Editor—In developing countries where resources are limited, oxygen is usually given straight into the incubator without blending, whereas in modern neonatal intensive care units nasal cannulas are more usual, as well as oxygen blenders and servo control systems.1 2

Oxygen concentrations were measured in four different models of incubators including Air Shields Isolette C2H2-1, ISIS Mediprema, Air Shields C100-200, and Air Shields Neocare 142 at oxygen flow rates of 1–15 l/minute at Gazi …