To the Editor.—I have read the seminar entitled "Coma and Hyperglycemia in the Absence of Ketonemia: Present in a 12-Year-Old Boy" by M. D. Kogut and B. H. Landing (Amer J Dis Child114:676-683 [Dec] 1967) and would like to reemphasize an often-forgotten facet of serum amylase values.
As Drs. Kogut and Landing state in their discussion, the rise of serum amylase in proven cases of acute pancreatitis is often transitory, and within 24 to 48 hours the amylase level decreases out of diagnostic range.1 Serum amylase is excreted by the kidneys. It appears that this substance is filtered by the glomerulus and is neither reabsorbed nor secreted by the tubules.2
In the case presented in Drs. Kogut and Landing's article, it seems reasonable to assume that there had been renal insufficiency and possibly shock for some time. Under these circumstances, the glomerular filtration rate would