Peritonitis in continuous ambulatory peritoneal dialysis. Culture of peritoneal dialysate fluid

Conventional aerobic and anaerobic culture of peritoneal dialysate effluent from patients in continuous peritoneal dialysis (CAPD) was compared to culture in a semiautomated blood culture system. During a two-year period 78 of 79 consecutive episodes of peritonitis among 45 Danish CAPD patients were cultured and the etiology of the infection found in 73 (94%). The sensitivity of the blood culture system was 88%, whereas the sensitivity of the conventional culture of the dialysate effluent was 81%. This difference is not significant (McNemar test; 0.5 > p > 0.3). The majority of isolates were Gram-positive bacteria dominated by coagulase-negative staphylococci (38%). In comparison, only 2% of the cultures of peritoneal dialysate effluent taken within the same period from patients without clinical signs of peritonitis were positive. All the Gram-positive aerobic bacteria were sensitive to vancomycin whereas 97% of the Gram-negative aerobic bacteria were sensitive to gentamicin. An initial empiric treatment of peritonitis with a combination of vancomycin and gentamicin is recommended.     

Stability of the peritoneal membrane in long-term peritoneal dialysis patients

It is now well established that the formation of free radicals and oxidative stress-induced neuronal cell death can be involved in various neurodegenerative disorders, including Alzheimer's disease and Parkinson's disease. The pineal hormone melatonin has been suggested to be a neuroprotective antioxidant. To better understand the molecular mechanism of this activity, we compared the ability of melatonin and its precursor, N-acetyl-serotonin (normelatonin), to protect human neuroblastoma SK-N-MC cells and primary cerebellar granular neurons against oxidative stress. We found that normelatonin and melatonin have differential neuroprotective effects depending on the neuronal cell type. Normelatonin was more protective against hydrogen peroxide (H2O2) and glutamate-induced cell death in SK-N-MC cells compared to melatonin which was more effective to protect primary cerebellar granular neurons against the toxicity of H2O2, glutamate and N-methyl-D-aspartate when compared to normelatonin. At the molecular level, we tested the capacity of normelatonin and melatonin to inhibit the oxidative stress-induced NF-kappaB activation in both neuronal systems. Whereas normelatonin was more potent in the suppression of the activation of NF-kappaB by H2O2 in SK-N-MC cells compared to melatonin, no apparent differences in the extent of suppression could be detected in primary neurons. Normelatonin's and melatonin's neuroprotective activity in SK-N-MC neuroblastoma cells may be mediated by the suppression of NF-kappaB activation.     

Acid-base balance in chronic peritoneal dialysis patients

Endogenous acid production has never been measured directly in dialysis patients and an empiric formula is used to estimate acid production from their protein catabolic rate. We have studied acid-base balance in 19 stable CAPD patients attending the peritoneal dialysis clinic of Mount Sinai Hospital. They obtained a 24 hour collection of peritoneal dialysis fluid and urine while consuming their usual diet and performing their usual activities. Total alkali gain was calculated from net GI alkali absorption plus urinary net acid excretion plus alkali gain from dialysate, while total acid production was measured directly from the urinary and dialysate excretions of sulfate and organic anions. Net GI alkali absorption was estimated from the difference between cations (Na + K+Ca + Mg) and anions (Cl + 1.8P) in the 24 hour dialysate and urine collections minus the daily total amount of lactate infused. All of our patients had a normal or high serum bicarbonate concentration, which was stable with time. Total alkali gain was virtually identical to total acid production (54.2 vs. 52.4 mEq/day) which suggests that these patients were in neutral acid-base balance. Net GI alkali absorption (22.7 mEq/day) was one of the same range as that of chronic renal failure patients not on dialysis and represented almost one half of the total daily alkali gain. The daily acid production of 52.4 mEq/day was numerically equal to 84% of the protein catabolic rate expressed as g/day, which is similar to the predicted value of 77% of PCR reported in the literature.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bacteremia complicating peritonitis in peritoneal dialysis patients

Bacteremia is a rare complication of peritonitis in end-stage renal failure (ESRF) patients treated by peritoneal dialysis. Three of our ESRF patients on peritoneal dialysis developed bacteremia during a peritonitis episode (1/19 peritonitis episodes). In 2 cases, the responsible organism was Escherichia coli and peritonitis was most likely associated with infection of the biliary tract. The 3rd patient had a perforation of the colon and Klebsiella spp. was the infective organism. Only the last patient survived but had to be transferred to hemodialysis. Bacteremia during peritonitis is infrequent in peritoneal dialysis patients and it appears to be related to other intra-abdominal events.     

