Appendicitis in children and radiation exposure from CT scans

Recently, medical writer and pediatrician Perri Klass wrote in the New York Times about evolving issues regarding the diagnosis of appendicitis in children, which are also applicable to adults. There is well-documented concern regarding the excessive radiation exposure associated with CT scans.

For example, a recent paper reported that a single abdominal CT scan with contrast delivers a radiation dose equal to undergoing more than 200 regular chest x-rays. The implications of this large dose of radiation are that an increase in cancer rates may arise in the future, especially if the CT scan is performed in a child.

The problem is how does one curtail the use of CT scans for the diagnosis of appendicitis when the test has become extremely accurate? Although Klass states that a normal appendix can be expected in 10-20% of appendectomies, those numbers are no longer valid. Even in a non-teaching community hospital, the rate of removal of a normal appendix during emergency surgery for the diagnosis of appendicitis should be well below 10%. She also repeats a commonly held misconception that a high rate of removal of normal appendices results in a lower rate of perforated appendicitis, which is not true. Some authors even believe that perforated appendicitis is a different disease than simple acute appendicitis.

I do not see the rate of CT scans for appendicitis decreasing because of three major factors.

1. Patients [or their parents] have come to expect accuracy in diagnosis. On more than one occasion, I have had the experience of seeing a teenage boy with classical symptoms and signs of appendicitis where the emergency physician has called me and said he did not think a CT scan was necessary. I examined the child and agreed. After I explained everything to the mother, she said, “What about the CT scan?” It then becomes hard to go ahead without the scan because in the unlikely event the boy did not have appendicitis, the mother would have accused me of performing unnecessary surgery. In fact, of my last 80 appendectomies, I have operated without a CT scan only four times. My rate of removal of a normal appendix is 6%. This is in a non-teaching community hospital with out-sourced CT scan readings at night.

2. Klass mentions the use of ultrasound as a substitute for CT scan. Although ultrasound does not involve radiation and is accurate according to some studies, the reality is that it is not always readily available at night [when most people with abdominal pain show up] in many community hospitals. The test is useless when the appendix is not identified, a situation that occurs frequently outside of academia. And unlike CT scan, ultrasound is far less likely to reveal an alternative diagnosis when the appendix is normal.

3. In a non-teaching hospital where there are no residents, it is very difficult to have every patient with a suspicion of appendicitis seen by a surgeon. When the emergency physician calls and says she has a patient with a positive CT scan for appendicitis, the diagnosis is correct more than 95% of the time. They rarely call when the CT scan is negative. Some scans are equivocal and the surgeon does have to see the patient and make a clinical decision. Regarding patients with positive CT scans for appendicitis, it pains me to say this but the history and physical exam are probably no longer relevant. This is particularly true now that all patients with abdominal pain receive narcotics within a few minutes of arrival to most EDs. It takes cojones to not go ahead with surgery when the CT scan is read as positive for appendicitis. I have done it once [successfully] in the last 19 months. Of course, I look at all the CT scans myself to usually confirm or rarely question the reading.

It comes down to this. Do you want an accurate diagnosis for yourself or your child with the possible increased risk of cancer years later or would you accept a higher rate of normal appendix removal? I believe that the general public would opt for the former.

Skeptical Scalpel is a surgeon blogs at his self-titled site, Skeptical Scalpel.

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  • http://www.MDWhistleblower.blogspot.com Michael Kirsch, M.D.

    CT scans on kids is good training for them since they can expect lots more of them as adults.

  • http://33charts.com DrV

    I would venture to estimate as a pediatric gastroenterologist, nearly all of my patients who present with pain to community emergency rooms get a CT. And this is pain due to rock hard stool noted on palpation of the LLQ. This is epigastric, postprandial pain. Invariably a 7 minute history establishes very clearly that appendicitis isn’t in the differential.

    Perhaps this is the case because of the evolving trend to order CTs from triage before PEx has been done?

    Huge problem that I feel represents sloppy medicine.

    I have too much to say about this.

    • richard scottr

      One wag said, “what is physical exam,” answer, “what one does when the ct scan is broken.”
      Obviously informed consent is essential for both surgery and ct scan. Obviously, good radiologists are equally important.
      many good points in the posts.

  • BladeDoc

    I disagree. What the public wants is an accurate diagnosis of appendicitis AND no risk of cancer. And they want it for free. And what do you mean he can’t play football next week? Don’t you know he’s on the junior junior second string varsity practice squad and will certainly get a scholarship?

