Emergency lights and sirens on ambulances may do more harm than good

Jonathan Studnek knows some people imagine that driving an ambulance at high speed with lights flashing and sirens wailing — racing through messily parted traffic to the scene of a crisis — is the best part of being an emergency medic.

For him, that couldn’t be further from the truth. “If you’ve been in the industry for any length, you know innately: When you’re in the front of an ambulance and the lights are on, that’s the most dangerous situation for you,” said Studnek, deputy director of Mecklenburg EMS Agency, which serves the Charlotte, N.C., region. “It’s not fun. It’s risky.”

Up until recently, Mecklenburg EMS was running “running hot”  — with emergency lights on and sirens blaring —  on three-quarters of runs, racing to get to the scene in under 11 minutes. But when the agency studied its internal data, it found only 5% of calls actually needed a high-priority trip to the hospital. “Not every patient that calls 911 has a life-threatening illness or injury,” Studnek said. “They need a quick dispatch, but they don’t need a red lights and sirens response. That’s the nuance.”

Theoretically, lights and sirens save lives by parting seas of traffic to rush patients to hospitals as fast as possible. But research into them echoes Mecklenburg’s takeaways: About 5% of EMS patients benefit, clinically, from quicker transports. Meanwhile, lights and sirens have been found to only save seconds or minutes at most — and almost triple the chance of crashing with a patient onboard.

And yet, more than three-quarters of 911 transports to U.S. medical facilities run hot.

“It’s engrained in our DNA,” said Mike Taigman, an improvement guide with EMS data consultant FirstWatch, founder of the National EMS Quality Alliance’s Lights and Siren Collaborative, and former street paramedic. “How do you know it’s an emergency vehicle? Look for the lights.”

In recent years, the field has begun to question their use, with leaders calling for medics to judiciously prescribe lights and sirens based on patient need, like any other medical treatment.

“Some emergencies can be fixed with some hand-holding and words of encouragement, and others require more drastic measures,” said Matt, a paramedic in Texas who requested to only be identified by his first name for privacy.

In March, Mecklenburg launched a new strategy that limits the use of lights and sirens exclusively to cries for help that are very potentially life-threatening  — cases like gunshot wounds to the chest, massive bleeding, and unresponsive patients — which make up about 1 in 5 calls. But for most calls, now, Mecklenburg paramedics and EMTs drive ambulances like they would any other vehicle. “It’s not that you sit back,” Studnek said. “You’re responding with the speed of traffic.”

In the field’s early days, emergency medical responders mirrored the fire service, which always used lights and sirens. Flames, after all, can engulf a home in just five minutes; when every second is precious, so is the speedy arrival of emergency responders.

But the earliest EMS providers were drivers (often police officers, morticians, or local volunteers) with little, if any, medical training. “You call, we haul — that’s all,” was a common industry expression. Valorizing speed in a profession that provided transportation — and not medical care — made sense.

Today, however, emergency medics undergo hundreds or thousands of hours of training. “Getting you to the hospital fast is not the value of EMS” anymore, said Douglas Kupas, medical director for the National Association of EMTs and president-elect of the National Association of EMS Physicians.

Emergency medics show up to people having heart attacks or strokes, to car crashes, boating accidents, stabbings, and shootings. They tend to fainting fits and seizures, and save people from choking and electrocutions. They also provide care in non-life-threatening situations such as broken bones and general feelings of weakness or unwellness. “We’re being called for someone who’s scared of the dark, someone who’s lonely, someone who just doesn’t know how to take their regular meds,” said Nathan Harig, assistant chief of Cumberland Goodwill EMS in Carlisle, Pa.

Often, emergency medics have the equipment and training to treat patients or stabilize them on scene. They can, for example, apply tourniquets to wounds, treat severe allergies with epinephrine, and treat asthma attacks with inhalers. Paramedics can start IVs, intubate patients who can’t breathe on their own, and treat overdoses with naloxone.

Only 1 in 14 of calls involve these kinds of potentially lifesaving interventions, according to a 2018 nationwide analysis of almost 6 million 911 records. Other studies suggest that truly time-dependent medical emergencies make up between 4.5% and 5.3% of all call volume. Even in those cases, the time saved by lights and sirens is slim — somewhere between 42 seconds and 3.8 minutes.

When Kenosha, Wis., examined its internal data, it found that flicking on lights got ambulances to the scene, on average, 38 seconds sooner — and did not get patients to the hospital any faster. “Thirty-eight seconds is meaningful if you’re not breathing, if your heart’s not beating,” said Nicholas Eschmann, Kenosha EMS’s recently retired chief.

Overemphasizing urgency in EMS is a little like trying to determine a football match’s winner by tracking the players’ running speeds and not the actual score, said Rick Ferron, interim chief of Niagara EMS, in Canada, which has winnowed down its use of lights and sirens to between 5% and 10% of calls. “We call ourselves emergency medical services, but it’s a bit of a misnomer,” Ferron said. “We can’t treat everything as if it’s a maximal emergency.”

