Serum and dialysate concentrations of cephalexin following repeated dosing in CAPD patients

Oral cephalexin, 1 to 2 g daily for 3 days, was given to six stable, noninfected patients receiving maintenance continuous ambulatory peritoneal dialysis (CAPD). The peak serum concentration after a 2 g initial dose was between 73 and 123 mg/L. On the second and third day in five patients who received a 2 g daily oral dose, the serum concentrations were between 35 and 118 mg/L in serum obtained 1 to 1.5 hours after the dosing. Similar serum concentrations were seen in one patient who only received a 1 g oral dose on the second and third day. Cephalexin concentrations in the peritoneal dialysate reached a peak on the first day between 4 to 14 hours after the dose and were between 31 to 78 mg/L. During the second and third day, the highest cephalexin concentration was 118 mg/L and the lowest was 12 mg/L. The data are consistent with the feasibility of oral cephalexin for treatment of CAPD-associated peritonitis with microorganisms that are sensitive to these levels of cephalexin.     

A randomized prospective comparison of oral versus intraperitoneal ofloxacin as the primary treatment of CAPD peritonitis

Summary: Oral ofloxacin has been successfully used in our centres for the primary treatment of peritonitis complicating continous ambulatory peritoneal dialysis (CAPD). In view of the progressive rise in the resistance rate to ofloxacin among peritoneal bacterial isolates, a study was conducted to determine if oral ofloxacin remains a viable first line treatment for CAPD peritonitis in our centres and if the result can be improved by changing from an oral to an intraperitoneal (i.p.) route. In patients on three 2 L daily CAPD exchanges, ofloxacin given at the i.p. dosage of 200 mg loading followed by 25 mg/L of peritoneal dialysate achieved overnight trough peritoneal levels which are at least four times the minimal 90% inhibitory concentration (MIC90) of most bacterial pathogens without significant accumulation in the systemic circulation. This i.p. dosage was therefore chosen for the clinical study and the result was compared to that using ofloxacin given in the oral dosage of 400 mg loading followed by 300 mg once daily as maintenance. of all the recruited episodes, 35 were eligible for analysis. the overall primary cure rate including primary failures and relapses was 55.6% (10/18) in the oral treatment group and 70.6% (12/17) in the i.p. treatment group. the corresponding figures for gram positive bacterial (g +) infections were 36.4% and 50%, for gram negative bacterial (g -) infections were 66.7 and 80% and for culture negative infections were 75 and 80%. In culture positive cases, all treatment failures were due to resistant infections which were observed in 42.3% of all bacterial isolates, 47.1% of g + isolates and 33.3% of g - isolates. Due to the high background level of bacterial resistance among our CAPD population, ofloxacin monotherapy given either by the oral or the i.p. route can no longer be recommended for the primary treatment of CAPD peritonitis.     

A randomized prospective trial of three different regimens of treatment of peritonitis in patients on continuous ambulatory peritoneal dialysis

A randomized prospective study was undertaken in patients on continuous ambulatory peritoneal dialysis (CAPD) to evaluate the efficacy of three different antibiotic regimens for the treatment of peritonitis. There were 39 episodes in each treatment group. Patients were treated with intraperitoneal (IP) cephalothin (250 mg/L) and tobramycin (8 mg/L) in group 1, oral ofloxacin (400 mg loading followed by 300 mg daily) in group 2, and a combination of ofloxacin (400 mg followed by 300 mg daily) and rifampicin (300 mg daily). Treatment duration was 10 days. The average culture-positive rate was 75%. The overall cure rate was 80.6% with IP antibiotics, 78.4% with oral ofloxacin, and 81.1% with ofloxacin and rifampicin. After the exclusion of tunnel infections and episodes of peritonitis due to Pseudomonas and resistant organisms, the corresponding figures were 100%, 90.6%, and 93.7%, respectively. Side effects were minimal with IP treatment and with oral ofloxacin, but severe nausea and vomiting occurred in some cases with the combination of ofloxacin and rifampicin. It was concluded that oral ofloxacin is an acceptable first-line therapy for peritonitis in CAPD patients.     

