*Saving Time, Saving Money: A Time and Motion Study with Contrast Management Systems

In 1929, in an attempt to find a safe way to inject drugs for cardiac resuscitation, a young surgical resident named Werner Forssmann inserted a catheter in his antecubital vein, positioning the catheter into the right atrium of the heart. He documented the event with a chest X-ray. Although he was dismissed from the hospital, he continued for years with self-experimentation. In 1956, he was awarded the Nobel Prize for his cardiology research efforts. Forssmann’s efforts were followed by the work of Melvin Judkins, as he perfected and introduced the transfemoral approach in 1967. In 1975, Andreas Gruentzig created a double-lumen catheter with an attached polyvinylchloride balloon. This catheter was the tool for the first human coronary angioplasty intraoperatively during bypass surgery. Andreas Gruentzig went on to perform the first catheterization laboratory percutaneous transluminal coronary angioplasty (PTCA) on an awake patient in Zurich.¹ Twenty-seven years later, diagnostic cardiac catheterization is currently recognized as the gold-standard method for evaluating coronary artery disease (CAD) and coronary anatomy.² Diagnostic catheterization procedures are performed 2.58 million times annually in the United States,³ and are routinely offered as an outpatient procedure for clinically stable patients. As more patients utilize this outpatient service, operational efficiency becomes a significant issue faced by busy catheterization laboratories. Opportunities exist for improved utilization of the procedure room through safer and faster diagnostic catheterization procedures using a power contrast injector system. Power contrast injection facilitates the use of smaller diameter catheters.⁴ Smaller diameter catheter use has been shown to improve patient safety through reduced morbidity and contrast dye administration, without sacrificing angiographic diagnostic quality.^5–7 Smaller diameter catheters permit rapid hemostasis and thus provide a means for early patient ambulation in the post-procedure room, making possible rapid discharge from the facility.^8,9 Most recently, early patient ambulation and discharge has also been credited with improved patient satisfaction and better post-procedure quality of life.^10,11 Despite this supportive clinical data, it appears that many physicians have been extremely reluctant to change from the manual procedure to power injectors. The purpose of this multi-center study was to evaluate diagnostic catheterization workflow and established protocols to determine the manner and extent to which utilization of the traditional manual contrast injection method for coronary and left ventricular imaging fared against the power contrast injection method. Data collected were analyzed in terms of operational efficiency and safety through the pre-procedure, intraprocedure and post-procedure phases. In addition, the data were analyzed to assess the economic impact on catheterization laboratories performing diagnostic procedures. Materials and Methods Data collection. To track workflow and identify opportunities for efficiency and cost effectiveness in the catheterization laboratory, pre-procedure, intraprocedure and post-procedure times and protocols for routine diagnostic catheterization were collected over a two-day time period at five participating catheterization laboratories. This study group included two teaching hospitals, two community hospital facilities, and one center with emphasis on cardiac care, where cardiac disease diagnosis and treatment are the primary missions of the institute. The nonrandomized sites were selected based on methodology (e.g. manual or injector), facility type, patient volume ,and willingness to participate in the study. Data on manual or power contrast injection method, as well as equipment set-up time, as well as contrast waste clean-up and disposal were collected through observation of the practices at each site. The two options available to perform the procedure are manual coronary angiogram, along with the Medrad power injector for left ventriculogram (n = 53), or the Medrad (n = 35) or Acist (n = 90) power injector systems, which the facilities had selected prior to data collection. Each of the five catheterization laboratories in the study is considered an “open” lab, meaning that they are available to various attending physicians with privileges. At four of the five sites, diagnostic catheterization procedural methods, including decisions regarding the use of manual or power contrast injection methods, as well as catheter size, varied according to the operator’s discretion. Intraprocedural diagnostic catheterization time data focused on arterial time, beginning at the time of arterial access and ending at the time of catheter removal. Arterial times were collected for routine diagnostic catheterization procedures, including angiography of both the right and left coronary arteries and left ventriculogram. Since the focus of the study was routine diagnostic catheterization procedures, interventional cases and complex patient cases with pre-existing venous and/or