Thursday, January 22, 2015

CAN YOU CHECK MY BLOOD PRESSURE, DOC?




THE DOCTOR'S BAG

BY

KEITH SOUTER  aka  CLAY MORE




We all try hard to have our stories ooze with authenticity. If a reader spots an anachronism in your tale the chances are high that he or she probably won't read much further. If you have a town doctor in the old west glibly reach for a blood pressure machine and take a patients blood pressure then you are in  anachronism-ville! Back then there was no such instrument in the doctor's bag. They had no awareness about th importance of blood pressure.

The history of blood pressure
Nowadays, the taking of a person’s blood pressure is regarded as one of the basic parts of a physical examination. It is interesting that the first experiments upon it were done not by a medical practitioner, but by a Church of England priest, the Reverend Stephen Hales in the eighteenth century.

The Reverend Stephen Hales  (1677-1761) was intensely interested in science and he had ample time to pursue his interest. He made contributions to botany, chemistry and medicine  Among other ingenious inventions he invented a a set of forceps for surgeons to use for the removal of gall stones. 


Rev Stephen Hales, DD, FRS (1677-1761)

He conducted twenty-five experiments on several dogs, three horses, a sheep and a doe. He published his findings in the Statical Essays in 1733. 


He deduced that the maximum pressure of the blood was reached at the end of a cardiac contraction. He further deduced that it would give an idea about cardiac output. He also deduced that the lowest pressure would be a measure of the resistance to flow and that it would be during the relaxation of the heart.

The first blood pressure machines
These were really extremely important findings, but it was not until a century later that any practical means of measuring the blood pressure could be developed. Even then the methods of measuring were invasive, involving canulating arteries, so they were of no use in clinical medicine. It then took another fifty years before a non-invasive  and practical method was devised.  

In 1896 Scipione Riva-Rocci invented the sphygmomanometer. This was done using an inkwell, copper piping, a bicycling wheel inner tube to form a mercury manometer. 


Dr Scipione Riva-Rocci (1863-1937)

It was subsequently refined by Von Recklinghausen in 1906, which used a moving needle to measure the pressure. In neither of these was a stethoscope used. Indeed, the stethoscope was still a relatively new instrument and it did not occur to anyone that there were useful sounds that could tell one about blood pressure.

The Korotkoff sounds
A Russian doctor, Nicolai Korotkoff (1874-1920) wrote a thesis about his use of the stethoscope to measure blood pressure in 1910. It was entitled Experiments for determining the strength of the arterial collaterals. In this book he outlined the method of taking the blood pressure that has been used right up until the present day.


 Dr Nicolai Korotkoff (1874-1920)

This involved applying a cuff attached to the sphygmomanometer and listening with a stethoscope over the brachial elbow at the elbow. The cuff is inflated until the radial pulse is no longer felt. The reason for doing this is to collapse the vessel, by making the pressure in the cuff greater than in the blood vessel. Then the cuff is slowly deflated. A series of different sounds will be heard. The first one is the noise of blood flowing. It is the maximum blood pressure. Then other sounds are heard, having a significance in relation to the cardiac cycle, although we need not go into the technicalities in detail here. The important sound was when the sounds disappeared, which represents the minimum blood pressure.


Sphygmomanometer used  by Dr Nicolai Korotkoff

Modern sphygmomanometers

Nowadays electronic sphygomomanometers are used, since they are extremely accurate at detecting blood flow. They have by and large replaced the traditional method of listening with a stethoscope, although a lot of doctors still trust to their ears and the traditional method of listening to the Korotkoff sounds.

The risks of high blood pressure (hypertension)
This condition is quite insidious, in that it creeps up on you, often without producing symptoms. It increases the risk of many conditions, including the following:

angina
myocardial infarction (heart attack)
stroke
aortic aneurysm
kidney disease
retinal problems
peripheral artery disease

It sensible for adults to have their blood pressure checked at least every five years until the age of eighty. It should be done annually after that. If it is found to be borderline at any stage then your doctor will want to monitor it more frequently. If it is persistently raised then there are excellent treatments that will reduce the risk of the conditions mentioned above. 

***

If this article whetted your interest in blood pressure then Dr Keith Souter's book Understanding and dealing with heart disease is available from Amazon in ebook or paperback




Clay More's novel about Dr George Goodfellow is published in the West of the Big River series by Western Fictioneers. 

Available at Amazon.com:

THE DOCTOR by CLAY MORE




And his collection of short stories about Doc Marcus Quigley is published by High Noon Press



Available at Amazon.com:


And his latest western  novel Dry Gulch Revenge was published by Hale on 29th August.


13 comments:

  1. Yep, I've read westerns that mentioned blood pressure, but luckily I haven't included it--only because it never occurred to me. Now I know. :) Thanks for the article!

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  2. Thank heavens for modern medicine and pharmacology!

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  3. Always good to learn what historicals ought to include and avoid in terms of physicians. Thanks, Keith! Also interesting to learn the Russian doc died so young. Hmm. 1918...

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    1. Hmm. Looked him up via Wiki - apparently he witnessed Tsarist atrocities and welcomed the Revolution. Died from tuberculosis in March of 1920 while serving in Petrograd.

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  4. Thanks, Jacquiie and Alison. The discovery of blood pressure and it's role in so many disorders has been one of the most significant discoveries in medicine. Tou are right, Alison, the development of the anti-hypertensive drugs has given us the potential to prevent many life-threatening diseases.

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  5. Thanks, Meg. Ah yes, 1920.

    Tuberculosis is on my list of topics to cover in The Doctor's Bag.

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  6. Keith, thanks for another wonderful article. I always love these pieces of yours and look forward to learning more about the doctors who discovered these amazing tests, remedies, cures...so interesting!
    Cheryl

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    1. Thanks, Cheryl. So many advances came out of the 19th century.

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  7. Now we have the equipment for daily BP readings, which I myself do. My NZ doc called me normal at 148/75. Here, normal is 130/70 and with meds, my daily one is about 115/65. More than you ever wanted to know about individual blood pressure.

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  8. Yet another great post. This one I understood better than some of the others, but the history, priceless to me. Thank you. Doris

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    1. My pleasure, Doris. I always like to research the history behind advances when I am writing a medical book. And I am always intrigued to know how doctors treated conditions in the past.

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  9. Thanks, Charlie. That just shows the way countries all have their own guidelines. There is a move towards ambulatory BP recording to establish the diagnosis. That is, one wears a cuff throughout 24 hours and a series of readings is recorded, rather than the traditional way of taking three spaced readings.

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  10. Thank you for another informative post - always love reading Old West medicine!

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