Serum vancomycin levels predict the short-term adverse outcomes of peritoneal dialysis–associated peritonitis

Background: The role of monitoring serum vancomycin levels during treatment of peritoneal dialysis (PD)–associated peritonitis is controversial. Substantial inter-individual variability may result in suboptimal serum levels despite similar dosing of vancomycin. The published predictors of suboptimal serum vancomycin levels remain limited. Methods: Data were retrospectively collected from 541 patients on continuous ambulatory peritoneal dialysis between 1 January 2018 and 31 December 312019. For gram-positive cocci and culture-negative peritonitis, we adopted a vancomycin administration and monitoring protocol. Short-term adverse outcomes of PD-associated peritonitis, including transfer to haemodialysis, death, persistent infection beyond planned therapy duration and relapse, were observed. The association between trough serum vancomycin levels and short-term adverse outcomes was evaluated. Results: Intraperitoneal vancomycin was used in 61 gram-positive cocci or culture-negative peritonitis episodes in 56 patients. Fourteen episodes of short-term adverse outcomes occurred in 12 patients, whose average trough serum vancomycin levels on day 5 of treatment were significantly lower than those who didn’t experience any adverse outcomes (8.4 ± 1.7 vs 12.5 ± 4.3 mg/L, p = 0.003). In gram-positive cocci or culture-negative peritonitis patients, those with higher day 5 trough serum vancomycin levels had a lower risk of short-term adverse outcomes (odds ratio: 0.6, 95% confidence interval: 0.4 to 0.9, p = 0.011). Receiver operating charecteristic curve (ROC) analyses showed that the day 5 trough serum vancomycin levels diagnostic threshold value for short-term adverse outcomes was 10.1 mg/L. After adjustments for gender, exchange volume and residual kidney function (RKF), baseline higher peritoneal transport was associated with a suboptimal (<10.1 mg/L) day 5 serum vancomycin level. Conclusions: Serum vancomycin levels are correlated with short-term adverse outcomes of PD-associated peritonitis, and higher peritoneal solute transport status is associated with suboptimal trough serum vancomycin levels on day 5.

Evaluation of intraperitoneal vancomycin in peritoneal dialysis-associated peritonitis

Background: Intraperitoneal (IP) vancomycin is recommended as one of the treatment options for gram-positive coverage in the management of peritoneal dialysis (PD)-associated peritonitis. There is a lack of literature supporting the optimal dose and approach to vancomycin therapeutic drug-level monitoring. Methods: A retrospective chart review was conducted using the BC Renal Agency PROMIS Database and our hospital records from 1 June 2011 to 1 July 2019. Adult patients with PD-associated peritonitis who received IP vancomycin and had at least one serum vancomycin level drawn were included. All patients received a loading dose of 30 mg/kg, which was repeated every 3–5 days depending on PD modality. Serum vancomycin levels were drawn prior to the second vancomycin dose, then at the discretion of the prescriber. The primary end point was the rate of therapeutic serum vancomycin levels ≥15 mg/L. Results: Twenty-three episodes of PD-associated peritonitis in 20 patients met the eligibility criteria. Only 15/23 serum vancomycin levels were drawn appropriately after the first dose. Sixty per cent of these levels were subtherapeutic at <15 mg/L. All subsequent serum vancomycin levels were above the therapeutic target. Most peritonitis episodes (78%) achieved resolution of infection. Residual kidney function was not significantly correlated with serum vancomycin levels ( p = 0.19). Conclusions: An IP vancomycin regimen of 30 mg/kg every 3–5 days resulted in subtherapeutic serum vancomycin levels in most patients following the loading dose but therapeutic levels thereafter. A large percentage of vancomycin levels were drawn inappropriately due to misalignment of outpatient follow-up visits and timing of blood work.

