Irrational fear of CT scans in appendicitis

By Skeptical Scalpel and Saurabh Jha*

Simple appendicitis cannot be distinguished from complicated appendicitis by clinical examination and laboratory findings say Finnish investigators. They looked at data from their randomized prospective trial of antibiotics vs. surgery for treatment of appendicitis and concluded that only CT scans could reliably differentiate the two entities.

The study involved adult patients from 18 to 60 years old; 368 of whom had uncomplicated acute appendicitis and 337 had complicated appendicitis—appendicolith, perforation, or abscess.

Duration of symptoms, C-reactive protein, white blood cell count, and temperature were significantly different between simple and complicated appendicitis patients. However substantial overlap of values meant they were not helpful in predicting the presence of complicated appendicitis.

Receiver operating curves for C-reactive protein and temperature areas under the curve do not exceed 0.77. Combining these parameters did not improve accuracy.

The paper concluded that CT scanning is essential in diagnosing acute appendicitis and identifying simple and complicated cases.

A companion study by many of the same authors looked at 1321 patients who presented with clinical and laboratory findings of possible appendicitis. Since their protocol called for confirmation of the diagnosis, all patients underwent CT scans, and 351 (27%) did not have appendicitis.

Health Care and the $20,000 Bruise: A different take

Twitter is buzzing about yet another medical billing horror story. This one appeared in the Wall Street Journal and was written by Eric Michael David who is an MD PhD JD and an officer at a biotech company.

He saw a large, swollen bruise on his three-year-old son's head several days after falling off his scooter. Other than the bruise, no other abnormalities were mentioned. He took the boy to "one of the top pediatric emergency rooms in the country" to have a CT scan done. It showed "a small, 11-day-old bleed inside his head, which was healing, and insignificant."

Dr. David received a bill for $20,000, $17,000 of which had been paid by his insurance company. He was responsible for the remaining $3000.

He noted a $10,000 charge for a trauma team activation which he said never happened. After a lengthy series of exchanges with the hospital's billing department and Dr. David having to prove that a trauma team activation was unwarranted and not permitted by certain regulations, he was able to have the charge rescinded.

The essay went on for some 1200 words listing the steps that he went through. He correctly described what a mess American healthcare delivery is and why as long as overuse and upcoding are rewarded, the Affordable Care Act will not fix it.

Dr. David was right to contest the $10,000 charge for a trauma team activation that wasn't indicated and didn't even occur.

What he didn't address was this.

Why would a doctor who said that he had "served on trauma teams in two of the busiest hospitals in New York City" feel the need to take his apparently asymptomatic son with an 11-day-old injury to an emergency room for a CT scan?

Doesn't this imply overuse of a different type?

Secondary questions:

Did anyone bring up the issue of radiation from the CT scan?
Did the docs in the ED think a CT scan was necessary?
"Inside his head" is a rather odd phrase. Does it mean intracranial? Intracerebral?
Was "one of the top pediatric emergency rooms in the country" the only option or could this asymptomatic boy have been seen in a doctor's office?
Why is the charge for a trauma team activation $10,000?

Uncertain diagnosis or CT scan radiation? Which would you choose?

It is so nice to be right.

To summarize what I wrote almost 4 years ago, here and here—based on my experience, patients and families will accept the theoretical risk of a future cancer if it means they'll get an accurate diagnosis.

A recent study validates that opinion.

MedPage Today reports that before receiving any recommendation for CT scanning, 742 parents of children who presented with head injuries were surveyed by researchers from Toronto's Hospital for Sick Children.

Parents, almost half of whom had previously known that CT scanning might cause a cancer to develop in the future, were told of the radiation risks of CT scanning in detail. The authors found that although the parents' willingness to go ahead with the CT scan fell from 90% before the explanation of risk to 70% after they were briefed about radiation, at crunch time only 42 (6%) of them refused to let their child be scanned.

And of the 42 who initially refused, 8 eventually went ahead with the scan after a physician recommended it.

So to put it another way, even after they were fully informed of the potential risk of CT scan radiation to their child (lifetime risk of cancer is about 1 in 10,000, according to the authors), nearly all parents opted for the scan.

Also of note are the following:

The median age of the children was 4.

12% of the children in the study had undergone at least one previous CT scan.

97% of the children were diagnosed with only concussions or mild head injuries.

An article in Scientific American puts some of the radiation risk into perspective. It is long, but worth reading as it explains how risk has been calculated, the best guess as to the true level of risk, and what radiologists are doing to lower the radiation exposure associated with CT scanning.

According to that article, "Any one person in the U.S. has a 20 percent chance of dying from cancer [of any type]. Therefore, a single CT scan increases the average patient's risk of developing a fatal tumor from 20 to 20.05 percent."

