Tuesday, April 26, 2011

Clever New Diagnostic Test for Pancreatitis Fails to Measure Up

Today Eurekalert!, a science news service, featured a story about a new diagnostic test that at first glance seems interesting and possibly of value. Researchers at the University of Texas have developed a simple, inexpensive test for diagnosing acute pancreatitis using an LED sensor, aluminum foil, gelatin, milk and lye. Using about $1.00 worth of materials, the test identifies the presence of high levels of a pancreatic enzyme, trypsin, in the blood and takes only a few minutes to do.

According to the press release on the Texas Science website, “The sensor could help prevent damage from acute pancreatitis, which is a sudden inflammation of the pancreas that can lead to severe stomach pain, nausea, fever, shock and in some cases, death.”

Unfortunately, the breakthrough is not really all that dramatic.

Acute pancreatitis usually resolves in a few days. It is treated conservatively using bowel rest, intravenous fluids to maintain hydration and pain medication.

Pancreatitis is commonly diagnosed by history and physical examination and confirmed by elevated levels of one or two blood tests, serum amylase and lipase. Lipase, which rises more slowly but remains elevated in the blood longer than amylase, is the preferred test. Checking on line reveals that a serum lipase test can be obtained for as little as $39.00 retail. The actual cost of performing the test is under $6.00. In a hospital emergency department, the result is available within an hour of obtaining a blood sample, which negates the small speed advantage of the gelatin-based test. And let’s not forget that according to Joint Commission and other regulatory organizations, any point-of-care test must undergo frequent calibration to assure consistent quality. Technically, even a simple test for occult fecal blood cannot be performed at the bedside in the 21st century.

It is not clear exactly how a diagnostic test that might save a few dollars and produces a result a little quicker than a standard blood test can prevent damage to the pancreas. Since the test is qualitative [elevated trypsin levels are present or not] rather than quantitative like the lipase test [a numerical value is reported], the gelatin test cannot be used to determine whether the level of pancreatic inflammation is increasing or not.

In fairness, the press release does point out that the gelatin test could be used in developing countries where automated blood analyzers might not exist or in situations where electrical power has failed. This of course is based on the assumption that aluminum foil, LED sensors gelatin etc are handy.

Bottom line. The test is ingenious but seems unlikely to replace standard blood tests for pancreatitis. Don’t believe everything you read in a press release.

[Note: Only 32 (7%) of the 451 words in this post were taken directly from the press release.] 

No comments:

Post a Comment