Changes in tissue oxygenation in response to sudden intradialytic hypotension.

A 76-year-old woman on hemodialysis (HD) for diabetic nephropathy was admitted to our hospital with occasional intradialytic hypotension (IDH). We continuously monitored the regional oxygen saturation (rSO2) in the brain, liver, and lower limb muscle during HD. The time course of changes in rSO2 ratios in each region was evaluated throughout HD. The rSO2 ratio was defined as the ratio of rSO2 value at t (min) during HD to the rSO2 value before HD. During the early phase of HD, blood pressure (BP) gradually decreased and both hepatic and lower limb muscle rSO2 ratios decreased with changes in BP, whereas the cerebral rSO2 ratio was relatively maintained. At around 90 min after HD initiation, the BP decreased to 71/46 mmHg (mean BP, 54 mmHg) and the previously maintained cerebral rSO2 ratio also suddenly decreased. Soon after the onset of IDH, ultrafiltration was stopped, normal saline was infused, and intravenous noradrenaline infusion was started. After the BP recovered, cerebral and hepatic rSO2 ratios improved, but the lower limb muscle rSO2 ratio remained low. After restarting ultrafiltration, improvement in the lower limb muscle rSO2 ratio was delayed, although cerebral and hepatic oxygenation were maintained. This observation aids in our understanding of the effect of IDH on regional tissue oxygenation.

Continuous monitoring of changes in cerebral oxygenation during hemodialysis in a patient with acute congestive heart failure.

A 71-year-old man undergoing hemodialysis (HD) was admitted to our hospital with congestive heart failure (CHF) and pneumonia. After admission, ultrafiltration with HD was urgently performed because of a lack of respiratory improvement despite the use of noninvasive positive pressure ventilation. During HD, cerebral regional saturation of oxygen (rSO2) was monitored by INVOS 5100c oxygen saturation monitor (Covidien Japan, Japan) to evaluate changes in tissue oxygenation. At HD initiation, cerebral rSO2 was very low at 34% under the fraction of inspiratory oxygen (FiO2) of 0.4. Ultrafiltration was performed at the rate of 0.5 L/h thereafter, cerebral rSO2 gradually improved even as inhaling oxygen concentration decreased. At the end of HD, cerebral rSO2 improved at 40% under a FiO2 of 0.28 as excess body fluid was removed. After pneumonia and CHF improved, he was discharged. Reports of the association between cerebral oxygenation and acute CHF status in patients undergoing HD are limited; therefore, in our experience with this case, cerebral oxygenation deteriorated with the CHF status but was improved by adequate body-fluid management during HD.

Differences in cerebral and hepatic oxygenation in response to intradialytic blood transfusion in patients undergoing hemodialysis.

Hemodialysis (HD) patients frequently experience severe anemia, requiring intradialytic blood transfusion. Severe anemia leads to deterioration of systemic tissue oxygenation. However, few reports have examined the effect of intradialytic blood transfusion on tissue oxygenation changes. This study aimed to (i) monitor the differences in tissue oxygenation in the brain and liver during intradialytic blood transfusion, and (ii) elucidate the clinical factors affecting cerebral and hepatic oxygenation. Thirty-eight HD patients with severe anemia requiring intradialytic blood transfusion were included (27 men, 11 women; mean age, 70.2 ± 1.6 years). Cerebral and hepatic regional oxygen saturation (rSO2) values were monitored using near-infrared spectroscopy (INVOS 5100c oxygen saturation monitor). Cerebral and hepatic rSO2 were significantly higher after than before blood transfusion (p < 0.001, both). Furthermore, hepatic rSO2 was significantly higher than cerebral rSO2 after transfusion (p = 0.004). In multivariable linear regression analysis, cerebral rSO2 changes were independently associated with the natural logarithm of hemoglobin (Hb) ratio (Hb after/before transfusion) (standardized coefficient: 0.367, p = 0.023), whereas hepatic rSO2 changes were independently associated with the natural logarithm of [Hb ratio/colloid osmotic pressure ratio (colloid osmotic pressure after/before transfusion)] (standardized coefficient: 0.378, p = 0.019). In conclusion, throughout intradialytic blood transfusion, brain and liver tissue oxygenation improved. Hepatic rSO2 was significantly higher than cerebral rSO2 at the end of HD. Furthermore, cerebral oxygenation changes were associated with only transfusion-induced Hb increase, whereas hepatic oxygenation changes were associated with both transfusion-induced Hb increase (positive changes) and ultrafiltration-induced colloid osmotic pressure increase (negative changes).

