Exclusives, Operations

Rethinking ALS Intercepts and Mutual Aide Agreements

This article focuses on the EMS standard operating procedure (SOP) known as the advanced life support (ALS) intercept.1 In the seven rural Midwest and Mountain West states in which the authors work it’s common for ambulance services to be staffed by volunteers with basic life support (BLS) training. These dedicated first responders have varied levels of NREMT credentialing including: EMT-Basic, Advanced EMT, and EMT-Intermediate (EMT-B, AEMT and EMT-I, respectively).2

All EMTs complete coursework in human anatomy, physiology, pathophysiology, emergency skills and patient assessment. The more advanced the EMT (e.g., advanced and intermediate certification) the more patient treatment skills they are usually allowed in their scope of practice. AEMTs will likely have permission to use IV and intraosseous fluid replacement therapy, insert multi-lumen upper airway adjuncts to assist with respiratory resuscitation, and administer a limited number of drugs. EMT-Is are additionally certified to prescribe more drugs than AEMTs. Paramedics receive the same training in human anatomy and physiology but are capable of administering the heart drugs needed to run a ST-segment elevated myocardial infarction (STEMI) or cardiac arrest patient in the field.3

When responding to time-critical events, such as sudden cardiac arrest or STEMI, a BLS ambulance service with EMT-B, AEMT and EMT-I first responders doesn’t possess the advanced training necessary to completely treat and stabilize the patient (e.g., administer cardiac drugs). Accordingly, many state laws require BLS units to initiate an intercept for patients suffering from major trauma, severe respiratory distress or arrest, and cardiac chest pain.4,5 Note that some states refer to the ALS intercept as a tiered-response or mutual aid. Further, intercepts can be via ground or air.6

The basic premise of the intercept is to get ALS care to the patient as soon as possible.  Therefore, once the ALS support is dispatched, it begins traveling toward the BLS unit, thus reducing the time to administering ALS support. The ALS support and BLS unit are in constant communication to determine the soonest location where the two of them can safely “intercept.”5

Buffalo EMS determines ALS support needed and initiates intercept.

In the seven rural states with which the authors are most familiar, it’s common practice for the paramedic to join the EMTs in the BLS ambulance at the intercept location. The conventional wisdom among EMTs is it takes too much time and unnecessarily jeopardizes the patient to move him/her from the BLS ambulance to the ALS ambulance. Once the paramedic joins the BLS team, the BLS ambulance continues to the definitive care facility. The ALS unit then follows the BLS unit back to the definitive care facility.

Questioning the Status Quo

During a recent exercise practicing an intercept between two Wyoming EMS services, one EMT questioned the wisdom of the conventional intercept standard operating procedure (SOP).5,7 The EMT noted his ALS service preferred to transfer the patient to their intercepting ALS unit rather than the paramedic joining the BLS ambulance.

A survey conducted after the exercise found both BLS and ALS first responders cited four advantages to transferring the patient to the intercepting ALS unit.

  1. The ALS unit may be better equipped (including needed drugs);
  2. The paramedic would be more familiar with the competencies and capabilities of his/her own EMT team;
  3. The ALS driver would be more familiar with the quickest routes; and
  4. The BLS unit would be able to return to its service area sooner to cover calls.

Patient transfer between two Wyoming EMS services is drilled during intercept practice.

The authors then completed a literature search to assess whether there was any research comparing the relative advantages of the two ALS intercept options. The search revealed the terms “intercept” and “tiered response” are commonly used and referenced by EMS providers and professionals but aren’t clearly defined. Multiple articles refer to a “tiered response agreement” or a “tiered response protocol”, but don’t illuminate the details of the agreement or protocol.8–12 One article recommended the scene time for transferring a paramedic from one vehicle to the other must be kept brief; less than one minute.8

We found 29 published prehospital care protocols from states across the country. (See Table 1 in References.) Fifteen state protocols had some reference or mention of an “intercept;” four of which had criteria for determining intercept requests. Generally speaking, reference to the intercept is found in the routine patient care/general procedures section of the SOPs, stating the goal is to provide definitive care to the patient and to consider requesting an ALS intercept when indicated in the protocols, if the patient worsens, or as needed.

We were able to find one protocol, Hospital Sisters Health System (HSHS) St. John’s Hospital EMS, definitively stating an intercept SOP and/or evidence of the efficacy/effectiveness of one option versus the other. Their protocol recommends: “Patients not be transferred from ambulance-to-ambulance. The higher-level personnel, along with proper portable equipment, shall board the requesting agency’s ambulance.  Exceptions to this need to be documented by the higher level agency along with the rationale for the transfer. If the patient is to be transferred, patient safety must be ensured taking into consideration weather, traffic, patient privacy, patient stability and ability to care for all potential patient needs. The higher level personnel will oversee patient care with the assistance of the requesting agency’s personnel. Once the higher level personnel have boarded the requesting agency’s ambulance, the higher level provider will determine the transport code for the remainder of transport: Code 1 (Signal 1) for emergency transport with lights and sirens in operation or Code 2 (Signal 2) for transport without lights and sirens and obeying all normal traffic laws.”13

The authors’ experience in seven Midwest and Mountain West states mirrors the literature. We didn’t find any ALS intercept SOPs between EMS agencies and seldom found ALS intercept specific mutual aid agreements (MAAs).14,15

Discussing the conventional intercept standard operating procedure could lead to improvements in efficiency and patient care.

Developing SOPs & Maximizing Reimbursement

One method for developing needed SOPs is to engage EMS agencies, hospitals and law enforcement dispatch services in process flow mapping.16,17  Using a simple methodology like process flow mapping, the authors were able to develop intercept SOPs in about an hour.

