Guidelines for Sustained Low‑Efficiency Dialysis (SLED) in ICU Patients with Acute Kidney Injury

1. Indications and Comparative Effectiveness

SLED is a practical, cost‑effective hybrid renal replacement modality that provides hemodynamic stability and clinical outcomes comparable to continuous renal replacement therapy (CRRT); it should be used interchangeably for hemodynamically unstable ICU patients with AKI, especially when CRRT resources are limited【1】.
No survival advantage has been demonstrated for CRRT over other modalities, supporting the interchangeable use of SLED for hemodynamically unstable patients【1】.

SLED can be delivered in centers that have standard intermittent hemodialysis equipment but lack dedicated CRRT infrastructure, making it feasible in resource‑limited settings【1】.
The feasibility of SLED may be constrained by the availability of dialysis personnel to cover extended treatment hours (e.g., 8‑hour sessions, six days per week)【1】.

Use an uncuffed, non‑tunneled dialysis catheter, preferentially placed in the right internal jugular vein; if unavailable, femoral or left internal jugular sites are acceptable, while subclavian placement should be avoided【2】.
Ultrasound guidance is recommended for all catheter insertions to improve placement accuracy and reduce complications【2】.
Obtain a chest radiograph after internal jugular or subclavian catheter placement before the first dialysis session to confirm correct positioning and rule out pneumothorax【2】.

Regional citrate anticoagulation is the first‑line strategy when anticoagulation is required; unfractionated heparin or low‑molecular‑weight heparin may be used if citrate is contraindicated【2】.
Bicarbonate‑buffered dialysate should be used instead of lactate‑buffered solutions, particularly in patients with circulatory shock, liver failure, or lactic acidosis【2】.
All dialysis fluids must meet AAMI standards for bacterial and endotoxin contamination to ensure safety【2】.

The target delivered dose for SLED should be equivalent to a CRRT effluent volume of 20–25 mL/kg/hour when expressed as a continuous equivalent【2】.
In practice, prescribed doses often exceed the delivered dose because of treatment interruptions; clinicians should monitor the actual effluent volume and increase the prescription by 20–25 % if the delivered dose falls short【3】.
Continuous monitoring of filter performance and circuit integrity throughout each session is essential to detect clotting or malfunction early【2】.

SLED leads to continuous losses of potassium, phosphate, magnesium, and amino acids; electrolytes should be checked every 2–6 hours during the initial phase and supplemented as needed【4】.
Therapeutic drug monitoring is recommended for beta‑lactam antibiotics and other dialyzable medications to avoid under‑dosing【2】.
Provide 1.5–1.7 g/kg/day protein once the patient is hemodynamically stable, acknowledging that SLED removes approximately 10–15 g of amino acids daily【4】.
Target total energy intake of 20–30 kcal/kg/day and supplement water‑soluble vitamins (thiamine, folate, vitamin C) to compensate for dialytic losses【4】.

In patients with acute brain injury or elevated intracranial pressure, CRRT is preferred because its continuous, slower solute removal minimizes intracranial pressure fluctuations【2】.
Severe cerebral edema also warrants CRRT to avoid rapid osmotic shifts associated with intermittent therapies【5】.
Extreme hemodynamic instability that requires minute‑to‑minute fluid adjustments is better managed with CRRT’s continuous fine‑tuning capability【5】.

SLED can be delivered over an 8‑hour session, six days per week, providing gradual ultrafiltration that avoids rapid intravascular volume shifts and is therefore suitable for vasopressor‑dependent ICU patients【6】.
When conventional CRRT machines or solutions are unavailable, SLED is indicated because it uses standard hemodialysis equipment with modified blood‑flow (≈200 mL/min) and dialysate‑flow (≈300–350 mL/min) settings【6】.

The Acute Renal Failure Trial Network (ATN) study showed that patients could be switched between SLED and CRRT as hemodynamic status changed without any impact on survival or renal recovery, confirming clinical equivalence of the two modalities【6】【7】.
Solute clearance with SLED is comparable to CRRT: a weekly Kt/V of 8.4 ± 1.8 translates to an equivalent renal clearance of 29 ± 6 mL/min, matching the CRRT target of 20–25 mL/kg/h【6】 (randomized trial).
When prescribed six days per week, SLED achieves the KDIGO‑recommended weekly delivered Kt/V of 3.9【6】 (guideline‑based target).

In approximately 65 % of treatments, SLED can be performed without systemic anticoagulation by using saline flushes alone, making it appropriate for patients at high bleeding risk【7】 (observational cohort).
Filter clotting rates are acceptable: 18 % with heparinized circuits and 29 % with heparin‑free circuits【7】.

The prescribed dose for SLED should aim to deliver an effluent volume equivalent to 20–25 mL/kg/h of CRRT, acknowledging that treatment interruptions and filter efficiency loss typically require a 20–25 % upward adjustment of the prescription【6】【7】.
Frequent measurement of the actual delivered dose is essential rather than assuming the prescription is met, to ensure adequacy of therapy【6】【7】.
Bicarbonate‑buffered dialysate (instead of lactate‑buffered) is recommended for patients with shock, liver failure, or lactic acidosis to avoid metabolic complications【7】.

Do not assume that CRRT is universally superior for hemodynamically unstable patients; modality selection should be based on local expertise, resource availability, and specific clinical scenarios【6】.
Kinetic modeling demonstrates that a Kt/V of 1.3 delivered three times weekly is not equivalent to a Kt/V of 0.65 delivered six times weekly; dosing calculations must reflect treatment frequency【6】.