Differences in tissue oxygenation and changes in total hemoglobin signal strength in the brain, liver, and lower-limb muscle during hemodialysis.

Near-infrared spectroscopy has been used to measure regional saturation of oxygen (rSO2) based on the total hemoglobin (t-Hb) signal strength. To date, few studies have investigated the changes of systemic oxygenation and t-Hb signal strength during hemodialysis (HD). This study aimed to (1) monitor rSO2 and t-Hb signal strength in the brain, liver, and lower-limb muscle during HD and (2) clarify the differences in rSO2 and t-Hb signal strength in each compartment. Fifty-three patients receiving 4-h HD were included and divided into three groups according to the compartments in which tissue oxygenation was measured as follows: brain (n = 44), liver (n = 42), and lower-limb muscle (n = 40). The rSO2 and t-Hb signal strength was monitored using an INVOS 5100c (Covidien Japan, Tokyo, Japan). The rSO2 levels were significantly lower in the brain than in the liver from HD initiation to the end (HD initiation: rSO2 in the brain and liver, 46.5 ± 1.3 and 52.4 ± 1.7%, respectively, p = 0.031). Furthermore, compared to the t-Hb signal strength ratio [value at t (min) during HD/initial value before HD] in the brain during HD, there were significant increases in the liver and lower-limb muscle, respectively. In conclusion, deterioration of cerebral oxygenation was remarkable compared to the hepatic oxygenation in HD patients. Our results, which revealed significant differences among the t-Hb signal strength ratios in the brain, liver, and lower-limb muscle during HD, might reflect the non-uniform body-fluid reduction within systemic tissues induced by ultrafiltration.

[A case of rapidly progressive glomerulonephritis exhibiting granulomatosis with polyangiitis (GPA) and extremely high level of PR3-ANCA with improvement of renal dysfunction after plasma exchange therapy].

A 68-year-old Japanese man was diagnosed with left otitis media with effusion and left uveitis more than 5 months before admission. He was urgently admitted to our hospital for progressive deterioration of his renal function [serum creatinine(Cr) 7.59 mg/dL] with proteinuria and urinary red blood cell casts, inflammation, and anemia. Additionally, his serum proteinase 3 antinuclear antibody (PR3-ANCA) level, determined by using the chemiluminescence enzyme immunoassay method, had increased to more than 3,500 U/mL. Hemodialysis (HD) was initiated on the third day after admission and renal biopsy was performed on the eighth day. The histological findings showed necrotic cellar crescents, hence, he was diagnosed as granulomatosis with polyangiitis on the basis of the clinical criteria. Methylprednisolone pulse therapy was administered from the 11th day. Thereafter, the administration of oral prednisolone (PSL) was started, and plasma exchange was initiated for the purpose of RP3-ANCA removal. In his clinical course, PSL was tapered as soon as possible because of the development of steroid psychosis, and we started intravenous cyclophosphamide on the 25th day instead of tapering the PSL. Subsequently, his renal function improved even without HD, and he was discharged on the 49th day. Although his PR3-ANCA level was still high after discharge, the administration of azathioprine led to a decrease in the PR-3 ANCA levels. About 2 years after discharge, the PR3-ANCA level decreased to 10.0 U/mL, and there has been no sign of GPA recurrence.

Renoprotective effects of thiazides combined with loop diuretics in patients with type 2 diabetic kidney disease.

