Relative Resuscitation Capacity: A Practical Framework for Pediatric Intravenous Access

Adequate intravenous (IV) access is a key component of anesthetic care, but this concept is often discussed in qualitative rather than quantitative terms, particularly within the pediatric subspecialty.

We propose a concept termed relative resuscitation capacity as a framework to standardize IV catheter sizes across patients of different sizes.

Manufacturer-reported IV catheter flow rates were used to calculate time to replace estimated blood volume (EBV). A short 16G catheter in an adult was defined to have a relative resuscitation capacity of 1, which serves as a reference point. Equivalent calculations were performed across a range of pediatric ages and catheter sizes and were normalized to this adult reference.

The following catheter-age pairings have a relative resuscitation capacity near 1, indicating a similar time to replace EBV compared to a 16G catheter in an adult: 6-month-old with 24G, 1-year-old with 22G, 6-year-old with 20G, 10-year-old with 18G.

Relative resuscitation provides a practical framework to equate IV catheter selection across patients of all ages. This approach helps to translate adult-based heuristics to pediatric practice and to define large-bore access quantitatively.