Peritonitis influences mortality in peritoneal dialysis patients

Mortality remains high in peritoneal dialysis (PD) patients. Known risk factors for mortality include age, diabetes, race, initial albumin level, and cardiovascular disease. Peritonitis is reported to cause death in 1 to 6% of PD patients but has not been well studied as a risk factor for mortality. This study examined 516 adults with a total of 896 yr on PD at one center to determine if peritonitis influenced mortality. Time at risk began on Day 1 of training and ended at death, transplant, or 60 days after transfer to hemodialysis or intermittent peritoneal dialysis. The overall mortality rate was 17.4/100 patient yr. Survival was lower for whites, men, diabetic patients, and older patients. Independent risk factors for mortality (by Cox proportional hazards) were race, diabetes, increased age, and increased peritonitis rate. Use of the Y-set was not associated with decreased mortality. Peritonitis was a risk factor only in whites, nondiabetic patients, and those patients over the age of 60. For every 0.5/yr increase in the peritonitis rate, the risk of death increased 10% in whites, 11% in those patients who were over the age of 60, and 4% for nondiabetic patients. Mortality rates did not decrease over time (1979 to 1995), although peritonitis rates fell significantly (P < 0.001). Rates of Gram-negative and fungal peritonitis showed no trend over time. Peritonitis contributed to 25 of 158 (15.8%) of deaths. Gram-negative/fungal peritonitis accounted for 14 deaths (9.5% of all Gram-negative/fungal episodes) whereas Staphylococcus epidermidis accounted for only 1 death (0.5% of all S. epidermidis episodes) (P < 0.001). Cardiovascular disease was more common in those patients whose deaths were unrelated to peritonitis (P < 0.01), whereas an infectious cause was more common in those patients whose deaths were peritonitis-related (P < 0.001). In this study, peritonitis was a risk factor for death in whites, nondiabetic patients, and older patients. However, the Y-set did not improve survival, perhaps because it does not decrease Gram-negative/fungal peritonitis. To have an impact on survival, efforts are needed to reduce the peritonitis that results from these more serious pathogens.     

Major determinants of hyperhomocysteinemia in peritoneal dialysis patients

The mechanisms leading to elevated total homocysteine concentrations in peritoneal dialysis patients are only partially understood. We show that a common polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene (C677T transition) results in increased total homocysteine levels in peritoneal dialysis patients compared to age- and sex-matched healthy individuals. The allelic frequency of the C677T transition in the MTHFR gene in peritoneal dialysis patients (0.29) was comparable to the frequency in healthy individuals (0.34). Separate comparison of the total homocysteine plasma levels between non-carriers of the MTHFR polymorphism (C/C), heterozygous (C/T) and homozygous (T/T) subjects was performed by analysis of covariance in the patient and the control group. In the patient group the mean total homocysteine level was 61.7 +/- 40.1 mumol/liter in individuals with the (T/T) genotype, which was significantly higher than the total homocysteine concentration of 23.1 +/- 15.8 mumol/liter in (C/T) patients and 22.2 +/- 11.1 mumol/liter for non-carriers (P = 0.0001). Vitamin B12 (P = 0.0001), folate (P = 0.0005), serum creatinine (P = 0.016), albumin (P = 0.0157) and dialysis center (P = 0.0173) significantly influenced total homocysteine plasma levels in peritoneal dialysis patients, whereas this was not the case for age, gender, weekly Kt/V, weekly creatinine clearance, residual renal function, duration of dialysis, mode of peritoneal dialysis and vitamin intake. Folate levels in peritoneal dialysis patients were significantly affected by the MTHFR genotype (P = 0.016). Elevated total homocysteine levels in diabetic patients with cardiovascular disease were associated with increased cardiovascular morbidity. In summary, the present study provides evidence that homozygosity for the C677T transition in the MTHFR gene, low vitamin B12 and low folate levels result in elevated total homocysteine levels in peritoneal dialysis patients.     