BACKGROUND/AIMS: Type 2 diabetic kidney disease (DKD) is frequently accompanied by uncontrollable hypertension due to the sodium sensitivity inherent in DKD and to diuretic-resistant edema. In general, diuretics are effective in treating this condition, but thiazide diuretics are thought to be innocuous in advanced chronic kidney disease (CKD). We examined the renoprotective effects of combination therapy with thiazides and loop diuretics in type 2 DKD patients with CKD stage G4 or G5. METHODS: This study included 11 patients with type 2 DKD and an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m(2) who were suffering from severe edema even with loop diuretics. Each patient received additional hydrochlorothiazide (HCTZ) therapy, which was continued for more than 12 months. We examined clinical parameters including blood pressure (BP), proteinuria, and eGFR before and after the addition of HCTZ. RESULTS: Patients received a 13.6 ± 3.8 mg/day dose of HCTZ in addition to loop diuretics (azosemide: 120 mg/day in 6 cases, 60 mg/day in 3 cases and furosemide: 80 mg/day in 1 case, 120 mg/day in 1 case). Side effects of HCTZ were not observed in all patients. After the addition of HCTZ therapy, systolic and diastolic blood pressures (S-BP, D-BP) as well as proteinuria significantly decreased (S-BP: at 6 months, p < 0.05 and 12 months, p < 0.01 vs. 0 month, D-BP: at 12 months, p < 0.05 vs. 0 month, proteinuria: at 6 months, p < 0.05 and 12 months, p < 0.01 vs. 0 month). The annual decline in eGFR was not significantly different before and after HCTZ therapy (-7.7 ± 8.5 and -8.4 ± 4.8 mL/min/1.73 m(2)/year, respectively). CONCLUSION: Our findings suggest that the combination of HCTZ and loop diuretics improves BP levels, and decreases proteinuria even in advanced stage type 2 DKD patients with severe edema. The addition of HCTZ therapy was not found to negatively affect the change in eGFR in the present study.

Low-density lipoprotein apheresis ameliorates monthly estimated glomerular filtration rate declines in patients with renal cholesterol crystal embolism.

The incidence of cholesterol crystal embolism (CCE) has increased along with increases in the prevalence of atheromatous diseases and intravascular procedures. CCE frequently results in the deterioration of renal function, which sometimes leads to end-stage renal failure. Although there has been no established therapy for CCE, the possibility that low-density lipoprotein apheresis (LDL-A) is an effective therapy for renal CCE was previously reported. However, whether LDL-A improves renal CCE remains uncertain. This study aimed to evaluate the effectiveness of LDL-A in renal CCE patients. Twelve renal CCE patients (9 men and 3 women, mean age 70.6 ± 1.7 years) were included in this retrospective study. All patients had received LDL-A therapy, and estimated glomerular filtration rate (eGFR) values were examined before and after LDL-A. In addition, monthly changes in eGFR before and after LDL-A were calculated for each patient. At initial diagnosis of renal CCE, the eGFR was 35.2 ± 4.8 mL/min/1.73 m(2). At the initiation of LDL-A, the eGFR significantly decreased to 11.0 ± 1.2 mL/min/1.73 m(2), and monthly changes in eGFR reached -7.2 ± 2.5 mL/min/1.73 m(2)/month. After the initiation of LDL-A, the progression of renal dysfunction stabilized in nearly two-thirds of patients, and monthly changes in eGFR after LDL-A significantly diminished to -0.3 ± 0.7 mL/min/1.73 m(2)/month (p < 0.05 vs. before LDL-A). Although 4 patients had to undergo hemodialysis, all patients were alive over 1 year after the initiation of LDL-A. LDL-A therapy ameliorated renal dysfunction in renal CCE patients.

Evaluation of cerebral oxygenation in patients undergoing long-term hemodialysis.

BACKGROUND/AIMS: Patients undergoing hemodialysis (HD) have higher occurrence rates of cerebral diseases, including uremic encephalopathy, cognitive impairment, dementia, and cerebrovascular disease, than the general population. During HD, ultrafiltration is performed to maintain an adequate fluid condition and is associated with subsequent blood volume (BV) reduction. We aimed to (1) monitor changes in cerebral oxygenation and BV reduction during HD, and (2) clarify the mechanism that influences cerebral oxygenation in HD patients. METHODS: Eighteen HD patients and 12 healthy controls were recruited. Regional saturation of oxygen (rSO2) was continuously monitored in the frontal cortex using INVOS 5100C before, during, and after HD, and in healthy controls. Relative change in BV (%ΔBV) was simultaneously monitored during HD using a BV monitor. RESULTS: Before HD, patients had significantly lower rSO2 values than controls (56.1 ± 1.4 vs. 70.4 ± 2.5%, p < 0.001). Although %ΔBV significantly decreased from 20 min to the end of HD (20 min: -3.3 ± 0.3%, p < 0.05; end of HD: -12.0 ± 1.0%, p < 0.01), changes in rSO2 values during HD were not significant. No relationship existed between rSO2 values and blood pressure levels, hemoglobin levels, oxygen pressure, HCO3(- ), oxygen saturation, and arterial O2 content before and after HD. Furthermore, changes in rSO2 were not correlated with changes in these parameters. CONCLUSION: rSO2 values before HD were significantly lower in HD patients than in healthy controls. rSO2 values were maintained during HD and were not influenced by BV reduction.