    What they will settle for is getting a CT now and getting to sue 20 years from now when the mesothelioma advertisements have turned into the “has you or a loved one ever gotten unnecessary RADIATION in the form of a CT scan?

    But I’m post call and a little grumpy.

  • CiCi

    Whatever happened to” rebound tenderness at Mc Birney’s point? Sorry about the spelling, been out of the Nursing biz for a while. But I diagnosed my own son,before I was even a nurse, by this basic physical exam technique. Are you telling the parents about the risk of the radiation exposure?

    • http://thedocsquawk.com thedocsquawk

      Would be nice if ultrasound were more available at all let alone at night. Have enough trouble trying to get one in the day let alone at night in a lonely ER.

  • Finn

    I’m one member of the public who resist a CT scan for what seemed to be appendicitis because of a history of ovarian cancer. Unfortunately, because of that same history, the physician would probably insist on the scan to make a diagnosis. But on my tally sheet, the benefit of avoiding unnecessary radiation exposure far exceeds the risk of removing a healthy appendix.

  • Beth

    What about a regular x-ray? Why can’t they diagnose appendicitis?

    • justin

      x-rays are good for bones and some specific soft tissue issues; seeing an inflamed appendix (let alone a normal appendix) is not easily done with an x-ray.

      • http://drpauldorio.com Paul Dorio

        “not easily done” — I’ve never seen an appendix on a plain x-ray. Obstruction yes. Appendicitis no. CT is the best but ultrasound is useful IF the inflamed appendix can be found. Due to anatomical position of the appendix, however, ultrasound only identifies a minority of cases.

  • http://www.preemieprimer.com Dr. Jennifer Gunter

    I think it should be case by case. A CT scan has a 1/1,000 risk of cancer for a 20 year old, it is higher for younger children. What is the risk of a major complication from appendectomy? Less or more? If the signs and symptoms for appendicitis are classic, then I would gladly let my children have surgery without a CT scan. If the signs and symptoms are not classic, then we would watch and wait or have the Ct scan depending on the situation (high WBC or not).

    As a chronic pain doc I see patients get CT scans before even getting and exam by the ER doc ALL THE TIME. The fact is a CT scan augments clinical practice not replaces.

    So no, a CT scan should be required before surgery. a 1/1,000 risk of cancer is pretty high. I am hoping Skeptical Scalpel tells his patients who ask about a CT scan about the radiation risks.

  • http://drpauldorio.com Paul Dorio

    “When the emergency physician calls and says she has a patient with a positive CT scan for appendicitis, the diagnosis is correct more than 95% of the time.”

    Yes.

    CT and radiologists have gotten so good at finding many diagnoses that a physician has to make a serious effort NOT to get a scan. Radiation risk is small, but real. Morbidity from undiagnosed appendicitis is NOT small and is also quite real. A ruptured appendicitis is a tragedy that should not happen because someone was concerned about future radiation risk.

    Having said that, we in the radiology community continue to look at ways to decrease radiation dose. It is my opinion that DrV and others are right, as is the author of this post:

    1- Physical and History by trained professionals is imperative.
    2- CT scan/Ultrasound/MRI are VERY useful adjuncts when physical exam findings warrant.
    3- Imaging confirmation and identification of the correct diagnosis decreases the number of unnecessary surgeries.

  • http://skepticalscalpel.blogspot.com/ Skeptical Scalpel

    @JenGunter Nearly every patient who is referred to me from the ED has already had a CT scan before I am called. I do not have a chance to discuss radiation risks with them.

    In the last 3 weeks I tweeted the following:
    JAMA editorial advises consent discussion of radiation risks should be held before CT done. Not done now in >90% of CTs http://tiny.cc/5edm4 and RSNA study says 16% per year increase in ED CT scan use 1995 to 2007 http://bit.ly/fCZRvy confirming my blog of 8/11/10 http://bit.ly/gzkJr5.

    The average patient I see is not capable of making a rational judgment of the pros and cons of CT radiation vs. accurate diagnosis. This isn’t surprising since even the “experts” can’t agree on what the radiation risks from CT are. Just for fun, try explaining all this to a pregnant woman with right-sided abdominal pain (I have) when MRI is not available and ultrasound (as usual) can’t locate the appendix.

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