Objectives: Safety reports are core components of secure medical systems, but their significance have remained obscure, mostly owing to limited quantitative approaches other than the numbers of reports. In 2005, we developed “management levels” and their equally converted points (p) of scores, which indicated the grades of required correspondences of medical systems. Moreover, products of those scores multiplied by risk levels (equally converted scores), “total scores” were also proposed for weighting harmful events from biphasic aspects; severity of patient damage and the required levels of correspondence as medical systems. In this study, we assessed this scoring system using extensive longitudinal experience.Methods: Risk, management and total scores were retrospectively surveyed between 2012 and 2022 when a consistent reporting system had worked throughout the study period.Results: The aforementioned three scores inconsistently decreased along with a decrease in number of safety reports from 2,445 to 1,194 cases, or 2,069 to 1,052 cases/105 admitted patients (c/pap) in eleven years. Of the scores, the most prominent decrease was found in the management scores from 2,164 to 1,070 points/pap (p/pap). The risk and total scores had decreased even more modestly: from 1,879 to 1,484 p/pap, and 5,470 to 4,007 p/pap, respectively. When compared with the proportion (%) of risk and management levels in 2012, risk level 0 decreased, and risk level 1 and 3a increased in 2022. However, the proportion of management levels did not change during this period.Conclusion: The proposed scoring system showed that the cumulative severity of patient damage did not worsen, or decrease in some years accompanied by decreasing correspondence levels of the medical system, although the numbers of reports also decreased. These findings show the appropriateness of the on-going safety activities of this hospital even when restricted to reported events. However, their effectiveness including unreported events, requires further study.

Introduction: We conducted usability evaluation practice among clinical engineering students, and we verified the effectiveness of the practice.Method: After lecturing on the four evaluation perspectives of usability (perception, cognition, behavior, and feedback) , students evaluated the home appliances and recorded the results in free-text form. To verify the effectiveness of our practice, the records of 59 students were sorted according to four evaluation perspectives.Results: Students made a mean of 5.6 usability remarks and used a mean of 3.2 evaluation perspectives. Of the evaluation perspectives, cognition (e.g., ease of understanding information) was the most frequently pointed out, with a mean of 2.2.Discussion: Students were able to evaluate appliances from various perspectives. This practice was effective because students were able to identify a number of cognitive usability problems that are considered difficult to detect with familiar devices.

Introduction: The theory of Human Factors (HF), which designs work and environment according to human characteristics, contributes to patient safety. However, there are not enough reports of systematic educational practices on HF. Our training was designed and practiced using SHEL, an explanatory model of HF.　Methods: Ten training sessions were conducted on the components of SHEL, including Software: manual design, Hardware: user-friendly medical device design, Environment: work environment design, Liveware (self) : human characteristics, and Liveware (others) : teamwork.　Reflection: The HF training using SHEL may lead to acquiring procedural knowledge of patient safety management, and to better understanding of HF by students. In addition, focusing on daily errors is expected to increase students’ learning motivation.

Objective: Peritoneal function during peritoneal dialysis (PD) declines over time due to peritoneal inflammation; however, the immunological mechanism has not been fully clarified. Here, we examined changes in each cellular fraction in the peritoneal dialysis effluent by flow cytometry and their relationship to peritoneal damage.Patients and Methods: We enrolled 23 patients who began PD between 2006 and 2017 and had available datasets of the peritoneal equilibration test and flow cytometric analysis for at least three consecutive visits, with an interval of six months from six months after introducing PD. The levels and changes in each cellular fraction, dialysate/plasma (D/P) creatinine ratio, and the forward scatter (FSC) ratio of mesothelial cells to lymphocytes were compared using a simple linear regression analysis.Results: Among the examined variables, only the fraction of CD8+ TCM cells during the first observation was significantly correlated with the change rate in the D/P creatinine ratio (β=1.47, P=0.001, adjusted R2=0.379). The CD8+ naïve T and CD8+ TCM cell fractions were negatively correlated with the change rate of the D/P creatinine ratio (naïve T cells: β=−0.058, P=0.022, adjusted R2=0.188; TCM cells: β=−0.096, P=0.046, adjusted R2=0.137). In addition, the change rates of the D/P creatinine ratio tended to be higher, though not significantly (one way ANOVA; P=0.080), in accordance with the increase in the change rate of the CD8+ effector memory T cells (TEM).Conclusion: The CD8+ naïve T and TCM cells may transition into TEM cells by repeated exposure to the dialysate over time. The TEM cells residing in the peritoneum may play a significant role in the progression of peritoneal damage.

