Medicine a humbling professionBy Rafael Castillo M.D.
Philippine Daily Inquirer
In a recent medical conference, someone raised during the discussion that treatment guidelines sometimes keep on changing which can be quite confusing to practising physicians. What was recommended five years ago may no longer be so in updated guidelines, based on data from more recent researches or clinical trials. Future trials may have different findings, so the guidelines would have to be revised again. A practising physician knows too well that the field of medicine is never an exact science, that despite all the advances in the last three decades, there are still a lot of questions that remain unanswered.
These questions would only be answered by relevant researches on the subject. We encourage young doctors to always have an inquisitive mind and keep on asking questions; and if these questions can’t find a satisfactory answer from available scientific data, they should do their own research work on the subject. But they would ask us back: “But, sir, where do we get the funding?” Indeed doing a research project can cost quite a sum, and without adequate funding from the government or other research agencies, it might be too much to get it from one’s own pocket.
That’s the frustration which many local researchers encounter—frequently, we just rely on hand-me-down scientific data from foreign researches. Our medical organizations also publish treatment guidelines, but frequently, these are based on foreign research data. While most of these American and European data would also be applicable to Filipinos, it would be better if we also have local data to back up our own treatment guidelines.
Treatment guidelines are generally evidence-based, that is, founded on scientific data. These guidelines have evolved in the last three decades from being previously “eminence-based,” or based on the experience of esteemed mentors or medical specialists to “evidence-based.” Expert bodies convene regularly to review all new research data especially from landmark researches and clinical trials and use these as the basis for treatment guidelines for practising physicians. These treatment guidelines are used as a reference in clinical practice to guide a physician on how best to manage their patients with similar cases described in the guidelines.
The treatment guidelines published by various expert bodies appear to be a practical reference and practice aid for all physicians. It is supposed to be based on hard data or accurate scientific evidences from landmark clinical trials and other researches, reinforcing an evidence-based clinical practice. But there are instances when hard clinical data are not available, and one can’t help but think that some parts of these internationally circulated treatment guidelines are based on expert opinion or what the members of these expert panels believe as best standard of care. So these guidelines are still partly eminence-based. One can therefore expect that in many instances, some of these expert opinions are subsequently proven wrong by well conducted researches, hence the revision of the guidelines.
BP lowering in diabetics
One such case is the treatment guidelines on how aggressive blood pressure (BP) lowering should be in diabetics. Although most guidelines advocate a more aggressive BP lowering in diabetics targeting a BP of less than 130/80 mmHg, recent research data seem to put this in question. Several years ago, the American Diabetes Association (ADA) released a position statement saying that “…there is no threshold value for BP, and (cardiovascular) risk continues to decrease well into the normal range.” This statement suggested that the lower the BP up to a level of around 115/75 mmHg or even slightly lower, the better for the patient.
Because of this aggressive approach in BP lowering for diabetics, several treatment guidelines from reputable international organizations recommend starting BP-lowering drug therapy at low BP levels like 130/80 mmHg if there’s diabetes, or even lower, say 120/80 mmHg if there’s established heart, brain or kidney disease.
For quite sometime, the guideline advocating aggressive BP lowering in diabetics was well accepted and practiced. Everyone believed it was well founded, or so everyone thought. Every physician appeared convinced that the lower the BP in hypertensive diabetics to as low as 110-115/70-80 mmHg, the better for the patient. Looking back though (and it’s always easier to analyze things in retrospect), hard data supporting a systolic BP (the upper number in a BP reading) less than 130 mmHg was lacking particularly in diabetics with concomitant narrowing of the arteries.
Recent clinical researches such as the Accord (Action to Control Cardiovascular Risk in Diabetes) trial showed that there was no difference in the reduction of cardiovascular risk in high-risk diabetic patients if the systolic BP was brought down with drug therapy to a moderate level of less than 140 mmHg or a more aggressive level of less than 120 mmHg. Aggressive BP lowering required more drugs to be used by the patient, higher cost of treatment and more side-effects.
So for diabetics, who usually have concomitant blockages in the heart arteries, bringing down the systolic BP to less than 140 mmHg, or somewhere in the range of 120 mmHg to 135 mmHg should be good enough. A more aggressive goal does not appear to be warranted, based on recent research data.
Well, the practice of medicine may be humbling but that keeps doctors, even senior ones, always on their toes; and eager to learn new ways of treating centuries-old diseases. That’s why when some old friends ask us if we’re still in practice (meaning still holding clinics and seeing patients), instinctively we answer—“We can never perfect the field of medicine, so we need to keep on practicing.”
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