Perspectives on the optimal timing of advance care planning among Japanese patients undergoing dialysis and clinicians: a cross-sectional study

KEY MESSAGES

The majority of dialysis patients and clinicians favor early advance care planning in our sample. Yet, there is a disconnect: only 11% of patients discussed future care with their clinicians. Our findings indicate Japanese dialysis patients and clinicians support proactive advance care planning at or before dialysis initiation.

BACKGROUND

Little is known about the optimal timing of discussions about advance care planning among dialysis patients and clinicians engaged in dialysis care. We aimed to explore the preferred timing for advance care planning and assess actual participation in advance care planning among dialysis patients and their clinicians.

METHODS

A scenario-based survey on Japanese patients aged ≥65 years on dialysis and clinicians involved in their dialysis care was performed. Participants were asked if they would feel prepared to engage in advance care planning with their clinicians, offering a choice among four hypothetical stages within the illness trajectory, extending from the initiation of dialysis to a later phase characterized by the patient's extreme frailty.

RESULTS

Overall, 181 patients and 128 clinicians participated in the study. Among these, 131 (72%) patients, and 84 (66%) clinicians indicated that they would prefer to initiate advance care planning around the time of dialysis initiation. Only 20 patients (11%) indicated that they had participated in advance care planning with at least one clinician, including 11 (6%) who indicated that they had discussed their preferences around life-sustaining treatments and 8 (4%) who had discussed their preferences around dialysis continuation.

CONCLUSIONS

While fewer than 11% of patients undergoing dialysis and their clinicians enrolled in our study had participated in advance care planning, most indicated that they would be comfortable initiating the discussion around the time of dialysis initiation. These findings suggest untapped opportunities to engage patients in advance care planning early in the course of their dialysis.

The association between high-dose allopurinol and erythropoietin hyporesponsiveness in advanced chronic kidney disease. JOINT-KD study

INTRODUCTION

To explore the association between urate-lowering agents and reduced response to erythropoietin-stimulating agents in patients suffering from chronic kidney disease G5.

METHODS

We conducted a cross-sectional, multicenter study in Japan between April and June 2013, enrolling patients aged 20 years or older with an estimated glomerular filtration rate of ≤15 mL/min/1.73 m2. Exclusion criteria encompassed patients with a history of hemodialysis, peritoneal dialysis, or organ transplantation. The patients were categorized into four groups based on the use of urate-lowering drugs: high-dose allopurinol (>50 mg/day), low-dose allopurinol (≤50 mg/day), febuxostat, and no-treatment groups. We used a multivariable logistic regression model, adjusted for covariates, to determine the odds ratio (OR) for erythropoietin hyporesponsiveness, defined by an erythropoietin resistance index (ERI) of ≥10, associated with urate-lowering drugs.

RESULTS

A total of 542 patients were included in the analysis, with 105, 36, 165, and 236 patients in the high-dose allopurinol, low-dose allopurinol, febuxostat, and no-treatment groups, respectively. The median and quartiles of ERIs were 6.3 (0, 12.2), 3.8 (0, 11.2), 3.4 (0, 9.8), and 4.8 (0, 11.2) in the high-dose allopurinol, low-dose allopurinol, febuxostat, and no-treatment groups, respectively. The multivariate regression model showed a statistically significant association between the high-dose allopurinol group and erythropoietin hyporesponsiveness, compared to the no-treatment group (OR=1.98, 95% confidence interval: 1.10-3.57).

CONCLUSIONS

Our study suggests that the use of high-dose allopurinol exceeding the optimal dose may lead to hyporesponsiveness to erythropoiesis-stimulating agents.

A multi-institutional, observational study of outcomes after catheter placement for peritoneal dialysis in Japan

BACKGROUND

This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications.

METHODS

Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest.

RESULTS

Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27-0.70) and straight type catheter (HR 2.14; 95% CI 1.24-3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30-5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines.

CONCLUSION

PD catheter placement in Japan was proven to be safe and appropriate.

Hopelessness and Depression Predict Sarcopenia in Advanced CKD and Dialysis: A Multicenter Cohort Study

BACKGROUND/OBJECTIVES

Depression and hopelessness are frequently experienced in chronic kidney disease (CKD) and are generally associated with lessened physical activity. The aim of this study was to quantify the associations between sarcopenia as determined by SARC-F with both depression and hopelessness.

DESIGN AND SETTING

This multicenter cohort study involving cross-sectional and longitudinal analyses was conducted in a university hospital and four general hospitals, each with a nephrology center, in Japan.

PARTICIPANTS

Participants consisted of 314 CKD patients (mean age 67.6), some of whom were receiving dialysis (228, 73%).

MEASUREMENTS

The main exposures were depression, measured using the Center for Epidemiologic Studies Depression (CES-D) questionnaire, and hopelessness, measured using a recently developed 18-item health-related hope scale (HR-Hope). The outcomes were sarcopenia at baseline and one year after, measured using the SARC-F questionnaire. Logistic regression models were applied.

RESULTS

The cross-sectional and longitudinal analyses included 314 and 180 patients, respectively. Eighty-nine (28.3%) patients experienced sarcopenia at baseline, and 44 (24.4%) had sarcopenia at the one-year follow-up. More hopelessness (per 10-point lower, adjusted odds ratio [AOR]: 1.33, 95% confidence interval [95% CI] 1.12-1.58), depression (AOR: 1.87, 95% CI 1.003-3.49), age (per 10-year higher, AOR: 1.70, 95% CI 1.29-2.25), being female (AOR: 2.67, 95% CI 1.43-4.98), and undergoing hemodialysis (AOR, 2.92; 95% CI, 1.41-6.05) were associated with a higher likelihood of having baseline sarcopenia. More hopelessness (per 10-point lower, AOR: 1.69, 95% CI 1.14-2.51) and depression (AOR: 4.64, 95% CI: 1.33-16.2) were associated with a higher likelihood of having sarcopenia after one year.

