Acute renal failure could this had caused my brother to die

Hello. Thank you for writing.

I'm very sorry for your loss. I can give you some general information.  But we cannot know the specifics of your (late) brother's condition.  This is a question to ask his doctor.

According to MayoClinic: Acute kidney failure, also called acute renal failure,  occurs when your kidneys suddenly become unable to filter waste products from your blood. When your kidneys lose their filtering ability, dangerous levels of wastes may accumulate, and your blood's chemical makeup may get out of balance.  Acute kidney failure can develop rapidly over a few hours or a few days.  It's is most common in people who are already hospitalized, particularly in critically ill people. Acute kidney failure can be fatal and requires intensive treatment.  

Helena