A case of sarcoidosis with severe acute renal failure requiring dialysis.

We report here a 79-year-old male having sarcoidosis without presentation of typical findings, such as respiratory symptoms, ocular signs, or skin lesions. Two weeks prior to admission to our hospital, he presented to a different hospital with acute renal failure, with blood urea nitrogen (BUN) and serum creatinine (Cr) levels of 67.9 mg/dl and 7.97 mg/dl, respectively, and was initiated on hemodialysis. The patient also exhibited fever, severe anorexia, and fatigue. We initially experienced difficulty in performing kidney biopsy due to a thrombocytopenia complication and severe general debility. Tuberculosis and other malignancies were not found. However, bone marrow biopsy revealed noncaseating granuloma with multinucleated giant cells, and the patient's serum angiotensin converting enzyme (ACE) level was slightly elevated at 24.3 U/l. We informed the patient and his family of the risk of a kidney biopsy and subsequently received informed consent for the procedure. The biopsy showed many epitheloid granulomas with multinucleated giant cells in the interstitium, from which we diagnosed sarcoidosis. The thrombocytopenia was subsequently found to be due to heparin-induced thrombocytopenia (HIT). After administering 20 mg/day of oral prednisolone, the patient's general condition improved rapidly. Therefore, it is important to take sarcoidosis into account as a differential diagnosis of acute renal failure, and kidney biopsy offers useful information in these cases.

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.

Risk Factors and Utility of Intraoperative Arteriovenous Fistula Blood Flow Level as a Surrogate Marker of Arteriovenous Fistula Failure in Patients with End-stage Renal Disease.

An arteriovenous fistula (AVF) can fail for different reasons at each stage after its creation. The study aimed to analyze the associations of the clinical and laboratory parameters, including the intraoperative AVF blood flow, with AVF failure at different periods (3 weeks and 3, 6, 9, 12, 24, and 36 months) after the AVF's creation and to evaluate the usefulness of the intraoperative AVF blood flow as a surrogate marker of AVF failure in patients with end-stage renal disease (ESRD). This was a single-center, retrospective cohort study that included 130 patients with ESRD who underwent the creation of new radiocephalic AVFs. The associations of the preoperative clinical and laboratory parameters and intraoperative flow with AVF failure in the different observation periods were investigated. Intraoperative AVF blood flow was significantly associated with AVF failure from 3 weeks to 24 months (P <0.05). Hemoglobin level and the size of the anastomosis were significantly associated with AVF failure at 6 months (P <0.05). In the analysis of the receiver operating characteristic curve, intraoperative AVF blood flow was significant from 3 weeks to 24 months (P <0.05). The intraoperative blood flow with the greatest sensitivity and specificity was 205-225 mL/min. Intraoperative blood flow was independently associated with AVF failure from 3 weeks to 24 months after the AVF's creation. An intraoperative AVF blood flow of >225 mL/min is crucial for long-term AVF patency. The intraoperative AVF blood flow level could be a surrogate marker of AVF failure in ESRD patients.

Factors associated with recovery of renal function in patients with multiple myeloma who were treated with hemodialysis.

