Objective To explore the association of access blood flow measured by ultrasound dilution and color Doppler ultrasound with patency loss of arteriovenous fistula (AVF). Methods This was a bidirectional cohort study. The adult patients who underwent maintenance hemodialysis (MHD) with AVF in Peking University First Hospital from January 1, 2018 to July 31, 2020 were enrolled. AVF blood flow was measured by ultrasonic dilution method (Qa), and color Doppler ultrasound in cephalic vein and brachial artery. Patients were divided into low Qa (<500 ml/min), normal Qa (500-1 500 ml/min) and high Qa (>1 500 ml/min) groups according to baseline AVF blood flow measured by ultrasonic dilution method. Qa was monitored every 3 months within the first year. The endpoint events of follow-up were defined as AVF patency loss or death. The deadline of the follow-up was July 31, 2022. Linear regression analysis was used to assess the change trend of Qa. Fine and Gray competitive risk model was used to evaluate the cumulative incidence of AVF patency loss. The Cox proportional hazards regression model was used to evaluate the association between access AVF blood flow and patency loss. Results A total of 163 patients were enrolled, with age of (57.0±13.7) years old and 110 males (67.5%). The median follow-up time was 45(22, 53) months. Forty-four patients (27.0%) had AVF failure, and 29 patients (17.8%) died. The cumulative incidence rates of AVF patency loss in patients with low Qa, low blood flow of brachial artery and cephalic vein (<500 ml/min), and in those with a downward trend of Qa were higher than those in patients with normal or high blood flow, and in those with a upward trend of Qa (Gray′s test, all P<0.05). After adjusted for age, sex, age of fistula, diabetes and vascular stenosis, multivariable Cox regression analysis results showed that baseline Qa<500 ml/min (HR=3.508, 95% CI 1.382-8.905, P=0.008), baseline brachial artery flow<500 ml/min (HR=2.413, 95% CI 1.058-5.503, P=0.036) and a downward trend of Qa (HR=2.498, 95% CI 1.241-5.027, P=0.010) were independently associated with AVF patency loss. Conclusions Patients with low baseline value or downward trend of AVF blood flow are at significantly higher risk of patency loss. The brachial artery measurement of AVF blood flow is the preference location for color Doppler ultrasonic.

Objective To investigate the association of early serum potassium level with all-cause mortality in adult maintenance hemodialysis (MHD) patients. Methods It was a retrospective cohort study. The data of patients newly entered MHD in the registration system of Zhejiang province dialysis quality control center from January 1, 2010 to December 31, 2019 were collected. Follow-up was conducted until December 31, 2020. The average value of predialysis serum potassium within the first 3 months starting hemodialysis was defined as early serum potassium, and patients were divided into 6 groups according to their early serum potassium levels. Death within 1 year of MHD patients was defined as short-term death. Kaplan-Meier method was used to compare the long-term and short-term survival rates of the six groups. Cox regression model was used to analyze the association of different serum potassium levels with the short-term all-cause mortality of adult MHD patients. Results A total of 27 362 patients aged (61.2±14.4) years old were included, including 16 775 males (61.3%), 1 303 patients (4.8%) with hypokalemia (serum potassium<3.5 mmol/L) and 10 034 patients (36.7%) with hyperkalemia (serum potassium≥5.0 mmol/L). Among them, there were 5 145 patients (18.8%) with serum potassium≥5.5 mmol/L. According to the early serum potassium levels, the patients were divided into group 1 (serum potassium<3.5 mmol/L), group 2 (3.5≤ serum potassium<4.0 mmol/L), group 3 (4.0≤serum potassium<4.5 mmol/L), group 4 (4.5≤serum potassium<5.0 mmol/L), group 5 (5.0≤serum potassium<5.5 mmol/L) and group 6 (serum potassium≥ 5.5 mmol/L), respectively. Until the end of follow-up, the follow-up time was (40.7±27.8) months and 5 400 patients died. Cardiovascular and cerebrovascular diseases [1 551 cases (28.7%)] and infections [366 cases (6.8%)] were the main causes of death. Kaplan-Meier survival analysis showed that the long-term and short-term cumulative survival rates in the serum potassium<3.5 mmol/L group were the lowest among the 6 groups (Log-rank test, χ²=119.0, P<0.001; χ²=74.6, P<0.001, respectively). Multivariate Cox regression analysis showed that early serum potassium<3.5 mmol/L was an independent influencing factor for short-term all-cause death in MHD patients (with 4.5≤serum potassium<5.0 mmol/L as reference, HR=1.54, 95% CI 1.26-1.89, P<0.001). In the subgroup of age≥65 years, multivariate Cox regression model showed that serum potassium<4.5 mmol/L was independently associated with short-term death in MHD patients (with 4.5≤ serum potassium< 5.0 mmol/L as reference, serum potassium<3.5 mmol/L, HR=2.16, 95% CI 1.69-2.75, P<0.001; 3.5≤serum potassium<4.0 mmol/L, HR=1.40, 95% CI 1.14-1.72, P=0.001; 4.0≤serum potassium< 4.5 mmol/L, HR=1.46, 95% CI 1.21-1.75, P<0.001), while in the subgroup of age<65 years, serum potassium level was not significantly associated with short-term mortality risk in MHD patients. The early serum potassium level was associated with the risk of short-term all-cause death in a "U" shape, and both low and high potassium levels increased the risk of short-term all-cause death. The optimal early blood potassium level was about 4.75 mmol/L. Conclusions The prevalence of hypokalemia at early stage of dialysis in adult MHD patients is about 4.8%. There is a U-shaped association between early serum potassium level and short-term (1 year) all-cause mortality risk, and early serum potassium<3.5 mmol/L is an independent risk factor for long-term and short-term all-cause mortality in MHD patients.

