NAVA-Bronch: A feasibility study
Research type
Research Study
Full title
Neurally Adjusted Ventilatory Assist (NAVA) use in infants with acute viral bronchiolitis: a randomised, crossover feasibility study
IRAS ID
217195
Contact name
Shane Tibby
Contact email
Sponsor organisation
Guy's & St Thomas' NHS Foundation Trust
Duration of Study in the UK
1 years, 6 months, 1 days
Research summary
This study aims to evaluate a novel mode of mechanical ventilation, Neurally Adjusted Ventilatory Assist (NAVA), in infants admitted to the paediatric intensive care unit (PICU) with acute viral bronchiolitis. This respiratory illness accounts for 12% of PICU admissions nationally. Current modes of ventilation are inefficient, often requiring prolonged use of sedative drugs for comfort and to improve synchronicity with the ventilator. Consequences of prolonged sedative use are muscle wastage including the respiratory muscles, increased risk of developing secondary infections and the potential for withdrawal and or delirium.
NAVA is a mode of ventilation that is delivered using our current ventilators (breathing machines). However it differs from current modes by providing respiratory support in proportion to neural drive (the signal from the brain to activate the diaphragm), via measurement of electrical activity of the diaphragm (the main muscle used to initiate a breath). This is measured by using a modified version of the patients’ nasogastric tubes (which are used in PICU to feed patients whilst on a ventilator).
Research in children to date has demonstrated that NAVA, compared to other ventilatory modes, allows for improved ventilator synchrony, reduced work of breathing and potentially less sedative use. This is consistent with our clinical impression (we have been using NAVA in an ad hoc way for >5 years). Although some of these studies included infants with bronchiolitis, the findings were not specific to this patient group. Of note, we do not yet know how to optimise NAVA settings in bronchiolitis, and whether current common sedative drugs (e.g. morphine) affect this, by decreasing respiratory drive excessively (potentially compromising NAVA utility).
We will evaluate how to optimise NAVA settings when compared to conventional ventilation in infants with acute viral bronchiolitis admitted to PICU. A range of NAVA settings will be systematically evaluated over two periods on consecutive days (maximum 4 hours per period per day). We will observe the effects of different levels of NAVA support on synchronicity, work of breathing and changes in physiological parameters. Patients will also receive 2 different adjustments to their morphine infusions in random order on the consecutive days: standard dose morphine (20mcg/kg/hr) and low dose morphine (5mcg/kg/hr). Both morphine doses are within the range currently used clinically. Patient comfort will be assessed frequently throughout, and the effects of morphine on diaphragmatic neural activity
will be recorded.REC name
London - Camden & Kings Cross Research Ethics Committee
REC reference
19/LO/0245
Date of REC Opinion
11 Mar 2019
REC opinion
Favourable Opinion