CONCLUSIONS

Among patients with different stages of CKD, both hopelessness and depression predicted sarcopenia. Provision of antidepressant therapies or goal-oriented educational programs to alleviate depression or hopelessness can be useful options to prevent sarcopenia.

Psychological Flexibility and Depression in Advanced CKD and Dialysis

Rationale & Objective

Depression is prevalent and highly associated with mortality among patients with chronic kidney disease (CKD). Psychological flexibility can be captured as acceptance in psychology, and its improvement by behavioral therapy is associated with reduced depression in some clinical settings. However, no study has been reported on patients with CKD. This study aimed to examine the association between psychological flexibility and depression in patients with CKD.

Study Design

Cohort study.

Setting & Participants

This multicenter study of 5 hospitals in Japan included patients with nondialysis stage 3-5 CKD or stage 5D CKD receiving hemodialysis or peritoneal dialysis.

Predictor

Psychological flexibility measured using the 7-item Acceptance and Action Questionnaire (AAQ-II).

Outcomes

The prevalence and incidence of depression after 1 year, which was defined by a score ≥ 16 points on the Center for Epidemiologic Studies Depression (CES-D) questionnaire.

Analytical Approach

Gamma regression was used in the examination of correlates of the psychological flexibility value. Modified Poisson regression models were fit for the prevalence and incidence of depression.

Results

The cross-sectional and longitudinal analyses included 433 and 191 patients, respectively. Lower (ie, worse) psychological flexibility levels were associated with hemodialysis and peritoneal dialysis. Higher (ie, better) psychological flexibility levels were associated with lower prevalence of depression (per 5-point increase; adjusted prevalence ratio, 0.75; 95% CI, 0.70-0.80) and lower incidence of depression (per 5-point increase; adjusted risk ratio, 0.72; 95% CI, 0.61-0.85).

Limitations

Depression was assessed using the CES-D questionnaire. Cultural differences may exist in the interpretation of AAQ-II scores.

Conclusions

Better psychological flexibility was associated with lower prevalence and incidence of depression in patients with CKD. Further studies are warranted to determine the possible prevention and treatment of depression by the development of behavioral interventions to improve psychological flexibility.

Association between health-related hope and adherence to prescribed treatment in CKD patients: multicenter cross-sectional study

Background

In chronic kidney disease (CKD), patients’ adherence to prescriptions for diet and for medications might depend on the degree to which they have hope that they will enjoy life, and that hope could vary with the stage of CKD. The aims of this study were to quantify both the association of CKD stage with health-related hope (HR-Hope), and the association of that hope with psychological and physiological manifestations of adherence.

Methods

This was a cross-sectional study involving 461 adult CKD patients, some of whom were receiving dialysis. The main exposure was HR-Hope, measured using a recently-developed 18-item scale. The outcomes were perceived burden of fluid restriction and of diet restriction, measured using the KDQOL, and physiological manifestations of adherence (systolic and diastolic blood pressure [BP], and serum phosphorus and potassium levels).

General linear models and generalized ordered logit models were fit.

Results

Participants at non-dialysis stage 4 and those at stage 5 had lower HR-Hope scores than did those at stage 2 or 3 (combined). Those at non-dialysis stage 5 had the lowest scores. HR-Hope scores of participants at stage 5D were similar to those of participants at stage 4, but they were lower than the scores of participants at stage 2 or 3 (combined). Higher HR-Hope scores were associated with lower perceived burdens of fluid restriction and of diet restriction (adjusted ORs per ten-point difference were 0.82 and 0.84, respectively). Higher HR-Hope scores were associated with lower systolic BP (adjusted mean difference in systolic BP per ten-point difference in HR-Hope scores was − 1.87 mmHg). In contrast, HR-Hope scores were not associated with diastolic BP, serum phosphorus levels, or serum potassium levels.

Conclusions

Among CKD patients, HR-Hope is associated with disease stage, with psychological burden, and with some physiological manifestations of adherence.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12882-020-02120-0.

Association between pill burden and interdialytic weight gain in patients with hemodialysis: A multi-center cross-sectional study

High daily pill burden affects quality of life and mortality. High interdialytic weight gain (IDWG) is associated with increased mortality. We examined the association between pill burden and IDWG in hemodialysis patients. This cross-sectional study was conducted in six dialysis centers in Japan in June 2017. The exposure was the number of daily tablets, and outcome was defined as 1 day of relative IDWG divided by post-dialysis weight from the previous session. Among 188 outpatients (mean age, 68.7 [SD, 10.3] years; men, 67.0%; median dialysis vintage, 76.0 [interquartile range, 36.5, 131.5] months), the mean number of daily tablets was 19.7 ± 9.9, and mean relative weight gain was 3.5 ± 1.2%. Multiple linear regression analysis showed a regression coefficient of 0.021 (95% confidence interval: 0.004-0.039), indicating that one additional tablet prescription increased the IDWG by 0.021%. In hemodialysis patients, the daily pill burden was a significant, independent risk for increased relative IDWG.

P1163IMPACTS OF IRON-BASED PHOSPHATE BINDER ON ANEMIA AND IRON METABOLISM IN PERITONEAL DIALYSIS PATIENTS: A CROSS-SECTIONAL, LONGITUDINAL MULTICENTER STUDY IN KANAGAWA, JAPAN

Background and Aims

Iron-based phosphate binder (IPB) is a noncalcium phosphate binder that demonstrated sustained serum phosphorus control, good tolerability and lower pill burden compared with sevelamer carbonate in a Phase 3 study conducted in dialysis patients. These efficacy of IPB has been demonstrated for hemodialysis (HD) patients, but few studies have focused on patients undergoing peritoneal dialysis (PD). We evaluated efficacy of IPB and focused on effects for anemia and iron metabolism in patients on PD.

