Pigeons and peritonitis?

We report an outbreak of fungal peritonitis due to Candida parapsilosis in 12 patients undergoing chronic ambulatory peritoneal dialysis (CAPD). All 12 patients were treated by removal of the CAPD catheter together with systemic antifungal therapy. There were no peritonitis-related deaths. Four patients were successfully returned to CAPD at a later date. Microbiological investigation during the outbreak demonstrated colonization of various areas of the CAPD Unit and medical ward with the organism. C. parapsilosis was also isolated from pigeon guano obtained from window-sills. The number of cases of peritonitis due to this organism decreased markedly after bird-proof netting was installed. We believe that this is the first report of an outbreak of CAPD peritonitis due to faecal carriage of C. parapsilosis by pigeons.     

Major reduction of CAPD peritonitis after the introduction of the twin-bag system

In recent years an impressive decrease in the incidence of CAPD-relatedperitonitis was observed in our centre, from 1.4 in the mid-eightiesto 0.4 per patient year in 1991. In order to analyse which factorswere most responsible for this decline, the present study wasperformed. From the start of our CAPD programme in 1982 untilSeptember 1991, 100 patients were enrolled. For each patient,time elapsed from catheter insertion until first peritonitisepisode was recorded. Outcome was measured as the peritonitis-freeinterval in days. The following variables have been evaluated:age, gender, type of catheter, type of system, presence of diabetesmellitus, leakage, break-in period, presence of an exit-siteinfection, and performing surgeon. Data were analysed firstby Kaplan-Meier product-limit estimate ofsurvival (peritonitis-freeinterval). Thereafter Cox proportional hazard analysis was appliedto the data, providing a conditional probability of peritonitisat each moment during follow-up, given a certain combinationof risk factors. Our results show that the system, in conjunctionwith the type of catheter, was a decisive factor in the declineof the peritonitis rate in our centre. Patients on the twin-bagsystem (twin-bag group) showed a significant increase in theperitonitis-free interval in comparison with patients usingother systems (non-twin bag group). Among the other variablesanalysed, only diabetes mellitus appeared to be relatively important.Episodes of culture negative peritonitis were more frequentlyobserved in the twin-bag group, compared to the non-twin baggroup. In absolute numbers Staph. non-aureus was the micro-organismmost effectively reduced.     

Intravenous versus subcutaneous administration of recombinant human erythropoietin in patients on haemodialysis and CAPD.

The most effective route of administration of rHuEpo is still a matter of discussion. Prospectively we studied subcutaneous (s.c.) versus intravenous (i.v.) administration in three comparable groups of patients; HD-s.c. (n = 9), HD-i.v. (n = 11), and CAPD-s.c. (n = 9). All the groups initially received 50 units/kg three times weekly. During the first 8 weeks dose adjustments were made only if target haemoglobin exceeded 11.3 g/dl (7 mM). Target haemoglobin was reached after 84 (42-98) days in the i.v. group and 42 (14-77) and 42 (28-56) respectively in the HD-s.c. and CAPD groups. The difference was statistically significant (P less than 0.05). Even the cumulative doses to reach target haemoglobin were significantly less in the two s.c. groups. To maintain haemoglobin at about 11.3 g/dl, weekly doses were as follows: HD-i.v. 125 U/kg (86-168), HD-s.c. 63 U/kg (20-85), and CAPD 72 U/kg (31-100). The total observation time after the target haemoglobin level was reached, was median 130 (114-264) days. The difference between the i.v. group and the two s.c. groups was statistically significant, (P less than 0.05) whereas there was no difference between the s.c. groups. We conclude that s.c. administration of rHuEpo is more effective in induction as well as in maintenance therapy and that s.c. administration is equally efficient in HD and CAPD patients.     

