Nephrology Dialysis Transplantation

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1 Nephrol Dial Transplant (994) 9: Original Article Nephrology Dialysis Transplantation Nocturnal intermittent peritoneal dialysis G. Woodrow, J. H. Turney, J. A. Cook, J. Gibson, S. Fletcher, A. J. Stewart and A. M. Brownjohn Renal Unit, Leeds General Infirmary, Great George Street, Leeds, UK Abstract. Automated methods of peritoneal dialysis have developed as alternative methods of treatment to. We review our experience of 4 patients treated with nocturnal intermittent peritoneal dialysis (NIPD). Patients receive a nocturnal exchange of 5-5 litres of dialysate with the peritoneum left dry during the day. If biochemical control is inadequate, litre of dialysate is left in during the day. Indications for NIPD included social reasons and failure due to poor ultrafiltration or problems related to raised intraabdominal pressure. Some features of biochemical control were less good with NIPD compared with with higher phosphate (.8mmol/l versus.83 mmol/, /><0.00); creatinine (56 umol/ versus 085 umol/, i><0.00); and potassium (4.9 mmol/ versus 4.64 mmol/, P=0.056) in patients changing between and NIPD. Overall peritonitis rate on NIPD was one episode per 4. months compared with a rate of one episode per.5 months for patients commencing over the same period. Conversion from to NIPD was successful in all six cases for problems related to raised intra-abdominal pressure on and in six of nine patients transferred due to poor ultrafiltration. NIPD is a useful form of treatment and we believe that the increased cost is offset by the reduced peritonitis rate. Key words: nocturnal intermittent peritoneal dialysis; peritonitis; ultrafiltration Introduction The development of automatic peritoneal dialysis cycling machines has allowed the use of alternative forms of peritoneal dialysis []. In nocturnal intermittent peritoneal dialysis (NIPD) patients undergo several exchanges of peritoneal dialysate by an automatic cycling machine overnight and the peritoneum is left dry during the day []. Continuous cyclic peritoneal dialysis (CCPD) is similar to NIPD except that a volume of dialysate is left in the peritoneal cavity for Correspondence and offprint requests to: Dr G. Woodrow, Renal Unit, Leeds General Infirmary, Great George Street, Leeds LSI 3EX, UK a prolonged diurnal dwell between the nocturnal periods of shorter exchanges [3-5]. The major problems of remain the inconvenience of frequent exchanges and the relatively high rate of peritonitis. NIPD and CCPD may be indicated for social reasons due to the convenience of having to perform only a single connection and disconnection from the abdominal catheter. This may help with employment and lifestyle for younger patients, and in older, more debilitated patients, may enable a helper to perform dialysis at home in patients unable to do themselves [6]. The relative ease of CCPD has made it successful in the treatment of paediatric patients [,8]. The decreased rate of peritonitis reported in most series of adult patients treated by CCPD is an additional benefit [9-]. It is thought that the adequacy of dialysis, and of middle molecule clearance in particular, are less good in NIPD than CCPD due to the absence of a diurnal dwell [6,3]. NIPD, however, may be of particular value in cases of failure because of fluid retention due to loss of ultrafiltration or a hyperpermeable peritoneal membrane [], and in cases where problems arise due to raised intra-abdominal pressure [4]. Subjects and methods Between 98 and the end of 99 we treated 4 patients with NIPD. Patients undergo dialysis at night with exchanges performed by an automated cycling machine (AMP 80/). We use 5-litre bags of dialysate (Baxter) and a 5-prong connecting line (AMP) modified by the use of Luer lock connections rather than spikes. The total volume of dialysate exchanged is between 5 and 5 litres (mean 6.6) depending on biochemical control, with between 5 and 0 (mean 8.0) exchanges of.5 to 3.0 litres (mean.) per night. Fill and dwell time is min (mean 46.0) with a drain time of 5-5 min (mean 0.6) giving a total treatment time of 8-0 h a night (mean 8.5). The peritoneal cavity is initially left dry during the daytime. In some patients, where biochemical control remains inadequate despite increasing nocturnal volumes or dwell times, litre of dialysate is left in the peritoneum as a long diurnal cycle. This should strictly be called CCPD and was required in 3 patients for biochemical control and in one for abdominal pain experienced with a dry peritoneal cavity. Patients commencing over this period performed 3 Downloaded from at Pennsylvania State University on March 4, European Dialysis and Transplant Association-European Renal Association

