Sunday, October 12, 2008
HIDA Scans: A call for a moratorium
We can all agree that baseball games last far too long. One of the biggest reasons for these protracted snoozefests are all the extraneous time waster crap that occurs. Batter stepping out of the box to adjust their wristbands and gloves. Or pick-off attempts, for example. Now I don't mean the quick move to first when there's an actual basestealer taking a big lead off first. I'm talking about those lazy, lobbed soft tosses to first when the slow, lumbering clean-up hitter is standing 7 inches from the bag. It's like the pitcher is saying, " you know, I'm really not ready to pitch to the batter. I think I'll kill some time by needlessly lobbing one to my first baseman." I can't stand it. It wastes time. It doesn't add anything. Nothing is gained. Ban it.
With health care costs spiralling out of control, it would be prudent to re-evaluate the American way of ordering test after test on patients who come into the hospital. We need to start asking ourselves: What can we eliminate? HIDA scans, in a way, are the general surgical equivalent to the lobbed pick-off throw to first. For the most part, they don't add much to the proceedings. Here's the typical scenario: Patient presents to ER with RUQ pain and nausea. An ultrasound is performed which shows multiple gallstones in the neck of the gallbladder. Some wall thickening of the gallbladder is noted. The patient is admitted to the internist on call (happens more often than you'd think). The internist then reads the official US report in the morning. Invariably, there will be sentence at the end of the report along the lines of this: "Recommend HIDA scan if there is concern for acute cholecystitis". So, the dutiful internist orders the "recommended" HIDA scan and gets a general surgery consult. General Surgeon comes to see patient but patient not in room. Down in nuclear medicine, the clerk says. So general surgeon leaves, comes back in an hour or two. Still no patient. Still in nuclear medicine for delayed images. General surgeon silently swears into his head. Returns at the end of the day. Patient clearly has RUQ tenderness, a positive Murphy's sign. The US shows stones. The HIDA hasn't been read yet. Doesn't matter. He books the patient for lap chole as soon as OR time available, which likely will be the following day. So now, the patient gets an extra couple days and an unnecessary test added on to his/her final bill.
A HIDA scan (hepatobiliary iminodiacetic acid scan) is an imaging procedure that involves injecting a radiotracer into a peripheral vein. The tracer gets picked up by the biliary system of the liver and is excreted via the common bile duct into the gallbladder and duodenum. A HIDA scan that shows non-filling of the gallbladder after a certain amount of time is diagnostic of acute cholecystitis; cystic duct obstruction being the sine qua non of the calculous biliary disease.
Sounds all well and good. But acute cholecystitis is, for the most part, a clinical diagnosis. RUQ pain. Nausea/bloating. Often developing after eating a fatty meal. Positive Murphy's sign on exam. An ultrasound demonstrating gallstones pretty much confirms the diagnosis. You really don't need anything more. A HIDA scan may or may not be positive, but the result is irrelevant. You already have a strong clinical suspicion of cholecystitis; so take out the gallbladder!
There are plenty of scenarios where a HIDA is warranted and useful:
-The demented old lady with gram negative sepsis who is a poor historian and has an unreliable physical exam.
-The ill patient in the ICU who has been on TPN for weeks and has an unexplained leukocytosis.
-Patients with symptoms of biliary dyskinesia (another blog post altogether)
-Evaluating for the possibility of a bile leak after biliary surgery
But straight-forward acute calculous cholecystitis in a reasonably healthy, alert patient should be obvious enough without biliary scintigraphy. Let's save ourselves the $1500 a pop that HIDA scans cost. Ultrasounds are cheap and highly sensitive. Enough is enough. Starting now, let's all try to limit how often we send our patients down to the basement of radiology for time-consuming, expensive, needless, and ultimately useless, testing. We can do it; I have faith.