Final answer:
The criteria for initiating renal replacement therapy in children are primarily based on the medical necessity, which is determined by the severity of kidney disease and not factors such as age, suitable donor availability, or financial resources.
Step-by-step explanation:
The criteria that are met before a child starts renal replacement therapy include the severity of kidney disease, not the child's age, the availability of a suitable donor, or the family's financial resources. Renal replacement therapy is initiated when kidney function drops critically low and cannot sustain life.
This can be seen in situations such as chronic kidney disease (CKD) with a Glomerular filtration rate (GFR) below 60 mL/min/1.73 m2, or in cases of acute renal failure where there is a sudden, sharp decline in kidney function. It's important to note that while age or financial resources may impact treatment options, they are not the primary criteria for starting renal replacement therapy. The most critical factor is the medical need as determined by the condition of the kidneys.