Walkaway PIRRT (as SLED) for Acute Kidney Injury

Experience of Sustained Low-Efficiency Dialysis (SLED) in an Intensive Care Unit of a Quaternary Care Hospital

BACKGROUND

In critically ill patients, sustained low-efficiency dialysis (SLED) has become a viable option for treating acute kidney injury (AKI) instead of continuous renal replacement therapy (CRRT). This study aimed to evaluate clinical outcomes in critically ill patients receiving SLED.

MATERIAL AND METHODS

In our ICU, we performed a retrospective cohort study on hemodynamically unstable patients requiring dialysis in the form of SLED. Demographics, clinical, and biochemical variables were analyzed.

RESULTS

A total of 58 patients were enrolled in the study. The mean age was 48.58 ± 15 with a male-to-female ratio of 3:1. Higher APACHE II score, high international normalized ratio, thrombocytopenia, and septic shock were found to be poor prognostic markers, with an overall observed mortality of 56.9%.

CONCLUSION

SLED can be considered as an alternative to CCRT for selected hemodynamically unstable patients requiring renal replacement therapy.

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.

Prolonged Intermittent Kidney Replacement Therapy

Kidney replacement therapy (KRT) is a vital, supportive treatment for patients with critical illness and severe AKI. The optimal timing, dose, and modality of KRT have been studied extensively, but gaps in knowledge remain. With respect to modalities, continuous KRT and intermittent hemodialysis are well-established options, but prolonged intermittent KRT is becoming more prevalent worldwide, particularly in emerging countries. Compared with continuous KRT, prolonged intermittent KRT offers similar hemodynamic stability and overall cost savings, and its intermittent nature allows patients time off therapy for mobilization and procedures. When compared with intermittent hemodialysis, prolonged intermittent KRT offers more hemodynamic stability, particularly in patients who remain highly vulnerable to hypotension from aggressive ultrafiltration over a shorter duration of treatment. The prescription of prolonged intermittent KRT can be tailored to patients' progression in their recovery from critical illness, and the frequency, flow rates, and duration of treatment can be modified to avert hemodynamic instability during de-escalation of care. Dosing of prolonged intermittent KRT can be extrapolated from urea kinetics used to calculate clearance for continuous KRT and intermittent hemodialysis. Practice variations across institutions with respect to terminology, prescription, and dosing of prolonged intermittent KRT create significant challenges, especially in creating specific drug dosing recommendations during prolonged intermittent KRT. During the coronavirus disease 2019 pandemic, prolonged intermittent KRT was rapidly implemented to meet the KRT demands during patient surges in some of the medical centers overwhelmed by sheer volume of patients with AKI. Ideally, implementation of prolonged intermittent KRT at any institution should be conducted in a timely manner, with judicious planning and collaboration among nephrology, critical care, dialysis and intensive care nursing, and pharmacy leadership. Future analyses and clinical trials with respect to prescription and delivery of prolonged intermittent KRT and clinical outcomes will help to guide standardization of practice.

[Present practise patterns of renal replacement therapy in German intensive care medicine]

About 50% of all critically ill patients develop acute kidney injury (AKI) and approximately 15% receive renal replacement therapy (RRT). Although RRT is frequently used in intensive care units in Germany, it is currently unknown which RRT procedures are available, which qualification the involved staff has, which anticoagulation strategies are used and how RRT doses are prescribed. To investigate quality and structural characteristics of the performance of RRT in intensive care units throughout Germany, the German Interdisciplinary Society of Intensivists (Deutsche Interdisziplinäre Vereinigung für Intensiv- und Notfallmedizin [DIVI]) performed an inquiry among their members. A total of 897 members participated in the survey in which practical aspects were queried. In 69.1% of the cases, RRT was performed in hospitals with more than 400 beds and in 74.5% in university hospitals or other primary care hospitals. Furthermore, 93.3% of clinics are equipped with continuous and 75.8% with intermittent renal replacement devices. In 91.9%, indication for initiation of RRT was performed by trained physicians specialized in intensive care medicine or nephrologists. Intermittent as well as continuous modalities are both present in three-quarters of cases, which allows for individualized therapy. However, the documentation of dialysis dose needs to be improved.

Integration of sustained low-efficiency dialysis into extracorporeal membrane oxygenation circuit in critically ill COVID-19 patients - a feasibility study

Background

Severe COVID‐19 can necessitate multiple organ support including veno‐venous extracorporeal membrane oxygenation (vvECMO) and renal replacement therapy. The therapy can be complicated by venous thromboembolism due to COVID‐19‐related hypercoagulability, thus restricting vascular access beyond the vvECMO cannula. Although continuous renal replacement therapy can be performed via a vvECMO circuit, studies addressing sustained low‐efficiency dialysis (SLED) integration into vvECMO circuits are scarce. Here we address the lack of evidence by evaluating feasibility of SLED integration into vvECMO circuits.

Methods

Retrospective cohort study on nine critically ill COVID‐19 patients, treated with integrated ECMO‐SLED on a single intensive care unit at a tertiary healthcare facility between December 2020 and November 2021. The SLED circuits were established between the accessory arterial oxygenator outlets of a double‐oxygenator vvECMO setup. Data on filter survival, quality of dialysis, and volume management were collected and compared with an internal control group receiving single SLED.

Results

This study demonstrates general feasibility of SLED integration into existing vvECMO circuits. Filter lifespans of ECMO‐SLED compared with single SLED are significantly prolonged (median 18.3 h vs. 10.3 h, p < 0.01). ECMO‐SLED treatment is furthermore able to sufficiently normalize creatinine, blood urea nitrogen, and serum sodium, and allows for adequate ultrafiltration rates.

Conclusions

We can show that ECMO‐SLED is practical, safe, results in adequate dialysis quality and enables sufficient electrolyte and volume management. Our data indicate that SLED devices can serve as potential alternative to continuous‐veno‐venous‐hemodialysis for integration in vvECMO circuits.