2 400 G. Woodrow et al. or 4 exchanges (mean 3.9) of between.5 and.5 litres (mean.9) per day using a variety of systems. Y disconnect systems were used by 5% of patients (Freeline II, Baxter, 38%, and Freeline Solo, Baxter, 9%). The remaining 43% used single-line transfer systems (System II Luer lock, Green shield, Baxter, 35%, including % who also used a locally constructed mechanical connection device and the remaining 8% used the Baxter system III CXD mechanical spiking system). Details of the patients treated by NIPD were obtained from medical and nursing notes and from biochemical records. In patients who switched between NIPD and and had uninterrupted treatment for 3 months before and after the change, mean biochemical values and haemoglobin concentrations for the 3-month periods before and after the change were compared by the Wilcoxon paired test. Peritonitis-free survival, technique survival, and patient survival for NIPD were compared with by Kaplan-Meier survival curves and the logrank method was used to determine the significance of the differences between the two treatments. Episodes of peritonitis were defined as the occurrence of cloudy dialysate containing more than 00 white cells/ml. Technique failure was defined as transfer to another mode of dialysis. Other causes of stopping dialysis (e.g. transplantation, death, recovery of renal function, and transfer to another unit) were considered as lost to follow up. For analysis of patient survival we considered deaths occurring whilst on treatment or in the month after stopping treatment if the cause of death was related to the previous dialysis. Patients currently or recently receiving NIPD were questioned to determine their subjective assessment of the acceptability of this form of treatment. We also determined change in body weight whilst on NIPD as a measure of effect on nutritional state. Results Patients starting NIPD were younger than those starting over the same time period, with a mean age at the start of NIPD of 4.9 years ( SD 3.) compared with 5.0 years ( SD 4.4) at the start of (/><0.00). When compared with the numbers of patients commencing over the same time, NIPD accounted for a significant proportion of patients treated by peritoneal dialysis on our unit (Figure ). The majority of patients treated with NIPD received this as their initial form of renal replacement therapy or converted from (Table ). Indications for NIPD were either social or as a result of problems associated with (Table ). The majority started NIPD for social reasons, either to help with employment or lifestyle in younger patients, or to allow a helper to perform dialysis at home for some older more disabled patients. Approximately one-third of the patients had converted from following problems of poor ultrafiltration and fluid retention, or complications related to raised intra-abdominal pressure. In patients who switched between and NIPD, comparison for the 3 months before and after the change revealed higher phosphate, creatinine, and N U M BE R YEAR H NIPD H Fig.. Numbers of patients commencing NIPD and (98-99). Table. Treatment prior to starting NIPD Conservative Haemodialysis Intermittent peritoneal dialysis Transplant 9 Total 4 Table. Indications for NIPD failure Loss of ultrafiltration/fluid balance Subcutaneous fluid extravasation Diaphragmatic leak Abdominal hernia Pain due to adhesions on Social reasons Employment Dialysis performed by helper Young families Lifestyle (especially in young patients) Total potassium concentrations on NIPD despite the patients being given stricter dietary advice regarding phosphate and potassium intake when on NIPD (Table 3). However, urea, bicarbonate, albumin, and haemoglobin concentrations were no different for the two forms of treatment (with no changes in doses of erythropoietin). Total body weight increased significantly in Downloaded from at Pennsylvania State University on March 4, 06

