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Evidence-Based Medicine vs Expert Opinion: Redefining Standards of Practice
January 13, 2006
In the wee hour of the night ,the medical resident on duty gets a call from the ICU. The patient with myocardial infarction on Bed 2 just developed sudden dyspnea.
He promptly sees the patient and makes a quick assessment. The patient is apparently in distress.There are coarse rales all over his lung fields.
"Prepare for intubation . Give him 40 mg of furosemide and 2 mg of morphine," the resident tells the nurse.
He then calls up and updates the consultant.
"Okay, hold the beta blocker for now and start him on an NTG drip. You can add digoxin to improve his LV function, " the attending physician advises.
In daily practice, we come across problems that call for sound clinical judgment. Oftentimes, these decisions spell the difference between life and death. We draw our decisions from our storehouse of knowledge and experience - whether it be from what we learned in medical school, from a clinical pearl we learned from a consultant during residency training, or from a journal that we have recently read. Let us examine how this clinical process works.
The attending physician's choice to start digitalis is based on his knowledge about the inotropic effect of digitalis in heart failure. He assumes that given the drug's mechanism of action and its importance in chronic heart failure therapy, the patient will benefit from it. But does the evidence really support a beneficial role for digitalis in acute heart failure following myocardial infarction? The evidence from the literature says otherwise:
- A substudy of the AIRE-Investigation Study revealed adverse effects on outcome with digitalis after MI with acute heart failure.(Lancet 1999;354:391-392)
- McClement and colleagues noted that the use of digitalis in acute heart failure following MI was a predictor of life-threatening proarrhythmic events. (J Am Coll Cardiol 1993;21:1419-1427)
- An increase of creatinine kinase was more pronounced in patients receiving cardiac glycosides.(Varonkov et al, Circulation 1977:55:719-727)
In view of these findings, the 2005 Task Force on Acute Heart Failure of the European Society of Cardiology stated that " inotropic support with cardiac glycosides cannot be recommended in AHF, in particular following myocardial infarction. An indication for cardiac glycosides in AHF may be tachycardia-induced heart failure e.g. in atrial fibrillation with insufficient rate control by other agents such as betablockers." (Eur Heart J Vol 2005 Vol 26 No.4).
This case illustrates the importance of evidence-based medicine (EBM) in clinical practice. It underscores the need for randomized controlled trials, systematic reviews, and meta-analysis in guiding clinical decision-making. Evidence-based medicine is a relatively new concept, replacing traditional medical paradigm which is based on authority and expert opinion. Compared to the latter, EBM provides more objective, scientific, and reliable answers to our questions. It encourages physicians to employ a certain treatment strategy because it works -not because it ought to work. And with the large boom in information technology, we have almost unlimited access to journals and the Internet which provide us with all the necessary data relevant to our practice .
That is not to say that EBM will totally replace expert opinion in the future. Not all clinical questions are covered by studies and not every question can be answered. In those instances, we can base our decisions on our experience or from recommendations of experts on that particular field.
So if one of these days your patient with chronic stable angina asks if it's all right to take Vitamin E you can say, "Well, there's nothing wrong in taking Vitamin E albeit you can't expect a beneficial effect on you heart condition. It's based on the Heart Protection Study, you know."
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HEART MURMUR
A young doctor was inching his stethoscope on the chest of his patient - a sexy and well-endowed lady. He muttered something and the woman suddenly slapped him hard on the face.
"What did you do that for ? I just said you have a heart murmur!" he barked.
The patient replied, "Oh, I thought you were saying 'hot momma'."
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MISSING MY FLIGHT
There's nothing better than going home on Christmas to be with family and friends. As a senior cardiology fellow at PGH, I only get to have a few weeks' vacation once a year and I was really looking forward to going home to Bacolod this Christmas. I took the first flight at 5:15 a.m. I had to wake up very early for the trip. Inside the plane, I settled on my seat near the window. Glancing outside, I saw one plane after another steadily streak across the pitch-black sky and headed to its destination. I was feeling queasy as usual. Flying makes my stomach churn a bit. I've had many trips before but I haven't overcome the feeling. It was that flight back in 2003. The weather was bad and the flight was turbulent. I clasped hard on my seat as the plane bumped up and down. I was relieved to make it on solid ground in one piece.
Anyway, the plane was taxiing towards the runway and then stopped. I thought it was just awaiting clearance to speed through the runway and take off. Surprisingly, the captain's voice cracked over the intercom. There was a problem with the hydraulic system and some repairs have to be made. The plane made a complete turn and headed back to its original spot. We were all advised to wait for further announcements.
I decided to cancel my flight. I didn't want to take chances. If something was wrong, anything can still happen along the way. Much as I wanted to go home, there were no other available flights until New Year. After a 2-hour delay, the plane took off and had an uneventful flight. I kept thinking maybe I just overreacted, but given the circumstances I still feel my response was rational.
So , here I am away from home this Christmas and New Year. It's nothing new though. I used to spend the Holidays at work, attending to patients at the hospital. And even though there will be no sparkling wine, juicy ham or quezo de bola shared in the company of family and friends, New Year for me still deserves a toast and a celebration for all the wonderful blessings God has given for the past year. Maybe this year you also missed something. Maybe not the trip back home as I did but an opportunity at something you've always wanted. Take heart for New Year gives a new lease on life, opens windows of new opportunities, and brings brighter prospects right into our doorsteps.
Happy New Year to Everyone!
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Views expressed on this column and any other by-lined articles on this site are the authors' own and do not necessarily reflect the views of the organization or its members.
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