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CHAPTER 116: Care of the Multiorgan Donor 1115

range, often produces the best results, while maintaining at least 1 mL/kg dysrhythmias, and coagulopathy, and may even cause cold diuresis and
per hour of urine output. Reduced diuresis despite adequate perfusion also predispose to sepsis. It is much better to prevent hypothermia,
pressure can be increased by mannitol administration, at the dosage of because once it has occurred it may be difficult to correct.
0.25 g/kg as an intravenous bolus. Fluid resuscitation therapy should be The recognition of the metabolic derangements following brain
directed toward euvolemia, rather than hypervolemia. death, including autonomic storm and hypothalamic-pituitary axis
Dysrhythmias are quite common and should be treated aggressively. dysfunction, has highlighted the need for hormonal resuscitation as an
Persistent bradycardia is treated with chronotropic agents or even pac- integral part of the donor management protocol. The recommended
47
ing. Minute ventilation should be adjusted to keep the CO and pH in hormonal resuscitation in the protocol consists of methylprednisolone
2
normal ranges. A recent study by Marcia and coworkers demonstrated in a 10 to 15 mg/kg bolus every 24 hours; triiodothyronine in a 4-µg
that a lung protective strategy (tidal volumes of 6-8 mL/kg and PEEP bolus followed by a continuous infusion of 3 µg/h; vasopressin in a
of 8-10 cm H O) increased the number of eligible and harvested lungs 1-unit bolus, then a continuous infusion at 2.4 U/h, titrated to a systemic
2
compared with a conventional strategy (tidal volumes of 10-12 mL/kg vascular resistance of 800 to 1200 dyn/s per cm ; and continuous infu-
2
and PEEP of 3-5 cm H O). PEEP can be optimized up to 10 cm H O sion of insulin titrated to maintain blood sugar at 120 to 180 mg/dL. The
57
2
2
along with low tidal volumes to maintain 95% oxygen saturation while use of steroids is based on the intensive effort to increase the number of
should be no higher than 50%. Peak usable lungs given the low recovery rate of lungs from potential donors. 59
preventing atelectasis. The Fi O 2
inspiratory pressures (PIP) are also important because high pressure Though initial evidence showed that vasopressin used with epi-
results in barotrauma and impaired venous return to the heart, thereby nephrine maintains hemodynamic stability and tissue viability, its
compromising cardiac output. Pressure control modes of ventilation implementation was not adopted universally. Rather DDAVP was used,
may be preferable for the minimization of these risks. Ideally PEEP with the assumption that the effectiveness of arginine vasopressin was
is maintained at <10 and PIP at <30 cm H O. Bronchoscopy may be related to its treatment of the diabetes insipidus that is commonly found
2
necessary for pulmonary toilet, to collect samples for microbiology, and in organ donors. DDAVP is an analogue that is highly selective for the
to reinflate atelectatic regions of the lung, thereby decreasing shunting. vasopressin V -receptor subtype that is found in the renal collecting
2
Bronchodilators should be administered. Continuous full monitoring is ducts, and has no vasopressor activity in humans, which is mediated by
of course essential. V -receptors on vascular smooth muscle. Arginine vasopressin was in
1
Maintenance of normal acid base balance in organ donors is often fact abandoned due to concerns that the vasoconstrictive effect could
) should be be harmful for donor organs. This resulted in unnecessarily excessive
difficult. Partial pressure of arterial carbon dioxide (Pa CO 2
maintained in the normal range and optimum pH is between 7.35 and fluid resuscitation with crystalloid, colloid, and blood products, along
7.45. Glucose consumption is also decreased and parenteral or enteral with higher doses of vasopressor agents with widely recognized adverse
nutrition must be decreased to avoid hyperglycemia and unnecessary effects. Many transplant centers consider a donor heart to be unsuitable
metabolic workload. Ongoing nutrition must be maintained, as it is if dopamine requirements exceed 10 to 15 µg/kg per minute, because at
associated with improved graft function, particularly for the liver graft. such doses it can also affect both kidney and liver. 48
58
In the liver, glycogen stores are depleted within 12 hours of brain death, Considerable debate is ongoing regarding the role of thyroid hormone
with suggested reduced resistance of the graft to ischemia. Persistent therapy in the management of organ donors. Several studies have shown
hyperglycemia despite reduced glucose administration can be treated no correlation between thyroid hormone levels and hemodynamic status.
