Physiological Response in Lung Transplant Recipients Undergoing Neurally Adjusted Ventilatory Assist

Not Applicable

• Conditions: Work of Breathing; Lung Transplant; Complications; Ventilator-Induced Lung Injury; Neurally Adjusted Ventilatory Assist
• Interventions: Device: NAVA ventilation

• Registration Number: NCT03367221
• Lead Sponsor: Policlinico Hospital

Brief Summary

Primary Graft Dysfunction (PGD) respresents the leading cause of mortality in early post-operative period of Lung Tranplantation (LTx). Protective ventilatory strategy could potentially reduce the risk of PGD in these patients. Neurally Adjusted Ventilatory Assist (NAVA) is an assisted ventilation mode that could allow to adopt this strategy. Aim of the study is to assess the feasibility of NAVA in the early post-LTx phase and to describe the breathing pattern and the physiological relationship between neural respiratory drive and different levels of ventilatory assist, in the absence of pulmonary vagal afferent feedback.

Detailed Description

Lung transplantation (LTx) is an important treatment option for select patients with end-stage pulmonary disease. Primary Graft Dysfunction (PGD) is the main cause of death; in the early period following LTx a protective ventilatory strategy (tidal volume - Vt of 6 mL/Kg + Positive End Expiratory Pressure) could potentially reduce the risk of PGD in these patients. 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). Actually, Guidelines about the adoption of a protective ventilatory strategy in the early post-opeartive period are lacking.

NAVA, because of its intrinsic properties (proportionality between respiratory drive and level of assist, prevention of diaphragm atrophy), could allow to reach the afore mentioned ventilatory strategy. So, aim of the study, is the evaluation of patients' neural breathing pattern during NAVA, in early post-operative period of LTx

Study Timeline

• Study Start: 2017-11-23
• Study First Submitted: 2017-11-24
• Status Verified: 2017-12
• Study First Submitted QC: 2017-12-07
• Last Update Submitted: 2017-12-07
• Study First Posted: 2017-12-08
• Last Update Posted: 2017-12-08
• Primary Completion: 2019-11
• Study Completion: 2019-11

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Age > 18 y.o.
• Admission to ICU for post-operative monitoring after LTx
• 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 & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
NAVA group	NAVA ventilation	NAVA ventilation

Primary Outcome Measures

Name	Time	Method
Evaluation of the variations of 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)	One hour after the recovery of spontaneous breathing	Electrical Activity of the Diaphragm (EAdi) (microVolt)
Evaluation of the variations of Neuro-Mechanical Coupling (expressed as microVolt of EAdi /cmH2O of airway pressure Ratio) in response to different levels of ventilatory assist at different degrees of lung inflation	One hour after the recovery of spontaneous breathing	Neuro-Mechanical Coupling (NMC) (microvolt/cmH2O)
Evaluation of the changes in the patient's neural breathing pattern (expressed as mL of Tidal Volume) at different levels of ventilatory assist	One hour after the recovery of spontaneous breathing	Tidal Volume (mL)
Evaluation of the variations of Neuro-ventilatory Efficiency (expressed as microvolt of EAdi / mL of Tidal Volume Ratio) in response to different levels of ventilatory assist at different degree of lung inflation	One hour after the recovery of spontaneous breathing	Neuro-Ventilatory Efficiency (NVE) (microvolt/mL)
Evaluation of the changes in the patient's neural breathing pattern (expressed as respiratory rate) at different levels of ventilatory assist	One hour after the recovery of spontaneous breathing	Respiratory rate (Breaths/min)

Secondary Outcome Measures

Name	Time	Method
Evaluation of the feasibility of Plateau Pressure during NAVA	One hour after the recovery of spontaneous breathing, with inspiratory hold manoeuvres	Plateau Pressure (Pplat)
Ultrasound assessment of the changes of Diaphragm's Thickening Fraction at different levels of Positive End Expiratory Pressure and at different NAVA gains	One hour after the recovery of spontaneous breathing	Diaphragm's Thickening Fraction (TF)
Assesment of the total asynchrony index (double triggering + missed efforts + inspiratory trigger delay +short cycling + prolonged cycling)	One hour after the recovery of spontaneous breathing	Total Asinchrony Index

Trial Locations

Locations (2)

University Hospital of Lausanne; 🇨🇭 Lausanne, Switzerland

Ospedale Maggiore Policlinico; 🇮🇹 Milan, Italy