Monday, January 30, 2012

The importance of patterns or, a treatise on how I didn't see that coming (again)

Part of being a good doctor is learning to recognize patterns. This can generally be agreed upon by medical professionals. A more subtle part of being beyond good and being excellent is realizing when to ignore the patterns so that you don't miss something really important.

Examples of recognizing patterns. A 2 year old, female spayed Poodle presents for generalized lethargy, vomiting, and diarrhea. Addison's disease is an important rule out. An owner that calls and reports that his Great Dane is retching non-productively retching. Think GDV. A 7 month old Labrador comes in for vomiting and not eating, think foreign body in the stomach or small intestines.

These are the patterns that every veterinarian learns. They are important. But they are "stereotypes" as it were. And as with everyday life, these stereotypes are sometimes wrong.

This morning, my colleague saw a patient. It was a 14 year old Golden retriever. She'd been vomiting off and on for a week. She briefly responded to medications, then she started vomiting again. My colleague treated her symptomatically and sent her home.

At the beginning of my shift, the dog came back. She had deteriorated through the day. Her breathing was labored, her heart rate was sky high, and she looked generally I'll. Her case perplexed me a great deal. Her heart rate was so high that I initially thought she had a primary cardiac disease. She was also having an intermittent arrhythmia. Xrays did not support heart enlargement, heart disease, or pulmonary edema, but they were suggestive of aspiration pneumonia. This often occurs in vomiting patients.

Bloodwork was equally unrewarding, being very non-specific and unexciting. I tried a dose of a beta blocker to slow her heart rate. It was unsuccessful. Thus, I assumed that her heart rate was related to something else - pain or dehydration. I administered a dose of pain medication, and the heart rate dropped immediately.

I returned to my xrays, suspicious. Then I talked to the owner and gave her the news. In a 14 year old, vomiting dog that is not responding to therapy, cancer has to be the #1 consideration. The dog's xrays looked consistent with an upper GI obstruction. Masses of cancerous origin can cause this.

After much discussion, we decided to explore her dog's abdomen. Guess what we found? A foreign body stuck in the middle of the intestines! It was a very nasty linear foreign body, but we were able to remove it and leave all of the intestines behind.

The lesson? Don't rule out differentials just because of patterns. A 14 year old dog can eat a foreign object just as easily as a 14 month old dog. Thankfully, I knew I was missing the cause of her problems and kept looking and probing to find the answer. Had I just gone with patterns, I likely would have told the owner cancer until proven otherwise. Instead, we took her to surgery, found the problem, and fixed it.


Nicki said...

What a good surprise and a good reminder!

foffmom said...

Very nasty linear what? Just curious. And if the protocols were always right, we would get bored. And robots would be doing diagnosis.

The Other Vet said...

Yeah... unfortunately, 14 year old Golden ill in ANY way is usually cancer until proven otherwise. That is a difficult thing to get past. You finally learn the patterns in vet school or even a year or so after and then you have to remember the pattern isn't always right.

And I feel for your associate. I think we've all been there at one point or another but I know, for me, it feels crappy when you miss something like that.

Amanda said...

What exactly made you decide to explore the abdomen?