Diagnosis of Acute Pancreatitis
Although acute pancreatitis is usually diagnosed clinically, computed tomography (CT) is important to differentiate between mild cases of acute pancreatitis (which only require rehydration as treatment) and severe pancreonecrosis (which requires surgical treatment).
Blood studies are usually performed to detect organ failure, determine if rehydration therapy is sufficient, if there is a need for antibiotics, and to offer prognostic information.
The golden standard for detecting and evaluating the severity of acute pancreatitis is the combination of abdominal ultrasound and computed tomography. Although it is important to note that imaging performed in the first 12 hours can be falsely reassuring, since the necrotic and inflammatory processes usually require 48 hours to fully manifest.
In recent years magnetic resonance imaging (MRI) is becoming more popular, as it can identify necrotized debris and pancreatic fluid collections. MRI is also more sensitive to venous thrombosis, pseudoaneurysms, vascular complications, and hemorrhage. Moreover, it can be used by patients that are allergic to CT’s contrast material. Using magnetic resonance cholangiopancreatography sequences, MRI can be used to detect little biliary stones and duct anomalies, which can give an insight as to the etiology of the acute pancreatitis and cancel out the need to perform endoscopic retrograde cholangiopancreatography.
Other methods, such as X-ray, lack the sensitivity and are unnecessary.
When acute pancreatitis is suspected, blood is taken from the patient to determine the levels of amylase and lipase to verify the diagnosis. Although this method is pretty reliable, it is impossible to assess the severity of the process using this method alone.
Raised levels of lipase can be detected after 4-8 hours after the onset of the disease. Amylase on the other hand can remain normal in 10 percent of the cases. Moreover, diseases such as inflammation of salivary gland, infraction, bowel obstruction, perforated ulcer, and cholecystitis can also increase the levels of amylase within the serum.
A common sign of alcohol-caused acute pancreatitis is when levels of lipase are about three times higher than levels of amylase.
Thus, it is unnecessary to test for both amylase and lipase. Testing just for lipase is sufficient.