MSM Post 005 Why are we still using lights and sirens?

Use of lights and sirens should be justified by the need for immediate medical intervention that is beyond the capabilities of the ambulance crew using available supplies and equipment.

-State of Massachusetts Routine Care Protocol

            There are times in EMS culture where we simply lie to ourselves about what works and what doesn’t. As an industry we hold on to many traditions that have existed for many years, simply because they are “what we do.” The use of lights and sirens has time and time again proven to be a dangerous practice that does not improve patient outcomes, and in fact makes the road more dangerous for everyone involved.

In 2015, the University of Massachusetts wanted to explore the beliefs of EMS providers pertaining to the use of lights and sirens during patient transport. They surveyed 108 employees asking for responses with ranges of agreement as to whether lights and sirens 1) reduced transport times 2) improved patient outcomes 3) increased the risk of collision during transport and 4) the use of lights and sirens reduced utilization of “mutual aid” services.[1] The surveys were all answered, and the results should not be surprising. The study found that 82% of transports were conducted with warning lights and sirens (WLS). ALS providers transported with WLS 89% of the time, and BLS used WLS 61% of the time. Respondents to the survey reported 147 collisions, 40% of which occurred during a WLS transport. This data alone should be upsetting, but the additional results from the study are more alarming.

Despite the fact that the use of WLS clearly increases the risk of collision, which has its own concerns such as injury to patients and crew, increased risk to the public, and increased insurance cost, providers felt that the use of WLS was justified because the use of WLS shortens transport times. Numerous other studies have shown that the reduction of transport times is at best 90 seconds with the use of WLS, a time that is not clinically significant. What is shocking about the first results is that those same providers who felt that WLS reduces transport time do not belief that WLS improve patient outcomes. It was also found that providers acknowledge that WLS increases the risk of collisions and reduces the utilization of mutual aid services.

We tend to use WLS when we feel that we need to get to the hospital “now”. The old adage of a “diesel bolus” being the best treatment for some patients still resonates with many EMS providers. One patient population that we feel the most affected by in the setting is pediatric patients. As providers, we tend to not be comfortable with pediatric patients, so we want to get those patients to the hospital as soon as possible. A 2016 study[2] analyzed 490 pediatric transports and found that almost 20% of transports used WLS without warrant. That is to say that 1 in 5 pediatric transports posed a risk to the patients, crew, and public completely unnecessarily.

So why do we do it? Are we simply adrenaline junkies who love the rush of driving as fast as we can and making loud noises while doing it? Maybe. Are we just adhering to what we’ve always done? That may be a factor as well. The real reason may be slightly more nuanced.

Most states and agencies do not have well-established protocols regarding the use of WLS. Generally, protocols may list vague reasons to transport with WLS such as “if the patient is critical” or if “the judgment of the crew” determines the use of WLS. The reality is that there is almost no use for WLS as they do not improve outcomes and pose a greater threat to everyone involved in the emergency. Even in an urban setting WLS will not significantly reduce response or transport times (you cant move traffic that has nowhere to go). Until we develop a culture of safety that prioritizes the patient and the public in this regard, providers should avoid the use of WLS. Just because we’ve used them for decades doesn’t mean they have any use. Just ask anybody with a Sega Dreamcast.

[1] Tennyson, et al. Western J. Emerg. Med. Vol. 16 #3 465-471

[2] Burns, et al Unnecessary use of red lights in pediatric transport Prehosp. Emerg. Care May/June 2016 20:3 354-361