the kidney functions are the bun and creatinine. i am not quite sure why you asked about those?
as far as the pericarditis:
one the only sure way to see if there is a blockage, and how much is to have a cath of the heart done.
non infectious pericarditis is not usually serious, and in most cases clears up on its own. -itis = inflammation. unfortunately, most people think of -itis as an infection. it can be caused by an infection, but isn't always the cause. examples: cholangitis, lyphangitis, prostatitis, pneumitis, and hepatitis. hepatitis is the same way. everybody hears it, and automaticly thinks of hepatitis a, b, c, d or e. those are the infectious types. however, there is a non- infectious hepatitis also, usually caused by a gallbladder problem, or stone in the cbd.
anyways, back to the pericarditis: when i have seen a real pericarditis, the ekg is normal, except all the t waves are inverted. if he has a fever also, and maybe even elevated white blood cell count, then he may have needed anti-biotics. usually the abx are rocephin or vanco.
unfortunately, there really isn't enough info here, for us to really know exactly what is going on?
hope it all works out.