyrus, insula, somatosensory cortex, angular gyrus, lateral prefrontal cortex, and supplementary motor area; 2) Connectivity between these regions for each frequency spectrum; 3) Pre-inspiratory potential; 4) Rieman classifier; 5) Coherence and Granger causality between each frequency spectrum and the scalene muscles EMG. These variables will be compared before and 1 hour after initiation of HFNC and between patients who will be intubated because of HFNC failure and those who will not.
Interventions
Two 10-minute recordings will be made. Each recording will include continuous collection of EEG, NIRS, and EMG data from the scalene muscles, as well as collection of intensive care monitoring variables every minute.
Sponsors
Study design
Eligibility
Inclusion criteria
* \- Age ≥ 18 years * Admitted to the intensive care within the last 48 hours * De novo acute hypoxemic respiratory failure with an indication for high-flow nasal cannula (HFNC), defined by the combination of the following three criteria: * Tachypnea \> 25 breaths/min or labored breathing * PaO2 (partial pressure of oxygen ) /FiO2 ( fraction of inspired oxygen ) ≤ 200 mmHg * Unilateral or bilateral alveolar opacities on chest X-ray * Decision by the attending physician to initiate HFNC treatment * After information, the patient or next of kind did not refuse to participate (according to the French law, written informed consent is waived)
Exclusion criteria
* \- Exacerbation of an underlying chronic respiratory disease * Acute cardiogenic pulmonary edema indicating non-invasive ventilation (NIV) * Hypercapnia \> 45 mmHg indicating NIV * Glasgow Coma Scale \< 13 * Imminent intubation * Underlying central neurological disease likely to alter EEG signals * Pregnancy or breastfeeding * Lack of health insurance coverage * Patient under legal protection
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| density of the gamma frequency spectrum of the EEG in the medial region of the right prefrontal cerebral cortex | before and 1 hour after initiation of high flow nasal cannulae | density of the gamma frequency spectrum (30 - 100 Hz) of the EEG in the medial region of the right prefrontal cerebral cortex, before initiation of HFO ( = high-flow oxygen), then 1 hour after its initiation |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The density of the gamma, beta, alpha, theta, and delta frequency spectrum | before and 1 hour after initiation of high flow nasal cannulae | The density of the gamma frequency spectrum (30-100 Hz) of the EEG in the following cortical regions: medial region of the left prefrontal cortex, anterior region of the right and left cingulate gyrus, posterior region of the right and left cingulate gyrus, right and left insula, right and left somatosensory cortex, right and left angular gyrus, right and left lateral prefrontal cortex, and right and left supplementary motor area. and the densities of the beta (13-30 Hz), alpha (8-12 Hz), theta (4-8 Hz), and delta (0.5-4 Hz) frequency spectra in each of the aforementioned right and left cortical regions. |
| Connectivity | before and 1 hour after initiation of high flow nasal cannulae | Connectivity between the medial region of the prefrontal cerebral cortex, the anterior region of the cingulate gyrus, the posterior region of the cingulate gyrus, the insula, the medial region of the prefrontal cortex, the somatosensory cortex, the angular gyrus, the lateral prefrontal cortex and the supplementary motor area, right and left, for the gamma (30-100 Hz), beta (13-30 Hz), right and left, alpha (8-12 Hz), right and left, theta (4-8 Hz) and delta (0.5-4 Hz), right and left frequency spectra. |
| pre-inspiratory potential | before and 1 hour after initiation of high flow nasal cannulae | the presence of a pre-inspiratory potential will be searched for |
| Riemann classifier | before and 1 hour after initiation of high flow nasal cannulae | The area under the curve of the receiver operating characteristics (ROC) of the Riemann classifier will be measured. |
| Coherence and Granger Causality | before and 1 hour after initiation of high flow nasal cannulae | The coherence between the EMG and the EEG frequency bands gamma (30-100 Hz), beta (13-30 Hz), right and left, alpha (8-12 Hz), theta (4-8 Hz), and delta (0.5-4 Hz), right and left. If significant coherence exists, the direction of the relationship is determined using Granger causality. |
| Oxyhemoglobin (HbO2) concentration | before and 1 hour after initiation of high flow nasal cannulae | Oxyhemoglobin (HbO2) concentration derived from optical densities (fNIRS) using the modified Beer-Lambert law, in the prefrontal and lateral regions of the cortex, right and left. |
| Change in amplitude for fNIRS frequencies (fNIRS) | before and 1 hour after initiation of high flow nasal cannulae | The change in amplitude for frequencies (fNIRS) between 1.0 and 1.25 Hz (related to heart rate), between 0.18 and 0.25 Hz (related to respiratory rate), between 0.08 and 0.13 Hz (related to myogenic frequency, sympathetic tone), between 0.05 and 0.07 Hz |
Countries
France
Contacts
APHP