3 Nocturnal intermittent peritoneal dialysis Table 3. Biochemistry and haemoglobin concentrations in patients switching beween and NIPD (mean values for 3-month periods before and after change) Phosphate (mmol/) Creatinine (umol/) Urea (mmol/) Potassium (mmol/) Albumin (g/) Bicarbonate (mmol/) Haemoglobin (g/dl) NIPD />=0.00 P = 0.00 P = patients while on NIPD and remained stable in 4 patients. Significant weight loss occurred in only five patients, of whom two had additional medical problems and one had inadequate control of uraemia requiring conversion to haemodialysis. The rate of peritonitis complicating NIPD was low at one episode per 4. treatment months (total of 4 episodes over 659 treatment months) compared with one episode per.5 treatment months (total of episodes over 5 treatment months) for patients commencing over the same period. In patients who received both NIPD and the peritonitis rate was one episode per 48 treatment months (6 episodes over 88 treatment months) on NIPD compared with one episode per 5. treatment months (43 episodes over 650 treatment months) on. Peritonitis-free survival was better for NIPD than, P<0.0 (Figure ). Changing from to NIPD for problems with poor ultrafiltration was successful in six of nine patients who received NIPD for between and 50 months (until the time of this study, transplantation, tube removal for peritonitis, or death). A further two patients had initial improvement in fluid control but later had to transfer to haemodialysis at 6 and 0 months for recurrence of resistant fluid retention. The FREE i CO - z o ERI OL "n-i J i_ NIPD remaining patient had poor ultrafiltration at the start of and NIPD was also unable to produce adequate fluid removal. The change from to NIPD in six patients for problems related to raised intra-abdominal pressure (subcutaneous fluid extravasation, diaphragmatic leak, hernias, and abdominal pain) was successful in all cases. The outcome of the majority of patients was to receive a transplant or continue successfully on NIPD (Table 4). There were 0 changes from NIPD to other forms of dialysis. These included the three patients with previous ultrafiltration failure on, two patients with peritonitis requiring tube removal (one of whom has returned to NIPD since the completion of this study), two patients with inadequate dialysis, one patient unable to cope due to social problems, one patient previously requiring a helper for dialysis whose health improved such that he could perform, and one patient converting to hospital-based IPD when terminally ill. Technique and patient survival for patients starting NIPD and from 98 to 99 did not differ, both P>0.5 (Figures 3 and 4). The mean duration of treatment of patients remaining on NIPD was.8 months (3-50). In patients receiving transplants the mean treatment time with NIPD was 4. months (3-58). The mean time on NIPD for treatment failures (including death) was.3 months (-64). Although mean treatment times were relatively short, largely due Table 4. Outcome of patients treated with NIPD Remain on NIPD Transplant Haemodialysis* Death IPD Renal recovery 9 5 Total 4 * Includes three patients transferring to NIPD due to failure. SURVIV Ul NIO X o UJ NIPO CAPO Downloaded from at Pennsylvania State University on March 4, 06 Fig.. Peritonitis-free survival is better for NIPD than, P<0.0, for patients starting treatment over the period Fig. 3. Technique survival is the same for patients commencing NIPD and, P>0.5, over the period

4 40 G. Woodrow et al. < a NIPD 0CAP0 Fig. 4. Patient survival is the same for patients commencing NIPD and, P>0.5, over the period to a good transplantation rate in this group, 8 patients (38%) were successfully treated for more than a year and nine (9%) for more than years. NIPD was well accepted by the patients, with 5 of 8 patients questioned being very satisfied with it. Of 0 of these who had also received other forms of dialysis (5 haemodialysis, 4 and IPD) nine said it was their preferred form of treatment. The three patients dissatisfied with NIPD included one with multiple medical problems, whose wife found the additional burden of performing NIPD too much to cope with, one who felt NIPD restricted his lifestyle more than, and one who had difficulty accepting any form of renal replacement therapy. Discussion Despite its success, continues to be affected by the two major problems of a relatively high incidence of peritonitis and the inconvenience of performing several manual exchanges a day. These problems have led to the development of alternative forms of treatment such as NIPD and CCPD [-5]. The increased convenience of these treatments make them more suitable for patients who are employed or have young families. They may also be of benefit in allowing a more active lifestyle in younger patients and