Total liquid ventilation in an ovine model of extreme prematurity: a randomized study

Background This study aimed at comparing cardiorespiratory stability during total liquid ventilation (TLV)—prior to lung aeration—with conventional mechanical ventilation (CMV) in extremely preterm lambs during the first 6 h of life. Methods 23 lambs (11 females) were born by c-section at 118–120 days of gestational age (term = 147 days) to receive 6 h of TLV or CMV from birth. Lung samples were collected for RNA and histology analyses. Results The lambs under TLV had higher and more stable arterial oxygen saturation ( p = 0.001) and cerebral tissue oxygenation ( p = 0.02) than the lambs in the CMV group in the first 10 min of transition to extrauterine life. Although histological assessment of the lungs was similar between the groups, a significant upregulation of IL-1a, IL-6 and IL-8 RNA in the lungs was observed after TLV. Conclusions Total liquid ventilation allowed for remarkably stable transition to extrauterine life in an extremely preterm lamb model. Refinement of our TLV prototype and ventilation algorithms is underway to address specific challenges in this population, such as minimizing tracheal deformation during the active expiration. Impact Total liquid ventilation allows for remarkably stable transition to extrauterine life in an extremely preterm lamb model. Total liquid ventilation is systematically achievable over the first 6 h of life in the extremely premature lamb model. This study provides additional incentive to pursue further investigation of total liquid ventilation as a transition tool for the most extreme preterm neonates.