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LIFE SUPPORT SYSTEM for PREMATURE BABIES * Life support has been defined as "the process of keeping a person alive by artificial inflation of the lungs, and, if necessary, maintaining the heart beat with a pacemaker". For treatment of prematurity, the index of the same reference refers the reader to "incubator", "neonatal care", and "ventilator"(1). Each of these parts is considered separately below. ARTIFICIAL INFLATION of the LUNGS: In 1891, George Fell, an American surgeon, forced respiration to treat victims of accidental morphine poisoning or drowning. Nine years later, Matas used positive-pressure ventilation through a tube in the larynx for operations on the open thorax. This was followed, in 1907, by a technique developed in F Ferdinand Sauerbruch of Leipzig, originally, had the idea of blowing air into the lungs to keep them inflated when opening the thorax - positive-pressure ventilation or insufflation - but in his animal experiments he found that the technique was actually harmful and concluded that positive-pressure ventilation should not be used to deliver anaesthesia to human patients. Others were influenced by Sauerbruch`s belief - delaying progress along the right lines. Sauerbruch reasoned that if positive-pressure on the inside would not work, then perhaps negative pressure on the outside might be effective. He then conducted dozens of animal experiments - opening the chest and placing an animal in a specially designed chamber, which had most of the air drawn out to lower the pressure. The lungs of the animal were effectively held in an inflated state by negative air pressure. From these animal experiments, Sauerbruch concluded that negative-pressure cabinets were the final solution to the problem of the open thorax. After Sauerbruch`s animal experiments, Samuel J Meltzer, in 1910, revived the technique of insufflation - in which air is continually blown into the lungs - in his own animal experiments. He is said to have found that the results of which indicated that the method could be a safe way of keeping the lungs inflated during surgery(2). In about 1915, E S Rowbottom and Ivan Magill, anaesthetists at Sir Harold Gillie`s plastic surgery hospital, Sidcup, Kent, were faced with a problem of not being able to fit a mask on the face of a patient because it would obstruct their work, so they considered positive-pressure insufflation through the trachea, but found that this caused many post-operative complications - despite the positive results obtained by Meltzer in his animal experiments(2). Rowbottom and Magill gave anaesthetic gas through a single tube down the trachea, under positive-pressure when the patient breathed in. Effectively, this meant blowing the air containing the anaesthetic gas into the lungs with bellows. Clinically, they had overcome the problem(2). PACEMAKER (see "Heart Pacemaker")
INCUBATOR: Heated rooms, to incubate eggs, were first used by the Ancient Chinese and Egyptians(3). Modelled on these ancient methods, Giovanni Bartista della Porta designed an incubator in 1588 (4). In 1609, Cornelius Drebbel invented the "Athenor", an incubator fitted with a thermostat(4), consisting of a coal-fired cabinet in which hot air circulated around an inner box containing eggs. The box, with the eggs, was protected by a water-jacket incorporating a thermostat tube filled with alcohol. As the alcohol expanded with the heat, mercury was pushed up in an adjacent U-shaped tube, which, in turn, moved a metal rod to open and close dampers controlling the intensity of the fire in the grate below the cabinet. In this way, Drebbel kept the temperature fairly constant(5). Almost 150 years after Drebbel, Rene Reaumur, in 1750, invented an incubator similar to that of Drebbel but it was less efficient. Reaumur`s incubator consisted of a circular stove surrounded by a heated platform on which eggs were placed to hatch(5). In 1770, John Champion of Bodin, in In 1891, Alexandre Lion of Nice made an incubator - based largely on Drebbel`s ideas - which was adapted for the intensive care of premature babies(8). Air in Lion`s incubator was purified through a filter and kept constantly fresh by means of a fan ventilator, while the temperature was regulated automatically by a thermostatic control. Lion set up centers in Nice, If babies were considered too weak to swallow, Lion arranged for them to be fed - through the nose - by a specially moulded spoon, or breast-fed by a "wet nurse" who had a tube attached to her nipple(9). Lion`s incubator - under the name "Couveuse" - was first introduced in London in 1897. In America, Dr Martin Cooney tried to persuade hospitals to adopt Lion`s technique. With the hospitals showing a lack of interest, Cooney installed the Child Incubator exhibition at Coney Island`s Dreamland in 1904. Of 8000 infants brought to Cooney, 7500 survived infancy in the Lion incubator(10). Modern electric incubators, which have become standard in some hospitals, are similar to that of Lion, with additional equipment to measure respiration and heart-beat(11). RESPIRATOR: Dr John Stenhouse, in 1853, invented a charcoal respirator, fitted with air filters(12); which was first used shortly afterwards at the Mansion House in In 1879, Woillez in Alexander Graham Bell (inventor of the telephone) began work on a way of preventing respiratory failure in new-born children after his own son died. He invented a vacuum jacket to cope with such emergencies, which according to his sketches (which survived) show an airtight iron "lung" surrounding the patient up to the neck. A hand operated pump was fitted to the chamber and when operated would then rhythmically raise and lower the air pressure inside, which in turn, would compress or expand the lungs(15). It was not until 1927 that Philip Drinker of Harvard produced his first model of his "iron lung"(16), which consisted of two vacuum cleaners that alternatively gave positive and negative pressure - producing carefully timed fluctuations of the thorax(17). After much improvement, and manufactured by Warren C Collins of Boston, the Drinker Respirator was used clinically for the first time on 12 Oct 1928(18). On 6 Oct 1932, a Drinker Respirator was used for the first time in 1. Smith,T [ed ed]. BMA Complete Family Health Encyclopaedia. 6th ed. Dorling Kindersley. 1993. 2. Reines,B. Heart Research on Animals. NAVS. 1985. 3. Brown,D. in Inventions that Changed the World. Reader`s Digest. 1982. 4. Carter,E. Dictionary of Inventions & Discoveries. Fredrick Muller. 1969. 5. Brown,D. in Inventions that Changed the World. Reader`s Digest. 1982. 6. Carter,E. Dictionary of Inventions & Discoveries. Fredrick Muller. 1969. 7. d`Estang,V-A. Book of Inventions & Discoveries. Macdonald Queen Anne Press. 1992. 8. Brown,D. in Inventions that Changed the World. Reader`s Digest. 1982. 9. Robertson,P [ed]. Shell book of Firsts. Ebury books. 1974. 10. WGBH Educational Foundation/WNET 13/ 11. Brown,D. in Inventions that Changed the World. Reader`s Digest. 1982. 12. Carter,E. Dictionary of Inventions & Discoveries. Fredrick Muller. 1969. 13. Desmond,K. Harwin chronology of Inventions, innovations, Discoveries from pre-history to the present day. Constable & Co. 1987. 14. Carter,E. Dictionary of Inventions & Discoveries. Fredrick Muller. 1969. 15. Harris,M. ITN Book of Firsts. Michael O`Mara Books. 1994. 16. Carter,E. Dictionary of Inventions & Discoveries. Fredrick Muller. 1969. 17. Harris,M. ITN Book of Firsts. Michael O`Mara Books. 1994. 18. Robertson,P [ed]. Shell Book of Firsts. Ebury books. 1974. |
c Scientific Anti-Vivisectionism
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