The Checklist Manifesto Page 3
Fifteen years ago, Israeli scientists published a study in which engineers observed patient care in ICUs for twenty-four-hour stretches. They found that the average patient required 178 individual actions per day, ranging from administering a drug to suctioning the lungs, and every one of them posed risks. Remarkably, the nurses and doctors were observed to make an error in just 1 percent of these actions--but that still amounted to an average of two errors a day with every patient. Intensive care succeeds only when we hold the odds of doing harm low enough for the odds of doing good to prevail. This is hard. There are dangers simply in lying unconscious in bed for a few days. Muscles atrophy. Bones lose mass. Pressure ulcers form. Veins begin to clot. You have to stretch and exercise patients' flaccid limbs daily to avoid contractures; you have to give subcutaneous injections of blood thinners at least twice a day, turn patients in bed every few hours, bathe them and change their sheets without knocking out a tube or a line, brush their teeth twice a day to avoid pneumonia from bacterial buildup in their mouths. Add a ventilator, dialysis, and the care of open wounds, and the difficulties only accumulate.
The story of one of my patients makes the point. Anthony DeFilippo was a forty-eight-year-old limousine driver from Everett, Massachusetts, who started to hemorrhage at a community hospital during surgery for a hernia and gallstones. The surgeon was finally able to stop the bleeding but DeFilippo's liver was severely damaged, and over the next few days he became too sick for the hospital's facilities. I accepted him for transfer in order to stabilize him and figure out what to do. When he arrived in our ICU, at 1:30 a.m. on a Sunday, his ragged black hair was plastered to his sweaty forehead, his body was shaking, and his heart was racing at 114 beats a minute. He was delirious from fever, shock, and low oxygen levels.
"I need to get out!" he cried. "I need to get out!" He clawed at his gown, his oxygen mask, the dressings covering his abdominal wound.
"Tony, it's all right," a nurse said to him. "We're going to help you. You're in a hospital."
He shoved her out of the way--he was a big man--and tried to swing his legs out of the bed. We turned up his oxygen flow, put his wrists in cloth restraints, and tried to reason with him. He eventually tired out and let us draw blood and give him antibiotics.
The laboratory results came back showing liver failure and a steeply elevated white blood cell count, indicating infection. It soon became evident from his empty urine bag that his kidneys had failed, too. In the next few hours, his blood pressure fell, his breathing worsened, and he drifted from agitation to near unconsciousness. Each of his organ systems, including his brain, was shutting down.
I called his sister, his next of kin, and told her the situation. "Do everything you can," she said.
So we did. We gave him a syringeful of anesthetic, and a resident slid a breathing tube into his throat. Another resident "lined him up." She inserted a thin two-inch-long needle and catheter through his upturned right wrist and into his radial artery, then sewed the line to his skin with a silk suture. Next, she put in a central line--a twelve-inch catheter pushed into the jugular vein in his left neck. After she sewed that in place, and an X-ray showed its tip floating just where it was supposed to--inside his vena cava at the entrance to his heart--she put a third, slightly thicker line, for dialysis, through his right upper chest and into the subclavian vein, deep under the collarbone.
We hooked a breathing tube up to a hose from a ventilator and set it to give him fourteen forced breaths of 100 percent oxygen every minute. We dialed the ventilator pressures and gas flow up and down, like engineers at a control panel, until we got the blood levels of oxygen and carbon dioxide where we wanted them. The arterial line gave us continuous arterial blood pressure measurements, and we tweaked his medications to get the pressures we liked. We regulated his intravenous fluids according to venous pressure measurements from his jugular line. We plugged his subclavian line into tubing from a dialysis machine, and every few minutes his entire blood volume washed through this artificial kidney and back into his body; a little adjustment here and there, and we could alter the levels of potassium and bicarbonate and salt, as well. He was, we liked to imagine, a simple machine in our hands.
But he wasn't, of course. It was as if we had gained a steering wheel and a few gauges and controls, but on a runaway 18-wheeler hurtling down a mountain. Keeping that patient's blood pressure normal required gallons of intravenous fluid and a pharmacy shelf of drugs. He was on near-maximal ventilator support. His temperature climbed to 104 degrees. Less than 5 percent of patients with DeFilippo's degree of organ failure make it home. A single misstep could easily erase those slender chances.
For ten days, though, we made progress. DeFilippo's chief problem had been liver damage from his prior operation: the main duct from his liver was severed and was leaking bile, which is caustic--it digests the fat in one's diet and was essentially eating him alive from the inside. He had become too sick to survive an operation to repair the leak. So once we had stabilized him, we tried a temporary solution--we had radiologists place a plastic drain, using CT guidance, through his abdominal wall and into the severed duct in order to draw out the leaking bile. They found so much that they had to place three drains--one inside the duct and two around it. But, as the bile drained out, his fevers subsided. His need for oxygen and fluids diminished, and his blood pressure returned to normal. He was beginning to mend. Then, on the eleventh day, just as we were getting ready to take him off the ventilator, he again developed high, spiking fevers, his blood pressure sank, and his blood-oxygen levels plummeted again. His skin became clammy. He got shaking chills.