Method

This study was a cross-sectional, longitudinal multicenter study conducted by PD OASIS, organized committee in Kanagawa Japan. We analyzed the effects of IPB during a 6 months observation period in chronic kidney disease patients on PD who had administrated IPB, Ferric citrate hydrate and Sucroferric oxyhydroxide, between 2017 and 2019. The primary endpoint was the changes of phosphate, and several secondary endpoints were assessed: calcium, intact PTH, RBC, hemoglobin, MCH, RDW-VC, Fe, TSAT, Ferritin, albumin, CRP, monthly dosage of Erythropoietin stimulating agents (ESA) and ESA resistance index (ERI).

In addition, we assessed the association between these markers and iron metabolism utilizing multivariate logistic regression analysis.

Results

A total of 102 patients were registered in the study who had received IPB.

The initial doses of Ferric citrate hydrate and Sucroferric oxyhydroxide were 1010.9 ±400.9 mg and 941.7 ±502.9 mg daily, finally increased to 1213.6 ±559.9 mg and 1310.0 ±521.8 mg respectively at the end of the observation.

We observed a significant reduction of serum phosphate to 5.27 ± 0.98 mg/dL from 6.56 ± 1.52 mg/dL with follow-up of six months (p < 0.01). At the end of the study, 76.4% of participants had achieved the target of less than 6 mg/dL. The hemoglobin, TSAT and Ferritin increased significantly from 10.47 ±1.26 g/dl, 27.95 ±11.05 % and 139.0 ±147.6 ng/mL to 11.17 ±1.16 g/dl, 40.46 ±15.00 % and 305.9 ±232.0 ng/mL respectively in six months (p < 0.01).

No significant changes of serum calcium, intact parathyroid hormone (PTH) and CRP occurred over the study period.

The monthly dosage of ESA was significantly decreased after administration with IPB and ERI significantly improved to 0.11±0.12 (μg/month/kg/g Hb) from 0.21±0.16 (μg/month/kg/g Hb) (p<0.01). Hemoglobin overshoot, an increase of more than 12 g/dl, was observed in 27.5% patients. This related low MCH and high RDW-VC at baseline which was proven by multivariate logistic regression.

Additionally, we assessed the factors of ferritin increase because it was remarkable in follow-up six months compared to HD patients. In multivariate analysis, phosphate (Odds ratio 5.85, 95%CI 1.18-91.77, p=0.027), intact PTH (0.99, 0.97-1.15, p=0.015), hemoglobin (Odds ratio 0.10, 95%CI 0.05-0.59, p=0.025), RBC (Odds ratio 1.16, 95%CI 1.04-1.41, p=0.003), and RDW-CV (Odds ratio 0.44, 95%CI 0.10-0.99, p=0.046) were significantly associated with ferritin increase more than 300 ng/ml ,after adjusted.

Conclusion

This study confirmed the efficacy of Iron-based phosphate binder, Ferric citrate hydrate and Sucroferric oxyhydroxide, in the treatment of hyperphosphatemia in PD patients. In addition, IBP caused secondary effects of anemia improvement and ESA dosage reduction resulting in ERI improvement. However, in this study, the increase in ferritin levels was remarkable. It may be because PD does not lose iron by treatment compared to HD. Therefore, we should check iron metabolism more frequently for PD patients taking IPB than HD patients. It is necessary to further investigate the effects of IPB on anemia and iron metabolism in PD patients.

Cardiac arrest during hemodialysis: a survey of five Japanese hospitals

AIM

Intraprocedural cardiac arrest is a serious complication among patients receiving hemodialysis. However, the frequency and reaction to these events remain unclear. This study aimed to explore the clinical picture of cardiac arrest during hemodialysis.

METHODS

Ten cardiac arrests that had occurred during 217,984 hemodialysis treatments in five Japanese hospitals, between 2008 and 2017, were reviewed. We investigated the underlying disease, vital signs, emergency responses, and outcomes using patient medical records.

RESULTS

The cardiac arrest rate ranged from 1.1 to 7.5 per 100,000 hemodialysis sessions. All included cases of cardiac arrest occurred in a hemodialysis unit and had been witnessed and reported by supervising clinicians. The initial rhythm was ventricular fibrillation/ventricular tachycardia in six patients (60%) and pulseless electrical activity/asystole in four patients (40%). Seven (70%) patients showed a return of spontaneous circulation (ROSC), and two (20%) patients were discharged with a cerebral performance category score of 1. There was a statistically significant difference in the ROSC rate (P = 0.048) only in the event of an emergency call. The SpO2 and respiratory rates had not been recorded in six patients. There was no significant difference in ROSC between initial rhythms of ventricular fibrillation/ventricular tachycardia and pulseless electrical activity/asystole.

CONCLUSION

We evaluated the frequency of cardiac arrest during hemodialysis. Overall assessment including respiratory status is needed at initiation of hemodialysis. In case of a sudden change in a patient's status, high-quality resuscitation treatment that includes an emergency call can improve prognosis.

Lower Diastolic Blood Pressure was Associated with Higher Incidence of Chronic Kidney Disease in the General Population Only in those Using Antihypertensive Medications

BACKGROUND/AIMS

The association of diastolic blood pressure (DBP) with incidence of chronic kidney disease (CKD) in the general population is not well examined.

METHODS

Using national health check-up database from 2008 to 2011 in the general Japanese population aged 39-74 years, we evaluated the association between DBP and incidence of CKD 2 years later in 127,954 participants without CKD. DBP was categorized by every 5 mm Hg from the lowest (<60 mm Hg) to the highest category (>100 mm Hg) and was further stratified into those with and without antihypertensive medications (BP meds). We calculated the OR for estimating adjusted risk of incident CKD using logistic regression model.