Detailed SOPs worked out beforehand will avoid confusion by improving radio communication efficiency, saving time and improving patient care. In effect, it signals to crew members that “we are on the same team.”  Detailed SOPs also provide the frame of reference necessary for training and quality improvement.17 Given the low cost and benefit of detailing, the authors encourage EMS agencies to meet and create intercept SOPs using techniques such as process flow mapping.

We also suggest using SOPS as a foundation for developing intercept MAAs between ambulance services. MAAs will help navigate the elephant in the room: reimbursement.

Payment is often oversimplified and rigid as most paying organizations (e.g., Medicare, Medicaid, private insurance) will only compensate one ambulance service on a call; this interferes with equitable reimbursement scenarios.4

In the states of Wyoming and Nebraska, for example, only the EMS unit transporting the patient can bill for the service. Therefore, if the paramedic from the ALS unit joins the BLS unit, then only the BLS unit can claim for reimbursement as the patient is in their unit for the entire transport. The ALS unit must “eat” the cost of providing the intercept. However, if the patient is transferred to the ALS unit, then both the BLS and ALS service can charge for the portion of the trip they transferred the patient.

This financial reality might unintentionally interfere with what is in the patient’s best interest. Therefore, in addition to the intercept communication protocol a MAA might also detail how each is compensated under the different intercept scenarios. For example, the MAA could detail the agreement as to how the ALS EMS service could potentially bill-back the BLS EMS service for some of the time and mileage in the event their paramedic joins the BLS unit.

Author Acknowledgements: The authors would like to thank Mr. Christopher Beltz for his invaluable support and contributions to this article.


1. Centers for Medicare and Medicaid Services. (2010.) Federal Code of Regulations, 10.5 – Joint Responses (Rev. 125, Issued 05-14-10, Effective: 01-04-10, Implementation: 06-15-10). Medicare benefit policy manual: Chapter 10–Ambulance services. Retrieved Dec. 17, 2018, from www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/downloads/bp102c10.pdf.

2. National Registry of Emergency Medical Technicians. (2018.) Emergency Medical Technicians (EMT). Retrieved Dec. 17, 2018, from www.nremt.org/rwd/public/document/emt.

3. McKay DR. (Dec. 3, 2018.)  EMT and paramedic. The Balance. Retrieved Dec. 17, 2018, from www.thebalance.com/emt-and-paramedic-526010.

4. Becknell J, Nudell N, Reinert A. (June 2011.) A crisis and crossroad in rural North Dakota emergency medical services. North Dakota Department of Health. Retrieved Dec. 17, 2018, from www.health.state.mn.us/divs/orhpc/resources/ems/ndremsip_final_report.pdf.

5. Myers LA, Russi CS, Schultz JL. Paramedic intercepts with basic life support ambulance services in rural Minnesota. Prehosp Disaster Med. 2010;25(2):159–163.

6. Guidelines for Helicopter Utilization Criteria for Scene Response. (Sep. 12, 2005.) New York State Department of Health. Retrieved Dec. 17, 2018, from www.health.ny.gov/professionals/ems/policy/05-05.htm.

7. Granillo B, Renger R, Souvannasacd E, et al. (2017). WYCODE full scale exercise after-action report and improvement plan. Client report – Wyoming Dept. of Health, Office of EMS. University of North Dakota Center for Rural Health.

8. Jacobsen B, Anderson C. ALS intercept and tiered response: Improving patient care or stealing the run? JEMS. 1992;17(10):65–71.

9. Nosal B. (April 1, 2005.) Emergency Medical Services 10-Year Plan. The Regional Municipality of Halton. Retrieved from http://sirepub.halton.ca/councildocs/cd/5/2005%20Health%20and%20Social%20Services%20Committee%20Staff%20Report%20mo0605%2012553.pdf.

10. Stiell IG, Wells GA, Field BJ. Improved out-of-hospital cardiac arrest survival through the inexpensive optimization of an existing defibrillation program: OPALS study phase II. Ontario Prehospital Advanced Life Support. JAMA. 1999; 281(13):1175–1181.

11. Stout J, Pepe PE, Mosesso VN Jr. All-advanced life support vs tiered-response ambulance systems. Prehosp Emerg Care. 2000;4(1):1–6.

12. Waien SA. (1999). Outcomes of cardiac arrest patients in metropolitan Toronto. (Doctoral dissertation, National Library of Canada).

13. Alpera M. (March 2017.) HSHS St. John’s Hospital EMS System: EMS operations/legal protocols. Retrieved Dec. 17, 2018, from www.st-johns.org/Education-Training/Emergency-Medical-Services/Files/Operations-and-Legal-Protocols.

14. Hazinski MF, Chameides L, Hemphill R, et al. (October 2010). Highlights of the 2010 American Heart Association guidelines for CPR and ECC. American Heart Association. Retrieved Dec. 17, 2018, from www.heart.org/idc/groups/heart-public/@wcm/@ecc/documents/downloadable/ucm_317350.pdf.

15. O’Gara PT, Kushner FG, Ascheim DD, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2013;61(4):e78–e140.

16. Renger R, McPherson M, Kontz-Bartels T, et al. (2016). Process flow mapping for systems improvement: Lessons learned. Can J Prog Eval. 2016;31(1):109–121.

17. Snyder KD, Paulson P, McGrath P. Improving processes in a small health-care network: A value-mapping case study. Business Process Management Journal. 2005;11(1):87–99.