Pharmacokinetics of intraperitoneal cefotaxime treatment of peritonitis in patients on continuous ambulatory peritoneal dialysis

The pharmacokinetics of intraperitoneal cefotaxime as the sole therapy in patients on continuous ambulatory peritoneal dialysis with peritonitis have been examined. The mean plasma concentrations achieved following 1 h of peritoneal instillation of 500 mg of cefotaxime were 5.0 +/- 1.6 micrograms ml-1. The average plasma concentration over 24 h was 6.9 +/- 0.4 micrograms ml-1 and was no different from that found following a further 9-11 days of successful treatment of the peritonitis. However, the mean dialysate effluent concentration of cefotaxime was increased following the resolution of the peritonitis, 165 +/- 22.7 mg per cycle on day 10 or 12 compared with 50.4 +/- 7.3 mg per cycle on day 1, suggesting enhanced peritoneal cefotaxime absorption during acute peritonitis. Nevertheless, during both periods, adequate concentrations of cefotaxime were achieved in dialysate to treat local complications, but plasma levels may be inadequate to treat systemic complications due to Staphylococcus albus.     

Oral Treatment of Peritonitis in CAPD Patients with Ofloxacin

Eighteen episodes of peritonitis in 16 CAPD patients were treatedwith oral ofloxacin 400 mg initially. followed by 300 mg dailyfor a total of 10 days. The culture-positive rate was 72.2%with Staphylococcal species as the most frequent isolates. Theoverall cure rate as defined by negative cultures 1 and 2 monthsafter discontinuation of antibiotics was 83.3%. The time takenfor the peritoneal effluent to clear completely was 5 days.With such a dosing regime, there was a significant increasein the mean serum trough level of ofloxacin from 2.28 mg/1 onday 1 to 5.83 mg/1 on day l0(P<0.001). There was no significantdifference in the serum levels attained whether or not phosphatebinders were concurrently given. Sideeffects were nausea andnon-specific dizziness. No patients had to discontinue treatmentbecause of sideeffects. Ofloxacin appeared to diffuse from theblood into the peritoneal fluid, and a highly significant correlationexisted between simultaneous blood and peritoneal effluent ofloxacinlevels (r=0.88, P<0.000l).     

Cefoperazone in the Treatment of Peritonitis in Continuous Ambulatory Peritoneal Dialysis Patients

Cefoperazone is a third-generation cephalosporin that is active against a broad spectrum of gram-positive and gram-negative bacteria. We added this antibiotic to peritoneal dialysis solution at a concentration of 62.5 mg/L to treat peritonitis in six continuous ambulatory peritoneal dialysis (CAPD) patients. Serum drug concentrations were obtained at 0, 0.5, 1, 2, 4, and 24 h after instituting antibiotic therapy. Rapid uptake by blood of the antibiotic across the peritoneal membrane occurred when the latter was inflamed. Adequate bactericidal serum levels for many bacteria were obtained in less than 4 h. Cefoperazone effectively eradicated peritonitis in all patients.     

Treatment of gram-positive peritonitis with two intraperitoneal doses of vancomycin in continuous ambulatory peritoneal dialysis patients

Eight patients with end-stage renal failure on continuous ambulatory peritoneal dialysis (CAPD), who developed peritonitis, received an intraperitoneal dose of vancomycin (30 mg/kg body weight) with 6 h of peritoneal dwell and then resumed their routine CAPD schedule. Vancomycin concentration in serum, peritoneal dialysate (PD) from an overnight dwell and 1, 2 and 3 h after a new exchange was measured at 48 h (in 5 patients) and 7 days (in 6 patients). Except for an occasional 1-hour peritoneal fluid sample on the 7th day, all samples had satisfactory vancomycin levels. Five of the 8 patients who had gram-positive peritonitis and 1 with 'sterile' peritonitis received another similar intraperitoneal dose of vancomycin at the 7th day. All of these patients had good therapeutic response with a negative PD culture 3 weeks after the cessation of therapy and no relapse of infection in at least 1 month of follow-up. We conclude that 2 intraperitoneal doses of vancomycin (30 mg/kg body weight) given 1 week apart with 6 h of intraperitoneal dwell is an effective and adequate treatment for gram-positive and 'sterile' peritonitis in CAPD patients.     