RESULTS

Participants were 62% female and 25.9% with BP meds, mean age of 76 years with estimated glomerular filtration rate of 78.2 ± 13.4 and DBP of 76 ± 11 mm Hg. Two years later, 12,379 (9.7%) developed CKD. Compared to DBP 60-64 mm Hg without BP meds as reference, multivariate analysis showed no difference in CKD risk at any DBP category among those without BP meds. However, in those with BP meds, risk increased according to lower DBP from 95 to 60 mm Hg (p for trend 0.05) with OR 1.51 (95% CI 1.14-1.99) in DBP <60 mm Hg. In subgroup analysis within those with or without BP meds, CKD risk was lower at higher DBP (p for trend 0.02) only in those without BP meds.

CONCLUSION

Lower DBP was associated with higher risk of incident CKD only in the general population taking antihypertensive medication.

External validation of the quick Sequential Organ Failure Assessment score for mortality and bacteraemia risk evaluation in Japanese patients undergoing haemodialysis: a retrospective multicentre cohort study

OBJECTIVES

We aimed to examine the validity of the quick Sequential Organ Failure Assessment (qSOFA) score for mortality and bacteraemia risk assessment in Japanese haemodialysis patients.

DESIGN

This is a retrospective multicentre cohort study.

SETTING

The six participating hospitals are tertiary-care institutions that receive patients on an emergency basis and provide primary, secondary and tertiary care. The other participating hospital is a secondary-care institution that receives patients on an emergency basis and provides both primary and secondary care.

PARTICIPANTS

This study included haemodialysis outpatients admitted for bacteraemia suspicion, who had blood drawn for cultures within 48 hours of their initial admission.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was overall in-hospital mortality. Secondary outcomes included 28-day in-hospital mortality and the incidence of bacteraemia diagnosed based on blood culture findings. The discrimination, calibration and test performance of the qSOFA score were assessed. Missing data were handled using multiple imputation.

RESULTS

Among the 507 haemodialysis patients admitted with bacteraemia suspicion between August 2011 and July 2013, the overall in-hospital mortality was 14.6% (74/507), the 28-day in-hospital mortality was 11.1% (56/507) and the incidence of bacteraemia, defined as a positive blood culture, was 13.4% (68/507). For predicting in-hospital mortality among haemodialysis patients, the area under the receiver operating characteristic curve was 0.61 (95% CI 0.56-0.67) for a qSOFA score ≥2. The Hosmer-Lemeshow χ² statistics for the qSOFA score as a predictor of overall and 28-day in-hospital mortality were 5.72 (p=0.02) and 7.40 (p<0.01), respectively.

CONCLUSION

On external validation, the qSOFA score exhibited low diagnostic accuracy and miscalibration for in-hospital mortality and bacteraemia among haemodialysis patients.

Association Between Staphylococcus aureus Bacteremia and Hospital Mortality in Hemodialysis Patients With Bloodstream Infection: A Multicenter Cohort From Japanese Tertiary Care Centers

Multiple studies have shown that Staphylococcus aureus bacteremia (SAB) has been a major cause of death in hemodialysis patients. We examined whether SAB is a risk for mortality among chronic hemodialysis patients in Japan where the standard vascular access is arteriovenous fistula (AVF). This was a multicenter, retrospective study of maintenance hemodialysis patients with bloodstream infection (BSI) from 2011 to 2013 at tertiary care centers in Japan. The endpoint was hospital mortality. Our cohort contained 32 SAB cases (14 MRSA and 18 MSSA) and 42 non-SAB cases. Hospital mortality was higher among SAB cases than non-SAB cases (46.9% vs. 23.8%, P = 0.038). In patients with BSI, SAB was significantly associated with hospital mortality after adjustment for potential confounders, including type of vascular access (OR 3.26). S. aureus was the leading cause of BSI and hospital mortality among this cohort. Therefore, initial empiric treatment should cover for S. aureus.

Development and Validation of a Clinical Prediction Rule for Bacteremia among Maintenance Hemodialysis Patients in Outpatient Settings

Background

To our knowledge, no reliable clinical prediction rule (CPR) for identifying bacteremia in hemodialysis (HD) patients has been established. The aim of this study was to develop a CPR for bacteremia in maintenance HD patients visiting the outpatient department.

Methods

This multicenter cohort study involved consecutive maintenance HD patients who visited the outpatient clinic or emergency room of seven Japanese institutions between August 2011 and July 2013. The outcome measure was bacteremia diagnosed based on the results of blood cultures. The candidate predictors for bacteremia were extracted through a literature review. A CPR for bacteremia was developed using a coefficient-based multivariable logistic regression scoring method, and calibration was performed. The test performance was then assessed for the CPR.

Results

Of 507 patients eligible for the study, we analyzed the 293 with a complete dataset for candidate predictors. Of these 293 patients, 48 (16.4%) were diagnosed with bacteremia. At the conclusion of the deviation process, body temperature ≥ 38.3°C, heart rate ≥ 125 /min, C-reactive protein ≥ 10 mg/dL, alkaline phosphatase >360 IU/L, and no prior antibiotics use within the past week were retained and scored. The CPR had a good fit for the model on calibration. The AUC of the CPR was 0.76, and for score CPR ≥ 2, the sensitivity and specificity were 89.6% and 51.4%, respectively.

Conclusions

We established a simple CPR for bacteremia in maintenance HD patients using routinely obtained clinical information in an outpatient setting. This model may facilitate more appropriate clinical decision making.

[Pathophysiology of secondary hyperparathyroidism.]

Secondary hyperparathyroidism(SHPT)is the result of a compensatory response of the calcium phosphate homeostatic mechanism. Vitamin D deficiency and chronic kidney disease, both representative pathophysiological causes of SHPT, have been related not only to skeletal disorders but also cardiovascular diseases, ADL and QOL. This relates the importance of SHPT as a pathological cause or marker of such states.

Anemia and Long-Term Renal Prognosis in Patients with Post-Renal Acute Kidney Injury of Nonmalignant Cause

BACKGROUND/AIMS

The renal prognosis of post-renal acute kidney injury (PoR-AKI) has not been verified so far. The objective of this study was to assess the association of baseline anemia with long-term renal prognosis in patients with PoR-AKI.