Objective To explore the risk factors of hypotension in patients with hemodialysis-related superior vena cava diseases. Methods This was a retrospective cohort study. The maintenance hemodialysis patients diagnosed as superior vena cava stenosis ≥50% or occlusion in West China Hospital of Sichuan University from January 1, 2019 to March 31, 2022 were selected. The patients were divided into hypotensive group and non-hypotensive group according to the occurrence of hypotension during non-dialysis period. The differences of general clinical data, cardiac ultrasound parameters and blood biochemical indexes between the two groups were compared. Multivariate logistic regression model was used to analyze the risk factors of hypotension in patients with hemodialysis-related superior vena cava lesions. Results A total of 202 patients with hemodialysis-related superior vena cava lesions were included, of whom 84 patients (41.6%) developed hypotension during non-dialysis. Compared with the non-hypotensive group, patients in the hypotensive group had longer dialysis age (Z=2.093, P=0.036), shorter left atrial diameter (t=2.316, P=0.022), lower aortic valve orifice flow rate (t=3.702, P=0.001) and serum calcium (t=2.320, P=0.021), thicker left ventricular posterior wall (t=3.042, P=0.003), lower proportions of hypertension history ( χ²=9.125, P=0.003), and higher proportion of residual superior vena cava ≤30% or occlusion ( χ²=8.940, P=0.003) and azygous vein opening ( χ²=11.067, P=0.001). Multivariate logistic regression analysis results showed that no history of hypertension (OR=0.383, 95% CI 0.156-0.943, P=0.037), slow aortic valve orifice flow (OR=0.207, 95% CI 0.062-0.695, P=0.011) and low blood calcium (OR=0.236, 95% CI 0.066-0.841, P=0.026) were the independent influencing factors of hypotension in patients with hemodialysis-related superior vena cava diseases. Conclusions Hemodialysis patients with severe stenosis or occlusion of the superior vena cava during non-dialysis have a higher risk of hypotension. No history of hypertension, slow aortic valve orifice flow, and low blood calcium are the independent risk factors of hypotension in patients with hemodialysis-related superior vena cava diseases.

