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Use of lights and sirens (L&S) is a medical intervention

Emergency Medical Services is characterized by evolution. As an example, in the 1970s, protocol mandated the use of Sodium Bicarbonate (NaHCO3) in cardiac arrest before epinephrine was administered. It was thought that the epinephrine would be ineffective without the NaHCO3. Research revealed that bicarb shifted the oxyhemoglobin dissociation curve to the left and reduced intramyocardial pH to 6.9 as the Nernst equilibrium was approached. Consequently, the role of bicarb in multiple clinical contexts has been re-evaluated with substantial changes in its implementation. The pattern of basic research, clinical application, and measurement of patient outcome forms the basis for the development of standards of care. Like bicarb use, the effect of our use of L&S has been subject to research, related to clinical practice, and shown to impact patient outcome. It can be argued that L&S use is a medical intervention and subject to a standard of care. 

Standard of care 

Standard of care (SOC) is a legal term, not a medical one. Most states follow a national standard. For example, Connecticut defines it as “that level of care, skill, and treatment which, in light of all relevant surrounding circumstances, is recognized as acceptable and appropriate by reasonably prudent similar health care providers.” The following factors are used to determine SOCs: 

  • Statutes and regulation (state, federal, local) 
  • Court opinions 
  • Authoritative guidelines 
  • Policies and guidelines from professional organizations 
  • Journal/research articles 
  • Accreditation standards 
  • Facility policies and procedures 

Recently fifteen professional organizations issued a “Joint statement on L&S vehicle operations on emergency medical services (EMS) responses”. There are countless articles in the professional literature regarding L&S. The other factors on the list are clearly applicable to L&S. “In light of all relevant surrounding circumstances” requires an understanding of the risks and benefits of L&S use that will inform the creation of a standard of care. 

Risks vs. benefits 

  • Traffic related fatalities for EMS practitioners are 2.5-4.8 times higher than other occupations 
  • 7.7% of EMS practitioners report being involved in a crash 
  • 100% of the crashes occurred in clear weather while using L&S 
  • Time saved with L&S range from 42 seconds to 3.8 minutes 
  • L&S use increase crash risk by 50% and triples the risk during patient transport 
  • Fatality breakdown in L&S crashes: the emergency vehicle operator is killed 4%, ambulance passengers 21%, occupants of other vehicles 63%, non-occupants (another term for innocent bystanders) 12% 
  • L&S are used in 74% of responses and 21.6% of transports for medical calls, but potentially lifesaving interventions are performed in only 6.9% of calls 

What should be done? 

Each ambulance service has a unique set of circumstances. Some providers may not know the percentage of L&S use on responses to scenes or transports to facilities. One first step may be to look at those numbers, determine what decision-making process initiates L&S use, and set a realistic goal for reductions in L&S use. The sponsoring organizations of the Joint Statement recommend the following guiding principles: 

  • Use L&S when their usage may be clinically important to the patient’s outcome. 
  • Dispatch centers should use Emergency Medical Dispatch (EMD) programs. Active physician participation is essential. Quality Assurance programs should determine that the protocols are used and measure the impact on patient outcomes. The evaluation should be ongoing and protocols should be revised as needed. 
  • Emergency response policies should be based on a community risk assessment with physician oversight. 
  • Drivers should be adequately screened and have robust emergency vehicle operation, initial, and ongoing training, which includes a practicum and is taught by an appropriately credentialed instructor. 
  • Governmental agencies should be informed of the risk and benefits of L&S use. Service agreements should reflect the tiered response time expectations associated with EMD. Quality of care metrics should replace time metrics in determining compliance with contractual obligations. 
  • Crashes and near misses should trigger incident reporting mechanisms that can be used for QA. 
  • Education must be used to alter the unrealistic expectations the public has of EMS providers that are fostered by the media. 


The use of lights and sirens has specific risks and benefits. They should be used only in those circumstances in which they have a positive impact on patient outcome. Ongoing analysis must be used to identify the conditions, specific to each ambulance provider, that merit L&S use. 


  • Cooke B, Worsham E, Reisfeld G. The elusive standard of care. J Am Acad Psychiatric Law. 2017;45:358-364. 
  • Vanderpool D, The standard of Care. Innovations in Clinical Neuroscience. 2021. Jul-Sep ;18(7-) : 50-51. 
  • Kupas DF, Zavadsky M, et alia, Joint Statement of Lights & Siren Vehicle Operations on Emergency Medical Services (EMS) Responses. February 14, 2022 
  • Jarvis JL, Hamilton V, et alia, Using red lights and sirens for emergency ambulance response : How often are potentially life-saving interventions performed? Prehosp Emerg Care. 2021; 25 (4): 549-555.