Relationship between hemoglobin variability and prognosis in dialysis patients

Objective To investigate the epidemiological characteristics of hemoglobin variability (Hb-Var) in dialysis patients, and to explore the factors related to Hb-Var and the relationship between Hb-Var and patients outcomes. Methods The study enrolled 178 hemodialysis and peritoneal dialysis patients in the Department of Nephrology, Peking University People's Hospital between October 2009 and March 2010. First six months were observation period, and then followed up for 12 months. The Hb-Var was described by residual standard deviation (Res-SD) and fluctuation across threshold of the Hb level. Non-fatal cardiovascular events and mortality were the primary endpoints. Results The Res-SD was (4.74±2.66) g/L in dialysis patients. Most patients fell into groups of high amplitude (HA) and low amplitude low (LAL), with frequency of 29.8% and 33.1% respectively. The related factors of Hb-Var were fluctuation of erythropoietin (EPO) dosage and hemodialysis. Kaplan-Meier survival curve and multivariable adjusted Cox regression indicated that Res-SD had no impact on the primary endpoints. Accumulative time to reach target hemoglobin level was an independent factor related to outcome. Conclusion Hb-Var occurs commonly in dialysis patients. The fluctuation of EPO dosage and dialysis style increase Hb-Var. Accumulative time to reach target hemoglobin level is an independent factor related to patients outcomes.     

Heart rate variability predicts mortality in peritoneal dialysis patients

Abstract

Background: The predictive value of heart rate variability (HRV) in peritoneal dialysis (PD) has never been tested. Methods: In this study, the associations between HRV measures and the mortality in 81 PD patients were analyzed. HRV was measured by using 5-min recordings of a stationary system by a standardized method. Both time domain and frequency domain parameters were analyzed. Results: During a follow-up period of 43.78?±?14.77 months, 25 patients died, four patients were transferred to hemodialysis. Of the 81 patients, the time domain parameters, such as the standard deviation of differences between adjacent normal sinus to normal sinus (NN) intervals (SDSD) and the square root of the mean of the squared differences between adjacent normal NN intervals (RMSSD), were higher; the frequency domain parameters, such as the ratio of low-frequency power to high-frequency power (LF/HF) and the normalized LF, were lower, and the normalized HF was higher in the non-survived group as compared with the survived group. A Cox proportional hazards model analysis revealed that, of the HRV measures, decrease of the normalized LF, LF/HF and increase of rMSSD, SDSD, normalized HF had significant predictive value for mortality. After adjustment for other univariate predictors including age, urine volume, renal Kt/V, high-sensitivity C-reactive protein (hs-CRP), the predictive value of decreased LF/HF remained significant. Kaplan–Meier survival analysis showed mortality rate was much higher in patients with a low LF/HF (median value of 1.56). Conclusion: The decreases of LF/HF which reflects impaired sympathetic nerve regulation is an independent predictor of mortality in PD patients.     

Determinants of haemoglobin carbamylation in haemodialysis and peritoneal dialysis patients.

BACKGROUND: Carbamylation is an irreversible process of non-enzymatic modification of proteins by the breakdown products of urea. For haemoglobin (Hb), the extent of carbamylation is a marker of urea exposure and has been proposed as an indicator of the control of uraemia by dialysis, analogous to the use of Hb glycosylation in diabetic patients. METHODS: We performed a cross-sectional study of haemodialysis (HD) and peritoneal dialysis (PD) patients in order to study potential determinants of carbamylated Hb (CarbHb) and to investigate the relationship between CarbHb and established measures of dialysis dose/adequacy by multivariate analysis. RESULTS: In 80 HD patients, CarbHb was independently predicted by post-dialysis urea (r=0.40, P:<0.01), serum albumin (r=0.24, P:<0.05) and serum bicarbonate (r=-0.40, P:<0. 05). No correlation was found between CarbHb and measures of dialysis dose/adequacy (Kt/V, urea reduction ratio, weekly dialysis duration, and normalized protein catabolic rate (nPCR)). In 42 PD patients, serum urea was the only significant independent predictor of CarbHb (r=-0.51, P:=0.001). No relationship was found between CarbHb and Kt/V, corrected creatinine clearance (CrCl) or nPCR in PD patients. CONCLUSIONS: Serum urea is the most consistent independent predictor of CarbHb in dialysis patients. This association in combination with the lack of a relationship with conventional measures of dialysis dose and a positive relationship with serum albumin suggest that a single measurement of CarbHb is unlikely to be a useful indicator of the adequacy of dialysis.     

