Article Text

Delivery of positive end-expiratory pressure to preterm lambs using common resuscitation devices
  1. Marta Thio1,2,3,4,
  2. Jennifer A Dawson1,2,3,
  3. Kelly J Crossley5,6,
  4. Timothy J Moss5,6,
  5. Charles C Roehr5,7,
  6. Graeme R Polglase5,6,
  7. Peter G Davis1,2,3,
  8. Stuart B Hooper5,6
  1. 1Newborn Research Centre, The Royal Women’s Hospital, Melbourne, Victoria, Australia
  2. 2Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
  3. 3Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Victoria, Australia
  4. 4PIPER – Neonatal Retrieval Services Victoria, The Royal Children’s Hospital, Melbourne, Victoria, Australia
  5. 5The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria, Australia
  6. 6The Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
  7. 7Department of Paediatrics, Newborn Services, University of Oxford, John Radcliffe Hospital, NHS Foundation Trust, Oxford, UK
  1. Correspondence to Dr Marta Thio, Newborn Research Centre, The Royal Women’s Hospital, Melbourne, Victoria, Australia; Marta.ThioLluch{at}


Background In neonatal resuscitation, a ventilation device providing positive end-expiratory pressure (PEEP) is recommended. There is limited information about PEEP delivery in vivo, using different models of self-inflating bag (SIB) at different inflation rates and PEEP settings.

Methods We compared PEEP delivery to intubated preterm lambs using four commonly available models of paired SIBs and PEEP valves, with a T-piece, with gas flow of 8 L/min. Peak inspiratory pressure inflations of 30 cmH2O, combined with set PEEP of 5, 7 and 10 cmH2O, were delivered at rates of 20, 40 and 60/min. These combinations were repeated without gas flow. We measured mean PEEP, maximum and minimum PEEP, and its difference (PEEP reduction).

Results A total of 3288 inflations were analysed. The mean PEEP delivered by all SIBs was lower than set PEEP (P<0.001), although some differences were <0.5 cmH2O. In 55% of combinations, the presence of gas flow resulted in increased PEEP delivery (range difference 0.3–2 cmH2O). The mean PEEP was closer to set PEEP with faster inflation rates and higher set PEEPs. The mean (SD) PEEP reduction was 3.9 (1.6), 8.2 (1.8), 2 (0.6) and 1.1 (0.6) cmH2O with the four SIBs, whereas it was 0.5 (0.2) cmH2O with the T-piece.

Conclusions PEEP delivery with SIBs depends on the set PEEP, inflation rate, device model and gas flow. At recommended inflation rates of 60/min, some devices can deliver PEEP close to the set level, although the reduction in PEEP makes some SIBs potentially less effective for lung recruitment than a T-piece.

  • PEEP delivery
  • self-inflating bag
  • low resource setting
  • T-piece
  • neonatal resuscitation

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  • Contributors MT conceived and designed the study. MT conducted the literature search, acquisition of data, analysis and interpretation of data, and writing of the first draft of the manuscript. JAD contributed to data acquisition, analysis and interpretation of data, and revision of the manuscript drafts. KJC, TJMM, CCR and GRP contributed to the acquisition and interpretation of data, and revision of the manuscript drafts. PGD and SBH contributed to the conception and design of the study, interpretation of data, and revision of the manuscript draft. SBH also supervised all aspects of the study.

  • Funding This research was supported by an NHMRC Program Grant (PG/1113902) and the Victorian Government’s Operational Infrastructure Support Program. MT is supported by an NHMRC Early Career Fellowship (ECF/1111134), TJM by an NHMRC Senior Research Fellowship, PGD by an NHMRC Practitioner Fellowship, GRP by an NHMRC Career Development grant and SBH by an NHMRC Principal Research Fellowship.

  • Competing interests None declared.

  • Ethics approval All experimental procedures were approved by the relevant Monash University Animal Ethics Committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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