Final answer:
The depth of puncture for infants might vary depending on the procedure but could be up to 15 diameters deep, taking into account newer research findings. It's crucial to balance the need for accessing blood or fluid and minimizing harm to the infant.
Step-by-step explanation:
The appropriate depth of puncture for infants can vary based on the procedure and the equipment used. However, it is essential that the depth of puncture is sufficient to access the necessary blood or fluid without causing harm to the child. An older "rule of thumb" for skin puncture suggested a depth of 7-8 diameters deep, but newer research indicates that it could be as much as 15 diameters deep. Furthermore, for procedures involving intravenous access or fluid administration, factors like the risk of blood loss and the size of the child must be considered, such as ensuring appropriate access and fluids for a potential blood loss of at least 500 ml or 7 ml/kg of body weight in children.