Lauren Lipscomb, Mercer University College of Pharmacy
The Kidney Disease Improving Global Outcomes (KDIGO) clinical practice guideline for AKI recommends initiating RRT emergently when life-threatening changes in fluid, electrolyte, and acid-base balance exist. This guideline sites a previous study that did not find differences in intensive care unit (ICU) or hospital mortality no matter when RRT was initiated. 
The Renal Association Guidelines for AKI recommend that the decision to start RRT should remain a clinical decision based on fluid, electrolyte, and metabolic status of the individual patient. These guidelines state RRT should be initiated once AKI is established, and the threshold for initiating RRT should be lowered when AKI occurs as part of multi-organ failure. 
|Title: Effect of Early vs Delayed Initiation of Renal Replacement Therapy (RRT) on Mortality in Critically Ill Patients with Acute Kidney Injury (AKI) |
|Design||Single-centered, two-group, parallel-group, randomized clinical trial; N= 231|
|Objective||Determine whether early initiation of RRT in patients who are critically ill with AKI reduces 90-day all-cause mortality|
|Study Groups||Early initiation group (n= 112); delayed initiation group (n= 119)|
|Methods||Early RRT was initiated within eight hours of diagnosis of stage two AKI using the KDIGO classification or if there were any absolute indications for RRT were present. Delayed RRT was initiated within 12 hours of stage three AKI diagnosis.|
|Duration||August 2013 to July 2015|
|Primary Outcome Measure||Mortality at 90 days after randomization|
|Baseline Characteristics||Characteristic||Early (n= 112)||Delayed (n= 119)|
|Mean age; y||65.7||68.2|
|Male sex; n (%)||78 (69.6)||68 (57.1)|
|Mean baseline creatinine; mg/dL||1.1||1.1|
|Estimated glomerular filtration rate (GFR); mg/dL||56.2 (13.8)||55.9 (14.5)|
|Blood urea nitrogen (BUN); mg/dL||38.5 (15.5)||47.5 (21.6)|
|Results||Primary outcome; n (%)||Early (n= 112)||Delayed (n= 119)||p-value|
|90-day all-cause mortality||44 (39.3)||65 (54.7)||0.03|
|Adverse Events||Common Adverse Events: N/A|
|Serious Adverse Events: new onset of arrhythmia: 0.89% early initiated RRT|
|Percentage that Discontinued due to Adverse Events: N/A|
|Study Author Conclusions||Among critically ill patients with AKI, early RRT compared with delayed initiation of RRT reduced mortality over the first 90 days. Further multicenter trials of this intervention are warranted.|
This study concluded that early initiation of renal replacement therapy in critically ill patients with AKI reduced mortality over the first 90 days of therapy when compared to delayed initiation. This study did have some limitations. Instead of being a multi-centered trial, this was conducted as a single-centered trial, which means that the results may not be indicative of the overall population. The study size was fairly small at 231 patients. Only surgical patients were used, so generalizability is very limited. In order to change the overall practice of RRT initiation, larger, more inclusive trials would need to be conducted.
- Kidney Disease Improving Global Outcomes clinical practice guideline for AKI http://www.kdigo.org/clinical_practice_guidelines/pdf/KDIGO%20AKI%20Guideline.pdf. 2012.
- The Renal Association. Acute Kidney Injury guidelines. http://www.renal.org/guidelines/modules/acute-kidney-injury#sthash.woAqAmYB.atP7cjWm.dpbs. 2011.
- Zarbock A, Kellum JA, Schmidt C, et al. Effect of Early vs Delayed Initiation of Renal Replacement Therapy on Mortality in Critically Ill Patients With Acute Kidney Injury: The ELAIN Randomized Clinical Trial. JAMA. 2016;315(20):2190-9.