You should spend about 20 minutes on Questions 1–13, which are based on Reading Passage 1 below.
The Making of Cardiopulmonary Resuscitation
In the 1950s a patient whose heart stopped in hospital had almost no chance of recovery. Surgeons could open the chest and massage the heart by hand, a technique used successfully since the early twentieth century, but it required a trained operator, a sterile theatre and an operating list. Outside the theatre, cardiac arrest was effectively a death sentence. Within twenty years, however, a set of simple techniques that almost anyone could perform with their hands had been assembled, tested and spread worldwide. The story of cardiopulmonary resuscitation, or CPR, is not the story of one invention but of three, developed separately and then joined together.
Attempts to revive the apparently dead are far older than modern medicine. Organised efforts on behalf of drowning victims began in the eighteenth century, when the Royal Humane Society, founded in London in 1774, offered rewards to rescuers and published instructions for treatment. The methods recommended — warming the body, tickling the throat and inflating the lungs with bellows — were mostly ineffective. In the nineteenth and early twentieth centuries a series of manual techniques appeared, in which the patient was rolled or pressed to imitate breathing; the best known, devised by Henry Silvester and later by Edward Schafer, were taught to lifesavers for decades, although nobody had shown that they worked.
The first of the three components was established in Baltimore in the late 1950s. Peter Safar, an Austrian-born anaesthetist, was convinced that the traditional methods wasted time and that air breathed out by a rescuer could keep a patient alive. Working with James Elam and others, he tested the idea on volunteers whose muscles had been temporarily paralysed and on patients in hospital. The experiments showed that mouth-to-mouth breathing could maintain adequate oxygen levels, and the results were published in 1958. Safar went on to argue that resuscitation should be taught to ordinary people, and he is often described as the father of modern resuscitation.
The second component emerged almost by accident at Johns Hopkins University. William Kouwenhoven had spent decades studying defibrillation, and during experiments his team noticed that pressing firmly on the chest of an anaesthetised dog produced a measurable pulse. Guy Knickerbocker, an engineer, and James Jude, a surgical resident, explored the observation systematically. In 1960 the group published a paper in the Journal of the American Medical Association describing closed-chest cardiac massage, in which the heel of the hand compresses the breastbone and squeezes the heart against the spine. Their first report covered a small number of patients, some of whom recovered.
Defibrillation, the third component, had its own history. In 1947 a surgeon named Claude Beck restarted the heart of a fourteen-year-old boy during an operation by applying electrodes directly to the muscle, the first successful human defibrillation. In 1956 Paul Zoll showed that a shock could be delivered through the unopened chest, and in the early 1960s Bernard Lown helped develop the direct-current defibrillator, which made the procedure safer. Because a heart in ventricular fibrillation cannot pump blood effectively however well it is compressed, restarting its rhythm was essential to any complete system.
Once the pieces existed, combining them was obvious in principle and difficult in practice. Safar and his colleagues argued that compressions and ventilation should be performed together, and they set out a sequence that became known as the ABC: clear the airway, breathe for the patient, then maintain the circulation. In Belfast in the mid-1960s Frank Pantridge installed a defibrillator in an ambulance and sent a doctor and a nurse to patients who had collapsed at home, creating the first mobile coronary care unit. It showed that lives could be saved before a patient reached hospital.
Standards came next. In 1966 a conference convened in the United States by the National Academy of Sciences published the first national guidelines, endorsing closed-chest CPR and recommending that training be extended beyond the medical profession. Revisions in the 1970s encouraged the teaching of the public on a large scale, and manikins for practice were developed so that skills could be rehearsed without risk to a patient.
International coordination arrived in the 1990s. In 1992 the International Liaison Committee on Resuscitation was formed to unite organisations that had until then issued separate advice, and in 2000 it published the first genuinely international guidelines, revised at intervals since, generally every five years. One of the most consequential revisions came in 2010, when the sequence was reordered so that compressions came first, because delay in starting them was the most common failure. In the same period evidence accumulated that untrained bystanders who performed compressions alone did at least as well as those attempting full CPR, and compression-only CPR was promoted for people with no training.
Survival after cardiac arrest outside hospital varies enormously between countries, and between cities within the same country, which suggests that organisation matters as much as technique. Research consistently associates CPR performed by a bystander with a substantially better chance of survival, and public defibrillators have improved outcomes where they can be reached within minutes. Yet even in well-served cities most people whose hearts stop outside hospital still die. Much of the progress came from testing simple ideas rigorously and then persuading institutions to change, rather than from a single brilliant insight.
