462 - Feasibility of Rescue Neurally Adjusted Ventilatory Assist in Very Preterm Infants and Impact on Cardiorespiratory Stability

Poster Number: 462
Publication Number: 462.229

Eman Hashim, The Hospital for Sick Children, Toronto, ON, Canada; Carmen Ma, Mount Sinai Hospital, Toronto, ON, Canada; Veena Deekonda, The Hospital for Sick Children, Toronto, ON, Canada; Bethany R. Correa, Mount Sinai Hospital, Burlington, ON, Canada; Nosheen Akhtar, Mount Sinai Hospital, Toronto.Canada, Toronto, ON, Canada; Amish Jain, University of Toronto/ Mount Sinai Hospital, Toronto, ON, Canada; Michelle Baczynski, Sinai Health System, Toronto, ON, Canada

Background: Neurally adjusted ventilatory assist (NAVA) may be an effective respiratory strategy delivering synchronized and proportional ventilatory support using a signal of electrical diaphragmatic activity (Edi) derived from a gastric feeding tube. However, there is limited data on its use in very preterm [VP, < 32 weeks gestational age (GA)] infants. In 2019, our tertiary neonatal intensive care unit (NICU) introduced non-invasive (NiNAVA) and invasive (iNAVA) NAVA as rescue modes to be used when other corresponding conventional modalities were deemed insufficient (worsening oxygenation or ventilation or causing excessive abdominal distension).

Objective: To describe the feasibility of NAVA in VP infants in a tertiary NICU, and examine its immediate effects on physiological clinical parameters of cardiorespiratory stability by comparing 24 hours before (pre-NAVA) and after (post-NAVA) initiation.

Design/Methods: Retrospective study including VP infants who were initiated on NiNAVA or iNAVA after receiving corresponding conventional ventilation for ≥ 24 hours. Initial NAVA settings were set to target a minimum Edi < 5µv and maximum Edi 10-15µv. The significance of symptoms necessitating a change to NAVA, and subsequent setting titrations were at the discretion of the clinical team and based on patient symptoms. For this study, demographic data, hourly ventilatory and cardiorespiratory parameters were collected and averaged for 24 hours pre-and post-NAVA initiation. Feasibility was defined as the ability to obtain an Edi signal and continuation of NAVA for ≥72 hours or de-escalation of respiratory support. Pre- and post parameters were compared using paired t-test for the whole cohort, and separately for NiNAVA and iNAVA

Results: The study included 29 infants (NiNAVA 22; iNAVA 7), the majority of whom were < 1000 grams at NAVA initiation (Table 1). NAVA was deemed feasible in 25 (86%) infants [18/22 (82%) NiNAVA; 6/7 (86%) iNAVA]; 3 infants required intubation between 24-72 hours despite NiNAVA, and in the 4th the mode was changed back by the clinical team. On pre-post analysis, NAVA use was not associated with any change in examined parameters, except an improvement in ventilation with iNAVA (Table 2). There were no procedure-related complications.Conclusion(s): Rescue use of NAVA may be feasible and well-tolerated in VP infants. These data support examining the impact of the primary use of NAVA on important clinical outcomes such as extubation success and bronchopulmonary dysplasia in this patient population.
Table 1. Baseline demographics of infants initiated onto NAVA
Table 2. Physiological clinical parameters of cardiorespiratory stability 24 hours before (pre-NAVA) and after (post-NAVA) initiation.