Editor—Based on careful invasive blood pressure measurements in a cohort of 61 very low birthweight (VLBW) infants during the first 24 hours of life, Leeet al 1 report on blood pressure standards in this population. The quality of the blood pressure readings was assessed using continuous video recordings of real time wave forms. The inclusion of a relatively large number (n = 28) of extremely low birthweight infants is another strength of this study.

In an attempt to define normal blood pressure values in a population that by definition is not “normal”, the authors have excluded very ill infants and infants requiring inotropic support. They have also excluded infants …