You should spend about 20 minutes on Questions 14–26, which are based on Reading Passage 2 below.
Standing In for the Heart
How the heart-lung machine keeps a patient alive during open-heart surgery
A heart-lung machine takes over the work of two organs at once. During open-heart surgery the surgeon needs a still, bloodless field in which to repair valves, replace arteries or close holes, yet the brain can survive only a few minutes without a supply of oxygenated blood. The machine solves both problems: it diverts blood away from the heart and lungs, adds oxygen, removes carbon dioxide and returns the blood to the body under pressure, so that the circulation continues while the heart is stopped. The idea is old. In 1953 the American surgeon John Gibbon used such a device to close a hole in the heart of a young woman, the first successful operation of its kind. The principles have changed little since then, although every component has been redesigned.
The circuit itself is simple in outline. Blood is taken from the body through a wide plastic tube, or cannula, placed in the right atrium, and drains by gravity into a reservoir placed below the level of the patient; the difference in height, rather than a pump, provides the suction. From there the blood is pushed onwards by a pump, passes through an oxygenator and a device that adjusts its temperature, and is finally returned through a second cannula into the aorta. Before any of this begins, the circuit is filled with a priming fluid so that the patient's blood is not suddenly diluted, and a drug called heparin is given to prevent clotting inside the tubing. Every connection is checked before the patient arrives.
The pump is the part with the longest pedigree. Most circuits use a roller pump, a design that Michael DeBakey adapted from industrial equipment in 1934, while he was still a medical student. Two rollers rotate along a length of flexible tubing and squeeze the blood forward, so that the fluid never touches the mechanism. Roller pumps are cheap, reliable and simple to sterilise, which explains their persistence. Because the flow is steady rather than pulsing, the patient's arteries receive a continuous stream; whether it matters that the pulse disappears is still argued over, and some surgeons prefer pumps that imitate the heartbeat.
Oxygenation has changed more dramatically. The earliest machines used bubble oxygenators, in which oxygen was bubbled directly through a pool of blood; effective but damaging to blood cells, they were largely replaced from the 1970s by membrane oxygenators, which separate gas and blood with a thin barrier. Modern devices contain thousands of hollow fibres, each with microscopic pores, through which oxygen flows while blood passes on the outside. Carbon dioxide leaves the blood by the same route. The gas mixture is adjusted continuously, and the amount passing through the fibres — the sweep gas — is a principal means of controlling the patient's carbon dioxide level.
Two further components deserve attention. A heat exchanger, which adjusts the temperature of the blood, allows the team to cool the patient during the most delicate part of an operation, reducing the body's requirement for oxygen, and to rewarm it afterwards. A separate line delivers a cold potassium-rich solution to the coronary arteries; this stops the heart beating, so that the surgeon can work on a motionless organ. Finally, a filter traps small clots and any air that has entered the circuit before the blood is returned to the body, because even a tiny bubble can block a vessel in the brain.
None of this runs unattended. A specialist known as a perfusionist sits at the console throughout the operation, watching flows, pressures, oxygen saturation and the level of anticoagulation, and adjusting the machine as the surgeon's needs change. Sensors sound alarms if a bubble is detected or a tube becomes kinked, and every circuit is prepared with a strict checklist. Records are kept for every operation, and the team rehearses emergencies such as a failure of the oxygen supply. The work is repetitive and highly responsible, and perfusionists train for years before they are left in charge.
The machine also has costs. Contact between blood and the artificial surfaces of the circuit sets off an inflammatory response that resembles, in some respects, the body's reaction to infection; patients may retain fluid, run a temperature or develop lung problems in the days after surgery, a cluster of effects sometimes called post-perfusion syndrome. Bleeding is a further risk, since heparin must be given in large doses and its effects reversed at the end of the operation. Why some patients react far more severely than others is not established, and researchers have spent years testing coatings intended to make the tubing more like the lining of a blood vessel.
Uses beyond the operating theatre have grown steadily. Simplified circuits can support a patient's lungs, or both heart and lungs, for days or weeks, a technique known as extracorporeal membrane oxygenation, or ECMO. It is used for severe respiratory failure, for some patients after cardiac arrest, and, in a small number of cases, as a bridge to transplantation. Demand rose sharply during the coronavirus pandemic, when many intensive care units treated patients with it. Smaller circuits, better coatings and portable equipment are now the main lines of research, and simulation training for perfusion teams has spread alongside them.
