Use of water vapor in the treatment of lower respiratory disease.

Use of bland aerosols, particularly mist tents, in the treatment of lower 
respiratory disease was reviewed and no convincing evidence of efficacy was 
found. This is not surprising because there is evidence that mist 
tents deposit little water in the lower respiratory tract. Mist tents 
may be detrimental, in some cases, because of bacterial contamination and 
because they can cause bronchospasm. 