Vertigo following aural suction: can it be prevented?

Suction toilet of mastoid cavities leads to unpleasant vertigo in many patients. We have shown that suction causes cooling within the cavity, in a series of 20 patients. This is of the same order of magnitude as a cold air caloric, showing the temperature drop to be an important factor. The relevant physical principles are examined. During suction a flow of cold, dry room air replaces the warm, moist cavity air, causing cooling both directly and by vaporization of water. Introducing humidified air at near body temperature should eliminate these effects and a study is being set up to evaluate the potential clinical applications of the method in the ENT Outpatient Department.