Malm L, White P
Department of Oto-Rhino-Laryngology, University Hospital, Lund, Sweden.
Acta Otolaryngol Suppl. 1992;493:133-6.
The presence of surface tension lowering substances (surfactants) is demonstrable in the Eustachian tube (ET) and the middle ear, both in animals and in humans. In the lungs, beta-adrenoceptor agonists stimulate the secretion of surfactant; and it has been suggested that beta-agonists have a similar effect both in the ET and the middle ear, because opening of the ET is facilitated by the non-selective beta-agonist, isoprenaline in the rat, and by the beta 2-agonist, terbutaline, in humans. Two studies are described: In one, children with otitis media with effusion took terbutaline or placebo twice a day for two weeks and no significant differences were found between the effects of the two treatments; in the other study, it was shown that surfactant markedly facilitated the opening of the Eustachian tube. Lung surfactant prepared from pigs and instilled as a single dose into the middle ear of healthy rats reduced the air pressure necessary to open the Eustachian tube by as much as 15-20% for as long as the experiments lasted (i.e., around one hour). Thus, possibilities of facilitating the opening of the Eustachian tube do in fact exist.
