Antibiotic Dosing in Sustained Low-Efficiency Dialysis in Critically Ill Patients

Characterization of Ganciclovir Dosing for the Management of Cytomegalovirus in Solid Organ Transplant Recipients Receiving Sustained Low-Efficiency Dialysis

BACKGROUND

The optimal dosing of intravenous ganciclovir in patients receiving sustained low-efficiency dialysis (SLED) remains unclear.

OBJECTIVE

The primary objective is to characterize the dosing of ganciclovir for treating and preventing cytomegalovirus (CMV) in Solid Organ Transplant Recipients receiving SLED. The secondary objective is to evaluate the safety and efficacy of the dosing practices described in this study.

METHODS

Retrospective review of electronic medical records from solid organ transplant recipients (SOTRs) admitted to the Medical Surgical Intensive Care Unit at the Toronto General Hospital (TGH) between November 28, 2016, and September 1, 2021, was conducted. Patients concurrently receiving ganciclovir and SLED were included.

RESULTS

Among the 27 encounters for CMV prevention, 18 patients underwent 8-hour SLED, 6 underwent 24-hour SLED, and 3 received other SLED durations. Most patients (80%) on 8-hour SLED began ganciclovir at 2.5 mg/kg/d, whereas 80% of those on 24-hour SLED started at 5 mg/kg/d. No breakthrough viremia occurred at 5 mg/kg/d, with 1 instance at 2.5 mg/kg/d. Cytopenia rates were higher at 5 mg/kg/d (33% vs 20%). For treatment (n = 20), 16 patients underwent 8-hour SLED, 2 underwent 24-hour SLED, and 2 underwent 12-hour SLED. Most (75%) on 8-hour SLED started at 2.5 mg/kg/d, whereas all on 24-hour SLED began at 5 mg/kg/d. Viral eradication rates were 75% and 60% at 2.5 and 5 mg/kg/d, respectively, with higher cytopenia rates at 5 mg/kg/d (37.5% vs 0%). Dose adjustments were primarily in response to refractory disease or cytopenia.

CONCLUSION AND RELEVANCE

At our institution, ganciclovir dosing patterns suggest that for patients requiring 8-hour SLED, there is clinician comfort in using 2.5 mg/kg/d for prevention and 5 mg/kg/d for treatment. In 24-hour SLED, 5 mg/kg/d may be considered for prevention. Higher doses may be considered for CMV treatment; however, we found greater variability in the dosing practices for these patients. Further research with larger sample sizes and ganciclovir drug-level assessments is needed to optimize dosing strategies for CMV treatment.

Vancomycin administration and AUC/MIC in patients with acute kidney injury on hemodialysis (HD): randomized clinical trial

The pharmacokinetics and pharmacodynamics (PK/PD) of vancomycin change during HD, increasing the risk of subtherapeutic concentrations. The aim of this study was to evaluate during and after the conventional and prolonged hemodialysis sessions to identify the possible risk of the patient remaining without adequate antimicrobial coverage during therapy. Randomized, non-blind clinical trial, including critically ill adults with septic AKI on conventional (4 h) and prolonged HD (6 and 10 h) and using vancomycin for at least 72 h. Sessions were analyzed and randomized into three groups (G): control (C), dose of 15 mg/kg after session), intervention (I) 2 h (dose of 7.5 mg/kg in the second hour and 7.5 mg/kg after) and IG continuous infusion (dose of 30 mg/kg in 24 h). Of the 316 patients recruited, 87 were randomized, and 174 HD sessions were monitored. For the analysis, 28 sessions belonged to the CG, 47 to the 2-hour IG, and 31 to the continuous IG. The groups were similar in age, weight, severity scores, use of nephrotoxins, sérum albumin, Kt/V, HD modality, ultrafiltration, and intradialytic intercurrences. The intervention groups showed a higher therapeutic concentration frequency than the control group (p < 0.002). The initial concentration was identified as a risk factor (OR 1.16, p = 0.001) for a non-therapeutic vancomycin concentration in the logistic regression. In contrast, the 2-hour IG was identified as a protective factor (OR 0.24, p = 0.04). Administration of vancomycin during dialysis proved to be a protective factor against concentrations outside the therapeutic target. Further studies are needed to suggest more appropriate doses of vancomycin for patients with AKI on dialysis therapy and to assess the impact of these results on clinical outcomes.

