Respiratory Drive and Inspiratory Effort in COVID-19 Associated ARDS

University of Turin

Status: Completed

Conditions: Weaning Failure; Acute Hypoxic Respiratory Failure; COVID-19 Respiratory Infection; Mechanical Ventilation Complication; COVID-19 Acute Respiratory Distress Syndrome; Respiratory Effort-Related Arousal; ARDS, Human

Treatments: Other: Respiratory drive and effort assessment

Study type: Observational

Funder types: Other

Identifiers

NCT06224010

CE 0084148

Details and patient eligibility

About

Data comparing respiratory drive and effort in critically ill patients with acute respiratory distress syndrome associated to different severity of COVID-19 penumonia (CARDS) and to other risk factors are lacking. Objectives: To assess respiratory drive and effort of CARDS patients at the first transition from controlled to assisted spontaneous breathing. The second aim was the rate of a composite outcome including the need of higher level of sedation

Full description

Multicenter cohort study in four Italian ICU including adults with moderate and severe CARDS (PaO2/FiO2 <100 mmHg) at ICU admission. An historical cohort of patients with ARDS from various etiologies used for comparison. Respiratory drive (P0.1), diaphragm electrical activity (EAdi), inspiratory effort derived from EAdi (∆PmusEAdi) and from deflection in airway pressure occluded (ΔPocc) (PmusΔPocc), dynamic transpulmonary driving pressure (ΔPL,dyn, the difference between peak and end-expiratory transpulmonary pressure) measured under assisted ventilation.

The main ventilatory pattern variables:

• Airway Occlusion Pressure (P0.1): Measurement of the decrease in airway pressure during an end-expiratory occlusion.
• Pmus-EAdi-derived (∆Pmus, EAdi): Measurement of the pressure generated by the respiratory muscles during inspiration derived by electrical activity of the diaphragm measurements.
• Transpulmonary pressure EAdi-derived (∆Plung,dyn): difference between peak and end-expiratory transpulmonary pressure .
• Occlusive Pressure Difference (∆Pocc): Evaluation of the pressure difference between the initial and final airway opening during inspiration.
• Pmus-∆Pocc-derived (∆Pmus, ∆Pocc): Measurement of the pressure generated by the respiratory muscles during inspiration derived by ∆Pocc (∆Pocc*0.75)
• Transpulmonary driving pressure ∆Pocc derived (∆Plung, ∆Pocc): calculated as (Peak airway pressure -PEEP) - 2/3 * ∆Pocc
• Diaphragmatic Electrical Activity (EAdi): Recording of the electrical activity of the diaphragm.
• Peak EAdi (EAdiPEAK): Determination of the highest recorded value of diaphragmatic electrical activity.
• Pressure time product of the trans-diaphragmatic pressure per breath and per minute(PTP/min): the integral of Pmusc-EAdi-derived during inspiration per breath.
• Inspiratory Delay (ID): Assessment of the time delay between the start of neural inspiration and the onset of mechanical ventilation.
• Neuro-ventilatory Efficiency (NVE): Measurement of the efficiency of the neural drive to the respiratory muscles.
• Peak Airway Opening Pressure (PawPEAK): Measurement of the peak pressure in the airway during inspiration.
• Inspiratory Pressure-Time Product (PmusEAdi/b): Calculation of the work of breathing by integrating the product of diaphragmatic electrical activity and the change in airway pressure during inspiration.
• Tidal Volume (VT): Measurement of the volume of air inspired and expired during each breath.
• Respiratory Rate: Calculation of the number of breaths per minute delivered by the mechanical ventilator.
• Inspiratory and Expiratory Time (Ti,MECH and Te,MECH): Determination of the duration of mechanical inspiration and expiration.
• Inspiratory Duty Cycle (TI/TTOT-neur): Calculation of the ratio of inspiratory time to total respiratory cycle time based on neural inspiration.

Enrollment: 56 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients with a diagnosis of acute respiratory distress syndrome based on the Berlin criteria.
• Patients with ARDS due to confirmed COVID-19 through real-time RT-PCR on nasopharyngeal swabs or lower respiratory tract aspirates.
• Patients who had received invasive mechanical ventilation for more than 72 hours.
• Patients who were candidates for assisted ventilation.

Readiness for assisted ventilation, which was defined by the following criteria:

1. Improvement of the condition leading to acute respiratory failure.

2. Positive end-expiratory pressure lower than 10 cmH2O and inspiratory oxygen fraction lower than 0.5.

3. Richmond agitation sedation scale score between 0 and -3.

4. Ability to trigger the ventilator, i.e., decrease pressure airway opening by more than 3-4 cmH2O during a brief (5-10 seconds) end-expiratory occlusion test.

   • Hemodynamic stability without vasopressor or inotropes, except for dobutamine and norepinephrine infusion below certain thresholds (dobutamine <5 gamma/Kg/min and norepinephrine <0.3 gamma/Kg/min).
   • Normothermia.

Exclusion criteria

• Patients affected by neurological or neuromuscular pathology and/or known phrenic nerve dysfunction.
• Patients with any contraindication to the insertion of a nasogastric tube, such as recent upper gastrointestinal surgery or esophageal varices.
• Patients < 18 years old

Trial design

56 participants in 3 patient groups

Non-COVID

Description:

* This group includes patients diagnosed with Acute Respiratory Distress Syndrome (ARDS) caused by etiologies other than COVID-19. * ARDS was defined following Berlin criteria (2012)

Treatment:

Other: Respiratory drive and effort assessment

COVID-Moderate

Description:

* Moderate COVID indicates a less severe level of hypoxemia compared to the Severe COVID group (according to Berlin criteria). * The moderate COVID group is further characterized by a diagnosis of moderate Acute Respiratory Distress Syndrome (ARDS), based on a P/F ratio (partial pressure of oxygen/fraction of inspired oxygen) at ICU admission. * The diagnosis of COVID-19 in these patients was confirmed using the Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) technique. * RT-PCR involves collecting a sample from the lower respiratory tract and detecting the presence of SARS-CoV-2 viral RNA.

Treatment:

Other: Respiratory drive and effort assessment

COVID-Severe

Description:

* The severe COVID group has a diagnosis of Acute Respiratory Distress Syndrome (ARDS) * The severity of COVID-19 in this group is determined by a P/F ratio at ICU admission, indicating a higher level of hypoxemia and a more critical clinical condition. * The diagnosis of COVID-19 in these patients was confirmed using the Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) technique. * RT-PCR involves collecting a sample from the lower respiratory tract and detecting the presence of SARS-CoV-2 viral RNA.

Treatment:

Other: Respiratory drive and effort assessment