Development of an educational simulator system, ECCSIM-Lite, for the acquisition of basic perfusion techniques and evaluation

Simulated cardiopulmonary bypass: a high fidelity model for developing and accessing clinical perfusion skills

BACKGROUND

Traditionally, novice perfusionists learn and practice clinical skills, during live surgical procedures. The profession's accrediting body is directing schools to implement simulated cardiopulmonary bypass (CPB) into the curriculum. Unfortunately, no CPB simulation models have been validated. Here we describe the design and application of a CPB simulation model.

METHODS

A CPB patient simulator was integrated into a representative operative theater and interfaced with a simple manikin, a heart-lung machine (HLM), clinical perfusion circuitry, and equipment. Participants completed a simulation scenario designed to represent a typical CPB procedure before completing an exit survey to assess the fidelity and validity of the experience. Questions were scored using a 5-point Likert scale.

RESULTS

Participants (n = 81) contributed 953 opinions on 40 questions. The participants reported that the model of simulated CPB (1) realistically presented both the physiologic and technical parameters seen during CPB (n = 347, mean 4.37, SD 0.86), (2) accurately represented the psychological constructs and cognitive mechanisms of the clinical CPB (n = 139, mean 4.24, SD 1.08), (3) requires real clinical skills and reproduces realistic surgical case progression (n = 167, mean 4.38, SD 0.86), and (4) would be effective for teaching, practicing, and assessing the fundamental skills of CPB (n = 300, mean 4.54, SD 0.9). Participants agreed that their performance in the simulation scenario accurately predicted their performance in a real clinical setting (n = 43, mean 4.07, SD 1.03) CONCLUSION: This novel simulation model of CPB reproduces the salient aspects of clinical CPB and may be useful for teaching, practicing, and assessing fundamental skills.

Simultaneous Control of Venous Reservoir Level and Arterial Flow Rate in Cardiopulmonary Bypass With a Centrifugal Pump

Cardiopulmonary bypass (CPB) is an indispensable technique in cardiac surgery, providing the ability to temporarily replace cardiopulmonary function and create a bloodless surgical field. Traditionally, the operation of CPB systems has depended on the expertise and experience of skilled perfusionists. In particular, simultaneously controlling the arterial and venous occluders is difficult because the blood flow rate and reservoir level both change, and failure may put the patient's life at risk. This study proposes an automatic control system with a two-degree-of-freedom model matching controller nested in an I-PD feedback controller to simultaneously regulate the blood flow rate and reservoir level. CPB operations were performed using glycerin and bovine blood as perfusate to simulate flow-up and flow-down phases. The results confirmed that the arterial blood flow rate followed the manually adjusted target venous blood flow rate, with an error of less than 5.32%, and the reservoir level was maintained, with an error of less than 3.44% from the target reservoir level. Then, we assessed the robustness of the control system against disturbances caused by venting/suction of blood. The resulting flow rate error was 5.95%, and the reservoir level error 2.02%. The accuracy of the proposed system is clinically satisfactory and within the allowable error range of 10% or less, meeting the standards set for perfusionists. Moreover, because of the system's simple configuration, consisting of a camera and notebook PC, the system can easily be integrated with general CPB equipment. This practical design enables seamless adoption in clinical settings. With these advancements, the proposed system represents a significant step towards the automation of CPB.

3D-Printed silicone anatomic patient simulator to enhance training on cardiopulmonary bypass

BACKGROUND

Simulator training is important for teaching perfusion students fundamental skills associated with CBP before they start working in the clinic. Currently available high-fidelity simulators lack anatomic features that would help students visually understand the connection between hemodynamic parameters and anatomic structure. Therefore, a 3D-printed silicone cardiovascular system was developed at our institution. This study aimed to determine whether using this anatomic perfusion simulator instead of a traditional "bucket" simulator would better improve perfusion students' understanding of cannulation sites, blood flow, and anatomy.

METHODS

Sixteen students were tested to establish their baseline knowledge. They were randomly divided into two groups to witness a simulated bypass pump run on one of two simulators - anatomic or bucket - then retested. To better analyze the data, we defined "true learning" as characterized by an incorrect answer on the pre-simulation assessment being corrected on the post-simulation assessment.

RESULTS

The group that witnessed the simulated pump run on the anatomic simulator showed a larger increase in mean test score, more instances of true learning, and a larger gain in the acuity confidence interval.