60
with insulin. Loss of the hypothalamic-pituitary axis can result in diabetes Contrarily, the implementation of the three-hormone resuscitation
insipidus. Associated electrolyte abnormalities are hypernatremia, hypo- therapy, with methylprednisolone, arginine vasopressin, and triiodothy-
calcemia, hypokalemia, hypophosphatemia, and hypomagnesemia. In ronine or levothyroxine, has been associated with an increased number
addition, the variety of strategies used to treat intracranial pressure may of transplanted hearts and improved short-term graft function. The
11
exaggerate the hypernatremic state. Aggressive correction of the elec- selection of donors who are predicted to benefit from hormonal resus-
trolyte state should be performed and levels should be checked every citation has been outlined. After conventional management to adjust
4 hours in order to prevent development of lethal dysrhythmias, myo- volume status, anemia, and metabolic abnormalities, the recommendation
cardial dysfunction, and rhabdomyolysis. Sodium levels should be kept is that an echocardiogram be obtained to rule out structural abnormalities
<155 mEq/dL, as liver primary graft nonfunction has been associated and document the ejection fraction. If the ejection fraction is <40%,
with hypernatremia. The diagnosis of central diabetes insipidus is easily a pulmonary artery catheter is placed and hormonal resuscitation is
made when more than 4 mL/kg per hour of dilute urine is produced, instituted. Subsequent cardiac function can be monitored using the
while the serum sodium is above 145 mmol/L. Hypotonic fluids can be pulmonary artery catheter.
used to restore intravascular volume with a simple volume-for-volume
replacement of the urine. Development of hyperglycemia may be caused SUMMARY
by the dextrose or glucose in the hypotonic intravenous fluids; but on
the other hand, it will help restore glycogen liver reserves in a setting Every effort to identify potential donors, obtain consent from their families,
of inadequate nutritional support. More practical is to use desmopres- convert potential donors to actual ones should be made since a large dispar-
sin (DDAVP) in a loading dose of 8 ng/kg, followed by an infusion of ity exists between the numbers of patients waiting for transplantations and
4 ng/kg per hour and a reassessment and titration up or down every available donors. A structured approach summarized in this chapter should
30 minutes; alternatively, a 1-µg bolus every 2 hours can be used as long be utilized to maximize the number of actual donors. Current management
as the urine output remains >300 mL/h. DDAVP has a longer half-life including hormone replacement therapy, protective ventilatory support,
and minimal vasopressor activity (2000:1) as compared to arginine and careful fluid therapy will enhance successful organ procurement.
vasopressin. Arginine vasopressin is particularly useful in hypotensive
patients in a continuous infusion of aqueous vasopressin at the dosage KEY REFERENCES
of 0.5 U/h, which can be titrated as necessary by monitoring the urine
output. A relatively small percentage of organ donors are resistant to • Angel LF, Levine DJ, Restrepo MI, et al. Impact of a lung trans-
aqueous vasopressin. In these cases, desmopressin acetate should be plantation donor-management protocol on lung donation and
considered. recipient outcomes. Am J Respir Crit Care Med. 2006;174:710-716.
Warmed intravenous fluid, heated humidified oxygen, and warm- • Feng S, Goodrich NP, Bragg-Greshamb JL, et al. Charasteristics
ing blankets may need to be used to limit hypothermia. The core associated with liver graft failure: the concept of a donor risk
temperature should be maintained above 35°C. Hypothermia contrib- index. Am J Transplant. 2006;6:783-790.
utes to donor hemodynamic instability, myocardial depression, severe

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