British Journal of Anaesthesia Local Complications of Thiopentone

laboratory. The existence even now of a number of "liver function tests" and the increasing interest in discriminant function analysis of their results only serve to emphasize the fact that there is no unique test of hepatocellular dysfunction which can be readily applied routinely to large numbers of specimens. We accept the role of hepatocyte preparations as models for the investigation of the toxic effects of drugs; their use may serve as a valid screening procedure before in vivo tests, but will not detect the possibility of idiosyncratic reactions or determine the extent to which such factors as obesity, smoking or drug-taking may affect the condition of a patient's liver after anaesthesia. Regarding some of the enzymes which Dr Sear puts forward as useful, the late J. H. Wilkinson, Inaugural President of the International Society of Clinical Enzymology, says (Wilkinson, 1976) that there have been few studies of the diagnostic possibilities of the scrum activity of alcohol dehydrogenase, although one group of workers reported in 1968 that the test was a useful indicator of acute parenchymal liver damage; and that sorbitol dehydrogenase (of which the richest source is the liver, while some occurs in the prostate and kidney) is of limited use in diagnosis owing to its relative instability in serum, with the result that the finding of a normal activity does not exclude liver disease. These, and the other enzymes mentioned by Dr Sear, have obviously not yet been shown to be of great value in the study of liver dysfunction. Further, in discussing liver cell necrosis and abnormal membrane permeability, we find Rosalki (1976) stating that "aspartate transaminase may be elevated in several non-liver diseases (especially heart disease) whereas non-hepatic alaninc transaminase elevation is unusual." Further support for our choice of enzymes could be quoted (Schmidt, 1978).