Interdialysis blood pressure control by long haemodialysis sessions

High blood pressure (BP) is a major factor contributing to thehigh incidence of cardiovascular morbidity and mortality inhaemodialysis (HD) patients. According to predialysis casualBP measurements, long HD has been shown to provide good BP control. To confirm this result during the period between dialysis sessions,we performed ambulatory monitoring of BP in 91 non-selectedHD patients (mean age, 58.7 (14.1) years; 14% incidence of nephrosclerosisand diabetes mellitus; treatment duration, 93.0 (77.2) months;3x8 h/week, cuprophane, acetate buffer in 95% of the patients).Only one patient (1.1%) was receiving an antihypertensive medication. Ambulatory BP results were systolic (S) BP, 119.4 (19.9) mmHg;diastolic (D) BP, 70.6 (12.9) mmHg; mean (M) BP, 87.6 (13.9)mmHg. These values were significantly lower than the casualpredialysis BP data and close to the reference values reportedby Staessen et al. in a meta-analysis including 3476 normotensivesubjects. The MBP was inversely correlated with the treatmentduration, but not with interdialysis weight gain. The MBP increasedsignificantly in the last part of the interdialysis period,and this rise was not correlated with the interdialysis weightgain. The nocturnal/diurnal ratios for SBP and DBP for the HDpatients (0.97 and 0.92) were higher than the reference valuesreported by Staessen, (0.87 and 0.83), and argued against anocturnal decrease in BP. We found that 52.1% of the patientshad an abnormal nocturnal BP fall (MBP fall <5%). This featureworsened during the second night of the interdialysis period. We confirm that interdialysis BP in HD patients treated by longHD and without antihypertensive drugs approached the levelsobserved in a normal population. Achievement of dry weight isthought to be the cornerstone of this good result, but we cannotrule out other mechanisms such as the optimal clearance of pressormolecules. The BP rise during the interdialysis period, independentof the weight gain, argues for such an accumulation. Despitegood BP control the circadian rhythm of BP is not restored inour patients, and remains to be studied.     

Does diurnal variation in blood pressure exist in CAPD patients?

The existence of diurnal variation in CAPD remains controversial.We therefore attempted to delineate the blood-pressure (BP)pattern in CAPD patients by ambulatory blood-pressure monitoring(ABPM). Initially ABPM was performed in 31 patients (21 M, 10F), mean age 65.4 years (26–87) using the Spacelabs model90207. The maximal normal BP preset on the recorder was 140/90mmHg. Daytime and night-time readings, recorded every 30 min,were defined as those from 0600 to 2100 and 2100 to 0600 hoursrespectively. Mean duration of dialysis was 15.2 months (3–76). There were 14 hypertensive patients, defined as a basal BP >140/90 mmHg, or those on antihypertens-ive medications. Takingthe group as a whole a significant difference between day andnight-time readings was found as regards minimal systolic BP(118 versus 107.6 mmHg), maximal systolic BP (181.6 versus 171.2mmHg), mean diastolic BP (83.9 versus 79.6 mmHg), and maximaldiastolic BP (121.7 versus 104.5 mmHg), P<0.05. Diurnal variation,defined in the initial study as a 10% decrease of MAP occurringduring any consecutive 4-h period, was present in 21 patients.In three the diurnal variation manifested as a paradoxical reductionof BP during the day. The only significant difference betweenthose with diurnal variation and those without was the durationof dialysis, being 19.2 ±19.9 versus 13.3 ±17.3months respectively, (P<0.05). In a second study 18 hypertensive CAPD patients were subjectedto ABPM. Nine of them had participated in the first study. Thesepatients were specifically asked to detail their periods ofsleep and arousal. Diurnal variation was here defined as a 10%decrease of MAP occurring 2 h after the onset of sleep. Diurnalvariation was found to exist in 10 patients (55%). Comparingthe day to night-time readings in this group, no significantdifferences were found in mean systolic and MAP. When, however,the arousal versus sleep period readings were compared, a significantdifference was observed in mean diastolic BP (83±14 versus77±17mmHg, P<0.01), and in the MAP (104 ± 18versus 98±20.5 mmHg, P<0.01). The mean systolic BPjust failed to reach statistical significance (141±26versus 137±30 mmHg) due probably to the small samplesize. We conclude that diurnal variation exists in the majority ofCAPD patients. Our findings support the concept that the setpoint model of diurnal variation, in which the major determinantis activity or arousal is the operative one in these patients.Due to disordered sleep patterns in patients on CAPD, diurnalvariation might thus be better elicited when taking into accounta decrease of MAP occurring during any consecutive 4-h period.     

