Pericardium is a fine biological sensor. It makes noise when the kidney is in distress .
We call this as uremic pericardial rub . This is not a universal phenomenon in renal failure.
Occurs in about 10% of renal failure .
- Chemical pericarditis . Uremic middle molecules ?
- Dialysis related pericarditis
- Associated infection
Two themes can occur .
- Pericarditis without effusion .
- Effusion without pericarditis
The later is more common .
Is it a exudate or transudate ?
Usually a transudate. Protein accumulation may occur .
Hemorrhagic or non hemorrhagic effusion ?
Again both can occur. Platelet dysfunction is well known feature of renal failure .Bleeding into pericardial space even a few cc of blood is suffice , to color the entire effusion red .
ECG features of uremic pericarditis , how is it different ?
The uremic pericarditis less often results in classical ST elevation (concavity upwards) instead the hyperkalemia features dominate , if present.
The reason for less conspicuous ST elevation is due to the relative lack of epicardial electrical injury . Further , the pericardial fluid is enriched with oppositely charged uremic molecules which neutralise’s the
electrical gradient .
Relationship of pericarditis with acuteness of renal failure
Though it can occur in any form of uremia.It is more often observed in rapidly worsening renal failure
Relationship to dialysis
- Presence of pericardial rub is a classical indication for dialysis .(But not presence of effusion per se )
- While pericardial rub disappears in many , a pericardial rub that is exclusively observed for the first time after dialysis is well known .
- The exact mechanism is not clear . One explanation could be the pericardial surfaces gets approximated once pericardial fluid is filtered by dialysis.
Tamponade is common .Usually tolerated well till late stages as LVH and mild PAH are common which resists fluid compression.
Constriction can rarely occur. Tuberculosis can co exist.
- Indomethacin /Other NSAIDS
- Surgery may be needed if recurrent pericarditis occur
Patients with pericardial rub should be dialysed heparin free .