Abdominal Pains: Carnett sign
Written by Editor   
Monday, August 22, 2016 12:00 AM

Gastroenterologists and other clinicians often see abdominal pain complaints for sundry reasons. A lot of times we don't find the explanation that necessarily gives the diagnosis, and we push the can down the road and refer it to somebody else, or the patient is left in the lurch without an explanation.

Here is a pearl of a physical technique that’s all about back to basics, beginning with taking a good history and then confirming that with a physical finding. Let me begin with a case scenario.

A 34-year-old woman had been in the emergency room (ER) twice in the course of the past month. She noted an onset of right upper quadrant pain that was fairly stabbing in nature, which had occurred during a trip to Europe. She was backpacking with her husband and child and was frequently struck by this pain. It was stabbing, somewhat positional, ameliorated with recumbency, never aggravated by meals, and became persistent and programmatically worsened over the course of the several days of the trip.

When she got back to the United States, she had such severe pain one night that she went to the ER. While there, she probably didn't get a physical exam, but she got a CT scan that showed nothing. They then referred her to a surgeon for possible biliary colic. The surgeon ordered an ultrasound and a CCK/HIDA scan, which was normal. The patient was told that it's not a surgical problem and that she could go back to her primary care doctor, which she did. There was really nothing else to be said in that intervention.

She then had another episode of abdominal pain, so she went back to the ER. Guess what she received yet again? Yes, another CT scan. The ER physician also suggested that she see a gastroenterologist.

During her history she recalled that she had had this episode when she was backpacking, swinging the backpack, and also carrying her child on her right hip. Therefore, she really had a lot of unusual positional requirements over the course of that week when the onset of the pain started.

With that in mind, think about what could potentially be causing a nongastrointestinal type of pain. Examination found that she was point tender in the right upper quadrant. Through a positional change and flexing her neck forward, the pain became exquisitely tender. This is all musculoskeletal pain.  

It goes back to something called the Carnett sign, which was first described by Dr John Carnett in 1926.  It basically involves a physical finding where, on an abdominal exam, you find the point of maximum tenderness. The way that Dr Carnett initially described it was that he would place his hands on that point of maximum tenderness and have his patients cross their arms and then do a sit-up. If that pain got worse, that was much more compatible with a musculoskeletal rather than an intra-abdominal source.

It's a great physical finding and something that you can do very easily. Compared with a CT scan, it’s something that doesn’t cost $1000 and has no radiation exposure, which was twice incurred on this patient. CT scans don't always beat history and physical examination.

When that diagnosis is made naturally one has to then explain to the patient why they have this pain.

In our patient’s history, it was pretty clear that she had done several things over the course of the week during her trip that had naturally torqued her abdominal musculature.  However, what I see in a lot of patients is a compression with age where they lose vertical height. As the vertical height goes down, their abdominal muscles get a little bit out of sort. During an examination have them turn around.  Then look at their pelvis. This allows to inspection of their pelvic balance, the pelvic brim. Sometimes what you'll see is a slight tilt, a leg-length discrepancy that occurs for whatever reason. They may have mild scoliosis or kyphosis, and this alteration of height or pelvic tilt will have changed their abdominal muscle bearing. They may need a referral to a physiatrist or doctor of chiropractic for leg-length discrepancy or heel lift, for exercises to allow for relaxing, stretching, and core strengthening.

What you can’t do is simply turn these patients away and say it's not gastrointestinal pain. When you find musculoskeletal pain, look for the possible etiology so that you can suggest potential next steps to the patient.  If you can understand the causality, you can then refer them for more appropriate treatment.  Medical physicians should check with chiropractic physicians, because this is stuff that we do EVERY day.

Take a good history and do a good physical exam, which doesn't necessarily need to include a CT scan. It's about a back-to-basics approach that we were taught a long time ago in our initial training: Examine the patient, talk to them, and listen to them. Remember the Carnett sign the next time you have a patient with abdominal pain.

Source:  http://www.medscape.com/viewarticle/866188