Ambulatory blood pressure monitoring in patients receiving long, slow home haemodialysis.

BACKGROUND: Good blood pressure (BP) control has been reported previously in haemodialysis (HD) patients receiving 8-h dialysis sessions. Home HD allows patients to dialyze for long periods, but there are few data on the BP control achieved by these patients. We studied BP control, using ambulatory blood pressure monitoring (ABPM), in our home-HD patients who were receiving long-hours dialysis. METHODS: Twenty-four patients aged 52.7+/-11 years underwent ABPM. They had been on home HD for 52.9+/-39 months and dialysed for 7.2+/-1.1 h thrice weekly. Two patients were taking antihypertensive drugs. Historical data on BP and weight gains were obtained from the patients' own records. Left ventricular (LV) mass was assessed by echocardiography and total body water (TBW) by bioelectrical impedance. RESULTS: The mean 24-h BP was 129+/-17 mmHg (systolic) and 83+/-14 mmHg (diastolic). The daytime BP was 131+/-17 mmHg (systolic) and 84+/-14 mmHg (diastolic), while the night-time BP was 126+/-22 mmHg (systolic) and 81+/-17 mmHg (diastolic). Six patients (25%) had a normal circadian BP rhythm, but the rest showed a subnormal fall or an increase in BP at night. Mean 24-h BP did not correlate significantly with time on dialysis, dialysis session length, Kt/V, haemoglobin, interdialytic weight gain, or TBW. Twenty-one patients (87%) had LV hypertrophy and 16 of these had diastolic dysfunction. LV mass index was inversely correlated with nocturnal BP fall (r=-0.54, P=0.03). Non-dippers had been treated longer than dippers (29 vs 59.2 months, P=0.03) but they were similar in respect to age, dialysis session length or Hb concentration. CONCLUSIONS: Long, slow haemodialysis at home provides satisfactory daytime BP control in the majority of patients without the need for antihypertensive drugs but abnormal circadian BP rhythm and LV hypertrophy remain common.     

Increased renal allograft thrombosis in CAPD patients

In a retrospective analysis of 202 renal transplant proceduresin the years 1989–1992 we identified an excess of graftslost from primary renovascular thrombosis in patients receivingcontinuous ambulatory peritoneal dialysis (CAPD) compared tohaemodialysis (HD) patients (9 CAPD versus 0 HD, Chi-squared=9.63;P<0.01). All graft losses from thrombosis occurred within16 days of surgery. Possible predisposing causes were identifiedin three patients. Donor age was greater in CAPD patients losingtheir kidneys from thrombosis compared to the overall CAPD group[means (SD) years, 43.0(12.9) versus 29.1(15.8); P=0.01] whereasno significant difference in haematocrit, platelet count, antibodystatus, cyclosporin use, perioperative hypotension, primarydiagnosis, smoking, or diabetes mellitus was found. Data fromthe EDTA registry for 1990–91 show that graft loss fromprimary renovascular thrombosis in UK-treated patients was reportedin 7.1% of CAPD recipients compared with 1.8% in haemodialysis.We suggest that CAPD patients are at greater risk of graft lossfrom renovascular thrombosis than HD patients and may requiremore intensive fluid and anticoagulant treatment in the perioperativeperiod.     

Pyridinium crosslinks in patients on haemodialysis and continuous ambulatory peritoneal dialysis

