Antimicrobial Treatment of Peritonitis Associated with Continuous Ambulatory Peritoneal Dialysis

A multitude of therapeutic regimens have been proposed for the management of peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD). There are, however, few clinical trials that have evaluated the efficacy of these proposed regimens in a prospective, comparative fashion. This retrospective report is a tabulation of the published data on antimicrobial treatment of CAPD-related peritonitis. The results are presented for combination and mono-drug therapies; Gram-positive bacterial, Gram -negative bacterial and fungal infections; intravenous, oral and intraperitoneal (i.p.) routes of drug administration; various dosages and dosing intervals; and clinical response and relapse rates. The apparent optimal combination regimen for empiric treatment of peritonitis is vancomycin administered in 1 dialysis exchange/week with ceftazidime. This regimen avoids the toxicity associated with the use of aminoglycosides while maintaining effectiveness.

Treatment in Pd Patients of Peritonitis Caused by Gram-Positive Organisms with Single Daily Dose of Antibiotics

This study was a retrospective case analysis of treatment results of peritonitis in PD patients caused by gram-positive organisms in two different but comparable periods.

Cases were entered, regardless of status of exit site, or whether it was the patient's first or subsequent peritonitis episode.

Failure was defined as either recurrence of peritonitis (with same organism within four weeks of cessation of treatment) or the therapeutic decision to remove the catheter.

Cefazolin used in doses of 1.5 g once a day intraperitoneally (1.0 g if body weight was < 50 kg) with initial tobramycin until culture results became available resulted in a 77% overall cure rate compared to 74% cure in a similar group treated with vancomycin 2.0 g IP weekly (1.0 g if body weight < 50 kg).

Peritonitis caused by methicillin-resistant coagulase-negative staphylococci showed a high failure rate; the change to vancomycin after the initial treatment of these cases would be justified.

The cure rate of peritonitis caused by S. aureus is disappointingly low (58% with vancomycin, 67% with cefazolin). This is due to the high rate of exit-site infections with this organism.

Pharmacokinetics of Intraperitoneal Cefazolin and Gentamicin in Empiric Therapy of Peritonitis in Continuous Ambulatory Peritoneal Dialysis Patients

Objective

The aim of this study was to measure and evaluate the appropriateness of the actual concentrations of serum and dialysate cefazolin and gentamicin in Thai continuous ambulatory peritoneal dialysis (CAPD) patients treated following the International Society for Peritoneal Dialysis (ISPD) 1996 recommendations for the empiric therapy of CAPD-related peritonitis.

Design

Prospective and descriptive study.

Setting

Institutional level of clinical care.

Patients

CAPD-related peritonitis patients were diagnosed by dialysate effluent white cell count of more than 100/mm3and polymorphonuclear leukocytes of at least 50%. There were 18 patients, all at least 15 years of age, entered; all completed the study.

Intervention

In accordance with the ISPD 1996 recommendations, the antibiotic regimen included continuous intraperitoneal (IP) cefazolin and once-daily IP amino-glycoside. Cefazolin was administered as loading and continuous maintenance doses of 500 and 125 mg/L dialysate, respectively. Gentamicin, 0.6 mg/kg body weight, was given IP once daily. Duration of treatment was 120 hours.

Main Outcome Measures

Serum and dialysate effluent samples of the 18 CAPD patients with peritonitis were measured and used for the synthesis of pharmacokinetic equations that could predict drug concentrations at any treatment time.

Results

Following administration according to the ISPD 1996 treatment recommendations, serum cefazolin reached levels higher than the recommended levels (8 mg/mL) at 3.3 minutes after drug administration, and persisted through the 5-day duration of the study. Dialysate cefazolin levels during the studied period also were persistently higher than the recommended values. The peak serum gentamicin levels were lower than the suggested values of 4 mg/mL, whereas the trough serum gentamicin levels were higher than the minimal toxic concentrations (2 mg/mL). Dialysate gentamicin levels were higher than therapeutic concentrations for only 4.75 hours in each day. It was difficult, using pharmacokinetic studies, to adjust the dosage regimen of gentamicin to achieve appropriately therapeutic levels in both serum and dialysate.

