[Experimental study on capacity of lung water regulation]

The capacity of the regulation of lung water after fluid overloading or blood letting was measured in 70 rabbits. Body fluid in the whole blood was increased in both overloading and blood letting. The lung blood volume was increased after crystalloid overloading, but statistically insignificant (P greater than 0.05). On the contrary, a very significant (P less than 0.01) increase of lung blood volume was observed in all animals overloaded with colloid fluids. Blood letting caused an insignificant (P greater than 0.05) decrease of lung blood volume. Total lung water was increased in either groups, but, it was statistically insignificant in crystalloid group and highly significant in crystalloid group. Colloid fluid overloading caused a marked increase (P less than 0.01) of extravascular lung water (EVLW). Interesting to note is that animals received crystalloid fluids amounted up to 3-fold of its blood volume did not show any significant (P greater than 0.05) increase of EVLW. It is concluded that the capacity of lung water regulation was extraordinary intact even after the overloading with crystalloids in an amount equivalent to 2.5-fold of its blood volume. This phenomenon was not seen in the colloids group.