Formula estimation of appropriate urinary catheter size in children

To perform proper and optimal catheterization, a urinary catheter of appropriate size has to be selected as the success of a procedure is often dependent on it. Catheterization of the urinary bladder is a common procedure in pediatric practice which is used for numerous diagnostic and therapeutic purposes. There are very few recommendations on how to choose the optimal size of a catheter on the basis of a child's age or weight. Based on a few published relationships between a child's age, body weight and urinary catheter size, as well as personal experience, the author has developed a formula for estimating urinary catheter size according to a child's weight that reads as follows: . Presented formula may prove useful in everyday clinical practice and especially in emergency settings.