BACKGROUND: The urine excretion of the pyridinium crosslinks of collagen,pyridinoline (PYD) and deoxypyridinoline (DPD) closely reflectbone resorption and their assay has been used as specific markersof mature collagen turnover. The aims of this study were toevaluate the use of these markers to predict the severity ofosteodystrophy in patients with chronic renal failure. METHODS: Using an isocratic ion-paired reverse-phase high-performanceliquid chromatography, PYD and DPD were determined in the serum,urine and dialysate of 48 patients with chronic renal failureundergoing haemodialysis (n=28) or continuous ambulatory peritonealdialysis (n=20). Nineteen apparently healthy subjects were studiedas controls. RESULTS: In all groups, serum and urine crosslinks excretion showed poorcorrelation with age. In the patients urine PYD/creatinine andDPD/creatinine were significantly (P0.03 and 0.001 respectively)higher than normal; urine PYD and DPD levels were highly correlatedwith each other (r=0.98) and with serum PTH (r=0.84 and 0.83respectively). The mean (SD) predialysis serum PYD, 269 (334)nmol/l, was significantly (P0.003) elevated compared with normalpatients, 4.1 (0.6) and pre-dialysis serum DPD was 82.9 (93.7)nmol/l. DPD was below the detection limit of the assay in normalsera. In the patients postdialysis decreases in serum PYD andDPD were statistically significant (P<0.0002 and P<0.0007respectively). PYD and DPD were found in the dialysate of patientson haemodialysis as well as 24-h dialysate in patients on CAPD.Dialysate PYD and DPD were highly correlated with each other(r=0.80) and with dialysate creatinine (r=0.76 and r=0.62 respectively).In the patients, the mean serum, urine and dialysate PYD andDPD increased with the duration on dialysis. These findingsconfirm that metabolic bone disease increases in patients withduration of chronic renal failure. CONCLUSION: Estimation of serum crosslinks levels has potential as an additionaltool in the diagnosis and monitoring of renal osteodystrophy.The ability to determine crosslink levels in serum and dialysateshould be particularly useful in patients who are unable toproduce urine.     

Blood pressure assessment in haemodialysis patients: Comparison between pre-dialysis blood pressure and ambulatory blood pressure measurement

Aim: Hypertension is common in haemodialysis (HD) patients. Determining the most appropriate method of blood pressure (BP) measurement, representative of target organ damage, is still an issue. BP variations between pre‐ and post‐HD treatment, or between on‐dialysis day and off‐dialysis day, are common. The aim of this study was to examine the possible differences between pre‐HD office BP (OBP) levels, inter‐HD (iHD) or HD day 24 h ambulatory BP measurement (ABPM) with 48 h ABPM, where the latter was considered the gold standard. Methods: 163 HD patients were studied. BP was monitored consecutively for 48 h with a Takeda TM2421 device, then sub‐analysed into two periods of 24 h: HD and iHD day. An average of 12 sessions pre‐HD OBP measurements was determined. Results: OBP significantly overestimates systolic (SBP) and diastolic BP (DBP) when compared with 48 h ABPM. SBP and DBP are significantly higher on iHD day than on HD day: 141.2 ± 20.8 versus 137.9 ± 20.9, and 77.1 ± 11.1 versus 76.1 ± 10.9 (P < 0.01). No differences of SBP night/day ratio were reported between 48 h ABPM and iHD 24 h ABPM or HD 24 h ABPM. The highest correlations were reported between 48 h SBP/DBP with iHD or HD 24 h ABPM (r² = 0.95, P < 0.001), while the lowest between 48 h SBP/DBP and OBP (r² = 0.40, P < 0.01, r² = 0.12, P < 0.01). The narrowest limits of agreement using the Bland and Altman test were reported between 48 h SBP or DBP and 24 h iHD or HD day ABPM. Considering 48 h ABPM, 80.5% of patients had BP higher than the norm, compared with 61.7% of patients in the case of OBP (χ² = 13.28, P < 0.001). The sensibility for detecting hypertension for iHD day 24 h ABPM was 98.4%, with specificity of 90%. The sensibility of 24 h HD day ABPM was 90.3%, with specificity 96.6%. In the case of OBP, sensibility and specificity were considerably lower, that is, 72.6% and 83.3% respectively. Conclusion: Significant differences are shown between OBP and 48 h ABPM in the recognition of a hypertensive state. OBP measurement has a lower sensibility and specificity than 24 h ABPM, which remains a valid alternative approach to 48 h ABPM in HD patients. Errors of OBP estimation should be taken into account, with possible negative impact on treatment strategies and epidemiology studies.     

Comparison of the rehabilitation status of continuous ambulatory peritoneal dialysis and in-centre haemodialysis in Chinese patients

