In reply to adeolatobi,
Your point "3. For optimal mucociliary function, dry O2 has to be heated and humidified to 37 degrees and 100% relative humidity, (RH) respectively." is widely accepted particularly for ventilated patients, but what is the foundation of the other common conception you list as "2. Administering dry O2 with saline or cold water bubble such as is common on the wards is as useless as administering dry O2 itself."? This is of course relevant and true with ventilated patients, but what of those in which the upper airway is not being bypassed? What is the role and or advantage of cold vs. heated humidification in an extubated patient on simple oxygen therapy?
What about those on NIV - I think all of us can understand the need to humidify with the higher flows and pressures, but should it be cold or heated given the upper airway is still in play? Why do manufacturers continue to supply and promote hot & cold systems for use with oxygen therapy & NIV? Is there an evidence base to support either way?