ABSTRACT
BACKGROUND AND OBJECTIVES: Nasal inhalation of hot humidified air may alleviate nasal symptoms associated with rhinologic disease. Thus, hot steam inhalation is often recommended as a home remedy for various nasal disorders such as the common cold and allergic rhinitis. But the mechanism of its effect is not fully known and correct guidelines for implementing hot steam inhalation have not been settled. We studied microcirculation of nasal mucosa using the nasal Laser Doppler Flowmetry (LDF) in ten healthy subjects in order to evaluate normal physiologic reactions to hot steam. MATERIALS AND METHODS: 10 healthy volunteers inhaled hot steam (about 42degrees C) 10 times, 20 times, 30 times, 50 times and 100 times respectively. Nasal LDF was then performed using a Peiflux 4001 (Perimed, Jartalla, Sweden) and the microcirculatory parameters perfusion, velocity, and concentration were each recorded at base line immediately, 15 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after hot steam inhalation. RESULT: Microcirculatory perfusion was highest at 15 minutes after hot steam inhalation regardless of how many times inhalation occurred. It was found that at 15 minutes, there was a significant increase of microcirculatory perfusion in subjects inhaling 50 times and 100 times (p<0.05). But, at 120 minutes, significant increase of microcirculatory perfusion was only seen in subjects inhaling 100 times (p<0.05). CONCLUSION: After inhalation of hot steam, an increased microcirculatory perfusion of nasal mucosa was registered. Up to inhaling of 100 times, it leads to effective increasement of microcirculation of nasal mucosa.