METHODS

We performed a multicenter retrospective cohort study. Consecutive adult patients from December 2006 to February 2010, who met the requirements as mentioned in the definition of PoR-AKI, were included. Patients without data on baseline renal function and at 6 months after PoR-AKI were excluded. We set baseline hemoglobin (Hb) level (g/dl) as the main exposure to be tested. The main outcome measure was long-term renal prognosis as determined by the difference between proximate estimated glomerular filtration rate (eGFR) at 6 months after diagnosis of PoR-AKI and baseline eGFR prior to the occurrence of the present PoR-AKI (ΔeGFR after 6 months) using the general linear model.

RESULTS

We included 136 patients with PoR-AKI. The most frequent cause of PoR-AKI was malignancy, accounting for 39.0% (n = 53) of cases. Multivariate analysis adjusted for possible confounders showed that ΔeGFR after 6 months significantly changed by -4.28 ml/min/1.73 m2 for every 1 g/dl lower Hb at diagnosis (95% CI 1.86-6.69, p < 0.01). An additional multivariate analysis that was stratified by the presence or absence of malignancy as the cause of PoR-AKI yielded the same significant result only in the stratum of the nonmalignant cause of PoR-AKI.

CONCLUSION

Patients with a nonmalignant cause of PoR-AKI who have baseline anemia may have poor long-term renal prognosis. In these cases, close observation of renal function after renal recovery may be required.

Factors Predicting Successful Discontinuation of Continuous Renal Replacement Therapy

This multicentre, retrospective observational study was conducted from January 2010 to December 2010 to determine the optimal time for discontinuing continuous renal replacement therapy (CRRT) by evaluating factors predictive of successful discontinuation in patients with acute kidney injury. Analysis was performed for patients after CRRT was discontinued because of renal function recovery. Patients were divided into two groups according to the success or failure of CRRT discontinuation. In multivariate logistic regression analysis, urine output at discontinuation, creatinine level and CRRT duration were found to be significant variables (area under the receiver operating characteristic curve for urine output, 0.814). In conclusion, we found that higher urine output, lower creatinine and shorter CRRT duration were significant factors to predict successful discontinuation of CRRT.

External Validation for Acute Kidney Injury Severity Scores: A Multicenter Retrospective Study in 14 Japanese ICUs

BACKGROUND/AIMS

Acute kidney injury (AKI) is associated with high mortality. Multiple AKI severity scores have been derived to predict patient outcome. We externally validated new AKI severity scores using the Japanese Society for Physicians and Trainees in Intensive Care (JSEPTIC) database.

METHODS

New AKI severity scores published in the 21st century (Mehta, Stuivenberg Hospital Acute Renal Failure (SHARF) II, Program to Improve Care in Acute Renal Disease (PICARD), Vellore and Demirjian), Liano, Simplified Acute Physiology Score (SAPS) II and lactate were compared using the JSEPTIC database that collected retrospectively 343 patients with AKI who required continuous renal replacement therapy (CRRT) in 14 intensive care units. Accuracy of the severity scores was assessed by the area under the receiver-operator characteristic curve (AUROC, discrimination) and Hosmer-Lemeshow test (H-L test, calibration).

RESULTS

The median age was 69 years and 65.8% were male. The median SAPS II score was 53 and the hospital mortality was 58.6%. The AUROC curves revealed low discrimination ability of the new AKI severity scores (Mehta 0.65, SHARF II 0.64, PICARD 0.64, Vellore 0.64, Demirjian 0.69), similar to Liano 0.67, SAPS II 0.67 and lactate 0.64. The H-L test also demonstrated that all assessed scores except for Liano had significantly low calibration ability.

CONCLUSIONS

Using a multicenter database of AKI patients requiring CRRT, this study externally validated new AKI severity scores. While the Demirjian's score and Liano's score showed a better performance, further research will be required to confirm these findings.

Validity of low-efficacy continuous renal replacement therapy in critically ill patients

The 1980s saw the use of continuous arteriovenous hemofiltration whose intensity hemofiltration rate was only 3 or 4 mL kg⁻¹ h⁻¹. With the installation of a blood pump, this dose went up to 8 or 10 mL kg⁻¹ h⁻1, and continued to increase, reaching about 20 mL kg⁻¹ h⁻¹ by the year 2000. Some studies found that a higher dose could be beneficial, and the world rapidly followed the trend, increasing the dose up to 35 mL kg⁻¹ h⁻¹. Then, two randomized control trials, namely the VA/NIH Acute Renal Failure Trial Network study and the RENAL study, came along in succession which changed the Kidney Disease: Improving Global Outcomes (KDIGO) recommendation to 20 to 25 mL kg⁻¹ h⁻¹. However, no good evidence exists to support this. Our recent multicenter retrospective studies from the JSEPTIC CRRT database show that the Japanese continuous renal replacement therapy dose of (14.3 mL kg⁻¹ h⁻¹) does not seem to have worse outcomes when compared with a higher dose.

Asymptomatic post-transplant lymphoproliferative disorder diagnosed at one year protocol renal allograft biopsy

Post-transplant lymphoproliferative disorder (PTLD) is a neoplastic complication with a potentially fatal outcome that develops as a consequence of immunosuppression, and is mainly associated with Epstein-Barr virus (EBV) infection. A 70-year-old woman underwent a live unrelated, ABO-incompatible renal transplant for end-stage renal disease. One year after transplantation, protocol biopsy revealed pathological changes indicative of the histological subtype of 'early lesions of PTLD' according to the World Health Organization classification, while the patient showed no clinical signs or symptoms. The patient was finally diagnosed with EBV-positive PTLD by in situ hybridization for EBER (EBV-encoded RNA), and was successfully treated based on the reduction of immunosuppression. Protocol biopsy within the first post-transplant year is the only diagnostic measure to detect asymptomatic early PTLD, which allows for early intervention and leads to better outcomes.

