The histopathological changes comparison in healthy rabbit lung ventilated with ZEEP, Sigh and PEEP

Our aim was to compare the effects of LV + ZEEP, LV + Sigh and LV + PEEP on histopathological changes with healthy rabbit lungs. Fifteen New Zeland rabbits were randomly divided into three groups (n = 5). Animals were ventilated for 3 hours with FiO₂:1.0, f:80/dk. Group1: Low volume (5 ml/kg) + ZEEP, Group 2: Low volume (5 ml/kg) + 10 cmH₂O PEEP, Group 3: Low volume (5 ml/kg) + Sigh. At the end of 3 hours the animals were sacrificed for histopathological evalotion. Lungs were removed and fixed in 10% buffered formaldehyde. Tissue sections were processed in the usual manner for light microscopic examination with Hematoxylin–Eosin stain. The pathological lesions were classified ranging from 0 to ++++. There were statistically significant differences between ZEEP and PEEP groups, ZEEP and Sigh groups (P < 0.05). The damage were prominent in the ZEEP group for alveolar hemorrhage and congestion. There were no statistically significance within groups for notrofill infiltration and density. But the damage were more significant than the others in the ZEEP group. We saw atelectasia only in the Sigh group.

The damage was more significant than the others in the ZEEP group. The atelectasia was seen only in the Sigh group. We conclude that adding Sigh and PEEP to low volume may decrease the damage and PEEP may be more effective to prevent atelectasia.