Expert Patients (high blood pressure)

         Widely available measurement of blood pressure (BP) came along in the late nineteenth century.  By the early 1920s The Metropolitan Life Insurance Company of New York had accumulated enough data about life expectancy compared to blood pressure readings at the time the insurance was issued to demonstrate that there was an accelerating reduction in life expectancy with increasing initial BP.  This increase became steep enough at about 140/90 (millimeters of mercury) to justify steep increases in life insurance premiums for insured people with high BP.  This is the origin of “normal BP” of 140/90.  More recently the BP goal for diabetic patients has been made more stringent by 10 or 15 mm of mercury by similar statistical methods.  This reduces their extra complications compared to normal people.

       There was no effective treatment of high BP until the 1940s when the Kempner rice diet was introduced.  For several years Wallace Kempner,M.D. kept publishing his successes without confirmation from any other group of researchers.  Finally a large academic medical center reproduced his results in a closed metabolic ward where it was found that very tiny and occasional deviations from the strict diet explained the prevalent failures---Kempner had achieved remarkable compliance from his patients.  The metabolic ward experiment also demonstrated that Kempner’s rice diet depended on an extremely low salt content for its effectiveness explaining the lack of success outside of North Carolina, Kempner’s home state.  During my internship in Detroit in 1946, the staff physician who most frequently prescribed the rice diet came to rounds one day with a postcard with Hebrew’s 13:8 as the only message, the reference, “Jesus Christ, the same yesterday, today and for ever,” a very monotonous diet indeed.

          Before effective treatment of high BP there was an additional diagnostic category: malignant or accelerated hypertension.  This referred to the occasional case which progressed to organ failure and death in weeks or months.  Modern treatment has rendered this diagnosis obsolete.  Even in the 1940s the Smithwick operation controlled some of these “malignant” cases by a total removal of the sympathetic nerve ganglia.  Now this surgery is never necessary.   Another obsolete treatment of high BP is phenobarbital, a long acting, rather safe sedative, which took the edge off the nervous component of high BP, but this component is a very small part of the hazard of high BP.

         Effective oral medication had to wait for diuretics.  These were initially developed for the treatment of dropsy, the old word for congestive heart failure.  Injectable diuretics had been effective treatment for dropsy for several years, so we doctors changed the name to congestive heart failure to make it easier to explain to patients that they weren’t going to die right away as had been the case with “dropsy”.  Soon it was noticed that Hydrodiuril, the trade name of one of the early oral diuretics, controlled the BP of hypertensive patients who happened to be taking it for congestive heart failure.  This medication now known by its generic name, hydrochlorothiazide (hctz for short), is still widely used for initial treatment of high BP and especially in quite small doses in combination with other medications.  In the 1960s the VA (Veterans Administration) demonstrated that their patients whose BP was normal on treatment had the same life expectancy as entirely normal people of the same age who had never had high BP.  For a long time now hypertensive patients who can document normal BP for 2 years can buy life insurance without any increased fee.  Such successfully treated people should lead entirely normal lives.  I tell them that if you are asked to take up bungee cord jumping, you cannot realistically reply, “I cannot do that because I am on medication” any more than a lady on birth control pills would use that excuse---both you and she are normal people taking medication as a preventive, so you should use a more universal reason for refusing bungee diving.

         Now, some details about the use of medications to treat high BP: these various medications work by about a half dozen different mechanisms.  For many patients small doses of several medications that work by different mechanisms are to be preferred to a large dose of a single one because the side effects of each are different and not additive.  In most cases a combination can be found without any side effects, and once a day dosage is usually possible.  For example, hctz has a side effect of depleting potassium from the body, but less so with a small dose.  Side effects and costs can both be reduced by eating less salt because such a diet increases the effect of the medications and may overcome the potassium depleting effect of diuretics completely.

         When establishing a new regimen for treating high BP it is convenient for patient and physician alike if a family member knows how to take BP.  Teaching this procedure on standard, trustworthy equipment  can be done on short notice.  Frequent home BP readings permit most dosage adjustments to be done between visits to the physician, which is more timely and convenient.  A series of readings under calm conditions even before starting treatment make good evidence to ratify a decision for what may be a lifetime commitment to daily medication.  High BP is seldom an emergency, but prompt control is still beneficial.  Transient elevations of BP due to emotional states and exercise are best ignored because they are normal---they occur in everyone.  Only in recent decades have we been aware of the large increases in BP which occur during exercise because normal values are restored so promptly on ceasing the exertion.  If these temporary elevations were harmful, physical fitness would be a health hazard.

         We have been discussing “essential hypertension”, by far the most common type of elevated BP.  This refers to high BP without any demonstrable underlying cause.  Most diseases of the kidney cause high BP as do several other much more rare diseases such as various tumors of the adrenal glands.  Coarctation of the aorta is a very rare congenital anomaly, but quite interesting because it illustrates the kidneys’ central role in controlling normal BP.  In coarctation there is a tight constriction of the aorta above where the arteries to the kidneys branch off.   This would prevent adequate blood flow to the kidneys except that they control the normal BP.  The result is high  BP in the upper half of the body and normal in the lower half including the kidneys.  Surgical correction of the constriction restores normal BP throughout the body.  A more prevalent similar situation, but still rare, is restriction of blood flow to one kidney by hardening of the artery to that kidney.  The deprived kidney signals for an increase in BP.  In this case either surgical repair of the obstruction or removal of the affected kidney restores normal BP.

           Early in the era of effective treatment of high BP we looked for these rare conditions before treating a new case of essential hypertension.  Now we know it is not cost effective, especially since failure to respond to drugs identifies the presence of these secondary causes of high BP right away.  So now we do a medical history, physical examination, and simple blood tests to rule out reduced kidney function and diabetes before initiating treatment as described above.  I hope this helps you understand what your doctor is up to in treating BP. 

John A. Frantz, M.D.

July 3, 2004                                                       Nose bleeds

          Not infrequently a new patient will be sent to the family physician’s office for evaluation of high blood  pressure detected in an emergency room incidental to treatment of a nosebleed.  When rechecked under more calm conditions the blood pressure may not be remarkably high after all.  The patient may even express gratitude to divine providence as if the nose bleed had acted like a “safety valve” in preventing a stroke.  A more mundane explanation is that long before going to the emergency room the patient and his helpers had been frantically engaged in futile attempts to stop the bleeding with the development of an increasingly hopelessly frantic atmosphere.  This is most likely the result if their attempts to stop the nose- bleed were accompanied by repeated efforts to clean out the blood clots.  Such cleaning would be a good head start if one were trying to set a record on how long you could keep an ordinary nosebleed going.

           How to stop a nosebleed: hang on for ten minutes without wiggling a finger and don’t try to clean the clots out of the nostril for half a day.