Summary: In Hong Kong, dialysis treatment has become more accessible in recent years. Due to a shortage of kidney donors patients are required to stay on dialysis for longer periods. the rehabilitation status of 181 end-stage renal failure (ESRF) patients on dialysis, 34 on in-centre haemodialysis (ICHD) and 147 on continuous ambulatory peritoneal dialysis (CAPD), at the Prince of Wales Hospital was studied. There was no statistically significant difference in physical functioning due to treatment type; however, CAPD patients were shown to be more socially active and had a better family life than ICHD patients (P < 0.01). There were no statistically significant correlations between physical functioning, social life or family life and the duration of dialysis in both ICHD and CAPD patients. In both groups of patients 52.9% of ICHD and 52.4% of CAPD patients had decreased employment status. All the patients were assessed by doctors-in-charge on their physical fitness for employment, 85.7% (n= 6) of the unemployed ICHD patients and 71% (n= 44) of the unemployed CAPD patients were considered to be physically fit to work. Due to the ageing of the general population and greater availability of dialysis treatment and higher survival rate of the chronically ill have led to an increase in the number of elderly patients on dialysis (aged 60 years and over). the proportion of elderly dialysis patients in our renal centre increased from 7–23% in the past 5 years. Continuous ambulatory peritoneal dialysis patients aged less than 60 years were found to be significantly more physically active and socially active than CAPD patients aged over 60 years (P < 0.01). In the aspect of a better family life for these patients, no statistically significant difference was found between the two groups. Rehabilitation of ESRF patients can be achieved by renal replacement therapy. It is concluded that CAPD patients have better adaptation in social life and family life than ICHD patients.     

Relationship of ambulatory blood pressure monitoring data to echocardiographic findings in haemodialysis patients

BACKGROUND: The present study was performed to assess the value of ambulatoryblood pressure monitoring (ABPM) in determining the adequacyof blood pressure (BP) control, and its relationship to echocardiographicfindings in haemodialysis (HD) patients. METHODS: We studied 40 non-diabetic adult patients who had been on regularHD treatment for a median duration of 43 months. Twenty-four-hourABPM was performed using a non-invasive ABP monitor (Pressurescan,ERKA). Casual BP (cBP) was defined as the average of two measurementsobtained at two HD sessions, one preceding and one followingthe ABP recordings, and was calculated for both the predialysisand postdialysis phases. Two-dimensional and M-mode echocardiographywere performed in each patient to determine interventricularseptal thickness (IVS), left ventricular posterior wall thickness(LVPW), left ventricular fractional shortening (FS), and leftventricular mass index (LVMI) RESULTS: According to average 24-h BP levels, 50% of the patients hadsystolic hypertension (HT) (>139 mmHg), and 72.5% had diastolicHT (>87 mmHg), while only 25% had been diagnosed as HT bycBP measurements (P>0.01 and P>0.0001 respectively). Diurnalvariation in BP was not present in about 80% of the patients.Echocardiography was normal in only four patients (10%). LVMIand LV wall thickness were correlated to ABPM data better thanto cBP measurements. Using stepwise linear regression analysis,LVMI and FVS were positively correlated with systolic BP load(P> 0.0001 and P=0.0001 respectively), and LVPW was positivelycorrelated with night-time systolic BP level (P>0.001). CONCLUSIONS: ABPM is necessary to assess the adequacy of BP control, andis well correlated to end-organ damage of HT in HD patients.     

Plasma ghrelin levels in patients undergoing haemodialysis and peritoneal dialysis.

BACKGROUND: Ghrelin has been characterized as a relevant physiologic regulator of appetite and body weight in humans. However, the potential relationships between ghrelin levels, inflammation and malnutrition in dialysis patients have not been adequately studied. METHODS: We used a cross-sectional design to study 20 haemodialysis (HD) and 21 peritoneal dialysis (PD) patients, and compared their plasma ghrelin (PGhr) levels with that of an age-matched control group. We also explored correlations between ghrelin and selected hormonal, renal adequacy, nutritional and inflammation markers in both groups. RESULTS: PGhr levels were higher in HD (median 119.8 pg/ml, range 71.1-333.7, P = 0.001) and PD (99.3, range 45.8-578.5, P = 0.045) patients than in healthy controls (78, range 29-158) (HD vs PD, not significant). Ghrelin levels were strongly and inversely correlated with age (r = -0.46, P = 0.02 for patients; r = -0.61, P = 0.001 for controls). Except for a positive correlation between ghrelin and growth hormone (r = 0.48, P = 0.002), univariate analysis failed to detect associations between PGhr and the measured hormonal values, renal adequacy, nutritional indicators and markers of inflammation. However, multivariate analysis revealed significant inverse correlations between PGhr levels and nutritional markers, including subjective global assessment (P = 0.013), albumin (P = 0.001), transferrin (P = 0.01) and protein nitrogen appearance (as an estimate of protein intake) (P = 0.035), after controlling for the confounding effect of age. CONCLUSIONS: PGhr levels were moderately and similarly increased in patients undergoing HD and PD. Age was a strong determinant of PGhr levels, both in uraemic patients and in healthy controls. Dialysis adequacy, residual renal function and inflammation did not appear to influence ghrelin levels in these patients. The negative correlation between PGhr and nutritional markers suggests that low dietary intake causes increases in ghrelin secretion in dialysis patients.     