arterial grafts and stents were excluded to keep arterial times very comparable. Arterial time data from one academic institution was extremely lengthy due to the involvement of teaching Fellows in the learning environment, and was thus excluded from the final data analysis of arterial times. In addition to the observed cases, 40–50 retrospective arterial times were collected in descending date order from four of the five participating sites. Arterial time was defined, collected, and excluded using the same parameters as those from the observed cases already mentioned. Post-procedural patient management data were provided by each participating site and included typical length-of-stay (LOS) protocols. Each facility set the discharge protocols according to catheter size and hemostasis technique, e.g., manual compression or closure device usage. Results Procedural variables. Arterial time averaged 14 ± 6.2 minutes (min) for the manual contrast injection group and 10 ± 4.0 min for the power contrast injection group (significant p Typical post-procedure discharge protocols. The five catheterization laboratories examined utilized similar discharge time protocols for routine, normal diagnostic catheterization procedures based on catheter size and hemostasis method. In summary, the discharge protocol following sheath removal of 2–3 hours (hrs) was established for 4 Fr catheters using manual compression (5–15 min) to obtain hemostasis. Likewise, the discharge protocol following sheath removal of 2–3 hrs was established for 5–6 Fr catheters using either an AngioSeal or Perclose arterial closure device. One site practiced a 6-hour discharge time with arterial closure devices. One site did not utilize 4 Fr catheters. This LOS comparison was based on the catheterization laboratory’s post-procedure protocol, as these varied between sites, as well as the size of the catheter used for the procedure. Economic analysis. Revenue for a diagnostic cardiac catheterization procedure is currently $1,338, based on the 2004 CMS reimbursement rate adjusted for wages.¹² In the United States, the average catheterization laboratory has two procedure rooms. Overall, the average number of procedure rooms ranged from 1.2 for non-hospital facilities and hospital facilities with fewer than 200 beds, to three or more rooms for hospital facilities with 400 or more beds.¹³Discussion. In this multi-center study, we observed the workflow and practices of five catheterization laboratories in a variety of settings including: two universities, two community hospitals, and one center of cardiac excellence. The focus was to evaluate how the traditional manual contrast injection method for coronary and left ventriculogram imaging faired against the power contrast injection method in terms of operational efficiency, cost-effectiveness, and patient safety through the pre-procedure, intraprocedure and post-procedure phases. The results of our non-randomized study suggest that there are operational and economic incentives associated with using the power contrast injection method over the manual contrast injection method. Our study data indicate that when both coronary artery and ventriculogram imaging are performed, power contrast injection methods required 5 min (31%) less hands-on time, on average, in the procedure room than the traditional manual method. These results extend the findings of previous studies indicating that operationally faster diagnostic cath procedures can be performed using a power contrast injection method, as compared to the manual contrast injection method.6 Our findings also shed light on the economic opportunities of operational efficiency. This study did not evaluate operational differences between manual and power contrast injector methods when only the coronary arteries were catheterized. Economic Significance The operational efficiency gained by utilizing the power injection method could provide the time to perform one additional case during an 8-hour shift in one procedure room each day. The additional revenue generated per room each day would be $1,338. As demonstrated in Figure 1, many facilities in the United States have two catheterization laboratories, opening the opportunity for two additional cases each day. When annualized (2 patients a day x 300 days x* 0.66% x $1,338) the additional revenue potential is $529,848. If the facility has three rooms, the annualized additional revenue rises to $794,772. *(the national mix of diagnostic-to-diagnostic plus therapeutic is 0.66–0.34%) Intraprocedure arterial time significance. It was observed that the manual injection method utilized an additional 5 min because essentially, two contrast delivery systems are set up, monitored, and utilized. Specifically, the 5-minute time difference, on average, was accounted for by 4-minute shorter arterial times and 1-minute shorter contrast media set-up time for the power injector method. This 4-minute difference, in average arterial time between manual injection and power injection methods, is in concert with previous studies and should not be underestimated. Khoukaz et al. data also demonstrated a 4-minute shorter arterial time for manual versus