Feeling the Pressure – The Health Care Blog

By Mike Magee

After Trump crashes the markets, citizens worldwide feel ‘the pressure’. But in the spirit of us to calm down, let’s consider the story of human cooperation and success from our past.

It is estimated that for the medical student about 15,000 new words will learn during the four years of training. One of those words is Sphygmomanometer. The chic at a blood pressure monitor. The Word is derived from the Greek σφυγμards Hygmos “Press”, plus the scientific term manometer (from the French Manomètre).

While medical students quickly remember and learn to use the words and tools that are part of their trade, few appreciate the centuries -long efforts to promote more insights, discoveries and technical performance that go into the discoveries.

Most students are familiar with the name William Harvey. Without modern tools, I have brought myself from inference instead of direct observation that blood was pumped by a four room heart by a “double circulation system” that is directly on the lungs and backs back via “closed system” and back to the brain and physical organs. In 1628 I already published the above in an epic volume, by Motu Cordis.

Much less knows much a century later, the German physiologist, John Müller, courageously announced that Hales was “discovery of blood pressure more important than the (Harvey) discovery of blood.”

Modern cardiologists seem to agree.

In 2014, the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood pressure reported that “with every 20 mm HG increased in systolic or 10 mm HG in diastolic blood pressure, there is a doubling risk of mortality due to both ischemic heart disease as stroke.”

But comparisons are toxic. It is not necessary to reduce Harvey that correctly estimates the human blood volume (10 pink or 5 liters), the number of heart contractions, the amount of blood that was exhibited with each beat, and the fact that blood was continuously reconculated – and did all 400 years of APHRA. But how to measure the function and connect those measurements with an incredibly significant clinical state such as hypertension is a remarkable story that required spanes and international scientific cooperation for two centuries.

Harvey was born in 1578 and died in 1657, twenty years before the birth of his Felow Englishman, Stephen Hales. Hales was a spiritual somewhat obsessive and intrusive fascination for investigating the natural sciences pulled sarcasm and criticism from the will of classical scientific and subtimes -friend, Thomas Twinning. I have a memorable inserted poem in Hales’ Honor entitled “The Boat of Hales”.

‘Green Teddington’s Serene Retreat
Meet for philosophical studies,
Where the good pastor Stephen Hales
Weighted moisture in a few scales,
To continue to place seas and dogs,
And stripped the skins of living frogs,
Nature, he loved her work atant
To search or subtimize torment. “

The torment line can be well -justified in the light of Hales Own from 1733 Report of his historic very first mention of the measurement of arterial blood pressure, illustrated below, and described here:

“” In December and made sure that mare was tied alive on her back; ze was veertien handen hoog, en ongeveer veertien jaar oud heb ik het in bhaspijp ingevoegd, waarbij boring een zesde van een inch in diameter was … Ik bevestigde bijna dezelfde diameter van de buis van de buis van de buis van de buis van de buis van de buis van de buis van de buis van de buis in de buik in de buik in de buik in de buik in de buik in de buik in de buik in de buis van de hoofde van het hart from the heart;

After the existence of ‘blood pressure’, the world would almost wait another century to gain access to a reliable tool for measuring. That progress came from the hands of the French physicist, Jean Léonard Marie Poiseuille. He was born in 1799, in the midst of the flames of the French Revolution. In 1828, as a promotion candidate, his dissertation about the use of Mercury Manometer, confirmed to an anticoagulant -raced cannula, in laboratory animal ships as small as a diameter of 2 mm, measurable and reproducible arterial pressure declarations, and earned him a gold medaly.

Carl Ludwig, to the 31-year-old professor in physiology, then decided that Poseuille was needed to make permanent and downward record. His solution in 1847 was to confirm at Float with a writing pen to the open Mercury column. While the mercury got up, the pen scratched a lecture on a rotating smoked drum.

But direct arterial puncture was impractical and invasive. By 1855, scientists suspected that exercising external back pressure on an artother could destroy the pulse under the obstruction, and that measuring the pressure was generated by an external obstructing rubber ball heart – the systolic pressure.

In 1881 an Austrian doctor with the name Karl Samuel von Basch created an extensive portable machine that is able to measure the internal water pressure in an inflatable rubber ball applied to the wrist on the radial artery. The pressure needs to eliminate the pulse below was about the peak pressure of the blood column when the heart contracted. Eight years later, the French doctor, Pierre Carle Édouard Potain, replaces the water through air for compression.

By 1896 the blood flow was appreciated as a series of waves that peaked when the heart contracted and then fell the heart. The wrist with rubber cup was replaced by an air -filled cuff wrapped around the upper arm that narrowed the larger brachial artery. A Russian surgeon, NC Korotkoff, in 1905, suggested that doctors instead of feeling the wrist. The sounds I described became known as Korotkoff sounds.

As described in a translation from 1941 of the Russian paper, Korotkoff wrote: “Based on this observation, the speaker came to the conclusion that a perfectly narrowed artery does not broadcast no sounds under normal circumstances … The sleeve is passed on the middle Thardle third of the arm; sleeve stop is completely blood flow … finally all the sound suite.

It is easy, in an era of semiconductors, photocelles and tension meters, to forget that progress in understanding the human circulation system took centuries to acquire and international cooperation. When Covid struck, houses that acquire the court of blood pressure monitors and press oximeters attached to an index finger and resulted in oxygen saturation of blood and pulse without a delay. For little more you have access to a portable ECG monitor in the comfort of your own home.

Mike Magee MD is a medical history and regular contribution to THCB. He is the author of Blue code: Inside America’s Medical Industrial Complex. (Grove/2020)