Pharmacokinetics of Intraperitoneal Vancomycin and Amikacin in Automated Peritoneal Dialysis Patients With Peritonitis

Objective: The study aimed to evaluate the vancomycin and amikacin concentrations in serum and dialysate for automatic peritoneal dialysis (APD) patients.Methods: A total of 558 serum and dialysate samples of 12 episodes of gram-positive and 18 episodes of gram-negative peritonitis were included to investigate the relationship between vancomycin and amikacin concentrations in serum and dialysate on the first and third days of treatment. Samples were analysed 30, 120 min, and 48 h after intraperitoneal administration of vancomycin in peritonitis caused by gram-positive agents and 30, 120 min, and 24 h after intraperitoneal administration of amikacin in peritonitis caused by gram-negative agents. Vancomycin was administered every 72 h and amikacin once a day. The target therapeutic concentration of amikacin was 25–35 mg/l at the peak moment and 4–8 mg/l at the trough moment; and after 48 h for vancomycin, 15–20 mg/l at the trough moment.Results: For peritonitis caused by gram-negative agents, at the peak moment, therapeutic levels of amikacin were reached in dialysate in 80.7% of patients with evolution to cure and in 50% of patients evaluated as non-cure (p = 0.05). At the trough moment, only 38% were in therapeutic concentrations in the dialysate in the cure group and 42.8% in the non-cure group (p = 1). Peak plasma concentrations were subtherapeutic in 98.4% of the samples in the cure group and in 100% of the non-cure group. At the trough moment, therapeutic concentrations were present in 74.4% of the cure group and 71.4% of the non-cure group (p = 1). Regarding vancomycin and among gram-positive agents, therapeutic levels were reached at the peak moment in 94% of the cure group and 6% of the non-cure group (p = 0.007). After 48 h, 56.8% of the cure group had a therapeutic serum concentration whereas for the non-cure group it was only 33.3% (p = 0.39).Conclusion: Despite a small sample size, we demonstrated peak dialysate amikacin level and peak serum vancomycin level correlates well with Gram-negative and Gram positve peritonitis cure, respectively. It is suggested to study the antibiotics pharmacodynamics for a better understanding of therapeutic success in a larger sample.

Incidence and risk factors of vancomycin-associated acute kidney injury in a single center: Retrospective study

Background: There is enough evidence to suggest that vancomycin increases the risk of acute kidney injury (AKI) but the exact mechanism is not well understood. This study aims to understand the incidence of vancomycin-associated acute kidney injury (VA-AKI) among hospitalized patients and to identify the risk factors for VA-AKI. Methods: Patients aged 18 and above who received a minimum of 24 hours of intravenous vancomycin and who had serial creatinine measurements over a 13-month period were identified through electronic records. Patients with pre-existing AKI, or eGFR of less than 30ml/min, and patients with end stage kidney disease were excluded. Results were analyzed using t-test and Fisher’s test. A logistic regression model was used to identify the predictors for VA-AKI. Results: From the 598 patients who met the inclusion criteria, 70 developed AKI. Compared to those without AKI, patients with VA-AKI had higher mean serum vancomycin trough levels (22.6 mg/L vs. 14.6 mg/L), and a statistically significant longer duration of vancomycin use (6.7 vs. 5.2 days). Multivariate analysis revealed that serum vancomycin level of > 20 mg/L was associated with a six-fold increase in odds of VA-AKI when compared to those with vancomycin levels < 15 mg/L. The presence of hypotension, iodinated contrast use, and concomitant use of piperacillin-tazobactam were all associated with increased odds of VA-AKI. Conclusion: The incidence of VA-AKI in hospitalized patients with eGFR > 30 ml/min was 11.7%. Serum vancomycin levels of > 20 mg/L, hypotension and administration of iodinated contrast significantly increased the risk of VA-AKI. Piperacillin-tazobactam, when used with vancomycin, was noted to be an independent predictor of AKI, regardless of serum vancomycin trough levels, prompting a reevaluation of the safety of this widespread practice as empiric therapy. Close monitoring of kidney function, avoiding high serum vancomycin levels, maintaining hemodynamic stability, and avoiding unnecessary use of iodinated contrast seem to be essential for the prevention of VA-AKI.