power injection methods (46 ± 19 versus 42 ± 15) in a more complex patient case mix that included both normal diagnostic and one-, two- and three-vessel disease patients.6 This 4-minute difference was considered statistically significant by the corresponding author, but not clinically significant. The operational impact of a 4-minute (29%) reduction in arterial time for the power contrast injection method is significant, given that the arterial time for an uncomplicated diagnostic catheterization procedure, by power contrast injection, averaged only 10 min ± 4 min (range 6–14 min) in this study. The manual contrast injection method averaged 14 ± 6.2 min. Expanding this time data over an 8-hour shift in a catheterization laboratory currently performing 10 diagnostic cases, results in nearly one additional hour of operator and staff time. This time, paid as regular or overtime, can be saved or utilized to perform an additional case that can be reimbursed. The additional intra-operative 4 min are accounted for by steps taken to safely change over the manual injection contrast system after completion of the manual coronary angiogram to the power injection method or vice-versa. These steps include staff moving the power injector into the sterile field and connecting the power contrast injector lines to the manifold. After connecting to the manifold, the manual contrast system must be primed and set to inject by the requisite filling, flushing, and tapping of contrast lines and careful visual scanning for air bubbles necessary during a safe changeover between contrast injection systems. Rarely, manual contrast injection is associated with iatrogenic air embolism, with a reported incidence of 0.1–0.3%.¹⁴ At the current catheterization procedure volume of 2.58 million, iatrogenic air embolism occurs in up to 2,580–7,740 cases annually. Also contributing to the additional time is that manual contrast injection operators have relied on staff to adjust the power injector volume and flow rate for the left ventriculogram. Contrast set-up, savings and disposal.The remaining 1 min of the 5-min hands-on time difference in the procedure room in favor of power contrast injection was accounted for by a 1-min shorter contrast media set-up time for the power injector method. Contrast set-up time was longer for the manual injection method by 1 min (1 min for the power injector method versus 2 min for the manual injection method). This is due to the redundant contrast set-up procedure required for the manual injection method which requires contrast set-up for the power injector for left ventriculography and another manual injector system for coronary angiography. It was observed that it took a staff member about 1 min to set up the manual contrast manifold, and then about another minute to also set up the contrast on the power injector. Contrast set-up includes hanging the contrast media and priming the contrast lines through each apparatus to remove air bubbles. This is simply double set-up time for the manual system compared to the power injector that needs only a single set-up. Furthermore, since there are two different contrast injection set-ups, there must be a careful intra-procedure switchover between the manual contrast injection manifold to the power injector manifold to prevent the introduction of air bubbles into the contrast delivery system. As mentioned earlier, this intra-procedure switching between contrast systems adds 4 min of arterial time, on average, for a diagnostic catheterization case. Having contrast set-up in two places also produces more contrast waste to dispose of after case completion. The participating sites that employed the manual injection method used two 100 mL contrast containers, one each for the power injector, and one for the manual injector. The normal diagnostic cases observed used about 70 mL total contrast volume, leaving about 130 mL for disposal, nearly enough for two additional diagnostic cases. The manual injection study group simply disposed of the full amount of remaining contrast in the manual manifold container and the power injector syringe system and/or container. The financial impact of this decision to dispose of all remaining contrast media is given in Table 1. Considering that contrast media presently costs an average of $0.35/mL, opting to dispose of all remaining contrast clearly comes with a price. The financial impact of this “dump it all” protocol costs about $45.50 for each normal diagnostic case, and when annualized for the average catheterization laboratory in the United States, it can range from $72,072 to $137,280 each year, depending on the institution’s case mix. In contrast, both sites in the study using the ACIST™ injector (ACIST Medical Systems, Eden Prairie, Minn.) for the power contrast injection method used a multiple-case barrel syringe with a unidirectional flow check valve that permits contrast to only flow to the patient, so that any remaining contrast in the container was carried over from case to case throughout the day. Contrast containers were also carried from procedure room to procedure room, as necessary. This functionality was not observed in those