Research recommendations

• Determine the optimal dose parameter that should be used in future trials comparing different intensities of dialysis in AKI patients. Some possible methods to explore are on-line Kt/V urea, urea reduction ratios, or application of the concept of corrected equivalent renal urea clearance for solute removal measurement and ultrafiltration effluent volume, or substitution fluid volume normalized by body weight and time for CRRT. Other aspects of intensity should also be studied, e.g., fluid control and acid-base and electrolyte balance. The comparators might be the standard ways to measure dose as Kt/V or prescribed effluent volume. Suggested outcome parameters are 60- to 90-day mortality, ICU and hospital LOS, and recovery of kidney function.
• Determine the optimal dose of RRT in AKI in homogeneous subpopulations, such as cardiac surgery or sepsis patients, and separately in ICU and non-ICU patients. Future RCTs should be controlled for timing of RRT initiation and, perhaps, for general care of patients (antibiotics, nutrition, kind and indication for vasoactive drugs, mode of mechanical ventilation). Studies should also assess the efficiency of RRT (since dose does not necessarily mean efficiency), assessing control of BUN, creatinine, fluid balance, and acid-base and electrolyte status. The comparators might be different efficiency targets. The suggested outcomes are 60- to 90-day mortality, need for vasopressor drugs, time on mechanical ventilation, ICU and hospital stay, and renal recovery.