Objective To investigate the effect of music therapy on depression and anxiety status in maintenance hemodialysis (MHD) patients. Methods The study was a single-center, open, and randomized controlled trial. The patients with regular hemodialysis of more than 3 months and the Beck depression inventory (BDI) scores ≥10 in China Rehabilitation Research Center from March 1 to April 24, 2021 were selected. Random envelope method was used to divide the enrolled patients into music group and control group. The music therapist selected the treatment music and established the preset repertoire library in the music therapy programs，and the total duration of music was about 2 hours. The music group received listening music therapy of 1.0 to 1.5 hours 3 times a week during routine hemodialysis treatment, while the control group only received routine hemodialysis treatment. All the enrolled patients completed treatment of 8 weeks. The BDI and state-trait anxiety inventory (STAI) were used to assess the psychological status of MHD patients before and after treatment. Results A total of 64 MHD patients were enrolled, aged (59.19±11.61) years old, among whom 38 patients (59.38%) were males. There were 32 patients in the music group and 32 patients in the control group. BDI scores [2 weeks (9.81±6.25) scores, 8 weeks (8.30±8.49) scores, F=49.75, P<0.001] and STAI scores [2 weeks (49.30±7.27) scores, 8 weeks (47.07±7.39) scores, F=13.09, P<0.001] in the music group decreased significantly after 2 weeks of treatment and remained stable for 8 weeks. After treatment, the BDI scores in the music group were significantly lower than those in the control group [2 weeks (9.81±6.25) scores vs (14.13±7.33) scores, t=-2.53, P=0.014; 8 weeks (8.30±8.49) scores vs(12.56±5.67) scores, t=-2.34, P=0.023], and STAI scores in the music group were significantly lower than those in the control group [2 weeks (49.30±7.27) scores vs (54.00±8.36) scores, t=-2.06, P=0.043; 8 weeks (47.07±7.39) scores vs (51.34±8.87) scores, t=-2.06, P=0.044]. Conclusion Music therapy can improve depression and anxiety of MHD patients quickly and effectively.

Objective To establish an in vitro culture system of small intestinal organoid in normal mice and perform functional identification, and to provide an in vitro research tool for material transport in the intestine under chronic kidney disease. Methods The small intestinal crypts of C57BL/6J mice were isolated, extracted and cultured in an in vitro three dimension culture system. The formation of small intestinal organoid was observed with inverted microscope. The tissue structure of the small intestinal organoid was observed by hematoxylin and eosin staining. The cellular composition of the small intestinal organoid was identified by immunofluorescence. The expression of substance absorption-related transporters in the small intestinal organoid was detected by real time fluorescence quantitative PCR. Results The small intestinal crypts were successfully extracted. The organoids of small intestine and different intestinal segments were successfully constructed. The cultured organoids had vigorous proliferation ability and maintained proliferation ability after passing through generations. Immunofluorescence results showed that the small intestinal organoids expressed mucin2, chromogranin A, oflm4 and lysozyme, which were different types of intestinal cell biomarkers. The PCR results showed that small intestinal organoids expressed calcium, phosphate and sodium absorption-related transporters, and the mRNA expression levels of major transporters for sodium and phosphate absorption in different intestinal segments-like organs were consistent with those in vivo, which was consistent with the characteristics of small intestinal segmental absorption. Conclusions The successful construction of small intestine and different intestinal segments organoids, and the first observation of the expression of substance absorption-related transporters in such organoid, provide a stable and convenient in vitro research tool for the development of intestinal substance transport in chronic kidney disease.

In recent years, the incidence rate of end-stage kidney disease (ESKD) in China has increased year by year. About 2% of patients enter ESKD every year. Peritoneal dialysis (PD) has been widely used in ESKD patients all over the world, especially in developing countries, because of its simple, safe, effective and home based treatment. Since continuous ambulatory peritoneal dialysis was introduced to China in 1978, Chinese nephrology professionals have made remarkable achievements in PD management after decades of joint efforts. However, they still face many challenges. In order to investigate the status of quality indicators of PD centers, the construction of centers, PD prescriptions and adjustments, diagnosis and treatment of complications, adequacy assessment, long-term follow-up status of patients, disease burden and risk perception of chronic kidney disease in China, the project group of the white paper carried out three rounds of questionnaires nationwide, objectively and comprehensively analyzed the survey results, and organized experts to prepare the white paper. The white paper clearly reviewed the current situation of PD construction and management in China, and also found some problems that need to be solved. It still needs to further standardize the staffing of PD centers, strengthen the training of PD professionals, expand the full-time medical staff, pay attention to quality management, reduce the incidence of PD related complications, and improve the long-term survival rate and quality of life of PD patients.