Once weekly intraperitoneal therapy for gram-positive peritonitis

The pharmacokinetics and clinical outcome following a 30 mg/kg/2 L intraperitoneal (IP) dose of vancomycin, which was administered once a week for 3 weeks, was studied in ten continuous ambulatory peritoneal dialysis patients with peritonitis. Vancomycin was 91% absorbed following the first dose and rapidly achieved therapeutic serum concentrations, 19 +/- 8 mcg/mL at 1 hour and a peak of 37 +/- 8 mcg/mL at 6 hours. Vancomycin was eliminated slowly with a mean total clearance of 7 +/- 3 mL/min/70 kg and a distribution volume of 1.2 +/- 0.3 L/kg. The resultant mean serum t1/2 over the first week was 184 hours and the mean serum concentration at 168 hours was 10 +/- 4 mcg/mL. Based on the positive clinical outcome (100% cure) among patients with uncomplicated gram-positive peritonitis, the potential use of this alternative vancomycin dosing regimen is proposed.     

Single UK centre experience on the treatment of PD peritonitis--antibiotic levels and outcomes.

BACKGROUND: There are few studies of the pharmacokinetics of vancomycin and gentamicin in peritoneal dialysis (PD) patients and the influence of antibiotic concentrations on treatment outcome. Concerns about resistance to ceftazidime and potential of aminoglycoside toxicity make the choice of empiric antibiotic difficult. METHODS: We retrospectively collected data from 613 patients on PD between 1 June 2002 and 31 December 2005. During this time, we adopted a protocol that minimized aminoglycoside exposure to patients with residual renal function and carefully monitored serum antibiotic concentrations. RESULTS: There were no statistical differences in mean day-5 vancomycin concentrations for continuous ambulatory peritoneal dialysis (CAPD) vs automated peritoneal dialysis (APD) and for anuric vs not-anuric patients. However, low levels (<12 mg/l) were recorded for 12.8% CAPD and 15% APD patients. These remained low at day 10 in 16% patients (25% if not anuric) despite incremental dosing. Vancomycin concentration did not predict cure or relapse of Gram-positive or culture-negative peritonitis. Gentamicin concentration (>2 mg/l in >50% patients) did not predict outcome of Gram-negative and culture-negative peritonitis. Moreover, cure rates were the same irrespective of whether gentamicin was continued for 14 days or was switched to ceftazidime after 5 days. CONCLUSION: We have confirmed that the International Society for Peritoneal Dialysis (ISPD) dosing guideline for vancomycin in CAPD and APD patients produces adequate serum concentrations of the antibiotics in the vast majority. However, large incremental dosing of vancomycin is needed if day-5 levels are low; especially for not-anuric patients. Whilst evidence of gentamicin toxicity in PD remains controversial, ISPD dosing regimen resulted in high levels for >50% patients. High gentamicin concentrations did not correlate with treatment success, but switching gentamicin to ceftazidime at day 5 appeared safe and limited aminoglycoside exposure. Increasing vancomycin and gentamicin concentrations do not appear to improve cure rates and alternative strategies (such as combination treatment) should be considered for future research.     

