Are APLS formulae for estimating weight appropriate for use in children admitted to PICU?

AimTo determine if the revised APLS UK formulae for estimating weight are appropriate for use in the paediatric intensive care population in the United Kingdom.MethodsA retrospective observational study involving 10,081 children (5622 male, 4459 female) between the age of term corrected and 15 years, who were admitted to Paediatric Intensive Care Units in the United Kingdom over a five year period between 2006 and 2010. Mean weight was calculated using retrospective data supplied by the 'Paediatric Intensive Care Audit Network' and this was compared to the estimated weight generated using age appropriate APLS UK formulae.ResultsThe formula 'Weight = (0.5 × age in months) + 4' significantly overestimates the mean weight of children under 1 year admitted to PICU by between 10% and 25.4%. While the formula 'Weight = (2 × age in years) + 8' provides an accurate estimate for 1-year-olds, it significantly underestimates the mean weight of 2-5 year olds by between 2.8% and 4.9%. The formula 'Weight = (3 × age in years) + 7' significantly overestimates the mean weight of 6-11 year olds by between 8.6% and 20.7%. Simple linear regression was used to produce novel formulae for the prediction of the mean weight specifically for the PICU population.ConclusionsThe APLS UK formulae are not appropriate for estimating the weight of children admitted to PICU in the United Kingdom. Relying on mean weight alone will result in significant error as the standard deviation for all age groups are wide.