Introduction: It is important to educate undergraduates about communication errors in clinical sites, but it is difficult for clinically inexperienced students to imagine those errors. Therefore, in this study, a board game (BG) was developed and put into practice to encourage students' understanding.　Methods: The BG consists of a board on which the patient's name is written and cards on which drug names are written. Students place cards on the board according to the teacher's instructions. These instructions include multiple traps based on actual incident cases. Through the game, students experienced errors.　Reflection: This BG contains gamification elements that make learning contents simple and fun and simulation elements that reproduce errors with high fidelity. By combining these elements, it is possible for each aspect of the ARCS model to be provided in a well-balanced manner, even in patient safety education for clinically inexperienced students.

Introduction: Recently, Escape Rooms have been included in educational content.　Method: An Escape Room style class was conducted for first-year medical students to review previously learned content and to learn how to collaborate with others. The class was 70 minutes in total, 45 minutes of that was spent playing games. These included not only puzzles and riddles but also simulation-based tasks such as BLS. Multi-ending style was also used to motivate students.　Result: In addition to the difficulty of making stories and puzzles, the management of staff and organizing of the games were also challenging for the class.　Discussion: There are few comprehensive studies on educational practices using escape rooms. Research is necessary to consider effective and practical training methods.

Objective: Living wills, written types of advanced directives, are now widespread in western countries, but in Japan, their recognition still remains restricted to a small part of the population. As an initial step to introduction of such patient-oriented medicine, we surveyed present recognition and acceptance patterns concerning living wills in a main regional hospital located in a suburban area of Tokyo.
Methods: Without any preceding guidance on living wills, the questionnaire on living wills was distributed to all the staff working at JA Toride Medical Center in September 2013, and their responses were collected for analysis within one month.
Results: Questionnaires were distributed to all hospital staff, 843 in total, and 674 responses (80.0% of distributed) were obtained. The term of living will was known by 304 (45.1%) of the respondents, and introduction of living wills to patients was accepted in 373 (55.3%) of the respondents, meanwhile, 286 (42.4%) respondents did not indicate their attitude toward living wills. As to styles of document form, 332 respondents (49.3%) supported selection of wanted or unwanted medical treatments and care from a prepared list, and 102 respondents (15.1%) supported description of living wills in free form. As preferred treatment options that should be provided as a checklist, cardiac massage (chest compression) and a ventilator were selected by more than half of the respondents. Based on their responses, we developed an original type of living wills available to patients visiting the hospital.
Conclusions: Although not all the respondents were aware of living wills even in this main regional hospital, introduction of living wills to patients was accepted by many of the hospital staff. Awareness programs or information campaigns are needed to introduce living wills to support patient-centered medicine.

Objective: The usefulness of estimated glomerular filtration rate may not be restricted to pre-dialysis patients, since we reported that estimated glomerular filtration rate was well correlated with measured total creatinine clearance in peritoneal dialysis patients. To clarify the clinical usefulness of estimated glomerular filtration rate as a parameter for peritoneal dialysis adequacy, we retrospectively surveyed estimated glomerular filtration rate and total creatinine clearance in peritoneal dialysis patients treated at JA Toride Medical Center.
Patients and Methods: A total of 114 data sets of estimated glomerular filtration rate and total creatinine clearance from 21 PD patients treated at JA Toride Medical Center were collected from November 2010 to October 2011. The patients consisted of 15 men and six women with an average age of 66.6 ± 12.6 years (46-95 years old). The average number of samples was 5.4 ± 1.5 (2 to 7) per patient.
Results: The collected data showed less correlation of estimated glomerular filtration rate and total creatinine clearance (r. = 0.435) than that of a previous cross-sectional study (r. = 0.836). As reported in pre-dialysis patients, the differences between estimated glomerular filtration rate and total creatinine clearance were correlated with total creatinine excretion in urine and PD effluent (r. = 0.821). The differences were also correlated with normalized protein catabolic rate, which was one of the main determinant factors for total creatinine excretion (r. = 0.636). A similar tendency was apparently observed in one patient with poor compliance to diet therapy and fluctuating dietary intake. From the analysis of these data, serum creatinine seemed to fluctuate less possibly due to compensatory capacity of the residual renal function in small solute clearance.
Conclusions: Consequently, estimated glomerular filtration rate was turned out to be a more stable parameter than total creatinine clearance, which might be a desirable feature in long-term follow-up of peritoneal dialysis patients.