Conclusions

The ISPD 1996 recommended dosage of continuous IP cefazolin could be appropriate for the treatment of CAPD-related peritonitis. Once-daily IP gentamicin administration, however, has less therapeutic benefit and should be re-evaluated.

Microbiological Surveillance of Peritoneal Dialysis Associated Peritonitis: Antimicrobial Susceptibility Profiles of a Referral Center in GERMANY over 32 Years

Objectives

Peritonitis is one of the most important causes of treatment failure in peritoneal dialysis (PD) patients. This study describes changes in characteristics of causative organisms in PD-related peritonitis and antimicrobial susceptibility.

Methods

In this single center study we analyzed retrospective 487 susceptibility profiles of the peritoneal fluid cultures of 351 adult patients with peritonitis from 1979 to 2014 (divided into three time periods, P1-P3).

Results

Staphylococcus aureus decreased from P1 compared to P2 and P3 (P<0.05 and P<0.01, respectively). Methicillin-resistant S. aureus (MRSA) occurred only in P3. Methicillin-resistant Staphylococcus epidermidis (MRSE) increased in P3 over P1 and P2 (P <0.0001, respectively). In P2 and P3, vancomycin resistant enterococci were detected. The percentage of gram-negative organisms remained unchanged. Third generation cephalosporin resistant gram-negative rods (3GCR-GN) were found exclusively in P3. Cefazolin-susceptible gram-positive organisms decreased over the three decades (93% in P1, 75% in P2 and 58% in P3, P<0.01, P<0.05 and P<0.0001, respectively). Vancomycin susceptibility decreased and gentamicin susceptibility in gram-negatives was 94% in P1, 82% in P2 and 90% in P3. Ceftazidim susceptibility was 84% in P2 and 93% in P3.

Conclusions

Peritonitis caused by MSSA decreased, but peritonitis caused by MRSE increased. MRSA peritonitis is still rare. Peritonitis caused by 3GCR-GN is increasing. An initial antibiotic treatment protocol should be adopted for PD patients to provide continuous surveillance.

Pharmacokinetics of intraperitoneal gentamicin in peritoneal dialysis patients with peritonitis (GIPD study)

BACKGROUND AND OBJECTIVES

Peritonitis is a major infectious complication in peritoneal dialysis patients, and intraperitoneal antibiotic administration is preferred to ensure maximal antibiotic concentrations at the site of infection. This study aimed to describe the plasma and infection site pharmacokinetics of intraperitoneal gentamicin in patients with peritonitis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This prospective pharmacokinetic study of intraperitoneal gentamicin was conducted in peritoneal dialysis patients presenting to hospital with clinically defined signs and symptoms of peritonitis. Twenty-four patients were administered a 0.6-mg/kg dose of intraperitoneal gentamicin, which was allowed to dwell for 6 hours. Serial blood and dialysate samples were collected for 24 hours after the first dose. Gentamicin concentrations in plasma and dialysate were measured using a validated assay.

RESULTS

The median percentage of the dose absorbed into the systemic circulation was 76% (interquartile range=69%-82%) and significantly different between patients with low average, high average, and high peritoneal membrane transporter status (P=0.03). The calculated pharmacokinetic parameters were plasma terminal elimination half-life of 24.7 (20.4-29.9) hours, terminal volume of distribution of 0.30 (0.20-0.36) L/kg, observed peak plasma concentration of 3.1 (2.4-3.4) mg/L, and observed trough plasma concentration of 1.9 (1.4-2.2) mg/L. The peak gentamicin concentration in dialysate was at least eight times the minimum inhibitory concentration of the likely pathogens.

CONCLUSIONS

The high systemic absorption of gentamicin in patients with peritonitis and prolonged plasma elimination half-life may lead to drug accumulation in the systemic circulation, increasing the risk of toxicity.

Optimising intraperitoneal gentamicin dosing in peritoneal dialysis patients with peritonitis (GIPD) study

Background

Antibiotics are preferentially delivered via the peritoneal route to treat peritonitis, a major complication of peritoneal dialysis (PD), so that maximal concentrations are delivered at the site of infection. However, drugs administered intraperitoneally can be absorbed into the systemic circulation. Drugs excreted by the kidneys accumulate in PD patients, increasing the risk of toxicity. The aim of this study is to examine a model of gentamicin pharmacokinetics and to develop an intraperitoneal drug dosing regime that maximises bacterial killing and minimises toxicity.