BACKGROUND: The presence of renal failure in patients with multiple myeloma (MM) has been considered an ominous prognostic factor associated with a significantly decreased life expectancy. The prognostic factors have seldom been analyzed to predict discontinuation of hemodialysis (HD) therapy in MM patients with renal failure after HD initiation. It is clinically very important to predict whether HD can be discontinued after introducing HD in such patients. METHODS: All medical and HD records were reviewed in MM patients who underwent HD in the National Center for Global Health and Medicine Hospital between January 1995 and May 2009. Thirty-two patients with MM had undergone HD. The clinical features and the factors that might be associated with recovery of renal function leading to discontinuation of HD in MM patients with severe renal failure were examined. RESULTS: The factors associated with recovery of renal function and discontinuation of HD were: low International Staging System (ISS) score (p = 0.0034); high response to chemotherapy (p = 0.036); low serum Ca (p = 0.006); low Cr (p = 0.019), and low serum ß2-microglobulin (sß2M) (p = 0.002). On multivariate analysis, low serum Ca and sß2M were significantly associated with HD discontinuation. Moreover, discontinuing HD was the significant factor associated with improved overall survival in MM patients who required HD at least once. CONCLUSION: sß2M and Ca were the laboratory parameters that were significant, independent prognostic factors for predicting the probability of recovery from severe renal failure and discontinuation of HD in MM patients who needed HD at least once.

Clinical factors affecting cerebral oxygenation in patients undergoing peritoneal dialysis.

BACKGROUND: Although cerebral regional oxygen saturation (rSO2) is significantly lower in hemodialysis (HD) patients than that in healthy controls, investigations on cerebral oxygenation in peritoneal dialysis (PD) patients are limited. We aimed to confirm the cerebral oxygenation status and identify the factors affecting cerebral rSO2 in PD patients. METHODS: Thirty-six PD patients (21 men and 15 women; mean age, 62.8 ± 12.7 years) were recruited. In addition, 27 healthy volunteers (17 men and 10 women; mean age, 43.5 ± 18.8 years) were recruited as a control group. Cerebral rSO2 was monitored at the forehead using an INVOS 5100c oxygen saturation monitor. RESULTS: Cerebral rSO2 was significantly lower in PD patients than that in healthy controls (57.0 ± 7.3% vs 68.9 ± 8.6%, p < 0.001); moreover, cerebral rSO2 was significantly correlated with natural logarithm (Ln)-PD duration (r = -0.389, p = 0.019) and serum albumin concentration (r = 0.370, p = 0.026) in a simple linear regression analysis. Multivariable linear regression analysis was performed using variables that showed a significant correlation and p < 0.20 (serum creatinine, serum sodium, Ln-C-reactive protein, and dosage of erythropoiesis-stimulating agent) with the cerebral rSO2. Cerebral rSO2 was independently associated with Ln-PD duration (standardized coefficient: -0.339) and serum albumin concentration (standardized coefficient: 0.316). CONCLUSIONS: Cerebral rSO2 was significantly affected by the PD duration and serum albumin concentration. Further prospective studies are needed to clarify whether preventing a decrease in serum albumin concentration leads to the maintenance of cerebral oxygenation in patients undergoing PD.

Antiepoetin antibody-related pure red cell aplasia: successful remission with cessation of recombinant erythropoietin alone.

An elderly patient with pure red cell aplasia (PRCA) with antierythropoietin (anti-EPO) antibodies is described. PRCA due to alloimmunization is a rare and severe complication of recombinant human erythropoietin (rHu-EPO) therapy. Most reported patients with PRCA were cured primarily by immunosuppressive drug therapy. The patient in this case, however, did not want to receive any immunosuppressive drugs. Therefore, rHu-EPO injection was simply discontinued, the severe anemia gradually improved, and the hemoglobin approached normal range. This case is very rare and significant in that there have been few such elderly patients with rHu-EPO-induced PRCA in whom PRCA remission was achieved, with decreasing antibody titers, after cessation of rHu-EPO alone. Further cases are needed to assess how PRCA should be treated in patients with anti-EPO antibodies.

Eosinophilic peritonitis induced by sucroferric oxyhydroxide.

A 49-year-old woman developed eosinophilic peritonitis 2 months after starting continuous ambulatory peritoneal dialysis because of congenital right kidney hypoplasia and chronic glomerulonephritis. This was shown to have been induced by sucroferric oxyhydroxide, an iron-based phosphate binder, using a drug-induced lymphocyte stimulation test. Her eosinophilic peritonitis was improved after stopping the administration of sucroferric oxyhydroxide without providing any immunosuppressive agents.

Cerebral oxygenation improvement is associated with hemoglobin increase after hemodialysis initiation.