You should spend about 20 minutes on Questions 27–40, which are based on Reading Passage 3 below.
Who Pays for the Fall?
Should publicly funded health systems meet the cost of injuries from high-risk sport?
Every few months a story appears about a climber, a downhill mountain biker or a ski tourer whose rescue or hospital treatment has cost the public an impressive sum. The figures are usually offered without context, and the conclusion is left implicit: that the rest of us have been made to pay for somebody else's thrill. The question underneath these stories is a serious one. Public health systems are funded by everyone and rationed according to need, so should they also meet the cost of injuries that the patient chose to risk?
Participation in high-risk recreation has grown. Ultramarathons, triathlons, off-piste skiing and enduro mountain biking all attract far more people than they did a generation ago, and the injuries that result — fractures, head injuries, spinal damage — are exactly the kind that consume trauma beds, operating time and helicopters. Injuries of this kind also tend to happen far from a hospital, so the cost of reaching a patient and bringing them to an operating theatre is added to the cost of treating them. Nobody disputes that these injuries are real or that treating them is expensive. What is disputed is whether the fact that the patient chose the risk should change the answer.
The case for charging is straightforward. Adults who take part in dangerous sports know what they are doing; they gain the pleasure and the status that come with it, while the costs fall on people who may never have climbed anything higher than a hill. Insurance is the normal way of handling risk, and those who take more of it might reasonably expect to pay more. There is also a worry about incentives: if the consequences are carried by everyone, the argument runs, people will take fewer precautions than they otherwise would.
Two objections seem to me decisive. The first concerns consistency. If voluntary risk disqualifies a patient from public care, the principle cannot be confined to adventure sports. Cycling in city traffic, horse riding, rugby, gardening and driving all carry risk, and so, in a slower way, do poor diet and inactivity. Every health system on earth treats the casualties of these activities without asking whether the patient deserved them, and inquiring into fault is expensive in itself. As for incentives, the evidence that insurance makes people careless in matters of health is, at best, mixed: few drivers become reckless because they are covered, and a skier is more likely to be deterred by the prospect of a broken leg than by the size of a hospital bill.
The second objection concerns the drawing of lines. Nobody can say precisely which activities are risky enough to trigger a charge. A hospital treating a broken leg from a mountain-bike race would need to know how technical the trail was, whether the rider was experienced, whether the injury was caused by another competitor, and whether the event was organised or informal. Rules would be written, inevitably, by people who do not do these sports, and they would be applied to a small and visible minority rather than to the far larger number of patients whose conditions are equally self-inflicted but less photogenic.
It is worth asking what a different arrangement would look like. New Zealand has for decades run a scheme that pays for the treatment and rehabilitation of everyone injured in an accident, regardless of fault, funded by levies on earnings, employers and vehicle owners; adventure injuries are covered like any others. Whatever its shortcomings, the scheme demonstrates that a system can meet these costs without turning every accident into an inquiry into character. Most wealthy countries already do something similar in practice, in that emergency treatment is given first and the question of payment, if it arises at all, comes later.
Rescue is a separate matter from treatment, and it is here that the argument for charging is strongest. A helicopter crew winching an unprepared walker off a cliff face is performing a service that the walker could have avoided needing. Yet even here the case is weaker than it looks. Some air rescue organisations are funded by voluntary membership rather than taxation, which spreads the cost without any inquiry into blame, and the countries that do bill people for rescue must accept a serious side effect: the possibility that someone will delay calling for help, or refuse it, in order to avoid a bill.
Prevention is where the public interest really lies. Better signage, avalanche forecasts, helmet rules in organised events and simple advice about fitness probably save more money than any charging scheme would recover. A sport that resists regulation may simply move its events to a country that asks fewer questions, so rules agreed by the governing bodies of the sports themselves are likely to be more effective than local charges. Commercial organisers, meanwhile, profit from risk and are in a position to manage it; requiring them to provide medical cover, as motor racing already does, is a reasonable condition of being allowed to operate.
My conclusion, then, is unashamedly unfashionable. Public systems should treat people injured in high-risk sport on the same terms as anyone else, not because the risk-taking is admirable but because the alternatives — an inquiry into fault at the hospital door, or a patchwork of private insurance that only the well-off can afford — are worse. Where money should be sought is from those who organise and profit from the risk, and where effort should go is into preventing the injuries in the first place. The question worth asking is not who deserves treatment, but who benefits from the danger.
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