helping them come to terms with renal replacement therapy. The reduced number of procedures required to perform NIPD and CCPD make them of great value where a helper performs or assists with treatment in patients affected by neuromuscular disorders, blindness, low intelligence or in poorly compliant patients [6]. CCPD has been of particular benefit in the treatment of paediatric patients [,8]. Some patients may dislike being restricted to their bed for the duration of the overnight cycles, but sleep disturbance due to machine alarms is uncommon. Peritonitis is a major problem in and is a frequent cause of interruption or cessation of treatment. Most published series of adult patients treated by CCPD have shown significantly lower rates of peritonitis than in, and numerous factors have been proposed to explain this [4,9-]. The reduced numbers of connections to, and disconnections from, the abdominal catheter may be of importance. Connections between sterile tubing and bags of dialysate fluid are less likely to be a source of contamination. Improved patient technique due to performance of all connections in the same environment, less patient fatigue due to performance of fewer connections and assistance of a helper may help reduce peritonitis rates. Host defences may be improved in NIPD and CCPD. Peritoneal dialysis has been shown to have adverse effects on the local immune response [5]. The low ph and high osmolarity of dialysate inhibit phagocytosis and killing by neutrophils and low concentrations of opsonins impair removal of bacteria [6-9]. Phagocytic capacity of peritoneal macrophages, IgG levels, C3 levels and opsonic activity of dialysis effluent have been shown to increase with increasing dwell times [,0]. Thus the absence of dialysate during the day in NIPD, or the prolonged diurnal dwell of CCPD may allow a period of recovery of host defences. It has also been suggested, that in CCPD the fact that drainage of dialysate fluid out of the peritoneum is the first event after connection, may result in washing contaminating bacteria out of the catheter rather than into the abdomen [4]. However, in our patients, where most do not have a diurnal dwell and the initial flow of dialysate after connection is into the abdomen, peritonitis rates are still low, with no difference between the patients with and those without a diurnal cycle. This suggests that this proposed mechanism is not of great importance in reducing the incidence of peritonitis in these forms of therapy. NIPD may be effective in cases where fluid removal by is ineffective due to increased peritoneal membrane permeability. In these patients relatively rapid absorption of glucose from the peritoneal cavity results in a shorter period of net ultrafiltration with subsequent reabsorption of dialysate. This may be overcome by the short cycle times of NIPD and the absence of a prolonged diurnal dwell []. Intra-abdominal pressure is greatest in the erect position and is increased by the presence of peritoneal dialysate [4]. In patients on this may cause abdominal hernias, diaphragmatic leaks, and extravasation of dialysate into surrounding tissues. NIPD may overcome these problems as dialysis is performed in the supine position when intra-abdominal pressure is lowest and fluid is not present during the day when the patient is ambulant. Biochemical control by NIPD with the absence of a diurnal cycle may be less good than in or CCPD and clearance of larger-molecular-weight substances may be particularly affected [6,3]. This may increasingly become a problem with time on treatment because of continuing loss of residual intrinsic renal function. It has been our experience, particularly in younger, more muscular patients, that after a while on NIPD it has become necessary to leave a volume of Downloaded from at Pennsylvania State University on March 4, 06