Peritonitis in peritoneal dialysis patients after renal transplantation

BACKGROUND: The occurrence of peritonitis in peritoneal dialysis patients after renal transplantation during immunosuppression might increase morbidity and mortality. Hence the timing of catheter removal is still controversial. The associated risk factors of this complication have not been analyzed. METHODS: We analyzed, retrospectively, the incidence of peritonitis within 90 days after transplantation, its associated morbidity and mortality, as well as risk factors. From 1980 until March 1995, 238 consecutive kidney transplants in peritoneal dialysis patients were performed. Univariate and multivariated logistic regression analysis were used to identify risk factors for the development of peritonitis. RESULTS: 232 cases (141 men, 91 women) were available for analysis. In 191 patients, the catheter was removed with a mean interval after transplantation of 122 days (range 0-573). Thirty peritonitis episodes with predominantly Staphylococcus aureus (10/30) or gram-negative bacteria (12/30) were observed. Independent risk factors before transplantation were the total number of peritonitis episodes (P<10(-5)), previous peritonitis with S. aureus bacteria (P<10(-5)), and male sex (P<0.004). Risk factors after transplantation were technical surgical problems (P<10(-5)), more than two rejection episodes (P<0.02), permanent graft nonfunction (P<0.026), and urinary leakage (P<0.035). CONCLUSIONS: Transplantation without simultaneous peritoneal catheter removal is feasible. However, this increases the risk of peritonitis after transplantation. Early catheter removal should be considered seriously in those patients at risk. When peritonitis develops, antibiotic treatment should be directed against gram-positive as well as gram-negative bacteria until culture results are available.     

Endothelium-dependent vasodilatation is impaired in peritoneal dialysis patients

BACKGROUND: Peritoneal dialysis (PD) patients have a high risk of cardiovascular mortality, which is not completely explained by conventional risk factors. Other factors related to chronic renal failure and/or dialysis treatment might lead to endothelial dysfunction, which is associated with an adverse cardiovascular outcome. One such factor is hyperhomocysteinaemia, which has a high prevalence in PD patients. METHODS: A vessel wall movement detector system was used to investigate endothelium-dependent, flow-mediated, and endothelium-independent, glyceryl trinitrate-induced, vasodilatation of the brachial artery in 29 PD patients and 29 control subjects. RESULTS: Endothelium-dependent vasodilatation was markedly reduced in the PD group: 5.7 +/- 1.0% vs 10.4 +/- 1.3% in the control group (P = 0.004). Endothelium-independent vasodilatation was not impaired. Plasma total homocysteine was elevated in the PD patients (45.2 +/- 6.2 micromol/l), but was not related to endothelium-dependent vasodilatation. CONCLUSION: Chronic peritoneal dialysis patients have impaired endothelium-dependent vasodilatation, which may reflect an increased susceptibility for the development of atherosclerosis and thrombosis.     

Body composition in patients treated with peritoneal dialysis

Calcitonin is a potent inhibitor of osteoclastic bone resorption and has been widely used for the treatment of osteoporosis. Nasal calcitonin, instead of injectable form, is more popular in Europe and United States, while only injectable form has been approved in Japan. The regimen, dose, frequency is remarkably different from study to study, and the standard regimen has not been established for osteoporosis. Fifty to 100 units of salmon calcitonin has been used daily intramuscularly in Europe. Recent trial using nasal calcitonin has shown the similar effects on the bone as the injectable form although the actual resorptionis not so high. In Japan, once weekly 20 units if eel calcitonin analogue injection has been approved for osteoporosis. After administration in the form of either nasal or injectable preparation, peak serum concentration reaches more than 100 pg/ml, far exceeding 10(-11) M, at which level osteoclast bone resorption is rapidly impaired with disappearance of actin ring formation. It is reflected by the decrease of urinary pyridinoline cross-links excretion. Consecutive treatment with calcitonin reduces the calcitonin receptors on the surface of osteoclasts as well as osteoclast precursors, while they are still TRAP positive, suggesting that they retain bone resorbing activity. That may be one of the mechanisms of escape phenomenon. We are not sure whether daily administration of calcitonin can avoid the escape phenomenon and can maintain the bone volume. The standard preparation should be determined by the longer clinical trials with new bone markers and bone mass measurement as the endpoints.     

