Does the RAM cannula deliver adequate CPAP?

An in-vitro study using an artificial airway model compared the mean airway pressure delivered by two types of devices, each attached to a ventilator – a standard nasal CPAP interface with the nares fully occluded, and RAM cannulae. The RAM cannulae were tested by┬ávarying the degree of nares occlusion, the depth of insertion into the nares, and simulated mouth leakage. While the standard CPAP device delivered mean airway pressures close to the set pressure, the pressures delivered by the RAM cannulae were lower than the set pressure. Lower pressures were delivered with less nares occlusion, shorter depth of insertion, and and with simulated mouth opening.

Factors influencing delivered mean airway pressure during nasal CPAP with the RAM cannula. Gerdes et al. 2015