title: Predicting fluid responsiveness in 100 critically ill children: the effect of baseline contractility.
abstract: OBJECTIVE
  Fluid overload is a risk factor for poor outcome in intensive care; thus volume loading should be tailored towards patients who are likely to increase stroke volume. We aimed to evaluate the paediatric predictive ability (stroke volume increase of at least 15 % after fluid bolus) of novel and established volumetric and dynamic haemodynamic variables, and assess the influence of baseline contractility on response.
  
  
  METHODS
  We assessed 142 volume loading episodes (10 ml/kg crystalloid) in 100 critically ill ventilated children, median (interquartile) weight 10 (5.6-15) kg. Eight advanced haemodynamic variables were assessed using two commercially available devices. Systemic ventricular contractility was measured as the maximum rate of systolic arterial pressure rise.
  
  
  RESULTS
  Overall, predictive ability was poor, with volumetric variables performing better than dynamic (area under receiver operating characteristic curves ranged from 0.53 to 0.67). The best predictor was total end-diastolic volume index; however, this did not increase in a consistent way with volume loading, with change post volume being weakly related to baseline values (r = -0.19, p = 0.02). A multivariable model quantified the importance of contractility in stroke volume response. Children with high baseline contractility (≥75th centile) typically achieved a positive stroke volume response when end-diastolic volume values changed by 10-15 ml/m(2.6), whereas patients with low contractility (≤25th centile) typically required end-diastolic volume increases of 35-40 ml/m(2.6).
  
  
  CONCLUSIONS
  Current paediatric predictors of volume response perform poorly; prediction may be improved if baseline contractility is taken into account.
authors.affiliation: Paediatric Intensive Care Unit, Evelina Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK.
authors.forename: Rohit
authors.initials: R
authors.lastname: Saxena
authors.affiliation: Paediatric Intensive Care Unit, Evelina Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Durward
authors.affiliation: Paediatric Intensive Care Unit, Evelina Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Steeley
authors.affiliation: Paediatric Intensive Care Unit, Evelina Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Murdoch
authors.affiliation: Paediatric Intensive Care Unit, Evelina Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, Westminster Bridge Road, London, SE1 7EH, UK. shane.tibby@gstt.nhs.uk.
authors.forename: Shane M
authors.initials: SM
authors.lastname: Tibby
mesh_terms: D002675:Child, Preschool; D016638:Critical Illness / Q000628:therapy*; D005440:Fluid Therapy; D005544:Forecasting; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D009200:Myocardial Contraction; D011446:Prospective Studies; D013318:Stroke Volume
keywords: Cardiac output; Contractility; Fluid responsiveness; Paediatric