Reducing Contrast-Induced Acute Kidney Injury in the Cath Lab at Houston Methodist Sugar Land Hospital

Can you tell us about your cath lab and hospital?

Anita Marban, Cath Lab Director: Houston Methodist Sugar Land Hospital  (HMSL) is a 347-bed community hospital. The hospital is one of the eight Houston Methodist System facilities serving the Houston area. As the hospital has grown, so has the cath lab.  The cath lab started as two rooms that were far from the emergency department (ED) and operating rooms (OR). As the hospital expanded and grew, the cath lab was strategically moved adjacent to the ED and directly under the OR. The hospital now has four cath labs, as well as additional shelf space for two more rooms that can be built out as the hospital grows with the community.

How many patients are you treating in your four cath labs?

Anita: The cath lab had over 2800 cases in 2017. These cases range from percutaneous coronary interventions (PCIs) to diagnostic procedures, to pacemakers, to electrophysiology (EP) studies that include ablations for atrial fibrillation and supraventricular tachycardia (SVT), pulmonary vein isolation (PVI), and patent foramen ovale (PFO) closures. The EP program is also growing.

Daniel Castro, RT(R): The most frequent procedures are PCIs, acute situations such as ST-elevation myocardial infarctions (STEMIs), and diagnostic left heart caths.

Anita: The cath lab team also performs complex PCIs and chronic total occlusion (CTO) cases. Houston covers a large area, so community hospitals are more and more central to providing patient care in the suburban areas. HMSL provides for the community’s health care needs. We of course have the Texas Medical Center, which is absolutely fantastic, but a lot of our patients are very close to their families, physicians, and networks they have established in Sugar Land, so HMSL works very hard to provide the same level of care that patients need. Patients requiring transcatheter aortic valve replacement (TAVR) are still treated at Houston Methodist Hospital in the Medical Center. Patients experiencing a STEMI, a non-STEMI, or anything involving pacemakers, EP studies for ablations, etc., can receive care right here in their community. 

What sparked your interest in looking at contrast-induced acute kidney injury (AKI)?

Daniel: It started back when the cath lab team reviewed data from the American College of Cardiology (ACC) National Cardiovascular Data Registry (NCDR) CathPCI Registry. The NCDR CathPCI registry collects and formulates the data that we provide them, and benchmarks the HMSL cath lab against other hospitals within the region. In 2015, the AKI results, to say the least, were not up to our standards. After we implemented evidence-based changes, at best the results now place us in the top 75th percentile for AKI rates in our region. 

Anita: Houston has a large diabetic and end-stage renal disease patient population who have additional co-morbidities. These patients spurred our cath lab team to look at the data. A large number of people aren’t even aware yet that they are diabetic. Southern states include large diabetic patient populations and undiagnosed diabetic patients. When the cath lab team decided to reduce AKI, all patient populations were considered. The literature review and community factors were taken into account to design a protocol that includes all patient populations. Every patient that comes to the cath lab with or without end-stage renal disease is evaluated for their risk of AKI. 

Daniel: AKI is potentially confounded by pre-existing co-morbidities and can lead to further complications. The literature review yielded a great deal of information and studies aimed at improving patient AKI outcomes. Contrast is highlighted as a modifiable risk factor for reducing AKI in the lab. This fact motivated the cath lab team to modify behaviors to be conscious of the amount of contrast patients receive. A protocol was implemented to reduce AKI rates. First, we had to figure out what the problem was, and the NCDR was telling us we had a problem. Understanding that an AKI is an increase of serum creatinine of ≥.3 mg/dl or more within 48 hours¹ led us to identify evidence-based solutions.

Anita: I became the cath lab nursing director in November 2017, but the cath lab team started looking for solutions to AKI in early November 2016. HMSL is a Magnet^® facility, and encourages the interprofessional team to identify best-practices. Whenever an evidence-based practice or quality improvement project arises, Mary Harris, MSN, RN, CCRN-K, Magnet Program Director, and Maureen Lall, PhD, RN, AANPCP and COHN-S, Director of Neuroscience and Spine Center, are key resources for education, research, data analysis, and best practice. As the cath lab staff reviewed the various elements of a protocol and considered using the DyeVert Contrast Reduction System (Osprey Medical, Inc.), all of the pieces started coming together through interprofessional collaboration. By using Mary and Maureen for guidance, the team started having regular meetings to review literature and look at data.  

How did you move forward once you had found the information you needed?

Daniel: We did end up with a plethora of information and needed to organize. The first step was staff education about the definition of an AKI, the nephrotoxic effects of contrast, and causes of complications. Once the staff education had taken place, we also looked at modifying physician behavior. We provide contrast safe limits during our time-outs using the Gurm ratio.^2-4 The Gurm ratio resulted from a study completed by the Blue Cross Blue Shield of Michigan Cardiovascular Consortium Percutaneous Coronary Intervention Quality Improvement Initiative (BMC2 PCI), which states that contrast-induced nephropathy approaches significance at 2x the estimated glomerular filtration rate (eGFR) and is dramatically elevated at 3x the eGFR.^2-4 The eGFR of each patient is calculated and discussed during the time-out, so that everyone in the room is aware of the patient’s maximum contrast dose limits. We routinely call out contrast amounts throughout the case, especially when we are approaching the safe limit, to create awareness. While approaching the safe limit, the physician can either decide to abort the case or try a different technique, which further enhances patient safety and interprofessional collaboration. In addition, the DyeVert system provides a tracking system in the lab through a monitor that displays the real-time use of contrast delivered to the patient.