CONCLUSIONS

Despite the small sample size, the results suggest that the anatomic simulator is a valuable instrument for teaching new perfusion students.

Comparison of a perfusion simulator to a clinical operating room: evaluation of eye tracking data and subjective perception. A pilot study

Background:

With the aim of evaluating the perfusion simulator at the German Heart Center Berlin, similarity between simulation and clinical operation room (OR) was investigated regarding subjective perception and eye movement.

Methods:

Eight perfusionists performed an operation on the heart-lung machine (HLM) wearing eye tracking glasses, each in real OR and simulator. The three most important phases for perfusionists (going on bypass, cardioplegia administration and coming off bypass) were considered. Additional to eye tracking data as objective measure, questionnaires were completed, and interviews conducted afterwards.

Results:

The structure of simulator and real OR is perceived as basically the same. Yet there are differences in the HLM-models used and the temporal sequence. Different perception of both situations is reported in interviews and reflected in significant differences in the rating scales (NASA-TLX) on three of six subscales. In eye tracking data, certain AOIs could be identified for the individual phases, both in OR and simulator—an indication of fundamental similarity. However, differences regarding the proportions of the individual AOIs, especially in the first and third phase, are leading to the assumption that the simulator, and especially the simulation process, is only valid to a limited extent regarding subjective perception and eye tracking data.

Conclusion:

The use of the simulator for (advanced) training is accepted and explicitly requested by perfusionists. Yet further research is needed to identify the decisive factors (like simulation duration or additional tasks) for a valid execution in the simulator. Furthermore, a larger sample size should be regarded to allow statistical analysis.

Survey of the Routine Practice Limits for Physiologic and Technical Parameters Managed by Clinical Perfusionists during Adult Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) is a highly technical clinical discipline with a recognized variability in practice. Professional standards and guidelines documents help direct clinical practice and reduce variability, but these guidelines are necessarily vague and fall short of providing specific objective recommendations of clinical practice metrics. If clinical practice metrics were known, they would be informative when writing departmental policy manuals, structuring quality improvement initiatives, describing product R&D specifications, and designing educational assessment rubrics. Therefore, to address this gap, we conducted a national survey of clinical practice with the purpose of producing a benchmark of the typical variability of specific technical parameters that are commonly managed during adult CPB procedures. A pool of expert clinical perfusionists collaborated to compile a data set of normal ranges for 41 individual physiologic and technical parameters (pressures, flows, saturation, times, solutions, and temperatures) that are commonly managed during adult CPB procedures. Results were collected using an online survey application. Respondent demographics and measures of central tendency with descriptive quartile statistics and confidence intervals for each parameter are presented. Of the 335 people who participated in the survey, 315 met the inclusion criteria. The geographic demographics of the respondents were representative of the American Board of Cardiovascular Perfusion's distribution of certified clinical perfusionists. Of the 41 parameters investigated, there were 13 hemodynamic parameters, 13 normal flow rates and technical circuit parameters, 10 blood gasses and hematocrit parameters, and five parameters of patient temperatures. The data presented here are informative and provide a consensus-based objective assessment of the standard practice for adult CPB as reported by practicing clinical perfusionists. Based on these survey data, we have identified the typical clinical limits for the 41 parameters that are managed during adult CPB. This information may be incorporated into guiding documents to support the work of clinicians, researchers, and educators.

Simulation versus live tissue training randomised trial for ECMO proficiency: is one better than the other?

Introduction

Extracorporeal membrane oxygenation (ECMO) is a classic low-volume high-risk procedure that requires just in time and/or refresher training through animal or simulation modalities. This manuscript evaluated the performance of ECMO personnel trained with both modalities to determine which is better suited for ECMO skills training.

Methods

Participants (physicians, nurses and respiratory/medical technicians) completed a series of ECMO scenarios with synthetic tissue cannulation task trainer as well as a live tissue model. Objective performance quality was based on task completion using a validated ECMO skills assessment tool.

Results

Thirty-eight individuals completed this study. Participants completed individual scenario tasks 3 min faster using the simulator (26 min vs 29 min; p=0.03). No differences were seen in percentage of individual tasks completed. In the group scenarios, participants completed a higher percentage of critical tasks using the simulator (97%) versus the animal model (91%; p=0.05), but no differences were seen in task completion times. Additionally, no differences were seen in either lab-based or participants’ prelab cognitive scores.

