What is the recommended limit for blood drawn from a child under 18 kg at a time?

The recommended limit for blood drawn from a child under 18 kg at a time is 10 mL. This guideline is based on the understanding that the volume of blood taken should be a small percentage of a child's total blood volume to avoid any adverse effects. Generally, it is recommended that no more than 1% of a child's total blood volume should be sampled at any one time to ensure the child's safety and well-being.

In pediatric patients, particularly those weighing under 18 kg, it is crucial to limit blood draws to smaller volumes to minimize the risk of complications such as anemia or hemodynamic instability. The 10 mL limit strikes an appropriate balance, providing enough volume for necessary testing while maintaining safety and reducing stress on the child. This practice is also supported by clinical guidelines that aim to protect vulnerable populations, especially young children, from potential harm during clinical procedures.