Plasma concentrations of 18-hydroxycorticosterone and aldosterone in continuous ambulatory peritoneal dialysis and hemodialysis patients

This study explores the hypothesis that the continuous ultrafiltration that accompanies continuous ambulatory peritoneal dialysis (CAPD) produces greater activation of the renin-angiotensin aldosterone axis than does the intermittent ultrafiltration that accompanies thrice weekly hemodialysis (HD). Plasma renin activity (PRA), active renin (AR), total renin (TR), inactive renin (IR), 18-hydroxycorticosterone (18-OH-B), aldosterone (PAC), and cortisol were measured in plasma from CAPD (n = 6) and HD (n = 10) patients. Blood from CAPD patients was sampled at 8 AM after overnight recumbency and at 12 noon after four hours ambulation. Blood from HD patients was sampled immediately pre-HD (8 AM) and post-HD (12 noon) at both 8 AM and 12 noon. PRA (P less than 0.01), AR (P less than 0.01), and AR/TR (100%; P less than 0.01) were higher in CAPD than in HD. IR and TR were not different in the two groups. Plasma 18-OH-B was normal in HD but markedly elevated in CAPD. 18-OH-B was higher in CAPD than in HD at 8 AM (P less than 0.05) and at 12 noon (P less than 0.05). Plasma cortisol was not different in the two groups. We conclude that the greater degree of renin activation in CAPD versus HD contributes to the higher levels of 18-OH-B and PAC observed in CAPD patients.     

Predictors of Peritonitis and the Impact of Peritonitis on Clinical Outcomes of Continuous Ambulatory Peritoneal Dialysis Patients in Taiwan—10 Years’ Experience in a Single Center

♦ Objective: Peritoneal dialysis (PD) has become more prevalent as a treatment modality for end-stage renal disease, and peritonitis remains one of its most devastating complications. The aim of the present investigation was to examine the frequency and predictors of peritonitis and the impact of peritonitis on clinical outcomes.♦ Methods: Our retrospective observational cohort study enrolled 391 patients who had been treated with continuous ambulatory PD (CAPD) for at least 90 days. Relevant demographic, biochemical, and clinical data were collected for an analysis of CAPD-associated peritonitis, technique failure, drop-out from PD, and patient mortality.♦ Results: The peritonitis rate was 0.196 episodes per patient-year. Older age (>65 years) was the only identified risk factor associated with peritonitis. A multivariate Cox regression model demonstrated that technique failure occurred more often in patients experiencing peritonitis than in those free of peritonitis (p < 0.001). Kaplan-Meier analysis revealed that the group experiencing peritonitis tended to survive longer than the group that was peritonitis-free (p = 0.11). After multivariate adjustment, the survival advantage reached significance (hazard ratio: 0.64; 95% confidence interval: 0.46 to 0.89; p = 0.006). Compared with the peritonitis-free group, the group experiencing peritonitis also had more drop-out from PD (p = 0.03).♦ Conclusions: The peritonitis rate was relatively low in the present investigation. Elderly patients were at higher risk of peritonitis episodes. Peritonitis independently predicted technique failure, in agreement with other reports. However, contrary to previous studies, all-cause mortality was better in patients experiencing peritonitis than in those free of peritonitis. The underlying mechanisms of this presumptive “peritonitis paradox” remain to be clarified.     

Serum concentrations and peritoneal loss of growth hormone and growth-hormone-binding protein activity in older adults undergoing continuous ambulatory peritoneal dialysis: comparison with haemodialysis patients and normal subjects

Serum concentrations and peritoneal losses of growth hormone(GH) and of growth-hormone-binding protein (GH-BP) activityin 13 patients undergoing continuous ambulatory peritoneal dialysis(CAPD) were compared with those of 13 patients on haemodialysisand 13 normal subjects. The individuals in the three groupswere matched by age (40–83 years), gender, and serum glucoseconcentration. In addition CAPD and haemodialysis patients werematched by haematocrit, serum creatinine and albumin concentrations,and period of time on dialysis (0.5–127 months). GH inthe serum and in the peritoneal effluent were measured by radioimmunoassay(RIA) and NB2 bioas-say. GH-BP activity was analysed by bindingassay and expressed as a percentage of the specific bindingof GH. In the haemodialysis patients, serum GH was significantlygreater and serum GH-BP activity significantly less than inthe CAPD patients and control subjects. Between the two lattergroups no significant differences in GH or in GH-BP activitywere observed. GH bioactive/immunoactive ratios in the threegroups were similar. Both GH and GH-BP were detected in theperitoneal effluent of CAPD patients, in whom an overnight (8-h)peritoneal loss of GH (8.0±1.4x 10^–3 ug/h/1.73m2) was strongly correlated with serum GH (r= 0.840). CirculatingGH and GH-BP activity were influenced by serum creatinine andhaematocrit. In addition a positive relationship was observedbetween GH-BP activity and body mass index and between GH andtime on dialysis. These data reaffirm that older adults undergoinghaemodialysis, unlike CAPD patients, exhibit persistent abnormalitiesin GH-GH-BP axis. The peritoneal losses of GH and GH-BP thatoccur during CAPD do not affect their respective serum concentrations.     