Anita: The DyeVert tracks contrast from a wireless (Bluetooth) connected syringe, so the exact amount used during the case is monitored and displayed on the monitor.

Does the DyeVert system also reduce contrast usage? 

Daniel: Yes, this is accomplished by diverting excess contrast away from the patient. Based on the company’s studies, about 40% of the contrast is diverted back into a reservoir, which then gets cycled back into the system. It essentially recycles the contrast in a closed loop. We use DyeVert for those at-risk patients, determined by their eGFR of ≤60, also known as chronic kidney disease. The DyeVert recently introduced their wireless device, which gives us real-time monitoring of contrast on the case. DyeVert tracks the contrast delivered to the patient and transmits it up on the monitor. We use the system for patients that have renal insufficiency or have chronic kidney disease as defined by an eGFR ≤60.⁵ 

Anita: Using DyeVert is now standard in the setup of our cases for patients with renal insufficiency. 

What benefits have you seen?

Daniel: We have seen a significant reduction in our AKI. Based on the executive summary published by the NCDR CathPCI Registry, our best month last year put us above the 75th percentile. In addition to the DyeVert system to reduce contrast to high-risk patients, Osprey Medical has provided us with a lot of support through education and awareness. They provided us with literature and educated staff on clinical guidelines. They also sponsor symposiums developed to train and educate staff on chronic kidney disease, the clinical society guidelines, and new technologies. This has helped our staff bring back this information to the cath lab to train other staff members.

How easy is the setup of the DyeVert system?

Daniel: The DyeVert is attached to the standard manifold and is part of the same loop. There is a slight learning curve initially, but the prep time adds maybe 30 seconds to a minute. 

What economic benefit has the hospital or cath lab realized?

Daniel: Cost savings are realized through the reduction of contrast use and the reduction of AKI occurrence to the patient, especially in regards to increased length of hospital stay. Also, fewer AKIs will minimize readmissions. If a patient comes back with an AKI or if they develop an AKI during the intervention, they can come back with a readmission due to a bleed or another myocardial infarct. We try to reduce contrast and AKIs because of their harm to the patient, especially if the patient has other co-morbidities. It is a very small percentage of AKI patients that end up having to go to dialysis. Mostly the risk is in how AKI interacts with patients’ other co-morbidities. 

What challenges did you experience along the way as you implemented methods aimed at reducing AKI?

Anita: The challenge that the team faced initially was getting the buy-in from the interprofessional team. All stakeholders needed to be included when they reviewed the data. A nurse can’t just mention it in a time-out. The cardiologist can’t just see it themselves prior to or after the procedure. Everything took the whole team to be on board. Not just recognizing it, but agreeing on the criteria we are going to be looking at, the limits we want to look at, and what we do with all this information. The team put a lot of effort into communication and interprofessional collaboration to really make that happen and get buy-in from everybody: the radiologic technologists, the nurses, the cardiovascular pre- and post-holding area, and the cardiologists. The other thing was collecting data and making sure that data was accurate. We wanted to make sure, when going back through charts and searching to find the information, that what we were getting was correct. We are fortunate to have our Magnet resources here at HMSL, Mary and Maureen, who evaluated the data produced by the team. Data were also shared with the cardiologists so they could give us feedback. Then, of course, when we transitioned to the Epic electronic medical records system, it made a huge difference in our ability to collate and extract data from a centralized location. We can see where we need to focus or where something might be starting to turn, rather than our data being months behind because of the time it takes for manual collection. 

Daniel: The NCDR is 6 months behind and so that is not acceptable if we are trying to monitor real-time progress. We were fortunate to be able to develop our own reports through the Epic software.

Do you have advice for others looking to follow you down this path?

Daniel: Our results are not difficult to reproduce. The advice I have starts with “know your score”. The NCDR CathPCI publishes an AKI score for every hospital. Partner with your quality person and see what your score is for the last quarter and the last year. Osprey Medical did a small survey of various labs and the results showed that 80% of nurses and technologists don’t know their lab’s AKI score. Once you know your score and want to implement protocols, first, create awareness. Next, gather support from your director, your chief cardiologist, and your staff. There are available tools, such as the Mehran score⁶, that provide risk factors and calculate risk based on co-morbidities. The Gurm ratio provides safe contrast limits tailored to the patient’s eGFR. Finally, consider the use of a contrast reduction system, especially for patients with compromised renal function and a GFR ≤60.

Are there other things you are incorporating into your AKI reduction protocols?