Ofloxacin pharmacokinetics in patients on continuous ambulatory peritoneal dialysis

Pharmacokinetics of ofloxacin (OFX) was studied in patients on continuous ambulatory peritoneal dialysis (CAPD) carrying out three exchanges per day. In 11 patients given 300 mg of OFX orally, serum OFX concentration peaked at 2.44 mg/l 3.7 hours after administration and the mean elimination half-life of OFX was 25 hours. OFX concentrations in peritoneal fluid underwent cyclical changes with each change of solutions, reaching beyond 0.5 mg/l after 2 hours of equilibration. There was a highly significant correlation between corresponding serum and peritoneal fluid concentrations of OFX after an 8 h equilibration (r = 0.85, p less than 0.001). In 5 patients given a 400 mg loading dose followed by 200 mg of OFX per day for 7 days, trough serum OFX concentrations ranged from 1.35 to 7.00 mg/l and no adverse effects were noticed. CAPD per exchange removed less than 2% of the total dose of OFX given.     

Initial Experiences with Continuous Ambulatory Peritoneal Dialysis

Continuous ambulatory peritoneal dialysis (CAPD) has been initiated on 51 patients: 27 females (mean age -- 43.9 years) and 24 males (mean age -- 46.4 years). This group has been observed for a total of 1420 patient weeks of treatment (27.3 patient years). Thirty-six episodes of peritonitis have been noted among 19 patients. The overall incidence was one episode per 39.4 patient weeks. Recurrent episodes of peritonitis resulted in discontinuation of CAPD in five (9.8%) of the patients. Three (5.9%) of the patients were unable to continue with CAPD because of its inability to control extracellular fluid balance. In the patients who transferred from intermittent peritoneal dialysis to CAPD, there was a 4.5 mg/dl drop in serum creatinine and a 34 mg/dl drop in mean BUN values. There was a rise of approximately 2 gm in the hemoglobin levels of this group of patients. If the problem of peritonitis can be solved, CAPD will become the dialytic treatment of choice for the majority of patients with end-stage renal disease.     

Serum kinetics of intraperitoneal moxalactam

Continuous intraperitoneal administration of antibiotics has been recommended as treatment for peritonitis. The necessity of simultaneous systemic administration of antibiotics remains undefined but usually is performed. Moxalactam kinetics in serum were studied in dogs receiving 15 mg/kg intravenously; 15 mg/kg intraperitoneally; 5 mg/kg hourly with peritoneal lavage; 15 mg/kg intravenously followed by 5 mg/kg hourly intraperitoneally; 15 mg/kg intraperitoneally after 24 hours of peritonitis; and 5 mg/kg hourly by peritoneal lavage after 24 hours of peritonitis. Intraperitoneally administered moxalactam resulted in sustained serum levels compared with intravenously administered drugs. Repeated exchanges in lavage fluid resulted in progressively higher serum levels with each exchange. Peritonitis results in statistically higher levels of serum antibiotic concentration when compared with controls. Continuous intraperitoneal lavage with antibiotics would not appear to require concomitant systemic drug therapy.     

Hyperleptinaemia and chronic inflammation after peritonitis predicts poor nutritional status and mortality in patients on peritoneal dialysis.