Conclusions

Regardless of their self-assessment or experience, participants’ objective performances were similar among both animal and simulation labs. Task completion times were quicker with simulation model. The distinction between simulation versus animal model may be less important as both demonstrate benefit in development of and/or maintaining skill competency. In the era of questioning the need for and costs of live tissue training, expanding the role of simulation may achieve similar training goals.

Simulation in perfusion: evaluating the efficacy of a specific training with eye-tracking

BACKGROUND

With the aim of integrating simulation training into the training of perfusionists, we examined whether the participants were able to transfer a specific learning content to the same and different situations and assessed their feedback on the simulation training. Eye-tracking was tested as a measure and supplemented by additional measures.

METHODS

A 2 × 2 mixed design was used, with test time (pre- and post-test) and training group (same and different content training) as factors. In the pre- and post-test, the participant had to handle a critical situation on the cardiopulmonary bypass, namely, a drop in arterial partial oxygen pressure. Between the two test times, the participant practised under guidance the handling of either the same critical situation (Group 1) or a different one, that is, impaired venous return (Group 2). Dependent measures were fixations of the eyes on specific areas of interest on the heart-lung machine, measures of latency and subjective assessments. Moreover, participants gave feedback on the simulation training.

RESULTS

Fixation analyses showed that the training led to an increased gaze on areas of interest relevant to the drop in arterial partial oxygen pressure in both groups, with a significant increase only for Group 1. The surveys revealed a great interest in the integration of simulation training into education.

CONCLUSION

In combination with other measures, eye-tracking is suitable for the evaluation of simulation training. Due to the positive training effects and positive participant feedback, the integration of simulation into the training of perfusionists is advocated. Concerning transfer of learning content, more research is needed.

Fundamental clinical skills of adult cardiopulmonary bypass: results of the 2017 national survey

INTRODUCTION

Training students to become entry-level perfusionists requires evaluation and assessment of their clinical skills. While our professional organizations have compiled resources which identify the profession's knowledge base and categorical skills applied to clinical practice, these resources are lacking the necessary detail to develop validated clinical assessment rubrics. Therefore, the purpose of this project is to identify, through expert opinion, the detailed fundamental skills necessary to perform adult cardiopulmonary bypass (CPB).

METHODS

We define a fundamental skill based upon frequency of use and risk of harm. A skill that experts report is conducted in >50% of their CPB cases - and, if not properly conducted, can cause harm, is deemed a fundamental skill. To identify these skills, a 73-question survey was developed and posted on PerfList and PerfMail from May 2017 to July 2017.

RESULTS

The results from 261 respondents were analyzed. The demographics of the participants were representative of the workforce. Twenty skills were surveyed and all 20 met the criteria to be identified as a fundamental skill. Data regarding the actions, assessments and behaviors that may be associated with fundamental skills were also identified.

CONCLUSIONS

Based upon this survey data, we have identified that there is consensus within our profession regarding the fundamental skills of adult CPB and a core body of actions, assessments and behaviors that experts perform when conducting these skills. This information may be incorporated into the entry-level educational process to inform curricula and design valid assessment rubrics.

Simulation-Based Assessment of ECMO Clinical Specialists

OBJECTIVE

The aims of the study were (1) to create multiple scenarios that simulate a range of urgent and emergent extracorporeal membrane oxygenation (ECMO) events and (2) to determine whether these scenarios can provide reliable and valid measures of a specialist's advanced skill in managing ECMO emergencies.

DESIGN

Multiscenario simulation-based performance assessment was performed.

SETTING

The study was conducted in the Saigh Pediatric Simulation Center at St. Louis Children's Hospital.

SUBJECTS

ECMO clinical specialists participated in the study.

MEASUREMENTS AND MAIN RESULTS

Twenty-five ECMO specialists completed 8 scenarios presenting acute events in simulated ECMO patients. Participants were evaluated by 2 separate reviewers for completion of key actions and for global performance. The scores were highest for the hemodilution scenario, whereas the air entrainment scenario had the lowest scores. Psychometric analysis demonstrated that ECMO specialists with more than 1 year of experience outperformed the specialists with less than 1 year of experience. Participants endorsed these sessions as important and representative of events that might be encountered in practice.

