Electrical Activity of the Diaphragm and Respiratory Mechanics During NAVA (NAVAMECH)

Evaluation of the Relationship Between Electrical Activity of the Diaphragm and Respiratory Mechanics During Neurally Adjusted Ventilatory Assist in Lung Transplant Patients and in Patients Affected by Acute Respiratory Failure.

Protective ventilatory strategy should be applied to reduce ventilator-induced lung injury (VILI) after Lung Transplantation (LTx) or in case of acute respiratory failure requiring invasive mechanical ventilation. Neurally Adjusted Ventilatory Assist (NAVA) is an assisted ventilation mode in which respiratory support is coordinated by the electrical activity of the diaphragm (EAdi). Aim of the study is to assess the physiological relationship between neural respiratory drive, as assessed by EAdi, and tidal volume, driving pressure, and mechanical power, at different levels of ventilatory assist, in the absence of pulmonary vagal afferent feedback or during acute respiratory failure. Additional parameters will be collected: Pmus, Pocc, transpulmonary pressure etc.

Study Overview

• Status: Recruiting
• Conditions: Ventilator-Induced Lung Injury; Lung Transplantation; Work of Breathing; Neurally Adjusted Ventilatory Assist; Acute Respiratory Failure (ARF)
• Intervention / Treatment: Device: NAVA GROUP

Detailed Description

Lung transplantation (LTx) is an important treatment option for select patients with end-stage pulmonary disease, while acute respiratory failure is a common disease among ICU patients. In the early period, following LTx or at the beginning of acute respiratory failure, a protective ventilatory strategy should be applied to reduce ventilator-induced lung injury (VILI). Neurally Adjusted Ventilatory Assist (NAVA) is an assisted ventilation mode in which neural inspiratory activity is monitored through the continuous recording of electrical activity of the diaphragm (EAdi) and then used to coordinate the respiratory support delivered by the ventilator.

NAVA, because of its intrinsic properties (proportionality between respiratory drive and level of assist, prevention of diaphragm atrophy), could allow the aforementioned ventilatory strategy, however it may require the integrity of the pulmonary vagal afferent feedback in order to avoid volutrauma. So, the aim of the study is the evaluation of the physiological relationship between EAdi and tidal volume, driving pressure and mechanical power, at different levels of ventilatory assist, in the absence of pulmonary vagal afferent feedback during early post-operative period after LTx and among critically ill patients affected by acute respiratory failure. Finally, additional parameters will be collected: Pmus, Pocc, transpulmonary pressure etc.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Annalisa Boscolo, MD; Phone Number: +390498213090; Email: annalisa.boscolobozza@aopd.veneto.it
• Study Contact Backup: Name: Nicolò Sella, MD; Phone Number: +390498213090; Email: nico.sella@hotmail.it

Study Locations

• Italy
  • Padova, Italy, 35120
    • Recruiting
    • Institute of Anaesthesia and Intensive Care, Padua University hospital
    • Contact: Annalisa Boscolo, MD, PhD; Phone Number: +393498324972; Email: annalisa.boscolobozza@aopd.veneto.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age > 18 y.o.
• Admission to ICU for post-operative monitoring after LTx or acute respiratory failure needing invasive mechanical ventilation
• Presence of spontaneous breathing activity
• Sedation titrated to a target RASS between 0 and -2
• Written informed consent obtained

Exclusion Criteria:

• Contraindication to nasogastric tube insertion (gastroesophageal surgery in the previous 3 months, gastroesophageal bleeding in the previous 30 days, history of esophageal varices, facial trauma)
• Increased risk of bleeding with nasogastric tube insertion, due to severe coagulation disorders and severe thrombocytopenia ( i.e., INR > 2 and platelets count < 70.000/mm3)
• Severe hemodynamic instability (noradenaline > 0.3 μg/kg/min and/or use of vasopressin)
• Postoperative extracorporeal respiratory support (ECMO)
• Pre-operative reconditioning of the transplanted lungs by means of ex-vivo lung perfusion (EVLP)
• Lung retransplantation
• Failure to obtain a stable EAdi signal

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: NAVA group; Nava ventilation	Device: NAVA GROUP; NAVA ventilation: Assisted Ventilation Mode, synchronized, through EAdi catheter, with patient's inspiratory effort and proportional to respiratory drive

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Electrical Activity of the Diaphragm (EAdi)	Evaluation of the variations of tidal volume Electrical Activity of the Diaphragm in response to different levels of ventilatory assist at different degrees of lung inflation (different Positive End Expiratory Pressure values). Electrical Activity of the Diaphragm (EAdi) (microVolt)	One hour after the recovery of spontaneous breathing
Tidal Volume (mL) and Respiratory rate (Breaths/min)	Evaluation of the changes in the patient's neural breathing pattern (expressed as mL of Tidal Volume) at different levels of ventilatory assist. Also patient's respiratory rate (Breaths/min) will be evaluated	One hour after the recovery of spontaneous breathing

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Driving pressure (DP)	Evaluation of the variations of DP in response to different levels of ventilatory assist at different degrees of lung inflation. The driving pressure formula is DP = P_plateau - PEEP. It represents the pressure difference between the plateau pressure (P_plateau) and the positive end-expiratory pressure (PEEP) during mechanical ventilation. Unit: mmHg or cmH2O.	One hour after the recovery of spontaneous breathing, with inspiratory hold manoeuvres
Occlusion Pression (Pocc)	Evaluation of the changes in the patient's respiratory effort (evaluated using Pocc) at different levels of ventilatory assist. The full breath occlusion pressure (Pocc) is the drop in airway-Pressre during a full occluded inspiratory effort. Unit: mmHg or cmH2O.	One hour after the recovery of spontaneous breathing

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
PaO2/FiO2 ratio	Evaluation of the changes in gas exchange, in particular in PaO2/FiO2 ratio, at different levels of ventilatory assist. The emogas analysis was collected from a peripheral artery.	One hour after the recovery of spontaneous breathing

Collaborators and Investigators

• Sponsor: University of Padova

Study record dates

Study Major Dates

• Study Start (Actual): December 27, 2022
• Primary Completion (Estimated): December 27, 2025
• Study Completion (Estimated): December 27, 2025

Study Registration Dates

• First Submitted: January 9, 2023
• First Submitted That Met QC Criteria: January 9, 2023
• First Posted (Actual): January 19, 2023

Study Record Updates

• Last Update Posted (Estimated): July 8, 2025
• Last Update Submitted That Met QC Criteria: July 1, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Keywords: Ventilator-Induced Lung Injury; Neurally Adjusted Ventilatory Assist; Lung Injury
• Additional Relevant MeSH Terms: Wounds and Injuries; Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Thoracic Injuries; Respiratory Distress Syndrome; Respiratory Insufficiency; Lung Injury; Ventilator-Induced Lung Injury
• Other Study ID Numbers: NAVAMECH

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No