Amylase isoenzymes in the evaluation of trauma patients

In traumatized patients, elevation of the levels of serum amylase is often noted and may lead to a diagnosis of pancreatitis or pancreatic injury. In the presence of multiple injuries, it is often difficult to evaluate clinically for pancreatitis or pancreatic injury. Since the serum amylase is derived from both the pancreatic and the salivary glands, it is useful to determine the origin of the elevated levels of serum amylase in these patients. A total of 31 patients including 21 trauma patients were studied, and the total serum amylase and also the pancreatic (P) and salivary (S) fractions were determined by isoelectric focusing. Compared with the normal control group, most trauma victims had elevated total amylase levels (normal, 30-128 U). In six patients with head and facial trauma, the P-fraction was 7.6 per cent, and the S-fraction was 92.4 per cent (normal, P 35-50%; S 50-65%), while in six patients with penetrating abdominal trauma, the P-fraction was 81 per cent, and the S-fraction was 19 per cent. These differences were statistically significant. The data demonstrate the value of measuring fractions of amylase in addition to total amylase levels. In patients with head and facial trauma alone, elevated levels of serum amylase are due to an increase in the salivary fraction. Elevation of total serum amylase in traumatized patients does not necessarily indicate pancreatic injury. Measurements of amylase fractions were thus useful in evaluation of trauma patients.