The hourly rate of urinary amylase excretion, serum amylase, and serum lipase. II. Patients with gastrointestinal and pancreatic disorders.

Gastrointestinal disease other than hepatobiliary and pancreatic disorders was associated with hourly rates of urinary amylase excretion above the limits of normal for control subjects (88 IU/hour compared with 69 IU/hour). In hepatobiliary disease, excretion rates of more than 88 but usually less than 190 IU/hour were sometimes found. Whilst rates of urinary amylase excretion were not helpful in the diagnosis of chronic pancreatitis or carcinoma of the pancreas, levels above 190 IU/hour were found in acute pancreatitis at a time when the serum levels were also diagnostic. After the acute episode the rate of urinary amylase excretion was moderately elevated for up to six days but did not reach diagnostic levels. Persistent elevation of serum amylase and lipase levels and hourly rates of urinary amylase excretion for more than six days suggested that a pseudocyst had developed. In acute pancreatitis the level of serum lipase was more frequently raised and persisted so for longer than either the serum or urinary amylase. Although the hourly rate of urinary amylase excretion is of little value alone, when performed in conjunction with evaluating the serum amylase and lipase it may provide useful additional evidence of pancreatic disease and it could be useful in the diagnosis of relapsing chronic pancreatitis.