Comparison of a paediatric emergency ruler with a digital algorithm for weight and age estimation

Emergency tapes like the "Paediatric-Emergency-Ruler" (PaedER) provide drug dosing and recommend medical airway equipment based on estimated patient bodyweight and age. Previous studies have revealed unsatisfactory accuracy in bodyweight estimation, due to the tapes' length-based weight categories. Therefore, we developed a digital algorithm allowing continuous length-based estimation of weight and age. The aim of this study was to compare the new algorithm with the PaedER regarding accuracy in estimating bodyweight and recommendation of medical airway equipment.

Patients with a body length suitable for the PaedER were included in this single centre, prospective clinical observation trial after obtaining informed written parental consent. Bodyweight estimations by the algorithm and PaedER within ± 10% and ± 20% of the actual bodyweight were compared. Furthermore, medical airway equipment suggested by the PaedER and algorithm were compared with the equipment actually used for anaesthesia. Wilcoxon- and McNemar-Tests were used for statistical analysis. Results are median (interquartiles), P < 0.05 was considered significant.

In total, 489 patients aged 2.0 years (0.4-5.9), with a body length of 89.0 cm (63.5-114.5), weighing 12.8 kg (6.3-19.6), were included. The algorithm's precision of bodyweight estimation within ± 10%/± 20% was significantly higher at 64.0%/91.6% than the PaedER at 55.4%/81.8% (P < 0.001). Compared to PaedER the algorithm showed a higher incidence of correctly recommended medical airway equipment based on its accuracy for age and bodyweight estimation.

The new digital algorithm is an alternative to conventional emergency tapes, showing improved accuracy regarding length-based estimation of bodyweight and recommendation of medical airway equipment.