Doctors are being urged to use both arms to determine blood pressure in paediatric patients, with a landmark Australian study suggesting single arm measurements could lead to a missed hypertension diagnosis.

Based on data from 118 children aged 7-18 attending either for an MRI or a cardiology outpatient clinic, the Murdoch Children’s Research Institute researchers found a median difference of 5mmHg in systolic BP between the right and left arms.

Among the 95 healthy children who all had normal aortas (with 15 having a history of tetralogy of Fallot), one-in-four had an inter-arm difference (IAD) in systolic BP on an initial reading.

Although seemingly small, this could make the difference between a classification of normal versus elevated BP or normal versus stage I hypertension, the researchers reported in the Journal of Hypertension.