Ever wonder how much of our clients money we waste running imaging diagnostics that will offer us little or no diagnostic information? You should. These are the questions that researchers into evidence based veterinary medicine seek to answer. In the near future, we might learn that what we do in veterinary medicine is, in many cases, wasteful and expensive.
At a recent series of lectures given by 2 folks from Banfield* about evidence based veterinary medicine and informatics, my mind got to wondering about how many imaging diagnostics we order that do little more than pad our pockets.
I offer the following three situations where we commonly order imaging studies to the evidence based medicine researchers (and Banfield) to question and decide – are we really just wasting peoples money?
Situation 1: Ordering an abdominal ultrasound in a young patient that presents with a history of chronic vomiting and has normal abdominal radiographs
I contend that ordering an ultrasound in a patient with this presentation is essentially a waste of money. Considering the disorders that could possibly cause this history, I am unable to think of a single disease process that is likely to present in a young patient in which an abdominal ultrasound study will alter the management of the case. Given that 99.99% of the causes for chronic vomiting with normal radiographs are inflammatory and will have minimal or no ultrasound changes why do we continue to order ultrasound studies in these cases? What is this mysterious disease process that we are trying to rule out?
I content that the next diagnostic step after radiographs in these cases should be a good old abdominal exploratory to obtain biopsies of the stomach and small intestines. My hunch is that the reason we recommend ultrasounds in these cases is to cover our collective behinds just in case a pet owner gets upset that we perform a negative explore.
My other hunch, is that if we frame the diagnostic options by saying...
"Ok owner - your dog has been defecating in the house now for a few weeks. It is a mess and your husband is about to leave you because of the smell and the fact that your one year old kid keeps crawling in it and tracking it all over the house. You have two options.
Option one is to go in surgically and see what is up and obtain biopsies and get an answer.
Option two is to spend $300.00 and poke around the outside with ultrasound but there is only a 0.01% chance that we will find anything significant. Also remember that unless your dog is in the 0.01%** of the cases we are going to be back to option one anyway."
very few pet owners will be giving us the green light on ultrasound in these cases.
Case 2: Ordering skull radiographs in a patient with nasal disease.
Ordering skull radiographs in a patient with nasal disease such as nasal hemorrhage or chronic nasal discharge is essentially a waste of money. The problem is that with just about any nasal disorder, the radiographic changes are so subtle that radiographs do not give us enough specific information to manage the case. Moreover these changes only happen late in the course of disease so radiographs will often be normal until late in the course of disease.
Although radiographic might allow us to say that there is “something” going on in the nasal cavity but don’t we already know there is something going on because the dog is bleeding or snotting all over our exam room?
I contend that nasal radiographs have essentially no place in veterinary medicine and a better way to image these patients is to simply skip the skull radiographs and go straight to nasal CT. Unlike skull radiographs, nasal CT offers very sensitive and moderately specific information that will assist in patient management.
Case 3: Ordering an abdominal ultrasound in a young patient with acute vomiting and diarrhea and normal survey radiographs.
Ok, I am prepared to be blasted for this one but my experience is that in the vast (vast vast) majority of cases, surgical abdominal disorders do not have diarrhea as a clinical sign. Can anyone remember a case where a vomiting dog with diarrhea and normal radiographs required surgical intervention? I cannot. Conversely, I can remember scanning loads of animals with this presentation and coming up with bupkis.
I contend that if abdominal radiographs are normal in a young patient with acute vomiting and diarrhea, abdominal ultrasound will not reveal any significantly useful information. These patients should be managed medically.
Bottom line: in many situations we order imaging studies to cover our collective behinds at significant cost to pet owners. Evidence based medicine should be applied to the imaging diagnostics we order so we can develop appropriateness criteria for ordering these studies. Unfortunately, all of us who run around with an ultrasound machine are paid by the study so we will never turn you down when you call us in to do an ultrasound. In fact, we often show up early and won’t even let things go to the next day because we know that the dog might get better before we get to put a probe on it. My thesis on “predatory referral imaging,” however, is a topic for another day.
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*yes that Banfield. If you get to hear Kerri Marshall DVM and Elizabeth Lund DVM speak - do it! I know what you are thinking, “ Banfield, that is where they do “cookie cutter medicine” or “force their vets” to practice a certain way. I really do not know what goes on at Banfield but before we throw stones, maybe we should consider the possibility that Banfield (and some very forward thinking informatics folks in Banfield) might be able to help us all practice better medicine and provide a better veterinary product for our clients. Maybe, just maybe, their “cookie cutter” algorithms are based on science aimed at better patient care. These guys have access to data and the tools to analyze it that no other organization in the world does.
**Juvenile lymphoma? Maybe?