DNR Patients and Outcomes of Surgery: Two Papers, Same Data, Different Results

Just the other day, a paper from Archives of Surgery reported that patients who have existing DNR orders have a higher postoperative mortality rate than patients who do not. This, of course was not surprising since people with DNR status are usually old and sick. The paper did receive some media attention with routine “churnalistic”* coverage. [HealthDay News, Medscape, MSN Health]

Having read the paper with mild interest, I didn’t think too much about it until yesterday when the May issue of the journal Critical Care Medicine [CCM] arrived. In it was a paper which is very similar to the Archives article. Let’s compare the two papers. The Archives paper was entitled “High mortality in surgical patients with do-not-resuscitate orders: analysis of 8256 patients,” and the CCM paper “Pre-existing do-not-resuscitate orders are not associated with increased postoperative morbidity at 30 days in surgical patients.”

Both papers used data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) Database for the years 200-2008. The Archives paper found some 4128 DNR patients while the CCM paper found only 2199. Both studies matched the DNR patients with non-DNR patients who had similar operations and demographics.

Both papers found that DNR patients were a little more than twice as likely to die within 30 days than non-DNR patients, but the mortality rates were markedly different. The Archives mortality rates were 23.1% for the DNR and 8.4% for the non-DNR versus the CCM cohorts which were 12.5% and 5.2% respectively.

The Archives paper noted a significantly higher rate of major complications for the DNR patients with no difference in minor complications whereas the CCM paper reported that the DNR patients actually had significantly fewer wound infections and no difference in the major complication rate.

I could go on but I think you get the idea. Both sets of authors did mention that their studies could be confounded by the limitations of retrospective studies and the use of an administrative database, such as the NSQIP.

What is not clear and certainly beyond my ability to explain, are the marked discrepancies in the number of patients found with DNR orders when the time period of both studies was identical and the substantial differences in mortality and complication rates.

Bottom line. Although they are at a higher risk of death, DNR patients may undergo necessary surgical procedures with a reasonable expectation of success.

*Churnalism is a news article that is published as journalism, but is essentially a press release without much added

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 21^st 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.]