Relationships between blood pressure variability and left ventricular parameters in haemodialysis and renal transplant patients

Blood pressure (BP) elevation and left ventricular hypertrophy (LVH) are important factors in the high cardiovascular mortality on the renal replacement programme. The relationship between these, predictable in essential hypertension, is less well defined in uraemia. We wished to examine the contribution of abnormal blood pressure variability (BPV) to the cardiovascular changes seen in uraemia and after renal transplantation. Twenty-four hour ambulatory blood pressure monitoring (ABPM), and simultaneous echocardiography, on a cohort of 35 long-term, long-hours haemodialysis survivors and 28 patients with stable renal transplants was undertaken. We also retrospectively compiled biochemical and clinical data. There were strong relationships between both diurnal and standard deviation measures of BPV and left ventricular cavity size and function: per cent fall in awake to asleep diastolic BP with fractional shortening index (FSI), r =0.28, P =0.039; with left ventricular mass index (LVMI), r =−0.35, P =0.011. This study suggests that reduced diurnal and short-term BP variability is cross-sectionally associated with a dilated, heavier left ventricle (LV) with worse systolic function. Thus, BPV may independently contribute to the abnormal LV structure and function commonly seen in uraemia.     

Relationships between blood pressure variability and left ventricular parameters in haemodialysis and renal transplant patients

SUMMARY: Blood pressure (BP) elevation and left ventricular hypertrophy (LVH) are important factors in the high cardiovascular mortality on the renal replacement programme. the relationship between these, predictable in essential hypertension, is less well defined in uraemia. We wished to examine the contribution of abnormal blood pressure variability (BPV) to the cardiovascular changes seen in uraemia and after renal transplantation. Twenty-four hour ambulatory blood pressure monitoring (ABPM), and simultaneous echocardiography, on a cohort of 35 long-term, long-hours haemodialysis survivors and 28 patients with stable renal transplants was undertaken. We also retrospectively compiled biochemical and clinical data. There were strong relationships between both diurnal and standard deviation measures of BPV and left ventricular cavity size and function: per cent fall in awake to asleep diastolic BP with fractional shortening index (FSI), r =0.28, P =0.039; with left ventricular mass index (LVMI), r =−0.35, P =0.011. This study suggests that reduced diurnal and short-term BP variability is cross-sectionally associated with a dilated, heavier left ventricle (LV) with worse systolic function. Thus, BPV may independently contribute to the abnormal LV structure and function commonly seen in uraemia.     

Accumulation of circulating advanced oxidation protein products is an independent risk factor for ischaemic heart disease in maintenance haemodialysis patients

Aim: Whether the burden of advanced oxidation protein products (AOPP) accumulation, a marker of oxidative stress, is affected by dialysis modality remains unclear. We compared the serum levels of AOPP in patients on haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) and tested the hypothesis that an accumulation of AOPP was an independent risk factor for cardiovascular disease. Methods: This was a cross-section study. A total of 2095 patients (1539 HD, 556 CAPD) were recruited from the nine largest dialysis centres in China. Persons in medical centres for disease screening were selected as controls. Patients maintained on HD were dialyzed twice or thrice weekly. CAPD patients used lactate-buffered, glucose-containing solutions. The patients' data were abstracted from the medical record. The serum levels of AOPP were determined by spectrophotometric detection. Results: The levels of AOPP were significantly elevated in both HD and CAPD patients compared to healthy controls. Accumulation of AOPP was more significant in HD compared to CAPD population. Meanwhile, AOPP accumulation was associated with the presence of ischaemic heart disease (IHD) only in HD, but not CAPD patients. A higher proportion of IHD was found in the HD population among those with higher levels of AOPP in each category of age and irrespective of the presence or absence of high triglyceride. Multivariate regression analysis indicated that accumulation of AOPP was an independent risk factor for IHD in HD population. Conclusion: Accumulation of AOPP was more significant in HD compared to CAPD patients. The level of AOPP was independently associated with IHD only in HD patients.     

