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Randomised weaning trial comparing assist control to pressure support ventilation
  1. Deena Shefali-Patel,
  2. Vadivelam Murthy,
  3. Simon Hannam,
  4. Silke Lee,
  5. Gerrard F Rafferty,
  6. Anne Greenough
  1. Division of Asthma, Allergy and Lung Biology, King's College London, London, UK
  1. Correspondence to Anne Greenough, Kings College London, Division of Asthma, Allergy and Lung Biology, Kings College Hospital, 4th Floor, Golden Jubilee Wing, London, SE5 9RS, UK; anne.greenough{at}


Objectives To determine if the work of breathing was lower, respiratory muscle strength greater, but the degree of asynchrony higher during weaning by assist control ventilation (ACV) rather than pressure support ventilation (PSV) and if any differences were associated with a shorter duration of weaning.

Design Randomised trial

Setting Tertiary neonatal unit

Patients Thirty-six infants, median gestational age 29 (range 24 to 39) weeks

Intervention Weaning by either ACV or PSV.

Main outcome measures At baseline, 24 hours after entering the study and immediately prior to extubation, the work of breathing (PTPdi), thoracoabdominal asynchrony (TAA) and respiratory muscle strength (Pimax) were assessed and weaning duration recorded.

Results There were no significant differences in the median PTPdi, TAA and Pimax results at any time point. The inflation times during ACV and PSV were similar. The median duration of weaning was 34 (range 7–100) hours in the ACV group and 27 (range 10–169) hours in the PSV group (p=0.88).

Conclusion No significant differences were found between weaning by PSV and ACV when similar inflation times were used.

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  • Contributors Professor Greenough and Dr Patel were responsible for the conception and design of the study, Dr Patel and Dr Murthy were responsible for the acquisition of the data and Drs Patel and Rafferty and Professor Greenough for the analysis of the data and drafting the article. All authors were involved in revising the article critically for important intellectual content.

  • Funding Charles Wolfson Charitable Trust.

  • Competing interests AG has held grants from various ventilator manufacturers and has received honoraria for giving lectures and advising various ventilator manufacturers. SH has received sponsorship for postgraduate courses from ventilator manufacturers.

  • Ethics approval King's College Hospital Research Ethics Committee.

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