David G Tingay1,2,3,4, Prue M Pereira-Fantini1,4, Regina Oakley1, Karen E McCall1, Elizabeth J Perkins1,2, Martijn Miedema1,5, Magdy Sourial1, Jessica Thomson1, Andreas Waldmann6, Raffaele L Dellaca7, Peter G Davis1,3,8, Peter A Dargaville1,9,10. 1. Neonatal Research, Murdoch Childrens Research Institute, Parkville, Victoria, Australia. 2. Neonatology, The Royal Children's Hospital, Parkville, Victoria, Australia. 3. Neonatal Research, The Royal Women's Hospital, Parkville, Victoria, Australia. 4. Department of Paediatrics and. 5. Neonatology, Amsterdam University Medical Centre, University of Amsterdam, Amsterdam, the Netherlands. 6. Swisstom AG, Landquart, Switzerland. 7. Dipartimento di Elettronica, Informazione e Ingegneria Biomedica, Politecnico di Milano University, Milan, Italy. 8. Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia. 9. Neonatal and Paediatric Intensive Care Unit, Royal Hobart Hospital, Hobart, Tasmania, Australia; and. 10. Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
Abstract
Rationale: The preterm lung is susceptible to injury during transition to air breathing at birth. It remains unclear whether rapid or gradual lung aeration at birth causes less lung injury. Objectives: To examine the effect of gradual and rapid aeration at birth on: 1) the spatiotemporal volume conditions of the lung; and 2) resultant regional lung injury. Methods: Preterm lambs (125 ± 1 d gestation) were randomized at birth to receive: 1) tidal ventilation without an intentional recruitment (no-recruitment maneuver [No-RM]; n = 19); 2) sustained inflation (SI) until full aeration (n = 26); or 3) tidal ventilation with an initial escalating/de-escalating (dynamic) positive end-expiratory pressure (DynPEEP; n = 26). Ventilation thereafter continued for 90 minutes at standardized settings, including PEEP of 8 cm H2O. Lung mechanics and regional aeration and ventilation (electrical impedance tomography) were measured throughout and correlated with histological and gene markers of early lung injury.Measurements and Main Results: DynPEEP significantly improved dynamic compliance (P < 0.0001). An SI, but not DynPEEP or No-RM, resulted in preferential nondependent lung aeration that became less uniform with time (P = 0.0006). The nondependent lung was preferential ventilated by 5 minutes in all groups, with ventilation only becoming uniform with time in the No-RM and DynPEEP groups. All strategies generated similar nondependent lung injury patterns. Only an SI caused greater upregulation of dependent lung gene markers compared with unventilated fetal controls (P < 0.05).Conclusions: Rapidly aerating the preterm lung at birth creates heterogeneous volume states, producing distinct regional injury patterns that affect subsequent tidal ventilation. Gradual aeration with tidal ventilation and PEEP produced the least lung injury.
Rationale: The preterm lung is susceptible to injury during transition to air breathing at birth. It remains unclear whether rapid or gradual lung aeration at birth causes less lung injury. Objectives: To examine the effect of gradual and rapid aeration at birth on: 1) the spatiotemporal volume conditions of the lung; and 2) resultant regional lung injury. Methods: Preterm lambs (125 ± 1 d gestation) were randomized at birth to receive: 1) tidal ventilation without an intentional recruitment (no-recruitment maneuver [No-RM]; n = 19); 2) sustained inflation (SI) until full aeration (n = 26); or 3) tidal ventilation with an initial escalating/de-escalating (dynamic) positive end-expiratory pressure (DynPEEP; n = 26). Ventilation thereafter continued for 90 minutes at standardized settings, including PEEP of 8 cm H2O. Lung mechanics and regional aeration and ventilation (electrical impedance tomography) were measured throughout and correlated with histological and gene markers of early lung injury.Measurements and Main Results: DynPEEP significantly improved dynamic compliance (P < 0.0001). An SI, but not DynPEEP or No-RM, resulted in preferential nondependent lung aeration that became less uniform with time (P = 0.0006). The nondependent lung was preferential ventilated by 5 minutes in all groups, with ventilation only becoming uniform with time in the No-RM and DynPEEP groups. All strategies generated similar nondependent lung injury patterns. Only an SI caused greater upregulation of dependent lung gene markers compared with unventilated fetal controls (P < 0.05).Conclusions: Rapidly aerating the preterm lung at birth creates heterogeneous volume states, producing distinct regional injury patterns that affect subsequent tidal ventilation. Gradual aeration with tidal ventilation and PEEP produced the least lung injury.
Authors: Natalie Batey; Caroline Henry; Shalabh Garg; Michael Wagner; Atul Malhotra; Michel Valstar; Thomas Smith; Don Sharkey Journal: Pediatr Res Date: 2022-03-03 Impact factor: 3.756
Authors: Arun Sett; Gillian W C Foo; Kelly R Kenna; Rebecca J Sutton; Elizabeth J Perkins; Magdy Sourial; Sheryle R Rogerson; Brett J Manley; Peter G Davis; Prue M Pereira-Fantini; David G Tingay Journal: Pediatr Res Date: 2022-09-27 Impact factor: 3.953
Authors: Regina B Oakley; David G Tingay; Karen E McCall; Elizabeth J Perkins; Magdy Sourial; Peter A Dargaville; Prue M Pereira-Fantini Journal: Front Pediatr Date: 2019-08-21 Impact factor: 3.418