The lower limit of intensity to control uremia during continuous renal replacement therapy

Introduction

The recommended lower limit of intensity during continuous renal replacement therapy (CRRT) is 20 or 25 mL/kg/h. However, limited information is available to support this threshold. We aimed to evaluate the impact of different intensities of CRRT on the clearance of creatinine and urea in critically ill patients with severe acute kidney injury (AKI).

Methods

This is a multicenter retrospective study conducted in 14 Japanese ICUs in 12 centers. All patients older than 18 years and treated with CRRT due to AKI were eligible. We evaluated the effect of CRRT intensity by two different definitions: daily intensity (the mean intensity over each 24-h period) and average intensity (the mean of daily intensity during the period while CRRT was performed). To study the effect of different CRRT intensity on clearance of urea and creatinine, all patients/daily observations were arbitrarily allocated to one of 4 groups based on the average intensity and daily intensity: <10, 10–15, 15–20, and >20 mL/kg/h.

Results

Total 316 patients were included and divided into the four groups according to average CRRT intensity. The groups comprised 64 (20.3%), 138 (43.7%), 68 (21.5%), and 46 patients (14.6%), respectively. Decreases in creatinine and urea increased as the average intensity increased over the first 7 days of CRRT. The relative changes of serum creatinine and urea levels remained close to 1 over the 7 days in the “<10” group. Total 1,101 daily observations were included and divided into the four groups according to daily CRRT intensity. The groups comprised 254 (23.1%), 470 (42.7%), 239 (21.7%), and 138 observations (12.5%), respectively. Creatinine and urea increased (negative daily change) only in the “<10” group and decreased with the increasing daily intensity in the other groups.

Conclusions

The lower limit of delivered intensity to control uremia during CRRT was approximately between 10 and 15 mL/kg/h in our cohort. A prescribed intensity of approximately 15 mL/kg/h might be adequate to control uremia for patients with severe AKI in the ICU. However, considering the limitations due to the retrospective nature of this study, prospective studies are required to confirm our findings.

Underestimating chronic kidney disease by urine dipstick without serum creatinine as a screening tool in the general Japanese population

BACKGROUND

It is not known if urine dipstick alone can identify chronic kidney disease (CKD) in the general Japanese population.

METHODS

We designed a cross-sectional study using data obtained in 2008 from a nationwide community-based health examination program for adults aged 40-74. The data consisted of blood tests, urine tests and questionnaire related to metabolic disorders. Those who had both serum creatinine measured and urine dipstick tested were analyzed.

RESULTS

Data were obtained from 538,846 people with a mean age of 62.8 years, consisting of 41.6 % males. Our study showed that 14.4 % had an eGFR below 60 mL/min/1.73 m(2), 5.2 % had proteinuria and 18.1 % had CKD. Within the population with CKD, non-proteinuric CKD accounted for 71.4 %. The proportion of non-proteinuric CKD was highest in stage G3a (91.8 %) followed by G3b (77.0 %) disease, and was greater in the more elderly and in females. The proportion of non-proteinuric CKD was 47.9 % in diabetes mellitus, 69.3 % in dyslipidemia, 66.8 % in hypertension and 57.1 % in metabolic syndrome. Furthermore, non-proteinuric CKD accounted for 78.1 % of the population without these lifestyle diseases, suggesting that even in the population without apparent risk, CKD is still prevalent and can be missed when urine dipstick is the only screening method used.

CONCLUSIONS

This study showed that a considerable population of CKD might be overlooked when only dipstick proteinuria is assessed for CKD screening. Hence, we strongly recommend that both urinalysis and serum creatinine measurement should be a part of the nationwide CKD screening system.

Who may not benefit from continuous renal replacement therapy in acute kidney injury?

This study aimed to identify factors that may predict early kidney recovery (less than 48 hours) or early death (within 48 hours) after initiating continuous renal replacement therapy (CRRT) in acute kidney injury (AKI) patients. This is a multicenter retrospective observational study of 14 Japanese Intensive care units (ICUs) in 12 tertiary hospitals. Consecutive adult patients with severe AKI requiring CRRT admitted to the participating ICUs in 2010 (n=343) were included. Patient characteristics, variables at CRRT initiation, settings, and outcomes were collected. Patients were grouped into early kidney recovery group (CRRT discontinuation within 48 hours after initiation, n=52), early death group (death within 48 hours after CRRT initiation, n=52), and the rest as the control group (n=239). The mean duration of CRRT in the early kidney recovery group and early death group was 1.3 and 0.9 days, respectively. In multivariable regression analysis, in comparison with the control group, urine output (mL/h) (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01-1.03), duration between ICU admission to CRRT initiation (days) (OR: 0.65, 95% CI: 0.43-0.87), and the sepsis-related organ failure assessment score (OR: 0.87, 95% CI; 0.78-0.96) were related to early kidney recovery. Serum lactate (mmol/L) (OR: 1.19, 95% CI: 1.11-1.28), albumin (g/dL) (OR: 0.52, 95% CI: 0.28-0.92), vasopressor use (OR: 3.68, 95% CI: 1.37-12.16), and neurological disease (OR: 9.64, 96% CI: 1.22-92.95) were related to early death. Identifying AKI patients who do not benefit from CRRT and differentiating such patients from the study cohort may allow previous and future studies to effectively evaluate the indication and role of CRRT.

A novel compound heterozygous mutation of Gitelman's syndrome in Japan, as diagnosed by an extraordinary response of the fractional excretion rate of chloride in the trichlormethiazide loading test

Gitelman's syndrome (GS), an inherited disorder due to loss of function of ion channels and transporters such as Na-Cl co-transporter (NCCT) in distal convoluted tubules, is characterized by hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis and hyperreninemic-hyperaldosteronism. A 39-year-old man was admitted to our hospital because of muscle weakness with such intractable disorders. We performed a thiazide-loading test, which revealed a poor response of the fractional excretion rate of chloride compared to healthy subjects. Based on these data, the clinical diagnosis of GS was made. Gene-sequencing analysis revealed compound heterozygous mutations of c.539C > A and c.1844C > T in SLC12A3, which is newly reported in Japanese GS.

