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Recurrent Acute Pancreatitis

Recurrent acute pancreatitis, of course by definition, are multiple attacks of the first item. Now idiopathic acute pancreatitis has a variable incidence in the literature; 10-40% is a good estimate depending of course on the population in the study and efforts made to establish the etiologic diagnosis. And Iíll expand on that, but of course depending on what tests you use, youíll get different incidences of idiopathic pancreatitis. The other point I would like to make about idiopathic acute pancreatitis, I think most of us would recall that this is a mild disease and I put a question mark behind it. Because there really is a paucity of data. Itís been suggested that this is a mild disease, clinically, but on the other hand Uhl et al have said that the course is really no different from other causes of pancreatitis.

Now, what are the causes of recurrent acute pancreatitis? They are many, of course. Cholelithiasis comes right at the top of our list, and weíll talk a lot about that in a minute. Alcohol is probably second, and Iíve listed a number of other causes here including medications, which usually arenít recurrent, hyper hypertriglyceridemia.

About 1-3% of pancreatic tumors present as ordinary episodes of pancreatitis. Hereditary pancreatis is not going to be the subject of my talk, but clearly, taking a careful family history is important. Anomalies of the pancreas are listed here.

Now when you evaluate a patient for recurrent acute pancreatitis, the history is very important. A careful family history for hereditary pancreatitis, a very careful history of alcohol use; 60 grams of alcohol is often the number which is given as the amount of alcohol that is required to be drunk, usually for 5-10 years, but maybe as little as two or three years for patients.

The laboratory tests that we do to evaluate these patients; amylase and lipase levels. Remember macroamylasemia. Not infrequently people get labeled as having pancreatitis because they have an attack of pain, the amylase is elevated. Nobody checks the amylase later and finds that it is still just as elevated. And since macroamylasemia affects a couple of percent of the population, this is an important consideration. Iím going to have more to say in a minute about liver tests.

The other issue is, does this patient really have acute pancreatitis or do they have attacks of acute pancreatitis in an individual who already has chronic pancreatitis. Be it alcoholic pancreatitis, which is pretty simple to elicit, or whether these are truly attacks of idiopathic recurrent pancreatitis. Because if you can demonstrate chronicity it removes the issue of, letís say, gallstones and removing the gallbladder from the picture.

If you remember nothing else that I say, recurrent acute pancreatitis, acute elevations of liver tests are valuable in the prediction of gallstones. I think nearly all of us know that, and perhaps we should just look back at the historical papers which allow us to say that. This is a study done 20 years ago by McMann and Pickford, published in the Lancet, 152 patients with acute pancreatitis. Tests done on the day of admission.

This is a ROC curve comparing laboratory methods used in the metaanalysis, in other words a pictorial display of the data Iíve just represented to you. One minus the specificity on the horizontal axis, sensitivity on the vertical axis, 100% specificity would be at zero, so that anything up here is good. Gives you 100% sensitivity and specificity.

The next important fact is a fact that we are all aware of, but perhaps would need some reminding of, is that occult microlithiasis, or sludge, is a cause of acute pancreatitis, with the accent on occult. Ultrasound is an imperfect modality for the diagnosis of gallstones, particularly in the setting of acute pancreatitis. If you look at the series, mostly published in the 80ís, the sensitivity may be as low as around 70% with the initial ultrasound examination, and the second or even third ultrasound - this is an important point - provides additional yield when patients are better. Many of us have had the experience of seeing patients with so-called idiopathic pancreatitis.