BACKGROUND: The serum leptin level is elevated in patients undergoing peritoneal dialysis (PD) and associated with a loss of lean body mass. The nutritional status of PD patients may further be worsened following peritonitis. We investigated the association between hyperleptinaemia, inflammation and malnourishment in PD-related peritonitis. METHODS: We conducted a prospective study on PD patients who developed peritonitis. Blood samples were obtained as baseline (D0) before the onset of peritonitis, and once peritonitis developed, leptin, adiponectin (ADPN) and other inflammatory markers were collected, on day 1 (D1), day 7 (D7) and day 42 (D42) of peritonitis. Patients were followed-up for any censor event or 1 year after peritonitis. RESULTS: Forty-two patients with a mean age of 62.9+/-13.2 years were recruited. Fourteen (33.3%) were diabetic. The serum leptin levels increased significantly from baseline to day 1 and 7, but fell back to the premorbid state at day 42. In contrast, the ADPN level decreased from a baseline value of 15.60+/-10.4 microg/ml to 13.01+/-8.1 microg/ml on day 1 (P=0.01) but rose to 14.39+/-8.9 microg/ml on day 7 (P=0.28) and 13.87+/-7.9 microg/ml on day 42 (P=0.21). High-sensitivity C-reactive protein (hs-CRP) increased significantly from baseline to day 1, 7 and even at day 42. The lean body mass (LBM) and nutritional markers decreased significantly after peritonitis. For patients with high hs-CRP (>3.0 mg/l) at day 42, there was a higher mortality rate than for those with lower hs-CRP (<3.0 mg/l, P=0.02), even if they were in clinical remission of peritonitis. CONCLUSIONS: Our study confirmed an increase in serum leptin during acute peritonitis and a prolonged course of systemic inflammation after apparent clinical remission of peritonitis. These factors related to the persistent chronic inflammation may contribute to the development of malnourishment and poor survival rate.     

Pharmacokinetics of mycophenolate mofetil in patients with end-stage renal failure

BACKGROUND: Mycophenolate mofetil (MMF) acts as a prodrug for the immunosuppressive drug mycophenolic acid (MPA). It is rapidly converted to MPA following oral ingestion. MPA is metabolized to MPA glucuronide (MPAG), which is renally excreted. This study examines the pharmacokinetics of MPA and MPAG in patients with end-stage renal failure who were on hemodialysis (N = 10) or peritoneal dialysis (N = 10) treatment. METHODS: After an overnight fast, a single oral dose of 1 g MMF was given. Plasma concentrations of MPA and MPAG were measured from 0 (predose) to 36 hours after administration, using high-performance liquid chromatography (HPLC). The area under the concentration time curve (AUC) from 0 to 36 hours was calculated using the trapezoidal rule. RESULTS: Mean (+/- SD) AUC for MPA was 55.7 +/- 32.6 mg/L.h for hemodialysis patients and 44.7 +/- 14.7 mg/L.h for peritoneal dialysis patients, which is similar to expected values for subjects with normal renal function. The mean (+/- SD) maximum plasma concentration (Cmax) for MPA was lower than would be expected for subjects with normal renal function (16.01 +/- 10.61 mg/L for hemodialysis, 11.48 +/- 4.98 mg/L for peritoneal dialysis). MPAG clearance was prolonged with AUC approximately five times what would be expected in subjects with normal renal function (1565 +/- 596 mg/L.h for hemodialysis, 1386 +/- 410 mg/L.h for peritoneal dialysis). There was no significant difference for any of the pharmacokinetic parameters between subjects on hemodialysis and those on peritoneal dialysis. Plasma concentrations of MPA and MPAG did not fall significantly during hemodialysis. No MPA was detectable in hemodialysis or peritoneal dialysis fluid, but small amounts of MPAG were detected in hemodialysis fluid in 1 out of 10 subjects and in peritoneal dialysis fluid in 3 out of 10 subjects. CONCLUSIONS: The accumulation of MPAG may be responsible for the poor gastrointestinal tolerance of this drug in dialysis patients and probably limits the maximum dose of MMF that can be tolerated.     

腹膜透析相关性腹膜炎经验用药分析

目的 研究华山医院及宝山分院腹膜透析（腹透）相关性腹膜炎的致病菌、耐药性及患者转归,为临床经验用药提供依据。 方法 回顾性分析2007年1月至2010年1月上述两医院腹透中心收治的93例腹透相关性腹膜炎的临床表现、致病菌、耐药性及转归。 结果 75例腹透液培养阳性,阳性率为80.2％,其中革兰阳性球菌45例,革兰阴性杆菌21例,真菌2例,革兰阳性杆菌1例,革兰阴性球菌1例,多种菌混合感染5例。革兰阳性球菌主要以凝固酶阴性的葡萄球菌为主,所有革兰阳性球菌对万古霉素均敏感,但对头孢唑林耐药率高达60.0%,而且耐药率有明显的逐年增加趋势。革兰阴性菌对头孢他啶的耐药率达到46.1％,所有革兰阴性杆菌对亚胺培南均敏感。因腹膜炎而退出腹膜透析有16例,退出率为17.2％（16/93）。腹腔使用万古霉素对残肾功能无显著影响。 结论 两院腹透中心腹透相关腹膜炎致病菌以革兰阳性球菌为多数。头孢唑啉耐药性逐年增高,目前不再适合作为初始治疗的经验用药。腹腔使用万古霉素可推荐作为革兰阳性菌致腹膜炎的初始经验用药。     