No one ever comments about weighing the potential harms that may have been prevented by a timely CT scan diagnosis against the radiation risk.

CT scans should be ordered judiciously. The area scanned and the amount of radiation should be limited as much as possible.

But if you need a CT scan to help diagnose your problem, go ahead and have it.

Bottom line. When it comes to accuracy in diagnosis vs. radiation-induced cancer risk, parents overwhelmingly chose the former.

Appendicitis: Accurate diagnosis or no radiation. You make the call.

Amid the mounting concern about radiation exposure and future increases in cancer rates comes a report from Washington State describing the benefits of imaging, particularly CT scanning, for the diagnosis of appendicitis.

The authors collected data from some 55 hospitals of all types and sizes over a six-year period for more than 19,300 patients older than age 15; 91% of patients underwent one or more imaging studies. There were 16,852 (87.2%) CT scans, 1160 (6.0%) ultrasounds and 108 MRIs (0.6%) with 1677 (8.7%) patients having no imaging.

If a patient had an imaging study, the rate of normal appendix removal was only 4.5% compared to 15.4% for those who were not imaged, p < 0.001. Stated another way, on multivariate analysis a patient who had no imaging was over 3 times more likely to have a normal appendix at surgery. Only 4.1% of those undergoing CT scan had a normal appendix compared to 10.4% of those who had only an ultrasound, p < 0.001.

The difference in the rate of normal appendix removal was true regardless of gender—men 3% with imaging vs. 10% without and women 6.9% vs. 24.7%, both statistically significant differences. In other words, nearly 1/4 of all women who were not imaged had a normal appendix at surgery.

Perforated appendicitis occurred in 15% of all patients, a figure that has remained constant over many years and has not been influenced by imaging.

The Washington appendicitis experience is probably generalizable because in most hospitals, CT scan is the preferred imaging modality over ultrasound, which is more operator-dependent, less accurate and less available during off hours than CT scan.

My personal experience is similar to that of the authors of the study. My rate of removal of a normal appendix when operating for the presumed diagnosis of appendicitis is 4.3% for my last 200 cases. Only 18 (9%) of my patients, all young males, had no imaging and just 1 had a normal appendix. CT scans were the only studies performed in 99% of my patients who were imaged.

I have previously written that patients and their families seem to prefer an accurate diagnosis over a theoretical slightly higher cancer risk 20 or 30 years later. The paper from Washington also confirms that a high accuracy rate of CT scanning for appendicitis is achievable outside of academic centers.

For many reasons, I can’t imagine the rate of CT scans for the diagnosis of patients with right lower quadrant pain decreasing. The accuracy of CT is no longer an issue. Most ED MDs are scanning everyone with right lower abdominal pain. They may tell you it’s because surgeons insist upon it, but whatever the reason, a lot of CT scans are being done. Another advantage of CT scanning is if the diagnosis is something other than appendicitis, the CT will very often reveal what is wrong with the patient. In a previous blog, I have mentioned before that it would be impractical to ask surgeons to examine every patient with abdominal pain, one of the more frequent complaints of patients presenting to emergency departments.

Face it, CT scanning for the diagnosis of appendicitis is here to stay. Whether implementation of protocols to lower the radiation dose of the devices will calm all the doomsday prophets remains to be seen.

[Thanks to Dr. Frederick Thurston Drake, lead author of the paper from Washington, for providing me with information not published.]

Radioactive man? Milford resident pulled over by state police

A few days ago, a 42-year-old man was stopped by a state policeman because radiation coming from his vehicle was detected by a device in the patrol car. Earlier that day, he had undergone a cardiac stress test which involved the injection of a small amount of radioactive isotope into his body. He was released when he produced a doctor’s note stating he had undergone the test. [Full story here.]

Two things make this story interesting.

One, the report reveals the fact that many police cars have radiation detectors that are so sensitive that a man emitting a small amount of radiation while driving could be fingered as a possible terrorist. Despite my being a news junkie, I did not know that such detectors were deployed. Did you?

Now the terrorists know too. What is to stop them from bringing a nuclear weapon into a city now that they are aware of the existence of these detectors and that a note from a doctor can get one off the hook?

The second interesting point involves the stress test. The story says the man had what seems to have been a transient hypertension. There was no mention of any cardiac symptoms or a family history of heart disease. The man is employed as a fireman, a strenuous occupation.

Why was a nuclear stress test ordered?

I am a mere, “non-cognitive” surgeon, but I believe that an asymptomatic 42-year-old fireman with hypertension, episodic or not, does not need a cardiac stress test.

Do you wonder why we spend so much on health care in the United States?