labs using Medrad power injectors. Staff at the Medrad injector facilities explained that using the contrast-saving tubing was cost-prohibitive for their respective operations. Post-procedure operational and cost-effectiveness significance. Efficient management of the post-procedure room supports efficiency gains in the procedure room. The account that power injectors facilitate the use of small diameter (6 On observation, it was noted that several operators used a two-handed technique to achieve adequate pressure for contrast delivery when using 5 Fr catheters. It has also been speculated that hand fatigue may develop, especially after performing a number of complex cases during the workday. The use of small catheters (8,9,10 It was interesting to observe that the discharge protocol for each of the sites studied applied these data to their practice of discharging normal diagnostic patients who were catheterized with 4 Fr diameter catheters, using only manual pressure to obtain hemostasis within 2–3 hours after sheath removal. These factors thereby determine length of stay in the facility, and the associated costs of the post-procedure room, such as patient care staffing. Likewise, those patients in the 6 Fr group who received an arterial closure device also had a discharge protocol of 2–3 hours. The main difference between these groups was not workflow, but purely the cost of the closure device. In isolation, a single arterial closure device costs about $200 per unit. If used systematically in the attempt to discharge patients rapidly, extended out to the current U.S. diagnostic cardiac catheterization procedures of 2.58 million, this becomes an annual figure of $516,000,000 — which is clearly no longer a small cost. Although the frequency is quite low, other studies have associated both larger catheter size (> = 6 Fr diameter) and arterial closure device use with access site complications, both minor and major.^15,16,17 Discharge times for normal diagnostic cardiac catheterization patients were longest (up to 6 hrs) when a larger catheter (> 5 Fr) was used and manual compression was applied to achieve hemostasis. This is a significant time difference of up to 4 hours in the post-procedure room when comparing the 4 Fr and 6 Fr groups, using manual compression. Workflow in the procedure room also has the potential to be negatively impacted if post-procedure room bed numbers and/or staffing are a limiting factor. If the goal is operational efficiency, not only must the procedure rooms operate efficiently, the post-procedure rooms must be managed effectively as well. Lastly, it has been shown in previous studies that patient satisfaction, morbidity, and quality of life are negatively affected when an extended amount of bedrest is required. Conclusions. In the catheterization laboratory, it appears that power contrast injection is about 31% (5 min) more efficient than the traditional manual method in terms of procedure room workflow. When both coronary angiography and ventriculography are performed, the 5-min time saving is realized in procedure room activities, including (4 min) shorter arterial times, a more streamlined contrast injection set-up (1 min), and reduced contrast waste. The power contrast injection method avoids the redundant contrast injection set-up with the traditional manual injection method that requires independent contrast systems for the manual injection syringe for the coronary arteries, and the power injector system used for the left ventriculogram. The 31% time saving can be used to perform an additional diagnostic catheterization procedure per procedure room per day/shift, without the cost of additional staff or procedure rooms. Not only does the power contrast injection method provide opportunities for efficiency in the procedure room, its use can help support effective patient management in the post-procedure room as well. Power contrast injection facilitates smaller catheter use and, as a result, provides a cost-effective approach to rapidly and safely discharge patients up to 4 hrs faster from the facility without the use of expensive arterial closure devices. In addition to procedural and post-procedural efficiencies, the power contrast injection method provides the opportunity to reduce the volume of contrast disposed of after a normal diagnostic case. A power injection system set-up with the multi-case contrast syringe can potentially save about 130 mL of contrast ($45.50) for each normal diagnostic case. The annualized contrast cost savings is about $104,676 for the average U.S. catheterization laboratory operating one procedure room. It appears that catheterization laboratory directors and managers could improve patient safety and efficiency by encouraging physicians to utilize the power contrast injector method over the present manual method. This change would not only improve laboratory efficiency, reduce contrast dye waste, and enhance patient safety and satisfaction due to improved ambulatory time, but it could also increase facility revenue (about $529,848 annually for a two-laboratory facility, depending on case mix).

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