5 Nocturnal intermittent peritoneal dialysis dialysate in the peritoneum during the day to control deteriorating blood biochemistry. However, there was no difference in urea and bicarbonate concentrations in patients changing between NIPD and, nor in serum albumin, which is a prognostic marker in patients on peritoneal dialysis []. The changes observed in body weight are further reassuring evidence of adequacy of dialysis in the majority of patients. The younger age and lower peritonitis rate for patients on NIPD may have been expected to result in better technique and patient survival than. However, it is likely that the inclusion of patients with previous failure and patients with various medical problems who were unable to perform will have counterbalanced this effect. Despite the relatively short mean period of time on NIPD, the successful treatment of several patients for more substantial periods of time and the rarity of treatment failure due to inadequate dialysis (excluding patients with previous failure) suggests that this may be a satisfactory alternative long-term form of treatment. In conclusion we feel that NIPD is a useful treatment for younger, more active patients and is also of value in allowing a helper to perform treatment for older debilitated patients. It may be successful for certain causes of failure and is associated with a lower peritonitis rate than. The use of automated methods of peritoneal dialysis accounts for a surprisingly small proportion of patients on renal replacement therapy in Europe []. This may be partly due to the higher cost compared with. NIPD has an annual cost of between.35 times (5-litre nocturnal exchange) and.85 times (5-litre nocturnal exchange) greater than (4 exchanges of litres per day using the Freeline Solo system) excluding the initial cost of the cycling machine (and its minimal maintenance costs). However, we believe that the increased cost of this treatment is offset by savings from the reduced peritonitis rate, as well as its other medical and social benefits. References. Sandroni S, Moles K. Cycler dialysis evolution. Adv Peril Dial 989; 5: 6-8. Twardowski ZJ. Nightly peritoneal dialysis. Why, who, how and when? ASAIO Trans 990; 36: Diaz-Buxo JA, Farmer CD, Walker PJ, Chandler JT, Holt KL. Continuous cyclic peritoneal dialysis: A preliminary report. Artif Organs 98; 5: Diaz-Buxo JA. CCPD is even better than. Kidney Int 985; 8[Suppl ]: S6-S8 5. Diaz-Buxo JA. Current status of continuous cyclic peritoneal dialysis (CCPD). Peril Dial Int 989; 9: Diaz-Buxo JA. Automated peritoneal dialysis therapies patient selection and dialysis prescription. Adv Peril Dial 989; 5:0-. Brem AS, Toscano AM. Continuous cyclic peritoneal dialysis for children: an alternative to hemodialysis treatment. Pediatrics 984; 4: Matthern WD, Morris CR, Heffley DL. A three year experience with CCPD in a university-based dialysis and transplantation programme. Clin Nephrol 988; 30[Suppl ]: S49-S5 9. Diaz-Buxo JA. Does CCPD lower the peritonitis rate? Contrib Nephrol 98; 5: Price C, Suki W. New modifications of peritoneal dialysis: options in the treatment of patients with renal failure. Am J Nephrol 98; :9-04. Diaz-Buxo JA. Comparison of peritonitis rates with CCPD, manual, Y-sets, O-sets, UV devices and sterile weld. Adv Peril Dial 989; 5: 3-6. Walls J, Smith BA, Feehally J, Taverner D, Turgan C. CCPD an improvement on. In: Gahl GM, Keisel M, Nolph KD, eds. Advances in Peritoneal Dialysis. Amsterdam. Excerpta Medica 98: Diaz-Buxo JA, Walker PJ, Burgess WP, Chandler JT, Fanner CD, Holt KL. 'Wet' is better than 'dry'. Pent Dial Bull 98; :S 4. Twardowski ZJ, Khanna R, Nolph KD et al. Intraabdominal pressure during natural activities in patients treated with continuous ambulatory peritoneal dialysis. Nephron 986; 44: Lewis S, Holmes C. Host defence mechanisms in the peritoneal cavity of continuous ambulatory peritoneal dialysis patients. Peril Dial Int 99; : 4-6. Harvey DM, Sheppard KJ, Morgan AG, Fletcher J. Effects of dialysate fluids on phagocytosis and killing of normal neutrophils. / Clin Microbiol 98; 5: Duwe AK, Vas SI, Weatherhead JW. Effects of the composition of peritoneal dialysis fluid on chemiluminescence, phagocytosis and bactericidal activity in vitro. Infect Immun 98; 33: Alboadi HM, Coles GA, Davies M, Lloyd D. Host defence in continuous ambulatory peritoneal dialysis: the effect of the dialysate on phagocyte function. Nephrol Dial Transplant 986; : 6-9. Topley N, Alboadi HM, Davies M, Coles GA, Williams JD, Lloyd D. The effect of dialysate on peritoneal phagocyte oxidative metabolism. Kidney Int 988; 34: Vlanderen K, defijter CWH, Bos HJ et al. The effect of dwell time on peritoneal phagocytic defence of chronic peritoneal dialysis patients. Adv Peril Dial 989; 5: Spiegal DM, Anderson M, Campbell U et al. Serum albumin: a marker for morbidity in peritoneal dialysis patients. Am J Kidney Dis 993; : Raine AEG, Margreiter R, Brunner FP et al. Report on management of renal failure in Europe, XXII, 99. Nephrol Dial Transplant 99 [Suppl ]: Downloaded from at Pennsylvania State University on March 4, 06 Received for publication..93 Accepted in revised form 9..93