Group work with patients on peritoneal dialysis

The patient in end-stage renal failure, whose life depends on an artificial kidney machine, must make major emotional and physical adjustments. The author describes how in-hospital group treatment can help these patients cope with their new life situation.     

Dialysate CA125 levels in stable peritoneal dialysis patients

Single-stage surgery is an acceptable option in the modern management of many acute colonic conditions. Anastomosing unprepared colon is a major concern. A technique is described that allows on-the-table colonic lavage to be performed without contamination of the abdominal cavity.     

Calcium and magnesium mass transfer in peritoneal dialysis patients using 1.25 mmol/L calcium, 0.25 mmol/L magnesium dialysis fluid

The percentage of melanoma patients diagnosed at an early stage is increasing. Many of these patients, particularly those with primary tumors thicker than 1.5 mm, harbor occult metastases in regional nodes and are eligible for regional lymphadenectomy as part of their primary management. Until the results of recently completed prospective randomized trials are available the role for elective lymphadenectomy in terms of survival benefit remains a controversial issue. A new technique, intraoperative lymphatic mapping and sentinel node biopsy, has emerged as a simple way to determine whether or not metastatic disease is present. An intradermal injection of a vital blue dye at the site of the primary tumor allows identification of a "sentinel" node in the regional basin. A study of 237 patients was recently reported by Morton et al. (Arch Surg 127:392-399, 1992; Surg Oncol Clin North Am 1:247-259, 1992) demonstrating that the sentinel node can be readily identified > 80% of the time and that histologic examination of the node results in at least a 95% accuracy rate in staging the nodal basin for metastases. Our present series substantiates the results of the original study. An international multicenter trial has been proposed to further confirm the accuracy and universal feasibility of this technique. Acceptance of this technique will lead to a selective approach to regional lymphadenectomy, as only patients with proven micrometastases will undergo lymph node dissections. This approach should satisfy both the advocates and the opponents of elective regional lymphadenectomy.     

Pharmacokinetics of cefamandole in patients undergoing hemodialysis and peritoneal dialysis

The pharmacokinetics of cefamandole nafate, a new parenteral cephalosporin derivative, were evaluated in 11 patients with chronic renal failure (creatinine clearance less than 5 ml/min), including five patients during hemodialysis, four patients during routine peritoneal dialysis, and two patients during the interdialytic period. Peak serum levels of cefamandole were comparable to those observed in patients with normal renal function. Clearance of the drug during the interdialytic period and during hemodialysis and peritoneal dialysis was minimal, with a resultant significant prolongation of serum half-life. The nondialyzability of cefamandole is in contrast with reported studies of cephalothin, where significant reduction of the serum half-life was achieved during hemodialysis but not peritoneal dialysis. The concentration of cefamandole in the peritoneal dialysate after parenteral administration was observed to be bactericidal for many gram-negative pathogens and, with the exception of Streptococcus faecalis, most gram-positive organisms found in bacterial peritonitis in patients with severe renal failure. The present data suggest that if stable bactericidal serum levels of cefamandole are to be maintained during hemodialysis and peritoneal dialysis, a parenteral loading dose must be administered followed by one-half the loading dose every half-life.     

Zinc modulates mononuclear cellular calcitriol metabolism in peritoneal dialysis patients

