The calculator in question is the KDIGO (Kidney Disease: Improving Global Outcomes) diagnostic criteria for acute kidney injury (AKI). This calculator is used in the patient population of individuals suspected of having acute kidney injury, which can occur in various clinical settings such as hospitalization, critical illness, or after certain procedures like surgery.

The KDIGO criteria for AKI are based on changes in serum creatinine levels and urine output. It helps in the early detection of AKI, stratification of its severity, and guides the management and treatment decisions. The clinical utility of this calculator is to identify patients at risk of developing complications related to AKI, including chronic kidney disease, end-stage renal disease, and increased mortality.

There are no specific exclusion criteria for the use of KDIGO criteria. However, it may not be applicable or accurate in patients with chronic kidney disease, as their baseline creatinine levels are already elevated. Also, it may not be suitable for patients with conditions that can affect serum creatinine levels independently of kidney function, such as muscle wasting diseases.

Diagnostic criteria for acute kidney injury

# Criteria
 A. Increase in serum creatinine by >= 26.5 mcmol/L [0.3 mg/dL] within 48 hours
B. Increase in serum creatinine to >= 1.5 times baseline within the previous 7 days
C. Urine volume of <= 0.5 mL/kg/hour for 6 hours

# Conditions
- A or B or C
- true