Organ Specific Issues

Multiorgan recovery should be the goal in all potential organ donors. Therapeutic interventions targeted to specific organs are generally unnecessary beyond maintenance of adequate oxygenation and perfusion. However, in the management of the abdominal organ donor certain issues may be significant.

Pancreas

Hyperglycemia is common in the organ donor. The etiology is multifactorial and likely due to a combination of catecholamine induced insulin resistance and rapid infusions of large volumes of glucose containing fluids. The goal of treating hyperglycemia is to minimize fluid losses secondary to the resultant obligatory osmotic diuresis. Donor hyperglycemia does not adversely affect posttransplant pancreatic allograft function and unless fluid losses are the issue, requires no treatment.

Hyperamylasemia of pancreatic origin has been well described in the severely brain-injured patient. This finding may occur in the absence of known abdominal trauma or history of pancreatitis. The putative mechanism is through a central nervous system regulation of serum amylase. Hyperamylasemia may also result from hypoperfusion of the pancreas or pancreatic ischemia occurring during any stage of the procurement process from initial injury to organ recovery.

As noted above, donor hyperglycemia is not a contraindication to pancreatic procurement unless the donor has a previous history of diabetes mellitus. Donor hyperamylasemia also does not preclude consideration of the pancreas. At the time of recovery, the donor surgeon must assess the pancreas for any evidence of trauma or pancreatitis. The pancreas is vulnerable to ischemia. Significant and prolonged hypotension in the donor coupled with the requirement for high dose vasopressor administration is a relative contraindication to pancreatic procurement.

Small Intestine

As small intestinal transplantation becomes increasingly widespread, a number of organ specific issues may arise. Some centers use a bowel prep consisting of antibiotics and mechanical irrigation, but these protocols have not yet become standardized. Based on original early experimental work on graft manipulation to remove "passenger leukocytes", donor treatment with antilymphocyte monoclonal antibodies or lymphoid irradiation may improve intestinal allograft survival. Analogous to nutritional support to improve cadaveric liver function post-transplant, these other two approaches are time consuming. Unless the donors are stable, application of these protocols is impractical and may contribute to donor instability and unnecessary organ loss.

Kidney

Radiocontrast agents

Protection of renal function from such potentially injurious agents as radiocontrast dyes is a common clinical problem. Donors must often undergo cardiac catheterization before the heart can be considered suitable for transplant. Radiocontrast dye administration may therefore contribute to renal dysfunction posttransplant. Furthermore, as improvements in neurosurgical care result in a decrease in deaths from cranial trauma, greater numbers of our donors sustain a cerebrovascular event. Therefore, we are increasingly selecting donors with preexisting hypertension and atherosclerosis. In these patients, clinically silent but histologically significant renal lesions may be present. Radiocontrast agents are particularly problematic in this situation.

Protection of renal function from radiocontrast dyes was recently examined in a series of patients with known serum creatinine abnormalities undergoing cardiac angiography. Hydration with 0.45% saline alone provided better protection against an acute decrease in renal function than hydration with 0.45% saline together with either mannitol or furosemide. These data suggest that addition of a diuretic to the fluid management of the organ donor prior to cardiac catherization is not indicated. Rather, assuring that the donor is volume resuscitated and diuresing adequately are sufficient protection against renal damage.

Mandatory Biopsy

Significant age related changes or glomerulosclerosis resulting from hypertension may be present in the organ donor despite a normal serum creatinine. Mandatory biopsy following recovery of the kidneys is therefore required in the older donor (> 50), in donors with a history of hypertension or diabetes or in donors with an abnormal urinalysis (e.g., unexplained hematuria, proteinuria). Glomerulosclerosis exceeding 20% is used as the cutoff by most surgeons. Sclerotic changes in excess of this normally result in discarding the kidneys although there is interest in using both kidneys from these marginal donors in a single recipient. This innovative approach is controversial and its proponents suggest that it will minimize unnecessary wastage of organs.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

Get My Free Ebook


Post a comment