Influence of blood volume on the blood pressure of predialysis and peritoneal dialysis patients treated with erythropoietin

Twenty-seven patients with renal failure (16 on CAPD and 11predialysis) were treated with erythropoietin. At 12 weeks,the mean haemoglobin concentration (±SEM) in the CAPDpatients had increased from 7.07 ± 0.20 to 10.88 ±0.45 g/dl (two-tailed paired t test, P<0.0001) and in thepredialysis patients from 6.90 ±0.35 to 10.05 ±0.47 g/dl (P< 0.0001). Predialysis patients were taking moreantihypertensive medication at baseline. No increase was requiredin either group after erythropoietin; there was no change inblood pressure in the CAPD patients, though in the predialysispatients the systolic blood pressure rose slightly from 132to 146 mmHg (P=0.029) and the mean blood pressure from 95 to103 mmHg (P=0.028). In 12 patients (6 on CAPD and 6 predialysis) the red cell volume,plasma volume, and total blood volume were measured before andafter treatment. In the CAPD patients there was a marked expansionof the red cell volume from 912±127 to 1471±222ml (P=0.004) and a concomitant contraction of the plasma volumefrom 3932 ±250 to 3178 ±326 ml (P=0.005), leavingthe blood volume unchanged from 4843 ± 352 to 4649 ±503ml. Predialysis patients had a similar expansion of the redcell volume from 733 ± 59 to 1304± 161 ml (P=0.017)but no contraction of the plasma volume (from 3417 ±354to 3314 ±260 ml), so that the blood volume tended toexpand from 4149 ±347 to 4618 ±414 ml (P= 0.053).The mean contraction of the plasma volume in the predialysisgroup was trivial (– 102 ±214 ml), whereas in theCAPD group it was large (–754 ±158 ml, P=0.034,two-tailed unpaired t test). Thereby the predialysis group experiencedan expansion of the total blood volume of 469±186ml,whereas the CAPD group experienced a contraction of the bloodvolume of –195±189 ml(P=0.031). We conclude that (a) increased blood volume may contribute tothe exacerbation of hypertension induced by erythropoietin therapy;(b) gradual reduction of plasma volume, aiming for a stabletotal blood volume, is an important strategy for the preventionand control of erythropoietin-induced hypertension; (c) as reductionof plasma volume may be more problematic in predialysis patients,adequate blood pressure control may consequently be slightlymore difficult, placing more reliance on antihypertensive medication.     

Measurement of peritoneal fluid handling in children on continuous ambulatory peritoneal dialysis using dextran 70

Fluid kinetics were studied in children treated with continuousambulatory peritoneal dialysis (CAPD) aged between 2 and 15years. Dextran 70 was used as a volume marker. A 4-h dwell wasstudied with a dwell volume of 40 ml/kg. Transcapillary ultrafiltrationwas measured as well as marker clearance, which is the bestavailable approximation of lymphatic absorption in the clinicalsetting. In 11 children in whom dialysate was used containing1.36% glucose transcapillary ultrafiltration was 250±79ml/4 h/1.73 m² and marker clearance 236±101 ml/4 h/1.73m². In 13 children dialysed with 3.86% glucose, transcapillaryultrafiltration was 829±226 ml/4 h/1.73 m² and markerclearance 307±176 ml/4 h/ 1.73 m². These values are similarto those found in adult patients. There was a positive correlationbetween age and transcapillary ultrafiltration in the groupreceiving dialysate containing 3.86% glucose (r= 0.69, P= 0.009).There was no correlation between age and marker clearance. Itis concluded that fluid kinetics in children and adults on CAPDare similar when corrected for body surface area. In young childrentranscapillary ultrafiltration is lower, probably because dwellvolume is low in relation to peritoneal surface area in thesechildren.