A neonatal insert adaptor for a capnometer breathe-through cell

This paper describes a neonatal insert for use with the Hewlett-Packard Model 47210A capnometer airway adaptor. Dead space using this adaptor is 4.2 ml, which compares to 28.4 ml with the standard adaptor system and 4.0 ml with the pediatric Y-piece and endotracheal tube alone. Resistance was evaluated by plotting pressure drop-flow relationships. For oxygen flow rates used of up to seven L/min, the neonatal insert reduced the pressure drop as compared to both the standard adaptor and the pediatric Y-piece and endotracheal tube alone. Pressure drops were not very much larger than calculated theoretical values.