Histopathological study of short and long-term pulmonary effects of nebulized sodium bicarbonate treatment in chlorine gas toxication-induced rats

Sodium hypochlorite (known as bleach) and hydrochloric acid are traditionally used as cleaning material. Mixture of these two liquids yields chlorine gas. Chlorine gas toxications are frequent reasons for emergency consultations. There is no accepted specific treatment for reduction of the pulmonary injury.In our study, we have investigated histopathologically the effect of nebulized sodium bicarbonate, the use of which is also controversial in the literature, in the treatment of pulmonary injury caused by chlorine gas inhalation.Rats were randomly distributed into 5 groups; 48 rats were used. Rats in Group 1 (n=8) were kept untreated throughout the study. Rats in Group 2 (n=8), Group 3 (n=8), Group 4 (n=12), and Group 5 (n=12) were exposed to 155 ppm chlorine gas inhalation for 5 minutes. Rats in Group 3 and 5 were additionally given nebulized sodium bicarbonate following chlorine gas inhalation. Rats in Group 2 and 3 were sacrificed 30 minutes after the chlorine inhalation, and rats in Group 4 and 5 were sacrificed 45 days after the inhalation for histopathological examinations.Histopathological examination of the lungs of rats in Group 2 and 3 showed acute injury. The injury in Group 3 was more severe than that of Group 2. Some of the rats in Group 4 and Group 5 showed similar interstitial fibrosis and alveolar emphysematous alterations.We concluded that nebulized sodium bicarbonate increases the severity of pulmonary injury in the short-term. It has no effects on the injury in the long-term.Key Words: Chlorine Gas, Exposure, Sodium Bicarbonate, Rats