384 - Severe Bronchopulmonary Dysplasia Ventilation using High Inspiration Time / High Tidal Volume (HiT) Strategy in the Neonatal Intensive Care Unit: a Two Center Retrospective Case Series

Publication Number: 1368.384

Brenda H. Law, University of Alberta, Edmonton, AB, Canada; vanessa godbout, Alberta Health Services, Sherwood park, AB, Canada; Wejdan Alzahrani, London Health Sciences Centre / Western University, London, ON, Canada; Ahmed Al Kamzari, London Health sciences center/ western uni, London, ON, Canada; Soume Bhattacharya, Western University, London, ON, Canada; Brooke Read, London Health Sciences Centre, London, ON, Canada; Joy McCall, London Health Sciences Centre- Children's Hospital, London, ON, Canada; Kevin Coughlin, Children’s Hospital at LHSC, London, ON, Canada; Renjini Lalitha, University of Western Ontario, London, ON, Canada

Background: Compared with traditional lung protective strategies, the High Inspiratory Time (IT) and High Tidal Volume (VT) strategy (HiT) may improve lung recruitment and gas exchange in infants with established bronchopulmonary dysplasia (BPD) and heterogenous lungs. However, the use of HiT in preterm infants with evolving BPD ( < 36 weeks corrected gestational age[GA]) is less well described.

Objective: 1. To describe the use of HiT ventilation strategy in preterm infants with evolving or established BPD in two tertiary care neonatal intensive care units (NICUs)
2. To examine in hospital outcomes of preterm infants managed with HiT

Design/Methods: Multicenter retrospective cohort study of infants born < 32 weeks admitted from April 2022 to April 2025 in 2 Canadian NICU and received HiT strategy during their NICU course. HiT strategy is defined as: 1) conventional ventilation in Synchronized Intermittent Mandatory Ventilation mode, 2) IT >0.4s, 3) VT ≥6ml/kg when volume targeting is used or positive inspiratory pressure settings to target VT ≥6ml/kg when direct pressure control is used, and 4) rates < 40 breaths/minute. Patient demographics, timing of initiation and starting parameters for HiT, ventilation parameters within 24hrs prior and after initiation, complications, and in-hospital outcomes were recorded.

Results: In 43 infants, median GA (IQR) at birth was 24+5 (23+5-25+2) weeks with median birth weight (IQR) of 630g (545-740). Table 1 summarizes patient characteristics at baseline and at HiT initiation. Median age (IQR) at first HiT initiation was 37 days (30.5-49), at a median corrected GA (IQR) of 30 weeks (29+1 - 32). 51.2% were switched from high frequency oscillation. First transition to HiT was successful in 39(90.7%) of infants (=remained on HiT with stable oxygenation and ventilation for at least 7 days or extubated from HiT within 7 days), 1 infant who failed initially was later successfully switched to HiT. Initial settings used had moderately long IT at a median of 0.5 (0.4-0.5) sec and high volumes at a median of 7.3 (6.6-8.9) ml/kg. (Table 2) 27 (62.7%) of infants had an improvement in oxygenation as demonstrated by a reduction in oxygen saturation index (see Table 2), and 27 (62.7%) had decrease in opioid use. All infants were on respiratory support at 36 weeks; 20 (47.6%) were in room air or low flow oxygen at 40 weeks, 6(14.3%) required tracheostomy.

Conclusion(s): HiT ventilation can be used to support preterm infants with evolving or established BPD previously on high frequency or low-volume conventional strategies, either as a bridge to extubation or to chronic ventilation.

Table 1. Patient Demographics and HiT Initiation


Table 2. HiT ventilation parameters and outcome