Vancomycin Serum Concentration after 48 h of Administration: A 3-Years Survey in an Intensive Care Unit

The present study assessed the proportion of intensive care unit (ICU) patients who had a vancomycin serum concentration between 20 and 25 mg/L after 24–48 h of intravenous vancomycin administration. From 2016 to 2018, adult ICU patients with vancomycin continuous infusion (CI) for any indication were included. The primary outcome was the proportion of patients with a first-available vancomycin serum concentration between 20–25 mg/L at 24 h (D2) or 48 h (D3). Of 3894 admitted ICU patients, 179 were included. A median loading dose of 15.6 (interquartile range (IQR) = (12.5–20.8) mg/kg) was given in 151/179 patients (84%). The median daily doses of vancomycin infusion for D1 and D2 were 2000 [(IQR (1600–2000)) and 2000 (IQR (2000–2500)) mg/d], respectively. The median duration of treatment was 4 (2–7) days. At D2 or D3, the median value of first serum vancomycin concentration was 19.8 (IQR (16.0–25.1)) with serum vancomycin concentration between 20–25 mg/L reported in 43 patients (24%). Time spent in the ICU before vancomycin initiation was the only risk factor of non-therapeutic concentration at D2 or D3. Acute kidney injury occurred significantly more when vancomycin concentration was supra therapeutic at D2 or D3. At D28, 44 (26%) patients had died. These results emphasize the need of appropriate loading dose and regular monitoring to improve vancomycin efficacy and avoid renal toxicity.

Nebulization of Vancomycin Provides Higher Lung Tissue Concentrations than Intravenous Administration in Ventilated Female Piglets with Healthy Lungs

Background Intravenous vancomycin is used to treat ventilator-associated pneumonia caused by methicillin-resistant Staphylococcus aureus, but achieves high rates of failure. Vancomycin nebulization may be efficient to provide high vancomycin lung tissue concentrations. The aim of this study was to compare lung tissue and serum concentrations of vancomycin administered intravenously and by aerosol in mechanically ventilated and anesthetized healthy piglets. Methods Twelve female piglets received a single intravenous dose of vancomycin (15 mg/kg) and were killed 1 (n = 6) or 12 h (n = 6) after the end of administration. Twelve piglets received a single nebulized dose of vancomycin (37.5 mg/kg) and were killed 1 (n = 6) or 12 h (n = 6) after the end of the aerosol administration. In each group, vancomycin lung tissue concentrations were assessed on postmortem lung specimens using high-performance liquid chromatography. Blood samples were collected for serum vancomycin concentration measurement 30 min and 1, 2, 4, 6, 8, and 12 h after the end of vancomycin administration. Pharmacokinetics was analyzed by nonlinear mixed effect modeling. Results One hour after vancomycin administration, lung tissue concentrations in the aerosol group were 13 times the concentrations in the intravenous group (median and interquartile range: 161 [71, 301] μg/g versus 12 [4, 42] μg/g; P &lt; 0.0001). Twelve hours after vancomycin administration, lung tissue concentrations in the aerosol group were 63 (23, 119) μg/g and 0 (0, 19) μg/g in the intravenous group (P &lt; 0.0001). A two-compartment weight-scaled allometric model with first-order absorption and elimination best fit serum pharmacokinetics after both routes of administration. Area under the time-concentration curve from 0 to 12 h was lower in the aerosol group in comparison to the intravenous group (56 [8, 70] mg · h · l−1vs. 121 [103, 149] mg · h · l−1, P = 0.002). Using a population model, vancomycin bioavailability was 13% (95% CI, 6 to 69; coefficient of variation = 85%) and absorption rate was slow (absorption half life = 0.3 h). Conclusions Administration of vancomycin by nebulization resulted in higher lung tissue concentrations than the intravenous route. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New