1. A threat to energy reserves
Developing infants need energy for growth and development. The depletion of heat and moisture can negatively impact energy reserves. Read more about the threat to energy reserves.
2. An immature mucociliary transport system
This is inherently compromised in an infant. The cilia are often too short and uncoordinated to effectively reach into the mucus layer. If low humidity gas is used with respiratory support, mucociliary clearance can be severely compromised.
3. Medical gases
These are extremely cold and dry. Their use in respiratory medicine often means low humidity gases are delivered to infants. The influence of this can be significant. The table opposite highlights various forms of humidified gas that can be delivered to infants in hospital.
4. A bypassed airway
Endotracheal or tracheostomy tubes bypass the upper airway where the majority of heat and moisture is normally added during inspiration. In this process, the filtering mechanisms of the upper airway are also bypassed.
5. Inspiratory flows
Even though medical gas flow rates may be classed as “low”, they may still make up a significant proportion of (or exceed) the infant’s minute volume. In effect, excessive heat and moisture are drawn away from the airway mucosa.