Recently developed consensus functional definitions on the basis of specific changes in the serum creatinine concentration and urine volume now complement anatomical approaches to diagnosis.
Classifications of Acute Kidney Injury and Chronic Kidney Disease
| Stage | Assessments | |
| Acute kidney injury | Serum Creatinine Concentration | Urine Output |
| 1 | 1.5–1.9 × baseline or >/=0.3 mg/dl above baseline | <0.5 ml/kg/hr for 6–12 hr |
| 2 | 2.0–2.9 × baseline | <0.5 ml/kg/hr for >12 hr |
| 3 | >/=3.0 × baseline, >/=4.0 mg/dl, or initiation of renal-replacement therapy | <0.3 ml/kg/hr for >/=24 hr or anuria for >/=12 hr |
| Chronic kidney disease | Definition | GFR (ml/min/1.73 m2) |
| 1 | Kidney damage with normal GFR | >/=90 |
| 2 | Kidney damage with mild decrease in GFR | 60–89 |
| 3A | Mild-to-moderate decrease in GFR | 45–59 |
| 3B | Moderate-to-severe decrease in GFR | 30–44 |
| 4 | Severe decrease in GFR | 15–29 |
| 5 | End-stage renal disease | <15 |
The stage of acute kidney injury is determined according to the Kidney Disease Improving Global Outcomes Acute Kidney Injury Classification, and that of chronic kidney disease according to the glomerular filtration rate (GFR). Kidney damage is usually detected by means of an increased urinary albumin-to-creatinine ratio. To convert the values for creatinine to micromoles per liter, multiply by 88.4.
References:
- Chawla LS, Eggers PW, Star RA, Kimmel PL. Acute kidney injury and chronic kidney disease as interconnected syndromes. N Engl J Med. 2014 Jul 3;371(1):58-66. [Medline]
- Stevens PE, Levin A; Kidney Disease: Improving Global Outcomes Chronic Kidney Disease Guideline Development Work Group Members. Evaluation and management of chronic kidney disease: synopsis of the kidney disease: improving global outcomes 2012 clinical practice guideline. Ann Intern Med. 2013 Jun 4;158(11):825-30. [Medline]
- Levey AS, Coresh J. Chronic kidney disease. Lancet. 2012 Jan 14;379(9811):165-80. [Medline]
Created Sep 12, 2014.