INTRODUCTION: Near-infrared spectroscopy has been used to measure the regional oxygen saturation (rSO2) of the brain, and decreases in cerebral rSO2 have been reported to lead to cognitive impairment in patients undergoing hemodialysis. However, reports about the association between changes in cerebral oxygenation and clinical parameters at hemodialysis initiation, including hemoglobin level, are lacking. METHODS: This study included 33 patients at the hemodialysis initiation phase. Cerebral rSO2 was monitored using an INVOS 5100C. Included patients were assessed twice (at hemodialysis initiation and 42.7 ± 20.8 days after the first measurement), and changes in cerebral rSO2 were compared with changes in clinical parameters. RESULTS: Cerebral rSO2 at the second measurement significantly increased compared with that at hemodialysis initiation (57.2 ± 6.8% vs 54.4 ± 8.8%, p < 0.05). Changes in cerebral rSO2 represented a significant correlation with changes in hemoglobin level, pulse rate, and serum albumin level. Multivariate linear regression analysis was performed using significant factors in simple linear regression analysis. Changes in hemoglobin (standardized coefficient: 0.37) and serum albumin (standardized coefficient: 0.45) levels were identified as independent factors influencing the changes in cerebral rSO2. CONCLUSION: Cerebral rSO2 was low in the presence of low hemoglobin levels at hemodialysis initiation and improved in response to hemoglobin increase in addition to changes in serum albumin levels. Attention should be paid to changes in hemoglobin levels even at hemodialysis initiation to prevent the deterioration of cerebral oxygenation, and this might contribute to the maintenance of cognitive function in patients undergoing hemodialysis.

Induction of hemodialysis with an arteriovenous fistula in a patient with hemophilia A.

An 88-year-old man with congenital hemophilia A developed end-stage renal disease due to microscopic polyangiitis. He was at risk for catheter-related infection because he was taking immunosuppressive agents for the treatment of polyangiitis. He was also unable to manipulate the peritoneal dialysis device. Therefore, hemodialysis using an arteriovenous fistula was induced for renal replacement therapy. Recombinant coagulation factor VIII (1000 IU) was administered via the venous chamber of the hemodialysis circuit 10 min before the end of each hemodialysis session, and nafamostat mesylate (25 mg/h) was employed as an anticoagulant during hemodialysis. His clotting factor VIII activity level increased to > 50% and activated partial thromboplastin time decreased to 50 s at the end of each hemodialysis session. This method allowed him to achieve hemostasis at the puncture site of the arteriovenous fistula and undergo stable hemodialysis with no complications, including bleeding. This case suggests that hemodialysis using an arteriovenous fistula with coagulation factor replacement and nafamostat mesylate in each hemodialysis session is a therapeutic option for end-stage renal disease in patients of advanced age with hemophilia at high risk of bleeding.

Factors Associated with Uremic Pruritus in Patients Undergoing Peritoneal Dialysis.

AIM: The aim of this study was to investigate different intensities of uremic pruritus in the daytime and nighttime, as well as contributing factors, in patients undergoing peritoneal dialysis (PD). METHODS: A total of 46 patients (31 males, 15 females) with a mean age of 59.4±14.7 years and mean PD vintage of 29.2±25.2 months were enrolled in this single-center, prospective, cross-sectional study. The intensity of uremic pruritus in the daytime and nighttime was assessed using a visual analog scale (VAS). The relationships between intensity and various clinical and laboratory parameters were analyzed using multiple linear regression analyses. RESULTS: The most common site of uremic pruritus was on the back (70%), followed by lower limbs (67%), chest and abdomen (59%), upper limbs (28%), and head and neck (22%). Mean VAS scores were higher in the nighttime compared with the daytime (4.5±3.3 vs. 3.5±2.7, P=0.02). Only male sex was correlated with higher uremic pruritus intensity in the daytime (standard coefficient [ß]=0.310, P=0.036). PD vintage (ß=0.415, P=0.004) and topical medicines, including moisturizer and topical corticosteroid use (ß=0.345, P=0.019), were independently correlated with higher uremic pruritus intensity in the nighttime. CONCLUSION: Uremic pruritus intensity was greater in the nighttime than in the daytime in PD patients. Male sex was associated with higher uremic pruritus intensity in the daytime, whereas PD vintage and topical medicine use were associated with higher uremic pruritus intensity in the nighttime.