Relationship between blood pressure during haemodialysis and ambulatory blood pressure in between dialyses

BACKGROUND.: Ambulatory blood pressure measurements in haemodialysis patientsare relevant in view of the high cardiovascular morbidity andmortality in chronic haemodialysis patients. METHODS.: Twelve normotensive patients were studied from the beginningof one dialysis until the end of the next (mean 64 h, SD 19h) using a Spacelabs oscillometric blood-pressure recorder. RESULTS.: A circadian blood pressure rhythm was present in six of the12 patients. In seven patients the lowest pressure recorded(including the dialysis sessions) occurred 5–6 h afterdialysis (late post-dialysis dip). Blood pressure did not increasesharply in the hours before dialysis although it increased slightlyin the interdialytic interval as a whole, at a mean rate of5.6 mmHg per 24 h (SD 4.1, P<0.001). We could not find ablood pressure measurement during dialysis (or combination ofmeasurements) which reliably reflects interdialytic blood pressure:the 95% confidence intervals were 25 mmHg or higher. CONCLUSION.: Ambulatory blood pressure measurements are needed for adequatemonitoring of the control of blood pressure in haemodialysispatients.     

Lipoprotein (a) in patients on maintenance haemodialysis and continuous ambulatory peritoneal dialysis

Lipoprotein (a) concentrations and apoprotein (a) isoforms weremeasured in 99 haemodialysis and 79 peritoneal dialysis patientsand compared with a normal population. Peritoneal dialysis patientsdemonstrated a threefold and haemodialysis a twofold increasein median Lp(a) values compared to controls (P0.001). The peritonealdialysis group had significantly more patients with Lp(a) valuesgreater than 30 mg/dl compared to controls, (53% versus 22%P0.001). In addition both patient groups demonstrated significanthypertriglyceridaemia (P0.001), reduction in HDL (P0.001) andelevation of the cholesterol/HDL ratio (P0.001) compared withcontrols. Peritoneal dialysis patients also demonstrated significanthypercholesterolaemia (P0.003). Lipoprotein (a) concentrations are considerably elevated inpatients on maintenance dialysis and this occurs in additionto the typical lipoprotein disturbances. This elevation mayincrease vascular risk, particularly in the peritoneal dialysisgroup who also have hypercholesterolaemia and reduced HDL.     

The Comparison in Terms of Early Complications of a New Technique and Percutaneous Method for the Placement of CAPD Catheters

Background. Starting continuous ambulatory peritoneal dialysis (CAPD) immediately after insertion of a peritoneal dialysis catheter is essential in end-stage renal disease (ESRD). In relation to the insertion methods, various mechanical and infectious complications may arise. In this study, we aimed to compare early complications of the laparoscopic tunneling method of CAPD placement that we developed recently in order to minimize the complications, with those of the conventional percutaneous method. Subjects and method. Included in this study were 12 consecutive patients with ESRD to whom we introduced catheters for CAPD by way of laparoscopic tunneling between April 2003 and July 2003 and followed up for at least 6 months, and 30 patients to whom the catheters were placed percutaneously in the same time period with the same follow-up time. The complications seen during the first 6 months after catheter placement with these two different methods were compared. Results. In all of the subjects, dialysis was started soon after catheter placement. No per-operative morbidity was seen in any of the patients. While with laparoscopic tunneling method no mechanical problem was seen, the percutaneous method resulted in early leakage in 10%, pericatheter bleeding in 3.3%, and hernia in 3.3% of the patients. As infectious complications, peritonitis occurred as one episode/36 patient-months in laparoscopic tunneling and one episode/22.5 patient-months in percutaneous method; catheter insertion site infection was seen in none in the laparoscopic method, while one episode/90patient-months was seen with the percutaneous method. Tunnel infection did not arise in any of the subjects. Conclusion. The authors of this study think that the peritoneal tunneling method for introducing CAPD, which has been recently developed and began to be routinely used by them, is rather safe in terms of early complications.     

Encephalopathy in patients on continuous ambulatory peritoneal dialysis and patients on chronic haemodialysis.

A group of 121 patients, 22 with a preterminal chronic renal insufficiency (PCRI), 74 on chronic haemodialysis (CHD), and 25 on continuous ambulatory peritoneal dialysis (CAPD), was evaluated by means of neurophysiological and neuropsychological studies to detect signs of central nervous system dysfunction. CHD patients were studied the day before dialysis treatment. In each patient the neurophysiological and neuropsychological studies were performed on the same day. The same overall result emerged from the neurophysiological and neuropsychological studies: all three patient groups showed significant deviations from the values obtained from a healthy reference group, whereas no differences were found between the three patient groups. Biochemical variables (a.o. PTH, Al, PO4) showed inconsistent or only minor correlations with the encephalopathic parameters. Apparently traditional biochemical variables are not a reliable measure to safeguard renal patients from neurotoxic damage. With respect to central nervous system dysfunction CAPD appears to be as 'safe' as CHD.