CONCLUSIONS

The scenarios could serve as a component of an ECMO education curriculum and be used to assess clinical specialists' readiness to manage ECMO emergencies.

The need for hybrid modeling in analysis of cardiovascular and respiratory support

The analysis of the efficiency and optimum use of cardiovascular and respiratory support systems is of great importance in research and development as well as in clinical practice. To understand the complex interaction between human cardiovascular or respiratory systems and the mechanical assist devices, a number of physical, computational or hybrid (physical-electrical or physical-computational) models/simulators have been developed and used in recent years. The hybrid models combine the advantages of both the physical models (interaction with assist devices) and of the computational/electrical models (accuracy, flexibility). This paper reviews the existing solutions and briefly describes their characteristics, advantages and disadvantages, chiefly emphasizing the features of the hybrid models that are most promising for future development.

Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System

Background:

Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model.

Objectives:

The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity.

Materials and Methods:

In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan.

Results:

The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds.

Conclusions:

Thus, we can conclude that a simulator system using an extracorporeal circulation system can be set to different models of dialyzers, and that the reproduced treatment scenarios can be used for simulation training.

Use of an extracorporeal circulation perfusion simulator: evaluation of its accuracy and repeatability

Medical simulators have mainly been used as educational tools. They have been used to train technicians and to educate potential users about safety. We combined software for hybrid-type extracorporeal circulation simulation (ECCSIM) with a CPB-Workshop console. We evaluated the performance of ECCSIM, including its accuracy and repeatability, during simulated ECC. We performed a detailed evaluation of the synchronization of the software with the console and the function of the built-in valves. An S-III heart–lung machine was used for the open circuit. It included a venous reservoir, an oxygenator (RX-25), and an arterial filter. The tubes for venous drainage and the arterial line were connected directly to the ports of the console. The ECCSIM recorded the liquid level of the reservoir continuously. The valve in the console controlled the pressure load of the arterial line. The software made any adjustments necessary to both arterial pressure load and the venous drainage flow volume. No external flowmeters were necessary during simulation. We found the CPB-Workshop to be convenient, reliable, and sufficiently exact. It can be used to validate procedures by monitoring the controls and responses by using a combination of qualitative measures.

An educational training simulator for advanced perfusion techniques using a high-fidelity virtual patient model

The operation of cardiopulmonary bypass procedure requires an advanced skill in both physiological and mechanical knowledge. We developed a virtual patient simulator system using a numerical cardiovascular regulation model to manage perfusion crisis. This article evaluates the ability of the new simulator to prevent perfusion crisis. It combined short-term baroreflex regulation of venous capacity, vascular resistance, heart rate, time-varying elastance of the heart, and plasma-refilling with a simple lumped parameter model of the cardiovascular system. The combination of parameters related to baroreflex regulation was calculated using clinical hemodynamic data. We examined the effect of differences in autonomous-nerve control parameter settings on changes in blood volume and hemodynamic parameters and determined the influence of the model on operation of the control arterial line flow and blood volume during the initiation and weaning from cardiopulmonary bypass. Typical blood pressure (BP) changes (hypertension, stable, and hypotension) were reproducible using a combination of four control parameters that can be estimated from changes in patient physiology, BP, and blood volume. This simulation model is a useful educational tool to learn the recognition and management skills of extracorporeal circulation. Identification method for control parameter can be applied for diagnosis of heart failure.

Construction of the Real Patient Simulator System

Simulation for perfusion education has been used for at least the past 25 years. The earlier models were either electronic (computer games) or fluid dynamic models and provided invaluable adjuncts to perfusion training and education. In 2009, the * North Shore-LIJ Health System at Great Neck, New York, opened an innovative “Bioskill Center” dedicated to simulated virtual reality advanced hands-on surgical training as well as perfusion simulation. Professional cardiac surgical organizations now show great interest in using simulation for training and recertification. Simulation will continue to be the direction for future perfusion training and education. This manuscript introduces a cost-effective system developed from discarded perfusion products and it is not intended to detail the actual lengthy process of its construction.

