What is the mechanism of renal failure in infective endocarditis ?
Posted Jul 08 2009 10:49am
Infective endocarditis (IE)continues to be a dreaded medical problem. The clinical outcome has not improved much , in spite of availability of powerful antibiotics. Early surgery in eligible patients could provide the best possible results.
One of the major determinants of morbidity and mortality in IE is the renal involvement.
Kidney gets affected in almost all the patients with IE. As IE is a a systemic illness and immunological activation is the norm , some degree of renal involvement is universal. Microscopic hematuria confirms this. This is due to clogging and globulin mediated damage to glomerular membranes. there is a linear co relation between the size of the vegetation and degree of renal involvement.
The following mechanisms are attributed for rapid deterioration of renal function in patients with IE .
Renal arterial emboli-occlusion-renal infarct
Immune complex mediated focal nephritis .
Diffuse , rapidly progressive glomerulonephritis
Drug induced renal dysfunction, especially with aminoglycosides, vancomycin etc
Finally & most importantly , the underlying cardiac condition, which result in refractory cardiac failure may either be primarily responsible for the renal compromise or aggravate the situation.
Combination of each of the above can occur
How to manage renal failure and IE ?
This forms a deadly combination. Aggressive planning , implementation , management is required. Cardiologists, cardiothoracic surgeons, nephrologists should discuss the strategies together.A microbiologist is also welcome !
If it is purely a pre renal failure due to CHF, there is no major worry.The pateint should do well withcardiac failure management.
The role of CT surgeon is always vital, since 75% of times , IE patients require valve replacement or vegetation/abscess removal as an emergency or semi emergency basis.
Pre operative and peri-operative dialysis will improve the results.
Renal replacement therapy , combined with valve replacement may be the ultimate therapy .It could be the most heroic way to save a patient but carries near death mortality.
If , there is strong evidence to suggest immune activation ,there could be a role for steroid administration. Literature does not address this issue . Long term follow up of renal function is required in these patients .
Renal failure in IE is common and the underlying mechanisms are often complex.Early intervention is the key as there is almost “no option” for conservative management in this situation.