The Rise and Fall of Modern Medicine (13 page)

It was undoubtedly a curious situation, with Ibsen, an anaesthetist who had no personal experience of treating polio, telling Lassen, the chief physician of the hospital to which all polio cases from Copenhagen and eastern Denmark were admitted, that his understanding of the final stages of the disease was mistaken. Lassen was unconvinced, but he gave Ibsen the benefit of the doubt. There followed one of the most dramatic and, in its consequences, profoundly influential moments in the history of medicine. Lassen picked a twelve-year-old girl, Vicki, ‘who was in a very bad condition with paralysis of all four limbs. She was gasping for breath. Her temperature was a hundred and two degrees Fahrenheit. She was cyanotic [blue] and sweating.' Ibsen asked the ENT surgeon to perform a tracheostomy, through which he introduced a cuffed tube attached to a ventilator bag. Initially he found it very difficult to inflate her lungs, as the airways were in spasm. Within minutes she was dying. Discreetly the hospital physicians who had gathered to observe
the new treatment realised they had duties elsewhere and started to drift away. The girl too was, not surprisingly, becoming very agitated, so Ibsen gave her a slug of the barbiturate Pentothal, at which point her own weak respiratory efforts ceased. And as she stopped breathing, her bronchi relaxed, and Ibsen was finally able to ventilate her. ‘When the other physicians returned . . . the girl's skin colour had returned to normal. Both body temperature and blood pressure were restored to normal too. This twelve-year-old girl was the first patient during the epidemic who survived as a result of this medical intervention.'

And now Ibsen was able to confound the sceptics. Were his theory correct, then when Vicki was transferred back to the iron lung respirator, the insufficient ventilation it offered should result in an accumulation of carbon dioxide in the blood that would cause her temperature and blood pressure to rise – and that is precisely what happened. Then, as Ibsen intermittently squeezed his ventilator bag, her condition improved again.

Lassen now energetically applied himself to the implementation of this new therapy, involving the mass recruitment of medical students already described. It is only a matter of elementary mechanics to devise a machine that can do the work of human hands, so by the following year ventilating patients for long periods of time became a practical proposition. The consequences were momentous.
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As the news of these remarkable events spread, many doctors travelled to Copenhagen to see for themselves. One was a neurologist from Oxford's Radcliffe Infirmary, Dr Ritchie Russell, whose monograph on polio was the standard text on treatment of the illness.
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Impressed by what he saw, he returned to England to rewrite his textbook and start treating patients with the new method. The first was a sixteen-year-old schoolgirl, Janet Deeley. She did not have polio but rather an acute
inflammation of the nerves – known as Guillain-Barré syndrome – of such severity that every muscle in her body was paralysed except for those that controlled her eye movements. There were mutterings from his colleagues that it was unethical to try to keep someone alive whose senses and reason were intact but trapped within an immobile body, but at Dr Russell's insistence an ENT surgeon performed a tracheostomy and she was linked up to a ventilator. In this way she was kept alive for six weeks until the inflammation in the nerves had subsided and the power began to return to her muscles. She later qualified as a nurse and for a while worked on the unit where she had been treated before marrying a farmer and having four children. Her recovery, as one of the physicians involved in looking after her, Dr A. Crampton-Smith, later observed, was a crucial moment, making it certain ‘that no patient could die of respiratory failure at the Radcliffe Infirmary without being ventilated. If she had died it might have set the whole business back many years, but she got better and that was the end of the argument . . . there could never be any question again of withholding artificial ventilation.'
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It is necessary here to take a few steps back to properly appreciate the science behind Ibsen's solution, which in turn requires trying to imagine the situation with which he was confronted. We know now that his solution was correct at two levels – first, the immediate cause of death in children with polio could be prevented by adequate ventilation; second, adequate ventilation, if continued for long enough, would ‘buy time' for the power of the respiratory muscles to recover. Back in 1952 neither supposition was at all obvious. So here was Ibsen summoned for his advice, walking the wards full of dying children struggling for breath, seeing the curtains drawn around the bed of yet another child who had just succumbed despite having been treated with
the ‘iron lung'. How did he grasp instinctively that the fundamental problem was one of inadequate ventilation of the lungs? How did he appreciate that, were this corrected and these children kept alive for long enough, the power of their respiratory muscles would eventually recover? Ibsen did not have a blinding flash of insight, but perceived a directly analogous situation to the circumstances of these dying children: every day in the operating theatre anaesthetists induced the same situation by deliberately paralysing the patients' respiratory muscles with the drug curare and then maintaining their respiration artificially.