We couldn't understand what had happened. He seemed to have developed an infection, but our X-rays and CT scans failed to turn up a source. Even after we put him on four antibiotics, he continued to spike fevers. During one fever, his heart went into fibrillation. A Code Blue was called. A dozen nurses and doctors raced to his bedside, slapped electric paddles onto his chest, and shocked him. His heart responded and went back into rhythm. It took two more days for us to figure out what had gone wrong. We considered the possibility that one of his lines had become infected, so we put in new lines and sent the old ones to the lab for culturing. Forty-eight hours later, the results returned. All the lines were infected. The infection had probably started in one line, which perhaps was contaminated during insertion, and spread through DeFilippo's bloodstream to the others. Then they all began spilling bacteria into him, producing the fevers and steep decline.
This is the reality of intensive care: at any point, we are as apt to harm as we are to heal. Line infections are so common that they are considered a routine complication. ICUs put five million lines into patients each year, and national statistics show that after ten days 4 percent of those lines become infected. Line infections occur in eighty thousand people a year in the United States and are fatal between 5 and 28 percent of the time, depending on how sick one is at the start. Those who survive line infections spend on average a week longer in intensive care. And this is just one of many risks. After ten days with a urinary catheter, 4 percent of American ICU patients develop a bladder infection. After ten days on a ventilator, 6 percent develop bacterial pneumonia, resulting in death 40 to 45 percent of the time. All in all, about half of ICU patients end up experiencing a serious complication, and once that occurs the chances of survival drop sharply.
It was another week before DeFilippo recovered sufficiently from his infections to come off the ventilator and two months before he left the hospital. Weak and debilitated, he lost his limousine business and his home, and he had to move in with his sister. The tube draining bile still dangled from his abdomen; when he was stronger, I was going to have to do surgery to reconstruct the main bile duct from his liver. But he survived. Most people in his situation do not.
Here, then, is the fundamental puzzle of modern medical care: you have a desperately sick patient and in order to have a chance of saving him you have to get the knowledge right a
nd then you have to make sure that the 178 daily tasks that follow are done correctly--despite some monitor's alarm going off for God knows what reason, despite the patient in the next bed crashing, despite a nurse poking his head around the curtain to ask whether someone could help "get this lady's chest open." There is complexity upon complexity. And even specialization has begun to seem inadequate. So what do you do?
The medical profession's answer has been to go from specialization to superspecialization. I told DeFilippo's ICU story, for instance, as if I were the one tending to him hour by hour. That, however, was actually an intensivist (as intensive care specialists like to be called). As a general surgeon, I like to think I can handle most clinical situations. But, as the intricacies involved in intensive care have grown, responsibility has increasingly shifted to super-specialists. In the past decade, training programs focusing on critical care have opened in most major American and European cities, and half of American ICUs now rely on superspecialists.
Expertise is the mantra of modern medicine. In the early twentieth century, you needed only a high school diploma and a one-year medical degree to practice medicine. By the century's end, all doctors had to have a college degree, a four-year medical degree, and an additional three to seven years of residency training in an individual field of practice--pediatrics, surgery, neurology, or the like. In recent years, though, even this level of preparation has not been enough for the new complexity of medicine. After their residencies, most young doctors today are going on to do fellowships, adding one to three further years of training in, say, laparoscopic surgery, or pediatric metabolic disorders, or breast radiology, or critical care. A young doctor is not so young nowadays; you typically don't start in independent practice until your midthirties.
We live in the era of the superspecialist--of clinicians who have taken the time to practice, practice, practice at one narrow thing until they can do it better than anyone else. They have two advantages over ordinary specialists: greater knowledge of the details that matter and a learned ability to handle the complexities of the particular job. There are degrees of complexity, though, and medicine and other fields like it have grown so far beyond the usual kind that avoiding daily mistakes is proving impossible even for our most superspecialized.
There is perhaps no field that has taken specialization further than surgery. Think of the operating room as a particularly aggressive intensive care unit. We have anesthesiologists just to handle pain control and patient stability, and even they have divided into subcategories. There are pediatric anesthesiologists, cardiac anesthesiologists, obstetric anesthesiologists, neurosurgical anesthesiologists, and many others. Likewise, we no longer have just "operating room nurses." They too are often subspecialized for specific kinds of cases.
Then of course there are the surgeons. Surgeons are so absurdly ultraspecialized that when we joke about right ear surgeons and left ear surgeons, we have to check to be sure they don't exist. I am trained as a general surgeon but, except in the most rural places, there is no such thing. You really can't do everything anymore. I decided to center my practice on surgical oncology--cancer surgery--but even this proved too broad. So, although I have done all I can to hang on to a broad span of general surgical skills, especially for emergencies, I've developed a particular expertise in removing cancers of endocrine glands.