Correlation between glycosylated hemoglobin and carotid intima-media thickness in non-diabetic peritoneal dialysis patients

Objective To investigate the correlation between glycosylated hemoglobin (HbA1c) and carotid intima?media thickness (CIMT) in non?diabetic peritoneal dialysis patients. Methods Forty?two non?diabetic peritoneal dialysis adult patients were enrolled in this study [mean age was (48.2±12.3) years, 50% was male]. CIMT was determined by carotid ultrasound. Patients were divided into two groups according to CIMT: CIMT normal group (CIMT＜0.9 mm) and CIMT thickening group (CIMT≥0.9 mm). HbA1c, 2?hour postprandial blood glucose (2hPBG) and other factors of the patients were analyzed with Spearman rank correlation and multiple linear regression. Results CIMT was correlated with age, 2hPBG, LDL?C, TG, TC, HbA1c in non?diabetic peritoneal dialysis patients (r＝0.355, 0.373, 0.416, 0.345, 0.351, 0.456, all P＜0.05). Multiple linear regression showed that HbA1c was the most powerful influence factor of CIMT（β＝0.459）. Conclusion HbA1c level is positively correlated with CIMT and may be a predictor of carotid atherosclerosis in non?diabetic peritoneal dialysis patients.     

Hyponatremia in peritoneal dialysis patients

BACKGROUND: Low serum sodium is uncommon in peritoneal dialysis (PD), which is surprising in view of the important role of normal kidney function to regulate water and sodium balance. METHODS: We report 2 cases of persistent hyponatremia with balance studies in Case 1. We performed measurements of dialysate sodium and volume output over 24 hours in a group of chronic PD patients. RESULTS: The low serum sodium concentration did not vary too much with overall fluid removal via dialysis in patient 1, mainly because large quantities of sodium were removed in the dialysate. In the 24-hour studies, a significant relationship was found between net daily PD sodium removal and net daily dialysate volume removed (r = 0.65). There was no relationship between net daily PD sodium removal and serum sodium concentration. There was a linear direct correlation between serum and dialysate sodium concentration (r = 0.8) as shown by others previously. CONCLUSIONS: These results suggest that the main determinant of PD sodium loss is net dialysate ultrafiltration volume. Water loss via dialysis is necessarily associated with sodium loss. In order to maintain a normal serum sodium concentration salt intake must be proportional to the water loss induced by dialysis. The stimuli that allow dialysis patients to maintain this delicate balance between water and salt intake are of considerable interest but remain undetermined.     

Encapsulating peritoneal sclerosis in paediatric peritoneal dialysis patients

Encapsulating peritoneal sclerosis (EPS) is a serious complication of chronic peritoneal dialysis (CPD). In contrast to the adult population, there are few studies regarding EPS in paediatric CPD patients, and the majority of reported patients are from Japan. The aim of the present report is to define the incidence of EPS in our paediatric CPD patients and to describe the clinical and laboratory characteristics. A total of 104 paediatric patients were followed from November 1989 to November 2003 and two were diagnosed as EPS (1.9%). The dialysis periods of these patients were 45 and 53 months with 6 and 8 peritonitis episodes, respectively. Clinical signs of EPS developed 7 and 14 days after the removal of the dialysis catheter, and CPD was replaced by haemodialysis because of persistent peritonitis. One patient was well after surgical management but died 6 months later. The second patient who was treated with prednisolone remained well at 16 months. In conclusion, EPS is a rare but important complication of CPD. We recommend that all patients on CPD who develop ultrafiltration failure be evaluated radiologically for the occurrence of EPS. Management should be tailored to the individual patient.     