Despite their lifesaving symbolism,  lights and sirens can actively cause harm.

A national 2019 study of about 20 million ambulance dispatches found crash rates more than doubled when lights and sirens were blazing during a run to the hospital.

This month, for example, a semitruck hit an ambulance as it drove through a red light with sirens on, leaving a Kentucky paramedic in critical condition after being thrown from the back of the vehicle. In May, a 74-year-old patient died after the ambulance transporting her collided with a semitruck and two cars on an Alabama state highway (four others, including the driver and paramedic with her, were injured). That same month, a Cumberland Goodwill ambulance was hit, hard, in the rear while cruising through an intersection with lights on. “They were the rescuers. Now they’re the ones that need rescue,” said Harig, the assistant chief.

Ambulance crashes have immediate and rippling repercussions. The original patient in need of help will have to wait even longer. The EMS agency might have to deploy a rig to tend to its own crash. Already understaffed ambulance services might be out a medic for weeks or months if they were injured. Insurance premiums on the vehicles might go up, and costly equipment inside the truck will likely need replacing.

More difficult to track are “wake effect” crashes, which don’t directly involve ambulances. Instead, they’re the after-effect of a passing ambulance, which causes other drivers on the road to behave unpredictably and erratically, slamming on brakes or suddenly veering to the side.  By one measure, every emergency vehicle crash leads to approximately four “wake effect” collisions in its path.

And crashes are not the only risk of running hot.

Avery, a paramedic in Pennsylvania who asked to be identified by first name only for privacy, said it’s challenging to stabilize a patient or communicate with a colleague when they’re weaving through traffic, sirens screaming. “It can make it harder for me to assess and treat my patients en route if I can’t stand up to move around, hear lung sounds over the sirens, or get an accurate blood pressure,” he said. “I’d rather have a smooth trip than a quick one where we can make more victims.”

For patients in critical condition, a harrowing trip to the hospital can cause damaging physiological stress, raising blood pressure and heart rates when oxygen is in precious reserve. For the general public, constant sirens are a nuisance, carry potential health risks, and can be scary and hazardous for people with vision, hearing, or sensory-processing disabilities. And once on scene, paramedics and EMTs have to snap out of a high-octane mindset to provide calm, thoughtful medical care. “That adrenaline dump and recovery takes a toll on people,” Studnek said — as does regularly flirting with the literal danger of career-ending and life-changing crashes.

“It’s stressful for us and for other drivers on the road,” said Matt, the Texas paramedic. “It just adds another layer of stress to the job.”

So why are lights and sirens still such a fixture in EMS?

For one, the field is a patchwork of agencies with their own unique structures and regulations. Some are operated by cities or counties, others by hospital systems. Some are nonprofit; others are for-profit private services. Their ranks might be full-time, highly-trained professionals, or all-volunteer. “If you’ve seen one ambulance service, you’ve seen one ambulance service,” Harig said. “That’s a challenge, in and of itself.”

In 2022, the National EMS Quality Alliance launched a collaborative project with 50 EMS agencies to reduce their lights and sirens use; NEMSQA plans to study their experiences and craft national guidance. Also last year, 14 associations representing ambulance agencies, emergency dispatchers, patient safety advocates, and medical professionals took a joint stance on lights and sirens, calling for, among other steps, improved triaging by call centers, more robust emergency vehicle driver training, and public outreach to address potential safety concerns. Emphasis on speed is also enshrined by insurers, Taigman said. Medicare, EMS’s biggest insurer, pays for ambulance transport at two rates — “emergency” and “non-emergency.” While Medicare doesn’t regulate their use, many EMS billing services use lights and sirens as shorthand for which code to choose.

Kupas said that performance agreements with municipalities also often require ambulances to arrive on scene within a particular time window, often eight minutes or less. “For decades, the time stamp was the only indicator of quality in developing these contracts,” he said. Many of those time frames, he said, rely on the findings of a 1979 Seattle study that concluded that cardiac arrest patients needed CPR within four minutes and definitive care within 10 minutes.

But the paper was conducted at a time before the advent of automated (and more widely accessible) defibrillators, and before bystanders could be coached through CPR by emergency dispatchers. Those requirements are “archaic,” he said. Still, in some cases, regulators fine emergency medical services for missing a slim time window.

EMS agencies have also dangled lights and sirens to attract adventurous would-be medics. “It was a popular recruiting tool,” Harig said. At the same time, the public has been trained over decades to equate lights and sirens with the most glaring  — and sometimes only — perceptible evidence that help is on its way. “It’s kind of been a community relations tool: you know we’ll be there as fast as possible,” he said.

That’s why, as Mecklenburg rolled out its new policy, Studnek delivered his message directly to the public at outreach events. “We will be there, and we will be there quickly,” he said. Flashing lights or not, “we will be there in your time of need.”