Thursday, July 30, 2009

End Stage Renal Disease and Renal Transplantation

Chronic glomerulonephritis, diabetic nephropathy, chronic tubulointerstitial disease, benign nephrosclerosis and polycystic kidney disease are the major causes of end stage renal disease (ESRD) and renal failure. Patients with ESRD exhibit a variety of abnormalities in their autonomic functions. Precise mechanisms of evaluating autonomic functions have revealed abnormalities in efferent parasympathetic pathway and baroreceptor sensitivity in patients with end stage renal disease. An increase in expiration-inspiration, lying standing and valsalva ratios, and baroreceptor sensitivity slope have been well documented in ESRD. Uremic patients with ESRD respond poorly to antihypertensive drugs as compared to otherwise healthy controls. Renal involvement in multiple myeloma is an other cause of ESRD and renal failure. Dialysis is an adoptive procedure in patients having end stage renal disease and ultimate surgical measure is renal (kidney) transplantation. Adequate dialysis in patients with ESRD reverses the elevated levels of urea, creatinine and electrolytes in blood.

Though renal transplantation is must in patients with ESRD, but it needs a lot of medication and post transplantation care for the successful adoption and survival of renal allograft. Systemic fungal infections (cryptococcosis, mucuromycosis, candidiasis, aspergillosis and mixed infections) have been documented after renal transplantation. Though these infections are treatable but may complicate the post operative care as additional medication will be required in addition to immunosuppressive therapy. High incidence of tuberculosis has also been observed in recipients of renal transplant along with viral infections like BK virus and cytomegalovirus (CMV). Adverse impact of pre-transplant polyoma virus (BK virus) infection on the graft survival has also been documented. Molecular technology has been developed for the early detection and identification of these viruses from the time of renal transplantation onwards by using protocol biopsies from the grafted kidney.

Acute Renal Failure: Medical and Other Causes

If we look at the spectrum of acute renal failure (ARF), we find that in more than 65% of cases medical causes or ailments are associated. Around 20% of cases generally have obstetrical causes and 15% of cases of acute renal failure may have surgical or other causes. Diarrhoea, mismatched blood transfusion, intravenous hemolysis in glucose-6-phosphate dehydrogenate (G-6-PD) deficient patients, hemolytic uremic syndrome (HUS), severe glomerulonephritis, falciparum malaria, snake bite, insect stings, septicemia and copper sulphate, mercuric chloride and zinc phosphide poisoning are some medical conditions in which if effective treatment is delayed may lead to acute renal failure. Intake of nephrotoxic drugs can also cause acute renal failure. Obstetrical causes include toxemia of pregnancy, postpartum hemorrhage, puerperal sepsis and post abortal sepsis. Major surgery may cause ARF in some cases. Nephrotoxic drugs and sepsis could be compounding factors in cases ARF with surgical cause.

Acute gastroenteritis, septicemia and HUS may singly or in combination be the major cause of ARF in tropical countries. Rhabdomyolysis has been observed to play a significant role in causing ARF in a variety of conditions including toxemia of pregnancy, status asthmaticus, status epilepticus, hypothermia, burns, dermatomycosis, wasp and hornet strings, and copper sulphate, mercuric chloride and zinc phosphide poisoning. The main causative factors for intravenous hemolysis in G-6-PD deficient patients include the commonly used drugs like aspirin, chloramphenicol, chloroquine, quinine and phenylbutazone. Bilateral mucuromycosis has also been documented to cause ARF even in non-immunocompromized subjects. Sometimes nephrectomy may be required in cases of ARF due to mucuromycosis. The spectrum of community acquired acute renal failure and hospital acquired acute renal failure is almost similar throughout the world. Decreased renal perfusion in cases of hypothermia and hypotension (low blood pressure) may cause ARF if not treated well in time. Timely treatment and hemo-dialysis or peritoneal dialysis can definitely benefit the patient in restoration of renal function and reversal of acute renal failure.