Treatment of porcine pulmonary surfactant for hydrochloric acid Induced early stage acute lung Injury in rabbit

Abstract

Objective To evaluate the therapeutic efficacy of intratracheal instillation of porcine pulmonary surfactant(PPS) on rabbits with hydrochloric acid induced early stage acute lung injury. Methods Eighteen healthy adult rabbits weighing 1.7-2.3 kg were randomly divided into healthy control group, model group and treatment group(6 in a group). The model of acute lung injury was set up in each of the animals of the model group and treatment group by intratracheal instillation of hydrochloric acid(pH = 1.5 2 ml/kg). Normal saline was given for the healthy control group. PPS (120 mg/kg,80 g/L)was administered 4 hours after hydrochloric acid instillation in the treatment group. While the healthy control group and model group were treated with normal saline instead of PPS at the same time. PaO2 and PaCO2 were examined for 10 hours after the start of experiment. The rabbits were killed and left lung was immediately deligated and removed. Left top lung was used for histological analysis, left lower lung was used for examining the ratio of wet and dry mass. The bronchoalveolar lavage fluid (BALF) of right lung was collected for measurement of total protein contents,total white blood cell numbers. Results PaO2 was higher in the treatment group than that in the model group (all P<0.01) ,but most of them were lower than that in the healthy control group (all P<0.01). PaCO2 in the treatment group was lower than that in the model group (all P<0.01), but higher than that in the healthy control group (all P<0.01). Compared with the model group, the ratio of wet and dry mass of left lower lung, the total protein and total white blood cell numbers in BALF significantly decreased in the treatment group (all P<0.01), but higher than those in the healthy control group (all P<0.01). The histological appearance meliorated in the treatment group compared with the model group,but remained to be inferior to the healthy control group. Conclusions PPS can improve PaO2 and PaCO2. The ratio of wet and dry lung, the number of white blood cell and total protein content in BALF in the treatment group were significantly lower than those in the model group. The histological appearance of the treatment group improves significantly. So it has benefits in the treatment of lung injury induced by aspiration of hydrochloric acid. Key words: Lung injury; Hydrochloric acid aspiration; Pulmonary surfactant; Treatment