How I prescribe prolonged intermittent renal replacement therapy

Prolonged Intermittent Renal Replacement Therapy (PIRRT) is the term used to define 'hybrid' forms of renal replacement therapy. PIRRT can be provided using an intermittent hemodialysis machine or a continuous renal replacement therapy (CRRT) machine. Treatments are provided for a longer duration than typical intermittent hemodialysis treatments (6-12 h vs. 3-4 h, respectively) but not 24 h per day as is done for continuous renal replacement therapy (CRRT). Usually, PIRRT treatments are provided 4 to 7 times per week. PIRRT is a cost-effective and flexible modality with which to safely provide RRT for critically ill patients. We present a brief review on the use of PIRRT in the ICU with a focus on how we prescribe it in that setting.

How I prescribe prolonged intermittent renal replacement therapy

Prolonged Intermittent Renal Replacement Therapy (PIRRT) is the term used to define 'hybrid' forms of renal replacement therapy. PIRRT can be provided using an intermittent hemodialysis machine or a continuous renal replacement therapy (CRRT) machine. Treatments are provided for a longer duration than typical intermittent hemodialysis treatments (6-12 h vs. 3-4 h, respectively) but not 24 h per day as is done for continuous renal replacement therapy (CRRT). Usually, PIRRT treatments are provided 4 to 7 times per week. PIRRT is a cost-effective and flexible modality with which to safely provide RRT for critically ill patients. We present a brief review on the use of PIRRT in the ICU with a focus on how we prescribe it in that setting.

Pharmacokinetics of Vancomycin in Critically Ill Patients Undergoing Sustained Low-Efficiency Dialysis

INTRODUCTION

Vancomycin pharmacokinetic data in critically ill patients receiving sustained low-efficiency dialysis (SLED) is limited. Published data using vancomycin with intermittent hemodialysis and continuous renal replacement therapy may not be applicable to hybrid dialysis modalities such as SLED. Current drug references lack recommendations for vancomycin dosing in patients receiving SLED.

OBJECTIVE

The objective of this study was to determine vancomycin pharmacokinetics during SLED.

METHODS

A total of 20 patients who were critically ill with oliguric or anuric renal failure who received vancomycin and SLED were included in the study. Surrounding one SLED session, serum vancomycin blood samples were drawn before the initiation of SLED, at the termination of SLED, and 4 hours after completion of SLED treatment. Following this, patients received vancomycin, dosed to target a goal peak of 20-30 mcg/ml. A vancomycin peak level was drawn 1 hour after the end of the infusion. SLED treatment duration was at least 7 hours. Continuous data are reported as median (interquartile range) and categorical data as percentage.

RESULTS

The vancomycin elimination rate and half-life were 0.051 hours (0.042-0.074 hours) and 13.6 hours (9.4-16.6 hours), respectively. SLED reduced vancomycin serum concentrations by 35.4% (31.5-43.8%), and vancomycin rebound was 9.8% (2.5-13.7%). The vancomycin dose administered post-SLED was 1000 mg (875-1125 mg). For 18 patients, the patient-specific volume of distribution was 0.88 L/kg (0.67-1.1 L/kg), vancomycin clearance was 3.5 L/hr (2.2-5.2 L/hr), and the area under the concentration-time curve during the study time period was 280.8 mg·hr/L (254.7-297.3 mg·hr/L).

CONCLUSION

Vancomycin is significantly removed during SLED with little rebound in serum concentrations 4 hours after completion of SLED. Based on study findings, patients who are critically ill require additional vancomycin dosing after each SLED session to maintain therapeutic post-SLED vancomycin concentrations. Therapeutic drug monitoring of vancomycin is recommended during SLED.

