Which factors could affect the modality selection of RRT?
There is debate whether continuous modalities are better than intermittent modalities in the treatment of AKI patients. IHD has several advantages:
• Short duration of therapy
• Rapid correction of electrolyte and acid-base disturbances
• Rapid fluid removal
• Availability of the machines
• Availability of trained nurses
Often the machines and nurses available to deploy continuous therapies are not available. However, in intermittent dialysis, the duration of the procedure, 3 to 5 hours, limits the control of fluid regulation and acid-base and electrolyte balance. Patients with hemodynamic instability may not tolerate the high ultrafiltration rates necessary to achieve a fluid balance. CRRT can offer advantages over IHD:
- • Slower fluid removal, which promotes hemodynamic stability
- • Better solute clearance
- • Better correction of acid-base and electrolyte abnormalities
- • Better metabolic control
Some data have suggested that intradialytic hypotensive episodes during IHD could decrease the rate of recovery of kidney function. Still, CRRT can also have some limitations and disadvantages, such as the need for continuous anticoagulation, patient immobilization, and greater human resource requirement, including the need for ICU monitoring. Although there are many arguments that favor the use of CRRT in critically ill patients with AKI, current evidence has not shown any benefit to employing CRRT over IHD in this group of patients. The hybrid modalities, SLED and EDD, can provide the same adequate solute control as IHD can, but require less intensive monitoring and time, compared to CRRT.
It is now recognized that more than one therapy can be utilized for managing patients with AKI. Transitions in therapy are common and reflect the changing needs of patients during their hospital course. For instance, patients in the ICU may initially start on CRRT when they are hemodynamically unstable, then transition to SLED-EDD when they improve, and leave the ICU on IHD.
