Cue the Cath Lab

     In the mid 1990s, Maine ambulance services started looking at the potential for reading 12-lead EKGs in the field. As the capabilities of cardiac monitors increased, so did state services' interest in providing 12-leads as part of prehospital care. For United Ambulance—a CAAS-accredited, nonprofit paramedic-licensed service operating in the central part of the state—12-lead capabilities were made possible with the purchase of several LIFEPAK 12 monitors in 1999.

     For the next two years, United encouraged 12-leads as part of its cardiac patient care. They were not required, however, and were not always utilized by staff at the two hospitals that jointly owned United, Central Maine Medical Center (CMMC) and St. Mary's Regional Medical Center. During this time courses on 12-lead EKGs were offered to United's paramedics by educators from both hospitals.

     In 2003, coauthor Kevin Kendall, MD, FACEP, began a limited review of United's prehospital 12-leads for accuracy. He also reviewed national literature comparing paramedics', cardiologists' and ED physicians' diagnoses of STEMIs (ST-elevation myocardial infarctions). These studies showed no significant differences in the abilities of these groups to recognize STEMIs.^1,2 On March 1, 2004, Kendall, in conjunction with United, started an 18-month comprehensive 12-lead EKG review focusing on rhythm interpretation and STEMI recognition. A total of 658 12-lead EKGs were reviewed, and the results were outstanding: Paramedics were diagnosing MI patients with a high degree of accuracy, and not even one STEMI had been missed.

     Although paramedics across the country use 12-lead EKGs for diagnosing STEMIs, the majority are required to send or bring a copy of the EKG to the receiving hospital for confirmation. With the recent opening of Central Maine Heart and Vascular Institute (CMHVI) at CMMC, activating the cath lab from the field became possible. The debate then turned to whether United would follow the national trend and transmit EKG data directly to the ED for confirmation, or would allow paramedics to activate the cath lab based solely on their diagnoses of STEMIs in the field. It was at this point that United's experience changed significantly from the rest of the country's.

     United was researching devices that could transmit 12-leads to the receiving hospital, but based on the positive results from Kendall's STEMI review, leaders decided this equipment cost was not merited. With the support of local cardiologists and CMHVI, they decided to allow United's paramedics to activate the cath lab directly from the field, without an accompanying 12-lead EKG transmission.

     On July 1, 2005, United became the first service in Maine to activate the cath lab from the field. Several measures were put into place to assure competency in STEMI recognition. Paramedics were required to have an approved 12-lead course and pass an exam. CQI indicators were expanded to include a review of every 12-lead EKG completed in the field. Each was reviewed by the medical director, CQI manager or both. Ongoing education, CQI and EKG testing continue to be vital parts of the program today.

     The criteria for cath lab activation was simple but effective:

1. Duration of symptoms less than 12 hours;
2. ST elevation greater than 1 mm in two or more contiguous leads;
3. Ongoing symptoms—e.g., chest pain or shortness of breath;
4. Palpable lower extremity pulses;
5. Informed patient consent.

     The actual activation process was reduced to five easy steps:

1. A patient meets the above criteria;
2. A paramedic notifies the CMMC emergency department medical control physician;
3. The paramedic gives all patient data and requests cath lab activation;
4. If the cath lab team is on site, the patient is brought directly to cath lab;
5. If the cath lab team is called in, the patient is managed in the ED until the cath lab is ready.

     The program was successful, and word spread rapidly among surrounding services because, like many paramedics around the country, United's often work two jobs or volunteer in their communities. "Why can I activate from United," they began wondering, "and not from the other service I work for?" As a result, 13 more services in the CMMC catchment area soon began field activation as well, using the same criteria as United.

     One more important piece was added to help ensure positive patient outcomes. St. Mary's Regional Medical Center signed an agreement with Central Maine Medical Center to divert all STEMI patients directly to the cath lab, thereby saving additional time and muscle in concert with the prehospital activation program.

     Thanks to the support of the local hospitals and the dedication to patient care of United's paramedics, this program continues to succeed and grow. Based on current data, our mean door-to-balloon time for prehospital STEMI is 43 minutes, compared to 77 minutes for patients arriving by private vehicle. We continue to work on improving our door-to-balloon times, especially for our rural station in Bridgton, which is more than 35 miles from a cath lab.

     United is now additionally focusing on response times, patient location and the ability to use various transportation resources, as well as reaching out to other services wishing to implement cath lab activation in their areas.

References

1. Sejersten M, et al. Am J Cardiology 90:995–97, 2002.

2. Whitbread M. Emerg Med J 19(1):66–7, 2002.

     Liz Delano, EMT-P, MS, is United Ambulance's education coordinator. Contact her at delanoe@unitedambulance.net. Joe LaHood, EMT-P, is the service's CQI manager. David White, EMT-P, is a paramedic with United, and Kevin Kendall, MD, FACEP, is the Tri-County Regional medical director.