Wednesday, 8 October 2008

Not Over Investigating Patients

Dear Bloggers

Today I would like to discuss about not over investigating patients.

When a patient has a problem, we as doctors have a duty to investigate the problem and to seek its source and hopefully we will find the problem and with even greater hope, there will be effective and curative treatment.

It is not always possible to get all the information from one test and it is quite usual for a combination of tests to be required to provide the jigsaw puzzle pieces to make up the full picture.

It is all too easy to order a panel of lab studies that tests for all manner of conditions including the serum rhubarb (a British medical joke!!) and to get CT this, and MRI that, until we have exhausted every known imaging and lab modality.

However, what we must ask ourselves is 'Will the test result make me change the treatment for this patient?'

For example, an elderly bed-bound patient with a previous large left sided cerebral infarct is admitted to your hospital after his second seizure in 6 months that terminates after 2 minutes without treatment. Infection is ruled out by normal lumbar puncture, normal urine exams and chest Xray. CT head performed on admission confirms the previous massive infarction but no new areas of infarction or bleeding. The patient is already taking warfarin for the paroxysmal AF albeit with a subtherapeutic INR at 1.7. On recovery, there is no new neurology (only existing previous neurology).

Does this patient need an MRI scan, an EEG and a cardiac echo?

There would be many physicians who would want to get all 3 modalities. There would be other physicians who might get one or two and some who would obtain none of the above.

Why would you not take all of these tests?

This patient has had a massive stroke and his risk factors for it i.e. the PAF is already being treated with warfarin although with a currently subtherapeutic INR. Will an echocardiogram result showing us left atrial thrombus, change our treatment of IV heparin until the INR is therapeutic for the warfarin to be continued alone? No.
The treatment of this patient would be with standard anticoagulation. An echocardiogram tells us there may be a thrombus but the treatment in this patient is the same. Hence, logically thinking, will this test actually change our management? No.

One word of warning here, infectious endocarditis of the left side of the circulation can lead to vegetation disseminating to the brain. Anticoagulation is a risk factor for this and if IE were to be considered, an echo would be useful and would lead to a change in treatment i.e. antibiotics / surgery / stopping warfarin. However, this is where history and physical examination become necessary tools. They are there to find out the risk factors for IE and to find the peripheral signs and the murmur. Blood cultures and raised ESR would also be helpful in investigating IE.

Do we need the MRI scan? Again, the CT has shown an old massive infarction with there being no new observable lesion and hence, if there is a small infarction, is this going to make us change our treatment? The patient is still at risk of thromboembolic phenomen from the PAF and will still require warfarinisation which we know is sub-optimal. Knowing if there is a new infarct is not going to lead to a change in treatment and so can it be justified to obtain an MRI looking for infarcts you are already treating? I don't think it can be justified unless the patient has IE and there is a worry about mycotic aneurysm formation. Again, it comes back to history and physical examination and whether you regard IE to be a likely cause in this patient.

Do we need an EEG to confirm the presence of epileptic activity in a patient with known structural brain disease who has already manifested two seizures in 6 months? No. If the patient had a normal brain on CT and was having seziures, an EEG might confer the location and type of the activity and might lead us to a more refined diagnosis with perhaps a different anti-convulsant drug. However, in a patient with obvious structural disease and seizures it is highly likely that the epileptic activity is arising from that location and obtaining an EEG to prove what has aleady be proven serves no purpose. Treatment with an anti-convulsant drug is necessary rather than waiting for tests that are only going to tell us what we already know and will not change our management or treatment !

In a society where diagnoses need to be made quickly and treatment started promptly, delaying because of unneccessary tests that will not alter our treatment is to the detriment of the patient.

With many of the world economies now struggling in the light of decreasing working population sizes, increased longevity of the elderly and the recent financial banking crisis to hit many of the wealthy nations, it is in the patient's best interests to reduce the unnecessary tests which will only lead to more expense for the patient or their family but which do not lead to a change in treatment.

I would be very interested to learn what your opinion is on this topic and how you would proceed in such a patient. Please leave a comment on the blog.

Please consider...

Below are the comments received from a medical student in Japan [comments have been moderated]

I totally agree with Dr B, while it might be hard to judge which tests are beneficial for patients, especially for fledglings such like students and interns. I think we need to keep learning and considering that thing from the patients. And if possible, I hope all Japanese medical students would have such education in the future.

I would like to mention about the necessity of explanation to the patients. I feel that Doctors often do not give enough explanation to them.

Japanese people are said to expect excessive tests now and again (maybe in outpatient ). Actually, I might be one of them because I have a experience once. Why do we (I) do that? The fact we are not fully educated might be one reason, but this subject seems to be difficult to be solved at once. The more important thing is that some patients should worry about their illness too much (like I was so). Doctors have to explain why they(doctors) decide to do or not to do tests and treatment (in addition, probable diseases, conceivable clinical courses, and so on.) We need to convince them in a short time!

...I apologize my unfounded thought and my poor English.

In any case, I think we need plenty of knowledge and skill for History Taking and Physical Examination. And I want to practice Medicine, always thinking 'why, why, why?'.

Thank you for such excellent comments.

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