Portal de Periódicos da CAPES

The Taxicab Theory Redux

2003; Lippincott Williams & Wilkins; Volume: 25; Issue: 5 Linguagem: Inglês

10.1097/00132981-200305000-00034

1552-3624

R Shinkman,

Traffic and Road Safety

hile on a trip to Palm Springs, a man in his late 50s with a history of good health experienced mild fatigue and bloating. He calls his daughter, a nurse at a Los Angeles-area hospital. She suggests that he drop by for an examination, and he agrees. A special education teacher, also in his 50s with a history of coronary artery disease, has a heart attack while on a field trip with his students. Instead of calling 9–1–1 to summon help, the school bus operator instead drives to the nearest hospital. Is the former individual exercising reasonable judgment? How about the latter? The debate between driving to the hospital emergency department versus being transported by ambulance is a faint but recurring theme in emergency medicine. “Ambulance operators are well educated, they have an idea of symptomology, and they'll call in to the hospital ahead of time.” Dr. Leslie Zun “hen you call 9–1–1, you may be more likely to be triaged to centers that will administer life-saving treatments like clot-busters.” Dr. John Canto Evolution of Ambulances The evolution of ambulances and their role in emergency medicine over the past four decades has dominated much of the debate. No longer mere wagons that transport the sick and injured to triage units, ambulances allow paramedics and emergency medical technicians to provide medications and other life-saving measures while en route to the hospital. “Ambulance operators are well educated, they have an idea of symptomology, and they'll call in to the hospital ahead of time,” said Leslie Zun, MD, the chairman of emergency medicine at Mt. Sinai Hospital Medical Center in Chicago. Yet a study of 800,000 heart attack victims published last January in the American Heart Association journal Circulation revealed that nearly half of the victims drove themselves to the hospital or were transported by relatives. “hen you call 9–1–1, you may be more likely to be triaged to centers that will administer life-saving treatments like clot-busters,” said John Canto, MD, the study's author and the director of the Chest Pain Center at the University of Alabama at Birmingham. “hy double your risk when it's was simple as calling 9–1–1?” Were it only that simple. According to Dr. Canto's study, 14.3 percent of those transported by ambulance died from their heart attacks versus 5.5 percent of those who arrived via private transportation. Dr. Canto's research is no aberration. In a 1996 study of heart attack victims in the Seattle area published in the Annals of Emergency Medicine, 5.6 percent of those transported by ambulance experienced cardiac arrest before arriving at a hospital. But among those who drove or were driven to the hospital, less than half of one percent arrested. The Taxicab Theory The latest research confirms what emergency physicians have long suspected, that patients experience better outcomes by taking private transportation to the ED rather than waiting for an ambulance. Michael Callaham, MD, in fact, dubbed it the taxicab theory in a 1995 EMN editorial. Researchers said younger patients in both studies were far more likely to drive or be driven to the hospital. Those who arrived by ambulance tended to be older and sicker. One urban legend has patients in an ED waiting room calling for an ambulance to ensure more prompt care Although little other empirical evidence exists linking positive outcomes to how a patient arrives at an ED, physicians still recommend that they be transported by ambulance. They cite not only access to triage, but the knowledge paramedics possess to transport a patient to the best possible hospital for treatment. Moreover, an EMS entry into the hospital is direct, with no time spent in a waiting area. Emergency physicians even have their own urban legend of patients already in an ED waiting room calling for an ambulance to ensure more prompt care. Dr. Zun said he has heard of it occurring in Chicago hospitals. Mark Bell, MD, the director of emergency services at Encino-Tarzana Regional Medical Center in suburban Los Angeles, said it also happens in his region, although not at his facility. “It's not uncommon at major university hospitals,” he said. Meanhile, a litany of cultural and demographic differences often determines who will arrive by ambulance versus private vehicle. “There's a certain attitude among some patients that they don't want to be brought in by ambulance,” said Dr. Bell. “They are in some state of denial, or are embarrassed by being sick, and don't want to admit to it.” Dr. Zun concurred. “People who drive themselves aren't was well-educated on what their medical troubles could be, or they're deniers,” he said. “They no longer have use of their left arm or left leg, but they think it's going to get better on its own.” Risks of Ambulances Perhaps ironically, lower-income patients — often assumed to receive the worst care — are more likely to arrive by ambulance because they do not own cars, Dr. Zun added. As for the two cases cited at the beginning of this article, they serve to add an extra element of uncertainty to the private transportation versus ambulance debate. The man complaining of mild fatigue and bloating who was driven by his travel companion to his daughter's hospital was developing septic shock. By the time he arrived at the hospital some 90 minutes after leaving Palm Springs, he was barely conscious. Although now slowly recovering, several of his major organs shut down, he suffered a minor stroke, and he nearly died. The cardiac arrest victim was a patient of Dr. Zun's at a hospital on Chicago's north side. His pulse was restored after being shocked a dozen times. He had no complaints of pain the following day, and felt ready to return home. “In that scenario, unless an ambulance was immediately available, they did the right thing by rushing him there on the bus,” Dr. Zun said.