Perfusion safety: new initiatives and enduring principles

Perfusion safety has been studied and discussed extensively for decades. Many initiatives occurred through efforts of professional organizations to achieve recognition, establish accreditation and certification, promote consensus practice guidelines, and develop peer-reviewed journals as sources for dissemination of clinical information. Newer initiatives have their basis in other disciplines and include systems approach, Quality Assurance/Quality Improvement processes, error recognition, evidence-based methodologies, registries, equipment automation, simulation, and the Internet. Use of previously established resources such as written protocols, checklists, safety devices, and enhanced communication skills has persisted to the present in promoting perfusion safety and has reduced current complication rates to negligible levels.

[Survey on the training and organisation of cardiopulmonary bypass for cardiac surgery in France]

INTRODUCTION

Cardiopulmonary bypass (CPB) is a medical act that can be performed by nurses as long as they are constantly supervised by a physician. No initial formalized training course is required. The personal responsibilities of nurses and physicians about CPB have not been defined.

OBJECTIVES

The purpose of this study was: to list perfusionists; to evaluate the training of perfusionists; to determine which physicians are considered as in charge during actions performed by paramedics, as well as their qualification; to point out the changes since 1997.

TYPE OF STUDY

Professional practice assessment.

METHODS

A questionnaire was sent to all perfusionists in activity in France.

RESULTS

There were 71% of replies. We found an aging of perfusionists (median 49 years vs. 40 years in 1997), a fall in the proportion of trained physicians (13% of perfusionists had a training course in adequacy with professional guidelines, 25% of perfusionists said they worked with a physician who could intervene at all time, and 61% declared only one physician was in charge). There is no CPB referent in 26% of perfusion units.

CONCLUSION

An urgent need appears to define the respective responsibilities of medical and paramedical perfusion staff, especially as this technique spreads out of the conventional cardiac surgery operating theatres.

Incident-simulating device with wireless control for extracorporeal circulation crisis management drills

Incidents during extracorporeal circulation (ECC) may lead to serious consequences, and troubleshooting exercises are becoming more important. We developed an incident-simulation device operated by remote control for ECC crisis management drills, and evaluated its efficacy at a seminar for perfusionists. This compact device consists of a transmitter and a receiving system and is run by dry batteries without a personal computer. A 4-channel radio-control system is used as the transmitter, and four servomotors placed in a box as the receiving system. To simulate occlusion of 3/8" arterial and venous lines, two servomotors with a rod rotate and the rod compresses the tube. The tilt angle of the stick and the servomotor rotation are in proportion, so that the degree of occlusion is controlled. As a result, the tube lumen becomes "stenotic" and then occluded, depending on the rotation. To cut off the power, the other two servomotors, with a relay system, work as a breaker. When the rod of the servomotor rotates, a micro-switch is turned off. The present device is able to increase perfusion pressure quickly and to simulate inadequate venous drainage quietly. At a seminar for perfusionists, an instructor manipulated the transmitter to create incidents and the participants handled the events effectively. In conclusion, incidents created by this device were perceived as similar to real ECC crises and this device may be useful and educationally effective when used in crisis management drills for perfusionists and trainees.

Quantitative evaluation of hand cranking a roller pump in a crisis management drill

The heart-lung machines for open-heart surgery have improved over the past 50 years; they rarely break down and are almost always equipped with backup batteries. The hand-cranking procedure only becomes necessary when a pump breaks down during perfusion or after the batteries have run out. In this study, the performance of hand cranking a roller pump was quantitatively assessed by an objective method using the ECCSIM-Lite educational simulator system. A roller pump connected to an extracorporeal circuit with an oxygenator and with gravity venous drainage was used. A flow sensor unit consisting of electromagnetic sensors was used to measure arterial and venous flow rates, and a built-in pressure sensor was used to measure the water level in the reservoir. A preliminary study of continuous cranking by a team of six people was conducted as a surprise drill. This system was then used at a perfusion seminar. At the seminar, 1-min hand-cranking drills were conducted by volunteers according to a prepared scenario. The data were calculated on site and trend graphs of individual performances were given to the participants as a handout. Preliminary studies showed that each person's performance was different. Results from 1-min drills showed that good performance was not related to the number of clinical cases experienced, years of practice, or experience in hand cranking. Hand cranking to maintain the target flow rate could be achieved without practice; however, manipulating the venous return clamp requires practice. While the necessity of performing hand cranking during perfusion due to pump failure is rare, we believe that it is beneficial for perfusionists and patients to include hand-cranking practice in periodic extracorporeal circulation crisis management drills because a drill allows perfusionists to mentally rehearse the procedures should such a crisis occur.