Objective: A direct renin-inhibitor (DRI), aliskiren, was administered to anuric patients to investigate whether it can be a new optional therapy against hypertension in hemodialysis (HD) patients. Patients: The patients that received aliskiren comprised 8 males and 2 females with a mean ± SD age of 63 ± 8 years (43-72 years). They were exposed to dialysis therapy for 118 ± 73 months (8-251 months), with diabetes mellitus in 4 cases, chronic glomerulonephritis in 4 cases, and other diagnoses in 2 cases. Methods: After the plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured before an HD session, aliskiren, 150 mg as an initial dose, was administered to the patients. PRA and PAC were also examined a week after initiating aliskiren. The blood pressure (BP) levels at the start of each HD session for a period of 2 weeks (6 HD sessions) were compared between before and after administration of aliskiren. The change of doses in other antihypertensive agents was also counted. Results: The averaged reduction of mean blood pressure was 4 ± 5 mmHg, and doses of antihypertensives other than aliskiren were reduced in 4 patients. Of the examined parameters, only the reduction rate of PRA x PAC seemed correlated with the BP lowering effect of aliskiren, which was calculated as the sum of the mean BP reduction in mmHg and drug reduction with 1 tablet (capsule)/day considered to be 10 mmHg. Conclusion: A DRI, aliskiren, was effective even in anuric dialysis patients, and monitoring of PRA and PAC was valuable for selecting cases responsive to aliskiren.

Objective: Since the conventional drip-infusion method for measuring inulin clearance (Cin) has problems related to its accuracy and performance, we explored a more accurate and concise method by rapid intravenous injection of a newly developed inulin fraction (Inulead^®), in which spot urine sampling was omitted and the administration period of inulin was shortened from 120 to 5 minutes. Patients and Methods: Twenty seven patients (M/F: 15/12, 67.8 ± 12.9 years old) admitted to the Nephrology ward were enrolled in this study. Inulead^®, 1500 mg dissolved in 150 mL of saline, was intravenously administered in 5 minutes. Then, sequential blood samplings and urine collection were performed for 24 hours. Cins were calculated by the following three formulae: (1) a pharmacokinetic analysis using a two compartments model based on the plasma inulin concentration to determine Cin, which was the administered dose divided by the area under the curve (AUC) from 0 to ∞, (2) urinary inulin excretion divided by the AUC for 24 hours and (3) the Bayesian method using a three-point set of plasma inulin concentrations to predict the change of inulin concentration to determine Cin as in 1. These Cins were compared with levels of estimated GFR (eGFR), creatinine clearance (Ccr), serum β2 microglobulin (β2MG) and serum cystatin C (Cys C). Results: Cins obtained by the above three methods were well correlated with each other (r. = 0.9088 – 0.9998) and with eGFR (r. = 0.8286 – 0.8650), Ccr (r. = 0.821 – 0.864), 1/β2MG (r. = 0.631 –0.752) and 1/CysC (r. = 0.830 – 0.857). The averaged differences of each Cin from eGFR were distributed between –4.4 and –4.5 mL/min. Conclusion: Since the Cins by rapid inulin injection showed satisfactory correlation and differences with other GFR parameters, this method will be a good alternative to the drip infusion method, and may reduce the burden of patients and medical staff.