Cooling in the Cath Lab: Miracle on Ice in Minnesota

Direct percutaneous coronary intervention (PCI) is the optimal method of reperfusion for ST-elevation myocardial infarction (STEMI), when performed in a timely manner by experienced operators. The Level 1 program at Abbott Northwestern Hospital (ANW) in Minneapolis, Minnesota, a tertiary center, began in 2002 with surveys, preparation and an information-seeking approach, in order to plan a successful method to correctly identify patients, have easy access to cardiologists and emergent transfer, and streamline care. ANW is a 619-bed hospital performing over 2,500 PCIs per year. The Level 1 STEMI program has a system for both local (ANW) arrivals and 33 outstate Minnesota community hospitals (Figure 1). One of the unique features of the Level 1 program is its transferring capabilities. The Minneapolis Heart Institute® (MHI) at ANW Level 1 MI Program works with 11 helicopter bases and more than 40 EMS units, covering a span of 210 miles. To improve patients’ timely access to PCI — even if their local hospital is located up to 210 miles away from a cardiac cath lab — a team of nurses, physicians, paramedics and ancillary staff developed and implemented a protocol that standardizes processes and ensures rapid patient transfer to a tertiary care hospital with a catheterization lab. Attention to standard procedures, as well as the smallest of details, has delivered successful outcomes to more than 2,700 patients! “Cool It” is created After ANW successfully implemented the process of STEMI with the 33 outstate regional community hospitals, we saw an opportunity to apply this same successful model to other cardiac emergency situations. While reviewing data in 2006, we found that many STEMI patients had also suffered sudden cardiac arrest (SCA). Interventional cardiologist Michael R. Mooney, MD, FACC, director of the cath lab, designed a therapeutic hypothermia (TH) program, called “Cool It,” to meet the needs of these patients. With early estimates of 12 cases per year, “Cool It” has far exceeded expectations, with 140 therapeutic hypothermia cardiac arrest patients from its inception in February 2006 through September 2009. This program was designed to quickly treat cardiac arrest patients who have a return of spontaneous circulation (ROSC) but do not regain consciousness, regardless of underlying rhythm or shock state, by sedating, paralyzing, and cooling them to a core temperature of 33º C for 24 hours per American Heart Association (AHA) guidelines (a 2A recommendation). Unique to our program and cath lab is to transfer straight to cath lab for simultaneous treatment of STEMI and cooling. With the launch of the “Cool It” program, the cath lab was challenged to create a system which would meet all of the needs of the patient while preserving door-to-balloon time. Building off an established regional STEMI system, we developed a standardized program for the “Cool It” patients — those with out-of-hospital cardiac arrest (OOHCA) and STEMI — with the following guidelines in place: • “Cool It” patients must have sustained a non-traumatic cardiac arrest with a return of spontaneous circulation (ROSC). • Patients presenting to referring hospitals are transferred up to 210 miles to the PCI center, MHI at ANW. • Ice packs are applied at referring hospitals and cooling is continued en route. • “Cool It” patients suffering from STEMI are taken directly to ANW’s catheterization lab for coronary angiography and PCI. • A STEMI order set which includes initiation of therapeutic hypothermia. • The Arctic Sun® Temperature Management system (Medivance, Inc., Louisville, CO) is applied on arrival to the catheterization lab. • The target core temperature of 33°C is maintained for 24 hours. • Re-warming is controlled at 0.5°C/hour. • Cerebral function after TH is measured at discharge using the five-point Pittsburgh Cerebral Performance Category (CPC) scale (CPC 1 and 2 are positive). The first TH case was performed at ANW in November 2006. Catheterization lab nurses and technologists apply the mechanical cooling device in the catheterization lab to maximize the benefits to the brain, while simultaneously treating the STEMI. TH is now the standard of care for all joint Level 1/”Cool It” patients. Cooling expands to first responders By establishing a database to measure times, outcomes and compliance to medications, an early discovery was made. For every hour to first cooling, the relative hazard of death increases 29%.1 This information was shared by the MHI Emergency Cardiovascular Program with our community hospital partners along with their vast EMS systems. Now, as the result of education and teamwork, cooling not only starts in these community hospitals, but also with their local EMS providers. In 2009, we are now receiving post arrest patients at goal temperature upon arrival to ANW. The early cooling applications are ice bags, exposure and quick transport with esophageal probes placed prior to transport, allowing recording temperatures as patients arrive straight to cath lab. “Cool It” protocols and processes Protocols were developed which followed advanced cardiac life support (ACLS) response to a cardiac arrest, but a request was added to repeat ECGs every 15 minutes once the patient has a ROSC. The fact that 50% (n = 140) of the patients had STEMI was the basis for creation of a STEMI/cardiac arrest