As an individual becomes hypothermic, several other physiological factors associated with respiratory function are influenced
- ciliary motility decreases
- bronchorrhea is present,
- the potential for noncardiogenic pulmonary edema increases as fluid shifts occur
- the contractile function of the diaphragm and intercostal muscles alters
- lung compliance decreases,
- the elasticity of the thorax decreases,
- anatomical and functional physiological respiratory dead spaces are increased whereas individual alveolar dead spaces are unchanged.
Pulmonary circulation time is usually prolonged unless there is intrapulmonary shunting.
Although hyperventilation is associated with cold stress, cold-induced respiratory arrest also occurs. This reflex may be important in victims of submersion hypothermia. Such a response causes the person who is submerged to aspirate water and consequently drown. Simultaneously, the cold water aspirate rapidly cools the brain and heart, because the heart continues to beat effectively while pumping cold blood, for 5 minutes after aspiration.