Sympathoexcitation by brain oxidative stress mediates arterial pressure elevation in salt-induced chronic kidney disease

Hypertension is very prevalent in chronic kidney disease and critical for its prognosis. Sympathoexcitation and oxidative stress have been demonstrated to be involved in chronic kidney disease. We have shown previously that sympathoexcitation by brain oxidative stress mediates arterial pressure elevation in the salt-sensitive hypertension model, Dahl salt-sensitive rats. Thus, we investigated whether sympathoexcitation by excessive brain oxidative stress could contribute to arterial pressure elevation in salt-induced chronic kidney disease model rats. Young (3-week-old) male Sprague-Dawley rats were randomly assigned to a uninephrectomy or sham operation and then subjected to either a normal salt (0.5%) or high-salt (8.0%) diet for 4 weeks. The young salt-loaded uninephrectomized rats exhibited sympathoexcitation, hypertension, and renal injury, proteinuria and global glomerulosclerosis together with tubulointerstitial damage. Under urethane anesthesia and artificial ventilation, renal sympathetic nerve activity, arterial pressure, and heart rate decreased to a greater degree in the salt-loaded uninephrectomized rats than in the nonsalt-loaded uninephrectomized rats and the salt-loaded or nonsalt-loaded sham-operated rats, when Tempol, a membrane-permeable superoxide dismutase mimetic, was infused acutely into the lateral cerebral ventricle. Oxidative stress in the hypothalamus, measured by lucigenin chemiluminescence, was also significantly greater. Furthermore, in the salt-loaded uninephrectomized rats, antioxidant treatment with chronic intracerebroventricular Tempol decreased sympathetic nerve activity and arterial pressure, which, in turn, led to a decrease in renal damage. Similar effects were elicited by treatment with oral moxonidine, the central sympatholytic agent. In conclusion, sympathoexcitation by brain oxidative stress may mediate arterial pressure elevation in salt-induced chronic kidney disease.

Rac1 GTPase in rodent kidneys is essential for salt-sensitive hypertension via a mineralocorticoid receptor-dependent pathway

Hypertension is a leading contributor to cardiovascular mortality worldwide. Despite this, its underlying mechanism(s) and the role of excess salt in cardiorenal dysfunction are unclear. Previously, we have identified cross-talk between mineralocorticoid receptor (MR), a nuclear transcription factor regulated by the steroid aldosterone, and the small GTPase Rac1, which is implicated in proteinuric kidney disease. We here show that high-salt loading activates Rac1 in the kidneys in rodent models of salt-sensitive hypertension, leading to blood pressure elevation and renal injury via an MR-dependent pathway. We found that a high-salt diet caused renal Rac1 upregulation in salt-sensitive Dahl (Dahl-S) rats and downregulation in salt-insensitive Dahl (Dahl-R) rats. Despite a reduction of serum aldosterone levels, salt-loaded Dahl-S rats showed increased MR signaling in the kidneys, and Rac1 inhibition prevented hypertension and renal damage with MR repression. We further demonstrated in aldosterone-infused rats as well as adrenalectomized Dahl-S rats with aldosterone supplementation that salt-induced Rac1 and aldosterone acted interdependently to cause MR overactivity and hypertension. Finally, we confirmed the key role of Rac1 in modulating salt susceptibility in mice lacking Rho GDP-dissociation inhibitor α. Therefore, our data identify Rac1 as a determinant of salt sensitivity and provide insights into the mechanism of salt-induced hypertension and kidney injury.

Mineralocorticoid receptor activation: a major contributor to salt-induced renal injury and hypertension in young rats

Excessive salt intake is known to preferentially increase blood pressure (BP) and promote kidney damage in young, salt-sensitive hypertensive human and animal models. We have suggested that mineralocorticoid receptor (MR) activation plays a major role in kidney injury in young rats. BP and urinary protein were compared in young (3-wk-old) and adult (10-wk-old) uninephrectomized (UNx) Sprague-Dawley rats fed a high (8.0%)-salt diet for 4 wk. The effects of the MR blocker eplerenone on BP and renal injury were examined in the high-salt diet-fed young UNx rats. Renal expression of renin-angiotensin-aldosterone (RAA) system components and of inflammatory and oxidative stress markers was also measured. The effects of the angiotensin receptor blocker olmesartan with or without low-dose aldosterone infusion, the aldosterone synthase inhibitor FAD286, and the antioxidant tempol were also studied. Excessive salt intake induced greater hypertension and proteinuria in young rats than in adult rats. The kidneys of young salt-loaded rats showed marked histological injury, overexpression of RAA system components, and an increase in inflammatory and oxidative stress markers. These changes were markedly ameliorated by eplerenone treatment. Olmesartan also ameliorated salt-induced renal injury but failed to do so when combined with low-dose aldosterone infusion. FAD286 and tempol also markedly reduced urinary protein. UNx rats exposed to excessive salt at a young age showed severe hypertension and renal injury, likely primarily due to MR activation and secondarily due to angiotensin receptor activation, which may be mediated by inflammation and oxidative stress.