Curare is a poison that blocks the neuromuscular junction, the site where the electrical impulses from the nerve release a chemical to stimulate movement of the muscle, and had been used for hundreds of years by South American tribes for hunting, being placed on the tip of the arrows that were then fired through a blowpipe. It was first used to facilitate surgery by Howard Griffith and Enid Johnson from Montreal in 1942 seeking to overcome the main impediment to surgical procedures, especially on the abdomen – the tendency of the muscles of the abdominal wall to go into spasm – which, as can be imagined, makes access to the contents of the abdominal cavity much more difficult. Griffith and Johnson found that within one minute of the administration of curare, the abdominal muscles became ‘as soft as dough', allowing the surgeon to operate ‘without any difficulty'.
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But the real potential of curare was not appreciated until 1946, when a Liverpool anaesthetist, T. Cecil Gray, reported on its use in over 1,000 cases in which it was not only helpful in relaxing the muscles of the abdomen during an operation but also, when given in a higher dosage than before, such that the respiratory muscles were paralysed, permitted much lower doses of anaesthetic to be given. His argument was as follows: the
standard anaesthetic practice at that time, hard as it may be to believe, was to induce anaesthesia with a heavy dose of barbiturate drugs or gas resulting in a state of ‘deep anaesthesia', but the patient continued to breathe spontaneously, ventilating his lungs with the help of an oxygen mask, as if he were asleep. Cecil Gray perceived that if the muscles were completely paralysed with curare, the state of deep anaesthesia would be unnecessary and it would be possible to get away with a much lower dose of anaesthetic, which was highly desirable for many reasons. The problem was obviously that this would interfere with the patient's own ability to breathe. His brilliant insight was to appreciate that this could be allowed to happen with the anaesthetist ‘taking over' and artificially ventilating the patient. Towards the end of the operation the effects of the curare would either be wearing off or could be reversed by another drug and the patient would then start breathing on his own.
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Within this historical perspective, Ibsen's suggestion to Lassen that his children with polio should have a tracheostomy and be artificially ventilated is more readily understandable. From his experience in the operating theatre Ibsen knew all about the consequences of inadequate ventilation, and the necessity to ensure adequate amounts of oxygen reached the lungs in patients whose respiratory muscles were paralysed by curare. All that was needed was to bring that experience to bear in the situation of children whose respiratory muscles were paralysed for a different reason, by the polio virus. The essence of his solution then was simply the transfer of knowledge and expertise from one discipline – anaesthetics – to another.

Following the staggering improvement in the survival of the polio victims at Blegdams Hospital – from just over 10 per cent to over 75 per cent – one would imagine it was a simple step to the modern intensive-care unit, where all seriously ill
patients are ventilated for long enough to allow their vital functions to recover. But this did not happen. Thus Dr Ritchie Russell in Oxford successfully treated many patients with polio and polyneuritis but did not broaden the scope of the treatment to include other groups of patients who would certainly have benefited, much the most important being those recovering from a major operation, for whom a period of continued assisted ventilation after they had left the operating theatre would be invaluable in buying time for their physiological functions to recover. Many surgeons were, however, implacably opposed to the proposal, fearing that post-operative ventilation could be interpreted as suggesting that ‘something had gone wrong', which in turn might be construed as a reflection on their surgical competence.
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And so in the early 1950s patients who had been ventilated during major surgery such as open-heart operations would be sent back to the ward ‘breathing spontaneously', and as a result would develop a whole series of medical complications to which they would succumb. The mortality rate in the early days of cardiac surgery was as high as that for infantrymen at the Battle of the Somme, which has usually been attributed to the relative inexperience of surgeons in undertaking these innovative operations, but in reality is due to the fact that most of these patients were inadequately ventilated following the operation. It was not until 1955, three years after the Copenhagen polio epidemic showed the life-saving possibilities of prolonged ventilation, that the same principle started to be applied to surgical patients. Figures from the Massachusetts General Hospital in Boston show that in 1958 only sixty-six patients were ventilated for twenty-four hours or longer following major surgery. By 1964 the numbers had risen to 400 and by 1982 to 2,000.
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It seems staggeringly obvious now that the only way of
ensuring adequate oxygenation of tissues when the function of the lungs is compromised for any number of reasons is to ‘stick a tube down and ventilate'. On this single manoeuvre the success of modern intensive care depends. How curious it took so long to happen!

‘A
ny surgeon who would attempt an operation of the heart should lose the respect of his colleagues,' declared the great German surgeon T. H. Billroth in 1893 – and for good reason, as any ‘attempt' would necessarily kill the patient. The heart remained out of bounds for surgeons for another fifty years, and tantalisingly so. The heart is anatomically much the most complex organ of the body and thus presents the widest range of possible defects that might be amenable to surgical correction. In the imagination of surgeons the heart was, like Mount Everest to climbers, the last great peak to be scaled. It could not, however, be climbed unless some means was found for taking over the function of the heart for long enough to permit surgeons to get inside to perform their operations, so the most important development in cardiac surgery was not surgical but technical – the heart-lung machine or ‘pump'.

In the five years from 1955 to 1960 the pump transformed cardiac surgery into much the largest and most sophisticated of all surgical specialties, whose influence in turn touched many other branches of medicine. It required, for example, the establishment of the first intensive-care units capable of keeping seriously ill patients alive for long
periods after surgery. Further, it seemed a most audacious thing in the 1950s, when death was still defined as a cessation of the heartbeat, for doctors to deliberately stop the heart and then restart it. Here, cardiac surgery enhanced still further the public's perception of medicine's apparently limitless possibilities
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‘Open-heart' surgery involves ‘opening up' the heart so the surgeon can repair defects in the walls between the chambers or replace diseased valves. The term might seem pedantic but in the early 1950s it was necessary to distinguish this type of operation from that which had preceded it, ‘closed-heart' surgery, where a surgeon corrected anatomical abnormalities ‘blindly', using his fingers or a knife, while the heart carried on pumping out blood. The scope of open-heart surgery, where the surgeon can actually see what he is doing, is obviously much greater but requires that, somehow or other, for the duration of the operation the function of the heart – in pushing blood first through the lungs to pick up oxygen and then around the circulation – must be ‘bypassed' or simulated by some other mechanism, otherwise known as the heart-lung machine, the pump oxygenator or simply the ‘pump'.

First the surgeon splits the sternum and pulls the chest open to reveal the beating heart within. Next the pump is set up. Two large catheters are inserted into the two large veins draining into the heart. These catheters are then connected by plastic tubing, which passes through a machine which pumps the blood from the veins into the ‘oxygenator' – a Heath Robinson-type device which acts as a lung where the blood comes into contact with air, giving up carbon dioxide and absorbing oxygen. The blood then exits from the oxygenator through more plastic tubing and is returned to the patient via a large catheter inserted into an artery in the groin.