Zinc has long been known to play a role in maintaining immunologic function. Hypozincemia, however, is common in patients with end-stage renal disease (ESRD) treated with continuous ambulatory peritoneal dialysis (CAPD). We previously demonstrated that zinc depletion limits the ability of animals to achieve maximum circulating calcitriol levels in response to the stress of calcium or phosphorus depletion. It was unclear, however, whether changes in the circulating levels of calcitriol in these settings was associated with a direct effect on renal 1-alpha hydroxylase activity, or whether the zinc dependence of the stimulated calcitriol response involved an integrated systemic response in intact animals. In addition it was unclear whether circulating zinc levels or zinc nutritional status modified calcitriol metabolism in humans. To better understand the role zinc plays in the immune response in patients with ESRD, we studied IL-1, calcitriol and tumor necrosis factor-alpha production by mononuclear cells from blood and peritoneal effluents of 22 patients with ESRD treated with CAPD. Macrophages from peritoneal effluents and peripheral blood mononuclear cells were isolated and pulsed with phytohemagglutinin in medium to which different concentrations of zinc chloride, copper chloride, and carbonyl cyanide p-(trifluoromethoxy)-phenyl-hydrazone (FCCP), an inhibitor of mitochondrial function were added. Supernatant interleukin-1, calcitriol, and tumor necrosis factor-alpha levels were subsequently measured. We demonstrated a zinc concentration dependent increase in stimulated IL-1 alpha and -beta, and TNF-alpha release in both peripheral mononuclear cells and peritoneal macrophages from patients with ESRD treated with CAPD. The effect is zinc specific, as it is not reproduced by copper or chloride supplementation. A zinc concentration dependent increase in peritoneal macrophage calcitriol release was also noted. FCCP blocked the cellular production of IL-1 alpha, IL-1 beta, and TNF-alpha, but had little effect on zinc-induced stimulated mononuclear cell supernatant calcitriol levels. The different shape of the zinc dose response curve, and the lack of correlation between paired IL-1 and calcitriol supernatant levels suggests the effect of zinc on mononuclear cellular cytokine and calcitriol production is mediated through different pathways.     

High serum D-lactate in patients on continuous ambulatory peritoneal dialysis

BACKGROUND: As abnormally high serum D-lactate levels may cause neurological impairment, we determined whether patients undergoing continuous ambulatory peritoneal dialysis (CAPD) with lactate-containing fluids have increased serum D-lactate concentrations. METHODS: D- and L-lactate concentrations were determined in peritoneal dialysis fluids and in serum from control subjects (n = 10), haemodialysis patients (n = 10), and CAPD patients (n = 30) before and after 1 h of dialysis. RESULTS: We found the median D-lactate concentration in Dianeal CAPD fluid to be 26 mM (range 19-27), whereas it was less than 0.5 mM in DPCA2 fluid. Control, haemodialysis, and CAPD (DPCA2) patient median serum D-lactate concentrations were below 0.07 mM. However, CAPD (Dianeal) patient serum D-lactate concentrations were 4-fold higher than controls (P < 0.0001), at 0.28 mM, an hour after instillation of D-lactate-containing fluid. Three patients, whose serum D-lactate averaged 0.59 mM, were found to have D-lactate concentrations at 0.22 mM after overnight cessation of dialysis. CONCLUSION: We conclude that CAPD with D-lactate-containing fluids raises serum D-lactate to abnormal levels.     

Nutritional knowledge of a group of patients in continuous peritoneal dialysis

The influence of nursing to the patient undergoing peritoneal dialysis is the focus of the present research report. By monitoring the patients knowledge, we can understand how nursing teaching influences patient's health and well being.     

Low seroconversion with hepatitis B vaccination in peritoneal dialysis patients

OBJECTIVE: To compare seroconversion using hepatitis B vaccine between hemodialysis (HD) and peritoneal dialysis (PD) patients. DESIGN: Data on PD patients vaccinated were collected retrospectively for the period 1992 to 1995. The data on HD patients were collected prospectively from 1991 to 1994. SETTING: A university outpatient dialysis center. PARTICIPANTS: All adult patients who received all four doses of hepatitis B vaccine while on dialysis were included (47 PD and 50 HD patients). INTERVENTION: Recombinant hepatitis B vaccine (Engerix), 40 micrograms IM was administered at 0, 1, 2, and 6 months. MAIN OUTCOME MEASURE: Seroconversion was measured after completion of the vaccination series. RESULTS: 74% of the HD patients seroconverted compared to 53% of PD patients (p = 0.03). Older, heavier patients compared to all the other patients had a lower seroconversion rate in both the HD patients (55% vs. 78 %) and PD patients (38% vs. 59%) (p = 0.03). CONCLUSION: The seroconversion rate to recombinant hepatitis B vaccine is lower in patients on PD than on HD for unclear reasons. Further studies are required to determine the etiology of this difference.