Natural history of mineral and bone disorders after living-donor kidney transplantation: a one-year prospective observational study

Mineral and bone disorders (MBD), including hypercalcemia and hypophosphatemia, are common complications after renal transplantation; however, the natural course of these disorders has not been well documented, and the pathogenesis of persistent post-transplant MBD still remains elusive. This study was carried out to show the natural history of mineral metabolism in recipients after living-donor kidney transplantation and also to clarify post-transplant risk factors of persistent hypercalcemia and/or hypophosphatemia at 12months after transplantation. Living-donor kidney transplant recipients (N=34) at Tokyo Women's Medical University were prospectively and consecutively recruited. Parameters of MBD, including intact parathyroid hormone and full-length fibroblast growth factor23, were followed. Serum calcium levels increased until the fourth week post-transplantation, after which it reached a plateau; and serum phosphate decreased substantially at one week post-kidney transplantation, but recovered to the reference level at two months. Fibroblast growth factor23 gradually decreased to comparable levels for renal function, while hyperparathyroidism persisted for 12months after transplantation. Multivariate linear regression analysis revealed that intact parathyroid hormone was the best correlating factor with both hypercalcemia and persistent hypophosphatemia at 12months. This study suggests the need for testing of other interventions used for treatment of hyperparathyroidism which may help to offer better management of MBD after kidney transplantation.

The relative role of fibroblast growth factor 23 and parathyroid hormone in predicting future hypophosphatemia and hypercalcemia after living donor kidney transplantation: a 1-year prospective observational study

BACKGROUND

Kidney transplantation (KTx) restores many of the disorders accompanying end-stage renal failure. However, hypercalcemia and hypophosphatemia are both common complications after renal transplantation. Prospective observation of these complications has not been well described and pre-transplant predictors also remain unknown. This prospective observational cohort study was carried out to clarify pre-transplant risk factors of persistent hypophosphatemia and/or hypercalcemia at 12 months after transplantation.

METHODS

Consecutive living donor KTx recipients (n = 39) at Tokyo Women's Medical University were prospectively recruited. Parameters of bone and mineral metabolism including intact parathyroid hormone (iPTH) and full-length fibroblast growth factor (FGF) 23 were followed.

RESULTS

FGF23 decreased to comparable levels for renal function while hyperparathyroidism persisted at 12 months after transplantation. Multivariate linear regression analysis revealed that pre-transplant iPTH correlated with hypercalcemia at 12 months and pre-transplant FGF23 was the best pre-transplant predictor of persistent hypophosphatemia at 12 months.

CONCLUSIONS

It is intriguing that although FGF23 is not a causal factor for hypophosphatemia at 12 months post-transplantation, it is a significant predictor of this common complication.

Mineralocorticoid receptor activation contributes to salt-induced hypertension and renal injury in prepubertal Dahl salt-sensitive rats

BACKGROUND

Excessive prepubertal salt intake permanently increases blood pressure (BP). We examined the role that the mineralocorticoid receptor (MR) plays in the salt-induced hypertension and renal damage of prepubertal Dahl salt-sensitive (SS) rats.

METHODS

Prepubertal (6 weeks old) and adult (10 weeks old) Dahl SS rats fed a high (8.0%) salt (HS) diet for 10 weeks were compared in terms of BP and renal function. The effect of treatment between the ages of 4 and 10 weeks with the MR antagonist eplerenone (0.125% in chow), the vasodilator hydralazine (50 mg/kg/day in drinking water) or the superoxide dismutase mimetic 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (tempol) (0.6 mmol/kg/day in drinking water) on the BP and renal function of prepubertal rats fed a HS diet for 10 weeks was also examined.

RESULTS

Excessive salt intake starting in prepuberty was associated with a higher BP increase and greater proteinuria than if it started in adulthood. Eplerenone moderately reduced BP and markedly improved renal injury during its administration in prepubertal rats. These effects continued after drug discontinuation. Hydralazine greatly decreased BP and reduced proteinuria, but these effects were completely lost after drug discontinuation. Excessive salt increased urinary 8-hydroxy-2'-deoxyguanosine levels, intrarenal macrophage infiltration and renal plasminogen activator inhibitor-1 and transforming growth factor-beta mRNA expression. Eplerenone, but not hydralazine, attenuated these salt-induced inflammatory reactions. Tempol improved salt-induced hypertension and renal injury, even after its discontinuation.

CONCLUSIONS

Dahl SS rats exposed to excessive salt in prepubescence show a permanent increase in susceptibility to salt-induced hypertension and proteinuria. MR activation may promote these effects at least in part by inducing oxidation and inflammation.

Effect of high fat loading in Dahl salt-sensitive rats

Salt sensitivity of blood pressure (BP) is speculated to be a characteristic in obesity-induced hypertension. To elucidate the influence of obesity on salt-sensitive hypertension, we examined the effect of fat loading on BP, renal damage, and their progression induced by salt excess in Dahl salt-sensitive (S) rats. High fat (HF: 45% fat diet: 8 weeks) diet increased BP with greater weight gain and visceral fat accumulation than low fat (10% fat) diet. In HF-fed rats, plasma glucose, plasma insulin, and urinary catecholamine increased, and urinary protein tended to be elevated. Moreover, excessive salt (8% salt diet: 8 weeks)-induced hypertension and proteinuria was accelerated in HF-fed rats. Therefore, fat loading increased BP in Dahl S rats possibly through insulin-resistance and sympathetic excitation. Moreover, fat loading accelerated salt-induced BP elevation and renal damage, suggesting excessive intake of both fat and salt, such as a civilized diet, exert the synergic harmful effects.

Improvement of cardiac function after kidney transplantation with dilated cardiomyopathy and long dialysis vintage

Patients with long dialysis vintage have low cardiac output for various reasons. Although kidney transplantation is known to improve cardiac mortality, patients are sometimes evaluated as contraindicated for transplantation because of cardiac risk. We successfully performed kidney transplantation for a patient with a long dialysis vintage and dilated cardiomyopathy. Sequential ¹²³I-metaiodobenzylguanidine (¹²³I-MIBG) scintigraphy suggested that amelioration of uraemia improved cardiac function. Kidney transplantation for patients with severely impaired cardiac function is safe and effective under careful perioperative monitoring irrespective of dialysis vintage. Sequential ¹²³I-MIBG scintigraphy can be used as an evaluation tool for the improvement in cardiac function.