Abstract
Editor:
We have found several inconsistencies within and between the recently published ISPD Peritonitis Recommendations: 2016 Update on Prevention and Treatment by Li et al. (1) and the ISPD Catheter-Related Infection Recommendations: 2017 Update by Szeto et al. (2) as detailed below (references cited from the International Society for Peritoneal Dialysis [ISPD] papers in question correspond to references from the original papers and they are noted in square brackets).
2016 Peritonitis Recommendations
Residual Renal Function (RRF)—No Need to Increase Dose of Antibiotic
The ISPD Recommendations for 2016 state, “It was recommended previously that for patients with substantial residual renal function, the dose of antibiotics that have renal excretion needs to be adjusted [12,13]. However, recent studies suggest that such adjustments are not necessary [284,304].”
This statement appears to be a direct contradiction to the references cited.
The Fish paper [284] specifically states vancomycin was dosed as “single dose of 30 mg/kg rounded to the nearest 500 mg for anuric patients, but increased by 25% if not anuric up to a maximum dose of 2.5 g.” (3)
The Blunden paper [304] specifically states “single dose of 25 mg/kg rounded to the nearest 500 mg for anuric patients but increased by 25% if not anuric.” (4)
In neither paper is there a statement contrary to increasing dose for residual function. Both papers detail an increase of 25% to the dose for patients with RRF.
Table 5 Antibiotic Dosing
Healthcare providers are not all familiar with the historical peritoneal dialysis (PD) literature. Consequently, they could misunderstand antibiotic dosing from Table 5, as most papers are on continuous ambulatory PD (CAPD), not automated PD (APD). This misunderstanding could result in under-dosing for APD patients. In the 2010 guidelines, the antibiotic dosing was listed separately for CAPD and APD, making it clear how the drug was studied. This in turn helps clinicians understand potential issues for under-dosing when using CAPD-studied dosing in APD patients.
There are also some inconsistencies within the table:
Ampicillin/sulbactam continuous dosing is listed as loading dose (LD) 750 - 100 mg/L. The 100 mg/L seems to be a typographical error. Perhaps it was to be 1,000 mg? However, reference [253] Lam, lists the LD as 1,500 mg in 2 L PD fluid (1,000 mg ampicillin and 500 mg sulbactam) (5).
Aztreonam continuous dosing has 2 references [243 and 244]. Reference [243] by Gerig does discuss dosing of Aztreonam (6). However, reference [244] by Anwar only discusses imipenem, vancomycin, and netilmicin (7). It has no mention of Aztreonam.
Imipenem/cilastin intermittent dosing is listed as 500 mg in alternate bags. However, reference [244] Anwar reports the dose is 1 g in alternate CAPD exchanges (2 g per day) for half of the patients, and the other half had 500 mg in alternate CAPD exchanges (1 g per day) (7). The 2 g per day had 85% resolution with 2 patients with seizures; 1 g per day had 42% resolution. Only the lower dose is referenced in the table.
Teicoplanin dose is listed as 400 mg/bag for LD and 20 mg/bag for maintenance dose (MD). This is not consistent with the paper by Lupo (8). Per Lupo, LD of 400 mg was administered IV; the MD was 40 mg/bag. It is important to note that the study was done with 2-L bags on CAPD, which is not specified in Table 5. The fact that this was studied in CAPD needs to be highlighted, as it is very hard to apply this dosing to APD with 5- or 6-L bags.
Vancomycin dosing is listed as 15 - 30 mg/kg Q 5 - 7 days. The reference [284] by Fish used a dose of 30 mg/kg rounded to the nearest 500 mg for anuric patients and increased the dose by 25% for non-anuric patients to a maximum dose of 2.5 g (3). In this paper, they checked the serum and PD effluent levels of vancomycin at day 5; there is no mention of day 7. When serum levels of vancomycin were checked at day 5, only 85% achieved a serum vancomycin level of > 15 mg/L. Additionally, when PD effluent vancomycin levels were checked on day 5, 23% of patients had a subtherapuetic level of less than 4 mg/L. There are no data supporting 15 mg/kg or 7-day dosing regimens.
Inconsistencies between 2016 Peritonitis Guidelines and 2017 Catheter-Related Infectious Recommendations
Figures 2 and 3 in Li (2016) indicate that if the peritonitis resolves but there is a persistent exit-site or tunnel infection you should consider simultaneous catheter removal and re-insertion (1). However, Szeto (2017) says (2):
“We suggest removal of the dialysis catheter in PD patients with exit-site infections that progress to, or occur simultaneously with, peritonitis (2C).”
“We suggest that, for patients who have undergone dialysis catheter removal for simultaneous exit-site or tunnel infection and peritonitis, any reinsertion of a PD catheter be performed at least 2 weeks after catheter removal and complete resolution of peritoneal symptoms (2D).”
The recommendations between Li and Szeto have 2 inconsistencies. First, Szeto states the catheter should be removed if there is peritonitis with a concurrent exit-site infection (2), whereas Li suggests treating through peritonitis with catheter removal only if the exit-site infection does not resolve (1).
The second inconsistency pertains to figures 2 and 3 in Li (2016), which suggest considering simultaneous catheter removal and re-insertion for resolving peritonitis with a refractory exit-site/tunnel infection (1). However, Szeto does not recommend simultaneous removal and reinsertion (2). Szeto recommends reinsertion after at least 2 weeks post-catheter removal and the complete resolution of peritoneal symptoms.
Perhaps the Szeto recommendation supersedes the Li recommendation? If so, this needs to be called out to the community.
2017 Catheter-Related Infectious Recommendations
Table 1 Prophylactic Antibiotics
Antibiotics recommended for the prevention of catheter-related infections are listed in Table 1 on page 144 of Szeto (2). Polysporin triple antibiotic ointment is included; however, polysporin is contraindicated for use as prophylaxis by the MP3 study by McQuillan (9). The MP3 study showed a higher rate of fungal peritonitis with polysporin use and states it should not be used for prophylaxis.
Table 4 Oral Antibiotics Used in Catheter-Related Infections
Table 4 on page 147 of Szeto, lists the dose for amoxicillin/clavulanate as 875 mg/125 mg BID (2). This is the dose for a person with intact renal function. The dose for a patient with a glomerular filtration rate (GRF) < 10 mL/min is either 500 mg/125 mg or 250 mg/125 mg QD (10).
Treatment of infections in PD is challenging for the clinician and critical for the patient. Guidelines need to be as clear as possible and we recommend these suggestions be considered.