Daniel: We are currently working to develop a tool to measure the occurrence of AKI to pre-existing morbidities, as a method to isolate our demographic of at-risk patients. We also created predictor models to associate contrast amounts with creatinine clearance. Currently, there are only two ways to reduce the incidence of AKI. First is to reduce the amount of contrast that is given to the patient and the second is to hydrate the patient. There is no pharmaceutical prophylactic on the market that will help reduce AKI. 

Anita: Another big push for us, now that we have the contrast awareness, is being able to obtain our data. Epic provides reports so we can pull out the information we need. We have criteria allowing us to specifically identify any patients that were at risk, and then we can see the status and outcomes of our AKI prevention. One thing we noticed over the past couple months was that we need a focus on hydration, especially for outpatients. We are working on pre-procedure checklists to provide to the physicians’ offices as well as making calls to the patients to let them know about hydrating, and then, as part of the protocol and in collaborating with the cardiologists, IV fluids prior to the procedure, during the procedure, and after the procedure. That is part of our Phase II — the next steps of where we are heading.

Daniel: Our missing piece of the puzzle is implementing a standardized protocol for hydration on every patient, granted the patient does not have congestive heart failure (CHF). 

Anita: Because of all our patients’ co-morbidities, fluid and hydration can be very complex. The cardiologist may want to hydrate or give fluids, but the nephrologist may not want the patient to get all that fluid. In implementing hydration, we have to expand our interprofessional team so that we can obtain buy-in from all the stakeholders to understand what our AKI protocol is and what we hope to achieve. Inpatients may already have a nephrologist or other specialist as part of their team. We are evaluating how we can bring these disciplines together so we are not just treating each individual organ, but treating the whole patient. It doesn’t help if the cardiologist orders three liters of fluid, and three days later, the nephrologist is trying to remove three liters. By collaborating up front, they may order dialysis immediately after a case, or they may change how much is filtered off for the patient, based on the patient having the intervention. We would like to broaden the scope of what we do in the cath lab so it is not just the cardiac piece, but we also bring in collaboration with the nephrologist and/or other specialties.

Any final thoughts?

Daniel: It is important that as new staff is hired, this protocol is part of their orientation education. Current staff also need a refresher. Education and awareness is a huge component.

Anita: Update the orientation packet to make sure that any changes or tweaks that are made in the protocol also become a part of that orientation for new staff. Also, if a new cardiologist starts, we increase their awareness.

Daniel: The NCDR, your quality person, and everyone in the cath lab puts in a lot of time and effort to gather patient data. Becoming familiar with the NCDR and their published data is a key step in improving patient safety. We continue to learn and improve our AKI reduction. There are other matrices in the NCDR. We plan on taking a similar approach and applying it to other NCDR CathPCI matrices. It is an improvement tool.

Anita: Sharing data has become a regular part of our communication. We have a huddle board where data gets presented. We share the NCDR CathPCI data so it is transparent to the whole team. When the data is transparent, the team may have ideas that I might miss or quality might miss. But somebody else may realize, “Hey, you know what, we could be doing this in our case to prevent this complication or to improve our quality of care.” Sharing that data is vital.

References

1. Tsai TT, Patel UD, Chang TI, et al. Contemporary incidence, predictors, and outcomes of acute kidney injury in patients undergoing percutaneous coronary interventions: insights from the NCDR Cath-PCI Registry. JACC Cardiovasc Interv. 2014 Jan; 7(1): 1-9. doi: 10.1016/j.jcin.2013.06.016.
2. Gurm HS, Dixon SR, Smith DE, et al; BMC2 (Blue Cross Blue Shield of Michigan Cardiovascular Consortium) Registry. Renal function-based contrast dosing to define safe limits of radiographic contrast media in patients undergoing percutaneous coronary interventions. J Am Coll Cardiol. 2011 Aug 23; 58(9): 907-914. doi: 10.1016/j.jacc.2011.05.023.
3. Gurm HS. Setting contrast thresholds in high-risk patients. Cath Lab Digest. 2017 Nov; 25(11): 1, 32. Available online at https://www.cathlabdigest.com/article/Setting-Contrast-Thresholds-High-Risk-Patients. Accessed May 16, 2018.
4. Gurm HS, Seth M, Mehran R, et al. Impact of contrast dose reduction on incidence of acute kidney injury (AKI) among patients undergoing PCI: a modeling study. J Invasive Cardiol. 2016 Apr; 28(4): 142-146.
5. Naidu SS, Aronow HD, Box LC, et al. SCAI expert consensus statement: 2016 best practices in the cardiac catheterization lab. Catheter Cardiovasc Interv. 2016 Sep;88(3):407-23. doi: 10.1002/ccd.26551
6. Mehran R, Aymong ED, Nikolsky E, et al. A simple risk score for prediction of contrast-induced nephropathy after percutaneous coronary intervention: development and initial validation. J Am Coll Cardiol. 2004; 44: 1393-1399.

Disclosures: Daniel Castro, RT(R), and Anita Marban, Cath Lab Director, report no conflicts of interest regarding the content herein.

The authors can be contacted via email at:

Daniel Castro, RT(R), dcastro@houstonmethodist.org

Anita Marban, Cath Lab Director, almarban@houstonmethodist.org