The result of the recent decades of ever-refined specialization has been a spectacular improvement in surgical capability and success. Where deaths were once a double-digit risk of even small operations, and prolonged recovery and disability was the norm, day surgery has become commonplace.
Yet given how much surgery is now done--Americans today undergo an average of seven operations in their lifetime, with surgeons performing more than fifty million operations annually--the amount of harm remains substantial. We continue to have upwards of 150,000 deaths following surgery every year--more than three times the number of road traffic fatalities. Moreover, research has consistently showed that at least half our deaths and major complications are avoidable. The knowledge exists. But however supremely specialized and trained we may have become, steps are still missed. Mistakes are still made.
Medicine, with its dazzling successes but also frequent failures, therefore poses a significant challenge: What do you do when expertise is not enough? What do you do when even the super-specialists fail? We've begun to see an answer, but it has come from an unexpected source--one that has nothing to do with medicine at all.
2. THE CHECKLIST
On October 30, 1935, at Wright Air Field in Dayton, Ohio, the U.S. Army Air Corps held a flight competition for airplane manufacturers vying to build the military's next-generation long-range bomber. It wasn't supposed to be much of a competition. In early evaluations, the Boeing Corporation's gleaming aluminum-alloy Model 299 had trounced the designs of Martin and Douglas. Boeing's plane could carry five times as many bombs as the army had requested; it could fly faster than previous bombers and almost twice as far. A Seattle newspaperman who had glimpsed the plane on a test flight over his city called it the "flying fortress," and the name stuck. The flight "competition," according to the military historian Phillip Meilinger, was regarded as a mere formality. The army planned to order at least sixty-five of the aircraft.
A small crowd of army brass and manufacturing executives watched as the Model 299 test plane taxied onto the runway. It was sleek and impressive, with a 103-foot wingspan and four engines jutting out from the wings, rather than the usual two. The plane roared down the tarmac, lifted off smoothly, and climbed sharply to three hundred feet. Then it stalled, turned on one wing, and crashed in a fiery explosion. Two of the five crew members died, including the pilot, Major Ployer P. Hill.
An investigation revealed that nothing mechanical had gone wrong. The crash had been due to "pilot error," the report said. Substantially more complex than previous aircraft, the new plane required the pilot to attend to the four engines, each with its own oil-fuel mix, the retractable landing gear, the wing flaps, electric trim tabs that needed adjustment to maintain stability at different airspeeds, and constant-speed propellers whose pitch had to be regulated with hydraulic controls, among other features. While doing all this, Hill had forgotten to release a new locking mechanism on the elevator and rudder controls. The Boeing model was deemed, as a newspaper put it, "too much airplane for one man to fly." The army air corps declared Douglas's smaller design the winner. Boeing nearly went bankrupt.
Still, the army purchased a few aircraft from Boeing as test planes, and some insiders remained convinced that the aircraft was flyable. So a group of test pilots got together and considered what to do.
What they decided not to do was almost as interesting as what they actually did. They did not require Model 299 pilots to undergo longer training. It was hard to imagine having more experience and expertise than Major Hill, who had been the air corps' chief of flight testing. Instead, they came up with an ingeniously simple approach: they created a pilot's checklist. Its mere existence indicated how far aeronautics had advanced. In the early years of flight, getting an aircraft into the air might have been nerve-racking but it was hardly complex. Using a checklist for takeoff would no more have occurred to a pilot than to a driver backing a car out of the garage. But flying this new plane was too complicated to be left to the memory of any one person, however expert.
The test pilots made their list simple, brief, and to the point--short enough to fit on an index card, with step-by-step checks for takeoff, flight, landing, and taxiing. It had the kind of stuff that all pilots know to do. They check that the brakes are released, that the instruments are set, that the door and windows are closed, that the elevator controls are unlocked--dumb stuff. You wouldn't think it would make that much difference. But with the checklist in hand, the pilots went on to fly the Model 299 a total of 1.8 million miles without one accident. The army ultimately ordered almost thirteen thousand of the aircraft, which it dubbed the B-17. And, because flying th
e behemoth was now possible, the army gained a decisive air advantage in the Second World War, enabling its devastating bombing campaign across Nazi Germany.
Much of our work today has entered its own B-17 phase. Substantial parts of what software designers, financial managers, firefighters, police officers, lawyers, and most certainly clinicians do are now too complex for them to carry out reliably from memory alone. Multiple fields, in other words, have become too much airplane for one person to fly.
Yet it is far from obvious that something as simple as a checklist could be of substantial help. We may admit that errors and oversights occur--even devastating ones. But we believe our jobs are too complicated to reduce to a checklist. Sick people, for instance, are phenomenally more various than airplanes. A study of forty-one thousand trauma patients in the state of Pennsylvania--just trauma patients--found that they had 1,224 different injury-related diagnoses in 32,261 unique combinations. That's like having 32,261 kinds of airplane to land. Mapping out the proper steps for every case is not possible, and physicians have been skeptical that a piece of paper with a bunch of little boxes would improve matters.