Effects of seasonal changes on peritoneal dialysis associated peritonitis in peritoneal dialysis patients

Objectives To investigate the effects of seasonal changes on peritoneal dialysis associated peritonitis (PDAP) in patients on peritoneal dialysis (PD), and to provide evidence for clinical prevention and treatment of PDAP. Methods All episodes of PD-related peritonitis during clinic follow-up in maintenance PD patients from Jan 1st, 2007 to Dec 31st, 2015 in Peking University People's Hospital were reviewed. The incidence of peritonitis, laboratory indexes, pathogens and clinical outcomes in different seasons were recorded and analyzed. One-way ANOVA and chi square test were employed to compare the incidence of PDAP and related data in different seasons, and Pearson correlation was used to analyze correlations between PDAP rate and monthly mean temperature and mean humidity. Results During nine years, a total of 119 PD patients occurred 190 times of peritonitis during home PD. The PDAP rate in summer was the highest, 0.21 episodes/year, followed by spring (0.16 episodes/year) and autumn (0.16 episodes/risk year), but there was no significant difference among peritonitis rates in four seasons. There were significant positive correlation between monthly mean temperature, monthly mean humidity and the peritonitis rate (mean temperature: r=0.828, P＜0.01; mean humidity r=0.657, P＜0.05). (2) As for bacteria, in Summer the PDAP rate caused by Staphylococcus aureus and Coagulase negative staphylococcus (CoNS), and Gram-negative bacteria was higher than that in other seasons, but there was no statistical difference. There were significant positive correlation between monthly mean temperature, mean humidity and the rate of CoNS peritonitis (mean temperature: r=0.704, P＜0.05; mean humidity: r=0.607, P＜0.05). (3) There were no statistical difference among results of PD related peritonitis in different seasons about general situation, clinical manifestation, causes of peritonitis and laboratory index before peritonitis episodes. PD procedure-related problems were the main cause of peritonitis in summer and autumn. (4) The cure rate of all peritonitis was 90%. The highest cure rate was in autumn and winter, while the lowest cure rate was in summer, but no statistical difference. Among the peritonitis episodes with treatment failure, 52.6% occurred in summer. Conclusions There is some correlation between the rate of PDAP and seasons. Higher temperature and higher humidity were significantly correlated with higher peritonitis rate, especially the rate of CoNS peritonitis. The prognosis of PDAP in summer was relatively poor, with higher proportion of hospitalization and lower cure rate.     

Pneumoperitoneum in peritoneal dialysis patients.

The prevalence and clinical significance of pneumoperitoneum in peritoneal dialysis (PD) patients is not fully defined in current literature and some reports suggest that unlike in non-PD patients, it is rarely caused by gastrointestinal perforation. We reviewed 403 chest X-ray films of the 118 PD patients following our PD program in 1995-96, in order to define the prevalence of pneumoperitoneum. We found pneumoperitoneum in 3.7% of the X-rays (15/403) from five patients (4.2%). Its causes might have been: faulty bag exchange technique in two cases and extension tube exchange in three. One patient suffered from a simultaneous episode of peritonitis. Our data and the literature review suggest that 0-11% of pneumoperitoneum episodes in PD patients are due to gastrointestinal perforation; the main causes generally are abdominal operations and catheter manipulation. The amount of air is not useful in assessing the cause of pneumoperitoneum, which takes some weeks to disappear. Computed tomography is more sensitive than standard X-ray in diagnosis.     