Methods/Design

This is an observational pharmacokinetic study of consecutive PD patients presenting to the Royal Brisbane and Women's Hospital with PD peritonitis and who meet the inclusion criteria. Participants will be allocated to either group 1, if anuric as defined by urine output less than 100 ml/day, or group 2: if non-anuric, as defined by urine output more than 100 ml/day. Recruitment will be limited to 15 participants in each group. Gentamicin dosing will be based on the present Royal Brisbane & Women's Hospital guidelines, which reflect the current International Society for Peritoneal Dialysis Peritonitis Treatment Recommendations. The primary endpoint is to describe the pharmacokinetics of gentamicin administered intraperitoneally in PD patients with peritonitis based on serial blood and dialysate drug levels.

Discussion

The study will develop improved dosing recommendations for intraperitoneally administered gentamicin in PD patients with peritonitis. This will guide clinicians and pharmacists in selecting the most appropriate dosing regime of intraperitoneal gentamicin to treat peritonitis.

Trial Registration

ACTRN12609000446268

Peritonitis Remains the Major Clinical Complication of Peritoneal Dialysis: The London, Uk, Peritonitis Audit 2002–2003

Background

Over the past two decades, the rate of peritonitis in patients treated by peritoneal dialysis (PD) has been significantly reduced. However, peritonitis remains a major complication of PD, accounting for considerable mortality and hospitalization among PD patients.

Objective

To compare the outcome of peritonitis in a large unselected group of PD patients with that from singlecenter and selected groups.

Method

We audited the outcome of peritonitis in PD patients attending the 12 PD units in the Thames area in 2002 and 2003. There were 538 patients on continuous ambulatory PD (CAPD) and 325 patients on automated PD (APD) and/or continuous cycling PD (CCPD) at the end of 2002, and 635 CAPD and 445 APD/CCPD patients at the end of 2003.

Results

There were 1467 episodes of PD peritonitis during the 2-year period, including 129 recurrent episodes, with the average number of months between peritonitis episodes being 14.7 for CAPD and 18.1 for APD/CCPD, p < 0.05. However there was considerable variation between units. Coagulase-negative staphylococcus (CoNS) was the most common cause, accounting for around 30% of all peritonitis episodes, including recurrences, followed by non-pseudomonas gram negatives and Staphylococcus aureus. Cure rates were 77.2% for CoNS, 46.6% for S. aureus, and 7.7% for methicillin-resistant S. aureus. The cure rate for pseudomonas was 21.4%, and other gram negatives 56.7%. In total, there were 351 episodes of culture-negative peritonitis, with an average cure rate of 76.9%. Cure rates were higher for those centers that used a combination of intraperitoneal gentamicin and cephalosporins than those centers that used oral-based regimes. A total of 296 PD catheters were removed as a direct consequence of PD peritonitis: 121 due to gram-positive and 123 due to gram-negative organisms. Only 49 catheters were reinserted and the patients returned to PD. 52 patients died during or subsequent to their episode of PD peritonitis, with an overall mortality rate of 3.5%.

Conclusion

This audit showed that, in a large unselected population of PD patients, the incidence of peritonitis was significantly greater than that reported in single-center short-term studies, and varied from unit to unit. Similarly, the success of treating PD peritonitis varied not only with the cause of the infection but also from unit to unit. PD peritonitis remains a major cause of patients discontinuing PD and switching to hemodialysis.

