title: Volume-targeted versus pressure-limited ventilation in infants born at or near term.
abstract: Our aims were to determine whether volume-targeted ventilation (VTV) or pressure-limited ventilation (PLV) reduced the time to successful extubation and if any difference was explained by a lower work of breathing (WOB), better respiratory muscle strength or less thoracoabdominal asynchrony (TAA) and associated with fewer hypocarbic episodes. Infants born at ≥34 weeks of gestational age were randomised to VTV or PLV. The WOB was assessed by the transdiaphragmatic pressure time product, respiratory muscle strength by the maximum inflation (Pimax) and expiratory (Pemax) pressures and TAA assessed using uncalibrated respiratory inductance plethysmography. Forty infants, median gestational age of 39 (range 34-42) weeks, were recruited. The time to successful extubation did not differ between the two groups (median 25, range 2.5-312 h (VTV) versus 33.5, 1.312 h (PLV)) (p = 0.461). There were no significant differences between the groups with regard to the WOB, respiratory muscle strength or the TAA results. The median number of hypocarbic episodes was 1.5 (range 0-8) in the VTV group versus 4 (range 1-13) in the PLV group (p = 0.005).
  
  
  CONCLUSIONS
  In infants born at or near term, VTV compared to PLV did not reduce the time to successful extubation but was associated with significantly fewer hypocarbic episodes.
  
  
  BACKGROUND
  In prematurely born infants, volume-targeted ventilation (VTV) compared to pressure-limited ventilation (PLV) reduces bronchopulmonary dysplasia or death. In addition, VTV is associated in prematurely born infants with lower incidences of pneumothorax, intraventricular haemorrhage and hypocarbic episodes.
  
  
  BACKGROUND
  Despite a high morbidity, few studies have investigated optimum ventilation strategies for infants born at or near term. In a RCT, we have demonstrated VTV versus PLV in infants ≥34 weeks gestation was associated with significantly fewer hypocarbic episodes.
authors.affiliation: Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's 22 College London, London, UK. prashanth.bhat@kcl.ac.uk.
authors.forename: Prashanth
authors.initials: P
authors.lastname: Bhat
authors.affiliation: Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's 22 College London, London, UK. dr.olie@gmail.com.
authors.forename: Olie
authors.initials: O
authors.lastname: Chowdhury
authors.affiliation: Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's 22 College London, London, UK. sandeep.shetty1@nhs.net.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Shetty
authors.affiliation: Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's 22 College London, London, UK. simon.hannam@nhs.net.
authors.forename: Simon
authors.initials: S
authors.lastname: Hannam
authors.affiliation: Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's 22 College London, London, UK. gerrard.rafferty@kcl.ac.uk.
authors.forename: Gerrard F
authors.initials: GF
authors.lastname: Rafferty
authors.affiliation: Division of Health and Social Care Research, King's College London, London, UK. janet.peacock@kcl.ac.uk.|NIHR Biomedical Centre, 23 at Guy's and St Thomas NHS Foundation Trust and King's College London, London, UK. janet.peacock@kcl.ac.uk.
authors.forename: Janet
authors.initials: J
authors.lastname: Peacock
authors.affiliation: Division of Asthma, Allergy and Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, King's 22 College London, London, UK. anne.greenough@kcl.ac.uk.|NIHR Biomedical Centre, 23 at Guy's and St Thomas NHS Foundation Trust and King's College London, London, UK. anne.greenough@kcl.ac.uk.
authors.forename: Anne
authors.initials: A
authors.lastname: Greenough
mesh_terms: D060666:Airway Extubation / Q000379:methods*; D002307:Cardiography, Impedance; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011897:Random Allocation; D012121:Respiration, Artificial / Q000379:methods*; D012132:Respiratory Muscles / Q000502:physiology; D014939:Work of Breathing / Q000502:physiology
keywords: Extubation; Respiratory muscle strength; Thoracoabdominal asynchrony; Work of breathing