Peritoneal eosinophilia in patients on continuous ambulatory peritoneal dialysis: a prospective study

A prospective study on peritoneal eosinophilia was conducted in 23 continuous ambulatory peritoneal dialysis (CAPD) patients for a mean period of 7.9 months. Peritoneal eosinophilia as defined by peritoneal eosinophil count exceeding 100/mm3 was found in 60.8% of patients. Most developed peritoneal eosinophilia within 3 months of the initiation of dialysis, although the phenomenon could occur as early as one day or as late as 6 months after dialysis. Fifty-seven percent of those with peritoneal eosinophilia also had peripheral blood eosinophilia. Although most peritoneal eosinophilic episodes subsided in a month, in one patient the process grumbled on for 150 days. The number of peritonitis episodes was not significantly different between patients with peritoneal eosinophilia and those without. The only distinction between the two groups of patients was that those who developed peritoneal eosinophilia had a significantly (P = .002) higher serum IgE concentration initially as well as throughout the period of observation.     

Icodextrin-induced peritonitis: study of five cases and comparison with bacterial peritonitis

BACKGROUND: An epidemic of aseptic peritonitis related to the presence of peptidoglycan contaminant in some batches of icodextrin solution (Extraneal, Baxter Healthcare Corporation) occurred in Europe in the first six months of 2002. METHODS: By case-control study we examined the clinical and biologic features of 5 patients with icodextrin-induced peritonitis (group AP) and compared them with 7 patients with bacterial peritonitis (group BP) recruited in our clinical center between January and June 2002. RESULTS: Diagnosis of icodextrin-induced peritonitis was confirmed in all cases by a positive reintroduction test with contaminated batches of icodextrin. No recurrence was observed on re-exposure to icodextrin free of peptidoglycan. Skin tests were positive with contaminated icodextrin in 2 of 5 patients, while they were negative with icodextrin solution free of peptidoglycan (<0.6 ng/mL). During peritonitis, serum level of C-reactive protein (CRP) was lower in group AP (42.4 +/- 34 mg/L) than in group BP (135 +/- 59 mg/L) (P= 0.01). Leukocyte number in peritoneal dialysis effluent was lower in group AP (284 +/- 101/mm3), with a lower neutrophil/monocyte ratio (N/M = 0.67) than in group BP (1410 +/- 973/mm3; N/M = 4) (P < 0.05). A low number of peritoneal fluid eosinophilia (11 +/- 8%) was detected in group AP. CONCLUSION: Icodextrin-induced peritonitis was associated with a burst of intraperitoneal cytokines. The phenotype of peritoneal neutrophils was different between aseptic and bacterial peritonitis, indicating that inflammatory stimuli that activate neutrophils in both types of peritonitis are clearly distinct. Finally, peritoneal injury measured by weight gain, peritoneal permeability, and CA125 concentration seemed to be less severe during icodextrin-induced peritonitis than during bacterial peritonitis.     