Initial treatment of peritoneal dialysis peritonitis without vancomycin with a once-daily cefazolin-based regimen

To reduce the use of vancomycin, the current recommendations of the International Society of Peritoneal Dialysis (PD) for the initial treatment of peritonitis complicating PD are to administer intraperitoneal (IP) cefazolin or cephalothin in every PD fluid bag, together with once-daily gentamicin. In view of the inherent impracticalities of this regimen, we studied the efficacy of once-daily cefazolin (1.5 g) IP with gentamicin IP as initial treatment for primary (nonrecurrent) PD peritonitis. This regimen has been used in all episodes of peritonitis not associated with tunnel or exit-site infections or fluid leaks. Sixty-nine episodes in 61 patients were analyzed (44 patients, continuous ambulatory PD; 22 patients, automated PD; and 3 patients, hospital-based intermittent PD), of which 38 episodes (55%) were gram-positive infections, 6 episodes (9%) were gram-negative infections, and 18 episodes (26%) had negative culture results. Four patients died within 4 weeks of infection (none considered attributable to inadequate treatment of their peritonitis). Ten catheters (14.5%) required removal to clear the infection; 7 catheters were in patients with gram-negative infections. The relapse rate within 4 weeks of ceasing antibiotic therapy was 8.9%. Compared with the results of 40 episodes of peritonitis treated initially with our previous IP vancomycin and gentamicin regimen, successful treatment (no death, catheter removal, or recurrence) was achieved in 52 of 69 episodes in the cefazolin group (75.4%) versus 23 of 40 episodes in the vancomycin group (57.5%; P: = 0.058). In conclusion, once-daily IP cefazolin and gentamicin for the initial treatment of PD peritonitis is at least as effective as a vancomycin-based regimen and is well tolerated.

Influence of intraperitoneal gentamicin on peritoneal transport in IPD patients

We have investigated the effect of intraperitoneal gentamicin on dialysis efficiency in 10 intermittent peritoneal dialysis (IPD) patients. The following parameters were measured: net ultrafiltration (UF); concentration ratios (D/P) of urea, creatinine, potassium; peritoneal clearances (ml/min) of urea, creatinine, potassium; mass transfer of sodium (MTNa); sodium sieving index (SCNa). It has been found that gentamicin significantly decreased D/P urea (p < 0.056) and D/P creatinine (p < 0.05). We found also a significant decrease of mean clearances of urea (p < 0.05) and creatinine (p < 0.05). The mean clearance of potassium did not significantly change. There was no significant change in UF, MTNa and SCNa. Our preliminary data suggest that gentamicin decreases the permeability of the peritoneum for certain low molecules in IPD patients, which may have a negative impact on dialysis efficiency.

Incidence and significance of pneumoperitoneum in continuous ambulatory peritoneal dialysis

In a retrospective study we reviewed upright chest x-ray films of 101 continuous ambulatory peritoneal dialysis (CAPD) patients to determine the incidence and significance of free subdiaphragmal air. A pneumoperitoneum (PP) was diagnosed if a minimal shadow of free air was detected under the diaphragm. The amount of free air was determined by measuring the height and width of the subdiaphragmal air shadow. Of all CAPD patients, 33.6% (34 of 101) had at least one occurrence of PP. Thirteen of these 34 patients (38.2%) were diagnosed within 30 days after catheter implantation, 10 patients (29.5%) acquired a PP during an episode of peritonitis, and in 11 patients (32.4%) no additional risk factor could be determined. Patients radiographed within 30 days after catheter implantation showed a statistically significant higher incidence of PP compared with the same patients radiographed later (22% v 10%; P < 0.05). The incidence of PP in CAPD patients suffering from peritonitis (33%) was significantly higher than in patients without peritonitis (10%; P < 0.001). The amount of free air did not differ statistically significantly between the investigated groups. Only two patients with PP and peritonitis had surgically confirmed visceral perforation. Therefore, the main reason for PP seemed to be handling faults during CAPD bag exchange. There was no correlation between the organisms causing peritonitis and PP or the CAPD connector system and PP. In conclusion, a PP occurs in approximately one third of all CAPD patients and a visceral perforation cannot be diagnosed by the occurrence and amount of free subdiaphragmal air.

Group B streptococcus: an unusual cause of severe peritonitis in young children treated with continuous ambulatory peritoneal dialysis

Peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients is only rarely caused by beta-hemolytical streptococci species. We describe two young children, aged 15 months and 5 years, respectively, who presented an unusually severe course of peritonitis due to group B beta-hemolytical streptococci. This course of the disease showed a strong similarity with neonatal streptococcal septicemia. In neonates, IgG2 deficiency is thought to be partly responsible for the severity of this condition. This may also be true for young children treated with CAPD, since IgG2 deficiency has been established for children.