Computerized tomography is another procedure that may be employed to confirm the diagnosis of pancreatitis. This procedure is sensitive in detecting calcification of the pancreatic tissues, as well as changes in tissue atrophication. Occurrences of fat deposits and dilation of pancreatic ducts can also be detected by computerized tomography. The sensitivity of the procedure has been estimated to be 80% (Luetmer et al. , 1989). Computerized tomography has been comparatively assessed with ERCP and has been categorized as less sensitive in fully diagnosing pancreatitis.
However, computerized tomography is a very reliable procedure in diagnosing other conditions that may affect the pancreas, including pancreatic cancer. There are also other classical function tests that may be used to confirm pancreatitis. These function tests have been adapted since the 1940’s and have been improved through the decades. The main goal of these function tests is to determine the levels the proteins that are secreted mainly by the pancreas in order to evaluate the capacity of this organ to perform its normal physiologic function in the body.
The secretin stimulation test is a procedure that involves the introduction of a tube through the mouth and directly it into the stomach and duodenum. The procedure involves the application of local anesthesia to the patient during the introduction of the tube. The end of the inserted tube is equipped with a vacuum and a cathode that determines the acidity of the fluids in the stomach and duodenal regions of the digestive tube (Lagerlof et al. , 1967). Consequently, secretin is administered through an intravenous line and is employed to infuse the stomach.
In classical tests, approximately 1 U/kg of secretin bolus is introduced during the procedure, which is considered as the supraphysiologic amount that is tolerated by the body. Today, approximately 0. 2 mg/kg is introduced to the patient during evaluation of the fluid in the duodenal region of the gastrointestinal system. The procedure involves determination of acidity, volume and bicarbonate levels through titration reactions using hydrochloric acid. It is now also possible to perform titration using analysis machines (Ceryak et al. , 2001).
It is also possible to couple the secretin stimulation test with assessment for the presence of microbes such as Giardia and other bacterial strains. The secretin stimulation test is considered as the most reliable functional test for pancreatitis. This is mainly based on the concept that bicarbonate is generated by the pancreas and thus determination of bicarbonate levels will provide information of the physiologic functioning of this organ at the time of presentation of the patient at the hospital (Heij et al. , 1986).
The secretin stimulation test is sensitive enough to detect 75% of the cases of acute pancreatitis, while it has been observed to be 97% sensitive in detecting chronic pancreatitis (Kitagawa et al. , 1997). However, it should be noted that the secretin stimulation test has also been reported to be a difficult procedure to perform because it entails the insertion of a tube through the oral opening and there are also chances that the procedure may generate false positive readouts (Sun, 1963).
Another functional test that could be employed to confirm the diagnosis of pancreatitis is the fecal elastase test. The enzyme elastase-1 is secreted by the pancreas and is mainly responsible for degrading protein during digestion of food. This reaction takes place before the food is transferred from the duodenum to the intestinal tract. The normal condition thus expects that the concentration of elastase in the stool of a healthy individual is 6-fold higher than that in the duodenum (Sziegoleit and Linder, 1991).
The amount of elastase is the feces is determined by the use of the enzyme-linked immunosorbent assay (ELISA) and the results may be compared with other enzymes such as lipase and amylase. In the case of a patient with severe pancreatitis, the usual elastase concentration observed is lower than 100 micrograms/gram of feces (Stein et al. , 1996), while the elastase values in a normal healthy individual is above 200 micrograms. Another functional test that could be performed in order to confirm the diagnosis of pancreatitis is the serum trypsin test.
This procedure is specifically design to determine the functioning of the pancreas by assessing the amount of trypsin in the serum of the patient. It has been determined that a patient with trypsin levels lower than 20 ng/mL is indicated of chronic pancreatitis. However, it should be understood that the serum trypsin test is only sensitive is screening for advanced stages of pancreatitis. In cases wherein the serum trypsin levels are between 20 to 29 nanograms, it is difficult to confirm that pancreatitis is indeed present in the patient.
It has been observed that mild cases of pancreatitis are hard to confirm through the use of the serum trypsin test. Another observation that can be used from the serum trypsin test is that readings of above 150 ng/mL can be considered as inflammatory stages associated with pancreatitis. It is also possible that a patient with pancreatitis may have normal levels of lipase and amylase, yet the serum trypsin levels are high. The serum trypsin test is, however, insensitive in differentiating bening cases of pancreatitis from simple inflammation of this organ (Lake-Bakaar et al. , 1980).