The influence of an arterial and venous air embolism on the hearing level in laboratory mini pigs

We examined the influence of an experimental venous and arterial air emboli sm on the hearing level in laboratory mini pigs. Before and after the injec tion of air a threshold ABR was measured in anaesthetized mini pigs (n = 15 ). A venous air embolism was performed in 6 animals: no changes in the hear ing level or in the interpeak latencies Jewett wave V-I were observed in an y of the animals before, during or after the application of air. In 9 anima ls the arterial embolism was done, 2 animals died and had to be excluded. I n 6 animals out of 7 a hearing loss was observed starting after the injecti on of 40 mi air and finally ending in deafness for these 6 animals. The det ected hearing loss is probably of cochlear origin, as no prolongations of t he interpeak latencies of Jewett wave V-I at 90 dB HL were observed prior t o the deafness. Our results show that air bubbles in the arterial circulati on lead to cochlear damage ending in deafness. Our research indicates that decompression sickness, which is comparable to the arterial air embolism, i s more often the cause of a sensorineural hearing loss after diving than pr eviously believed.