Fatigue in chronic peritoneal dialysis patients

Fatigue is a common complaint in long termdialysis patients that may influence theirquality of life. The present study was carriedout in order to evaluate the prevalence andcourse of fatigue in a group of chronic PDpatients and to find the possible factor(s)related to its development. We retrospectivelyreviewed 100 charts of the patients previouslyon PD. The presence or absence of fatigue inthe 1st and last clinic visits and the 1st and2nd changes in fatigue state were studiedaccording to the monthly clinical records ofthe primary nurses. Data regarding dialysatevolume, urine volume, weekly erythropoietin(EPO) dose, hemoglobin, hematocrit, blood urea,serum creatinine, residual renal creatinine andurea clearances, dialysate to peritonealcreatinine ratio (D/P Cr), total weekly Kt/Vand total creatinine clearance/l.73 m² bodysurface area (TCrCl) were collected. Fifty-fivepatients were male and 45 female. The mean ageat the 1st clinic visit was 61.3 ± 16 years.At the 1st visit 55 patients had fatigue and 45did not. In 32 of the 55 patients fatiguedisappeared after a mean duration of 7.9 ± 8.4months and in 31 of the 45 patients fatigueappeared after a mean duration of 8 ± 6.8months. So at the last visit the frequency offatigue increased significantly from 55% to67% (p < 0.001). In patients with fatigue themean age and female percentage were higher(64.2 ± 14.1 vs 57.8 ± 17.6, p = 0.05 and 1.2vs 0.5, p < 0.05 respectively), mean hemoglobinconcentration was lower (104.4 ± 14.7 vs110.6 ± 14.2 g/L, p < 0.04) and mean EPO dosewas higher (6379.6 ± 7142 vs 3395.4 ± 4337.8units/week, p < 0.02) at the 1st clinic visit.EPO dose was also higher in patients withfatigue at the last visit (8253.7 ± 10317.3units/wk vs 4736.4 ± 5432.5, p < 0.03). Nocorrelation was found between dialysis adequacyaccording to either weekly Kt/V or TCrCl andnutritional state according to nPCR andfrequency of fatigue. We conclude that fatigueis a common symptom in PD patients and it'sprevalence increases over time. Anemia seemsto be the most important factor associated withfatigue. Dialysis adequacy and nutritionalstate did not show any correlation with thefrequency of fatigue in our study.     

Avoiding harm in peritoneal dialysis patients

This review is focused on minimizing complications and avoiding harm in peritoneal dialysis (PD) patients. Issues related to planning for PD are covered first, with emphasis on PD versus hemodialysis outcomes. Catheter types and insertion techniques are described next, including relevant recommendations by the International Society for Peritoneal Dialysis. A brief review of both noninfectious and infectious complications follows, with emphasis on cardiovascular and metabolic complications. Finally, recommendations for preventing PD-related infections are provided. In conclusion, with proper catheter insertion technique, good training, and attention to detail during the tenure in PD, excellent outcomes can be obtained in a well-informed motivated patient.     

Hyperkalemia in chronic peritoneal dialysis patients

Background. Chronic peritoneal dialysis (PD) patients often develop hypokalemia but less commonly hyperkalemia.Methods. We explored incidence and mechanisms of hyperkalemia in 779 serum samples from 33 patients on PD for 1 − 59 months. Normal serum potassium concentration was defined as 3.5 − 5.1 meq/l.Results. Mean monthly serum potassium concentrations were normal (except for 1 month), but we observed hypokalemia (<3.5 meq/l) in 5% and hyperkalemia (>5.1 meq/l) in 14% of 779 serum samples. Incidence of hyperkalemia did not change over time on PD: Year 1 (15%), Year 2 (11%), Year 3 (19%), Years 4–5 (22%). Hyperkalemia was mostly modest but occasionally extreme [5.2–5.4 meq/l (55%), 5.5–5.7 meq/l (21%), 5.8–6.0 meq/l (10%), >6.0 meq/l (14%)]. Of 31 patients (2 excluded due to brief PD time), 39% displayed hyperkalemia only, 23% displayed hypokalemia only, and the remainder (38%) displayed both or neither. Comparing hypokalemia-only with hyperkalemia-only patients, we found no difference in potassium chloride therapy, medications interrupting the renin-angiotensin system, small-molecule transport status, and renal urea clearance. We compared biochemical parameters from the hypokalemic and hyperkalemic serum samples and observed lower bicarbonate concentrations, higher creatinine concentrations, and higher urea nitrogen concentrations in the hyperkalemic samples (p < 0.001 for each), without difference in glucose concentrations.Conclusion. We observed hyperkalemia 3 times as frequently as hypokalemia in our PD population. High-potassium diet, PD noncompliance, increased muscle mass, potassium shifts, and/or the daytime period without PD might contribute to hyperkalemia.