Latest Japanese Clinical Practice Guideline for acute kidney injury

Latest Japanese Clinical Practice Guideline for acute kidney injury has been released and the same has appeared in Journal of Intensive Care. Acute kidney injury (AKI) is a syndrome which has a broad range of etiologic factors depending on different clinical settings. The present guideline for AKI has been developed by a multidisciplinary approach with nephrology, intensive care medicine, blood purification, and paediatrics. Of note, clinical practice for AKI management which was widely performed in Japan was also evaluated with a comprehensive literature search.

Major Recommendations -

• AKI is a syndrome associated with a broad spectrum of diseases and a variety of underlying pathologies. Therefore, differentiation of the causes and elimination of the reversible factors are always required.


• The KDIGO criteria are superior to the RIFLE criteria and to the AKIN criteria in predicting survival outcomes; therefore, we suggest using the KDIGO criteria to diagnose AKI. However, it is unknown which criteria should be used to predict the renal outcomes.


• Whenever possible, the baseline renal function should be determined using multiple methods, and the potential presence of chronic kidney disease (CKD) and other comorbidities should be assessed.


• In the RIFLE, AKIN, and KDIGO criteria, the inclusion of the urine output along with the serum creatinine to determine the AKI stage yields more accurate reflections of the survival outcomes and the renal outcomes than the determination of the AKI stage based on the serum creatinine alone. Therefore, we suggest that the AKI staging should involve the urine output whenever possible.


• We suggest that factors such as age, preoperative renal dysfunction, and the duration of the cardiopulmonary bypass should be assessed as risk factors.


• In liver transplantation, we suggest that the preoperative model for end-stage liver disease (MELD) score, the intraoperative blood transfusion volume, the intraoperative hypotension, and the use of vasopressors should be assessed as risk factors for AKI development. The potential risk factors related to other non-cardiac surgeries are unknown.


• Factors such as aging, renal impairment, and cardiac dysfunction should be assessed as risk factors.


• Pre-existing renal dysfunction, aging, and the use of renin-angiotensin-aldosterone system inhibitors should be assessed as risk factors.


• Hospital-acquired AKI has a worse survival prognosis than community-acquired AKI. In addition, the relationship between the severity and the mortality may differ between the two types of AKI. Therefore, we suggest that they should be differentiated from one another.


• Septic AKI may lead to a higher mortality than non-septic AKI; therefore, we suggest that they should be discriminated from each other.


• The in-hospital mortality may be higher in renal AKI than in pre-renal AKI; therefore, we suggest that they should be differentiated from one another.


• Due to their potential utility in the early diagnosis of AKI, we suggest measuring the urinary NGAL and L-type fatty acid-binding protein (L-FABP). However, the utility of the urinary cystatin C is limited; therefore, we cannot make a recommendation about its use.


• Although the urinary NGAL is of limited utility in predicting the AKI severity and mortality, we suggest measuring urinary NGAL. The utilities of the urinary L-FABP and cystatin C in this regard are unclear.


• Although the urinary NGAL is of limited utility for the differentiation of pre-renal AKI from renal AKI, we suggest measuring urinary NGAL. The utilities of the urinary NAG, L-FABP, and cystatin C in this regard are unknown.


• Although low-dose atrial natriuretic peptide has been suggested to be useful for prevention of AKI, relevant reports remain insufficient. Evidence of low-dose atrial natriuretic peptide for the treatment of AKI is limited.


• We do not recommend loop diuretics for the prevention of AKI. We also suggest that loop diuretics should not be administered for the treatment of AKI, except to correct fluid overload.


• We recommend not using low-dose dopamine to prevent or treat AKI.


• We suggest that the administration of calorie and protein as nutritional support for AKI treatment be tailored to the severity and the underlying disease. For severe AKI, we recommend enteral nutrition whenever possible. Unless there is an advanced electrolyte imbalance, strict protein restriction is not necessary.


• There is little evidence to support the idea that the early initiation of blood purification for AKI improves the outcomes. The timing of the initiation should be decided in broad consideration of the clinical symptoms and disease conditions.


• Improvements in the clinical data and the urine output can be used to determine the timing of the blood purification discontinuation.


• There is no evidence allowing for the recommendation of an optimal blood purification dose. The dose must be determined individually by considering disease conditions.


• In hemodynamically stable patients, blood purification may be performed either continuously or intermittently. In hemodynamically unstable patients, continuous blood purification is preferable.


• Nafamostat mesilate may be considered for patients with a high risk of bleeding. For patients with active bleeding, blood purification without the use of anticoagulants may also be considered.


• The long-term outcomes of AKI are poor. Therefore, we suggest confirming patients’ condition at approximately 3 months later and conducting long-term follow-up in accordance with their condition.


• Age ≥ 3 months: We suggest using the KDIGO AKI diagnostic criteria to predict the survival outcomes. For children of age < 3 months, we suggest using the modified KDIGO diagnostic criteria for neonates.


• The use of biomarkers for the early diagnosis of AKI or to predict the survival outcomes cannot be recommended in children.


• When determining whether blood purification is indicated in pediatric AKI, we suggest considering the fluid overload assessment in addition to absolute indications.


• For pediatric AKI patients requiring blood purification, an appropriate modality tailored to the patient’s constitution and disease condition should be considered.


• For pediatric AKI patients requiring blood purification, an appropriate modality tailored to the patient’s constitution and disease condition should be considered.

The present guideline recommends the use of the KDIGO criteria for the diagnosis of AKI; however, caution is necessary in applying these criteria to elderly patients.