approach. The protocol now states, “if ST elevation is found, treat patient with rectal ASA, heparin, and clopidogrel, and begin cooling.” Further work was done to assure the one call to MHI cardiologists now included the information of the patient needing both PCI and TH. For those STEMI/cardiac arrest patients coming to ANW, a page system to notify the cath lab can now also activate additional resources by adding “Cool It” to the Level 1 page. While focusing on door-to-balloon times for STEMI, cardiologists sought a device that would allow immediate access to the groin, but also demonstrated excellent temperature control. The Artic Sun device was chosen because of the ease of use with “pads” that could quickly be applied while still allowing groin access (Figure 2). The cath lab has a systematic approach to laying out the cooling pads on the cath table (Figure 3), multiple pumps with tubing ready and 1-2 extra personnel to assist. The cooling device is ready to hook up to an esophageal probe, which will have been placed either at an outstate hospital or during transport. In cases where a probe was not placed, a thermomister bladder catheter is placed both to run the machine and continually display the patient’s body temperature. The cath team records temperature during the catheterization procedure. Each member of the cath team has a specific role in preparing both the cath lab and the patient. Registered nurses (RNs) prepare sedation and paralytic drips, while technologists prepare the cooling device and the cath table for STEMI. The “Cool It” program involves an expanded team that includes respiratory therapy (all patients arrive intubated) and pharmacy to assist with the numerous necessary medications. Both an in-house cardiologist and intensivist will report to cath lab to assist the interventionalist as well. Once the vessel is opened and treatment completed, a pulmonary artery catheter is placed while an arterial line is left in place for frequent blood draws. The patient then moves to the cardiac care unit for phase 2 of the cooling. Line placement is especially important for these patients, as it is often challenging to place lines in a vasoconstricted, hypothermic patient. Following 24 hours of cooling, patients are re-warmed at 0.5˚C/hour, back to 37˚C. ANW results Key to the success of the “Cool It” program is education of the team. From EMS (prehospital), community hospitals, EMS (transportation units) and the staff of ANW hospital, much time and effort went to sharing and learning what staff could do in order to move quickly and efficiently. Door-to-balloon times show an average of only a 6-minute time increase to place the patient onto the cooling device upon arrival in cath lab. From February 2006 to October 2008, 104 cardiac arrest patients have been treated with therapeutic hypothermia. Fifty percent (50%) were STEMI, 40% were in cardiogenic shock and 76% were transfers from community hospitals. Our results are as follows: • Survival from VT/VF without shock (HACA criteria): 76% • Survival for higher risk patients (PEA, asystole, and shock states): 39% • Neurological scoring: for STEMI survivals (CPC in Class 1 or 2): 97% While focusing on the data showing a 29% increased risk of death for every hour of delay to cooling, our team began looking for methods to decrease the time to applying cooling. While the data shows (any method) of cooling that is started and then transitioned to the mechanical device, we have seen a dramatic decrease in the time of return of spontaneous circulation (ROSC) to application of first cooling. The cath lab has effectively decreased the time to apply the device through creativity and team input. Importantly, while cooling was initially being started after the PCI, it is now done prior to the procedure. The actual time to place the cooling pads averages 6 minutes. Teamwork and education led to success To initiate the “Cool It” program, members of the ANW cath lab were critical in its entire development. As cath lab nurse Jeff Eurich, RN, states, we were “cardiocentric in our thinking, but saving the heart without a functioning brain did not make sense. Therapeutic hypothermia is every bit as essential to the brain as STEMI care is to the heart. The trick is to figure out how to technically do it.” Education and practice were key components. Cardiovascular technologist Stacy Tonne helped design the flow and choreography to position staff, equipment and physicians to decrease chaos and increase organized efficiency. The ANW cath lab has been able to put together a training manual to assist all new staff as well as update current staff on any improvements to the process. As the data validated the early onset of cooling, witnessing successful outcomes sealed the deal for the cath lab staff. Data collection in emergency departments as well as the cath lab remains imperative in order to look for areas of improvement. n The authors can be contacted at barbara.unger@allina.com Additional reading: Winslow R. How Ice Can Save Your Life: 'Therapeutic Hypothermia' Can Protect the Brain in the Aftermath of Cardiac Arrest. The Wall Street Journal, October 6, 2009. Available online at: https://online.wsj.com/ article/SB10001424052748703298004574455011023363866.html#articleTabs%3Darticle/ OR https://tinyurl.com/ycnjxvq/. Accessed October 8, 2009.

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