The Effect of Ēthrane on Renal Function — an Experimental Comparison with Penthrane in Pigs

Summary

Three groups of four female Yorkshire pigs each were exposed to 24 hours’ anesthesia under Ēthrane (enflurane) 1 – 1.5 vol.-%, 3 – 3.5 vol.-% and under Penthrane (methoxyflurane) 1 – 1. 5 vol.-% respectively.

During anesthesia the results of clearance tests (PACAH, inuline, creatinine) were within the normal limits in all examined animals.

Only in one animal of the enflurane group, in which hypoxia and cardiac arrest occurred (pig no. 7) did the histochemistry of LDH reveal a decrease of aerobic activity in the kidneys. In all other animals the LDH histography was normal.

In pig no. 7 (enflurane group) the common histology showed indistinct vacuolization of the proximal tubular epithelial cells. All other animals seemed to be normal.

The kidneys of the enflurane groups were examined after Epon embedding. At both light and electron microscopic levels a fine vacuolization of proximal tubular epithelial cells was found in all animals, being most pronounced in pig no. 7.

Distinct vacuolar dystrophy was revealed accidentally in two pigs under 48 and 36 hours’ methoxyflurane anesthesia in surgical experimentation complicated by progressive thrombosis of the aorta.

It is suggested that the renal changes both in these pigs and in pig no. 7 were due to disturbed physiology and not to the anesthetic employed.

The pathogenesis of the pernicious changes (vacuolar dystrophy) in the other animals of the enflurane groups remains open to speculation.

Further investigation is needed to differentiate the roles played by altered physiology, surgical interference and anesthetic agents or their metabolites in the development of renal damage.