Outline the anatomy and physiology of humidification during normal breathing (50% of marks). Describe the mechanisms of humidification used within Intensive Care practice (50% of marks).
For a good answer candidates were expected to provide information on essential facts such
as, normal inspired air has low water content, normal humidification provides for saturated
water vapour 47mmHg at sea level at the alveolus, which correspondsto an absolute
humidity of 44 g/m3 (or 100% relative humidity) at 37.C. Furthermore, candidates were
expected to outline the basics of the anatomical features of the respiratory tractthat
promotes humidification e.g. lining of nose and hypopharynx dissolving warm water vapour
into the dry inhaled air, the fact that the turbinates act to increase surface area and that full
saturation is achieved by the time air reaches the upper trachea. For the second part of the
question candidates were expected to mention, and briefly describe, the mechanisms of
achieving humidification, e.g. bubble systems, heat-moister exchange filters, heated water,
ultrasonic, etc.mechanisms. Candidates generally did not have sufficient knowledge of the
basic conepts or a structured approach to this topic.
a) Anatomy and physiology of humidification during normal breathing:
b) Mechanisms of humidification used within Intensive Care practice
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