Vancomycin for Dialytic Therapy in Critically Ill Patients: Analysis of Its Reduction and the Factors Associated with Subtherapeutic Concentrations

This study aimed to evaluate the reduction in vancomycin through intermittent haemodialysis (IHD) and prolonged haemodialysis (PHD) in acute kidney injury (AKI) patients with sepsis and to identify the variables associated with subtherapeutic concentrations. A prospective study was performed in patients admitted at an intensive care unit (ICU) of a Brazilian hospital. Blood samples were collected at the start of dialytic therapy, after 2 and 4 h of treatment and at the end of therapy to determine the serum concentration of vancomycin and thus perform pharmacokinetic evaluation and PK/PD modelling. Twenty-seven patients treated with IHD, 17 treated with PHD for 6 h and 11 treated with PHD for 10 h were included. The reduction in serum concentrations of vancomycin after 2 h of therapy was 26.65 ± 12.64% and at the end of dialysis was 45.78 ± 12.79%, higher in the 10-h PHD group, 57.70% (40, 48–64, 30%) (p = 0.037). The ratio of the area under the curve to minimal inhibitory concentration (AUC/MIC) at 24 h in the PHD group was significantly smaller than at 10 h (p = 0.047). In the logistic regression, PHD was a risk factor for an AUC/MIC ratio less than 400 (OR = 11.59, p = 0.033), while a higher serum concentration of vancomycin at T0 was a protective factor (OR = 0.791, p = 0.009). In conclusion, subtherapeutic concentrations of vancomycin in acute kidney injury (AKI) patients in dialysis were elevated and may be related to a higher risk of bacterial resistance and mortality, besides pointing out the necessity of additional doses of vancomycin during dialytic therapy, mainly in PHD.

Pediatric Continuous Renal Replacement Therapy (PCRRT) expert committee recommendation on prescribing prolonged intermittent renal replacement therapy (PIRRT) in critically ill children

INTRODUCTION

Recently, prolonged intermittent renal replacement therapies (PIRRT) have emerged as cost-effective alternatives to conventional CRRT and their use in the pediatric population has started to become more prominent. However, there is a lack of consensus guidelines on the use of PIRRT in pediatric patients in an intensive care setting.

METHODS

A literature search was performed on PubMed/Medline, Embase, and Google Scholar in conjunction with medical librarians from both India and the Cleveland Clinic hospital system to find relevant articles. The Pediatric Continuous Renal Replacement Therapy workgroup analyzed all articles for relevancy, proposed recommendations, and graded each recommendation for their strength of evidence.

RESULTS

Of the 60 studies eligible for review, the workgroup considered data from 37 studies to formulate guidelines for the use of PIRRT in children. The guidelines focused on the definition, indications, machines, and prescription of PIRRT.

CONCLUSION

Although the literature on the use of PIRRT in children is limited, the current studies give credence to their benefits and these expert recommendations are a valuable first step in the continued study of PIRRT in the pediatric population.

Renal Replacement Therapy in the ICU

OBJECTIVES

The incidence of acute kidney injury in critically ill patients is increasing steeply. Acute kidney injury in this setting is associated with high morbidity and mortality. There is no doubt that renal replacement therapy for the most severe forms of acute kidney injury can be life saving, but there are a number of uncertainties about the optimal application of renal replacement therapy for patients with acute kidney injury. The objective of this synthetic review is to present current evidence supporting best practices in renal replacement therapy for critically ill patients with acute kidney injury.

DATA SOURCES

We reviewed literature regarding timing of initiation of renal replacement therapy, optimal vascular access for renal replacement therapy in acute kidney injury, modality selection and dose or intensity of renal replacement therapy, and anticoagulation during renal replacement therapy, using the following databases: MEDLINE and PubMed. We also reviewed bibliographic citations of retrieved articles.

STUDY SELECTION

We reviewed only English language articles.

CONCLUSIONS

Current evidence sheds light on many areas of controversy regarding renal replacement therapy in acute kidney injury, providing a foundation for best practices. Nonetheless, important questions remain to be answered by ongoing and future investigation.