Use of deferasirox (Exjade) for iron overload in peritoneal dialysis patients

A 54 year old male with b‐Thalassemia major developed ESRD and was managed with continuous ambulatory peritoneal dialysis. Although not able to be transfused due to high titre red cell antibodies he did require management of iron overload. Deferasirox (Exjade) was administered orally. There was concern that excretion of iron via the peritoneal dialysate may raise the risk of iron‐dependent infections (Yersinia and Rhizopus).Whilst receiving Exjade 1000mg /day, a total collection of 12.7L of peritoneal dialysate was collected over a 24 hour period by the patient. The dialysate total iron levels were measured by ICP‐MS at 0.46mmol/L which equates to 0.33mg of Fe in total. Over a 6 month period his serum ferritin fell from 3869μg/l to 1545μg/l. There were no episodes of peritonitis. Since only 7‐8% of the deferasirox and iron complex is excreted through the urine, the amount of Fe seen in the patient's dialysate might be expected to be up to 1.5‐1.6mg. Yet, the results of the Fe levels in the patient’s PD fluid was a meagre 0.33mg, about five times lower than expected.Whilst only moderately effective at a dosage of 1000mg/day, deferasirox may be a safe agent for iron removal in iron overloaded peritoneal dialysis patients, as relatively low dialysate iron levels reduces the risk of Yersinia and Rhizopus infection.     

Sustained-release bezafibrate corrects lipid abnormalities in patients on continuous ambulatory peritoneal dialysis

A study was undertaken in 24 Chinese patients on maintenance continuous ambulatory peritoneal dialysis, using bezafibrate in its sustained-release form to correct lipid abnormalities. Six patients who received 400 mg/day developed severe muscle weakness with grossly elevated creatine phosphokinase activities within 3 weeks. The drug was discontinued and the symptoms disappeared. The remaining 18 patients received 400 mg/week for 8 weeks. There was a significant decrease in serum triglyceride (2.74 +/- 0.33 to 1.86 +/- 0.17 mmol/l at the 4th week and 1.65 +/- 0.4 mmol/l at the 8th week). Concomitantly, serum total cholesterol decreased. Serum high-density lipoprotein cholesterol increased significantly (from 1.18 +/- 0.082 to 1.36 +/- 0.060 mmol/l at the 4th week and 1.40 +/- 0.103 mmol/l at the 8th week). Post-heparin lipoprotein and hepatic lipases were measured by a substrate-specific method. The former increased significantly (p = 0.000) after bezafibrate treatment while the latter did not change. All parameters of lipid metabolism returned towards baseline 4 weeks after discontinuation of therapy. The drug was well tolerated at 400 mg/week and there was no significant rise in serum creatine phosphokinase.     

Usefulness of peritoneal fluid amylase levels in the differential diagnosis of peritonitis in peritoneal dialysis patients.

Peritonitis continues to be a major cause of morbidity in peritoneal dialysis patients despite recent technological advances (Y systems) that have reduced peritonitis rates to much more acceptable levels. Most of the time when a peritoneal dialysis patient presents with peritonitis, it is infectious in origin. However, these patients occasionally develop other intra-abdominal pathology that requires more intensive medical care or, at times, surgical intervention. To help in the early differential diagnosis of the cause of peritonitis in these patients, peritoneal fluid amylase levels were prospectively obtained from 50 patients presenting to the hospital with peritonitis. Thirty-nine of them had typical infectious peritonitis, and their mean peritoneal fluid amylase level was 11.1 (range, 0 to 90). Six patients had pancreatitis and a mean peritoneal fluid amylase level of 550 U/L (range, 100 to 1,140 U/L). Five patients were found to have other intra-abdominal pathology, and their mean peritoneal fluid amylase level was 816 U/L (range, 142 to 1,746 U/L). In patients who did not respond to initial therapy, sequential peritoneal fluid amylase levels did not increase in patients with typical infectious peritonitis whereas it did increase in patients with other intra-abdominal pathology. In conclusion, it was found that peritoneal fluid amylase levels were helpful in the differential diagnosis of peritonitis in these patients. An elevated level (greater than 100 U/L) differentiated those patients with other intra-abdominal causes of peritonitis from those with typical infectious peritonitis.