The Potential Organ Donor
For the potential organ donor, the following measures can be used to en-
hance organ viability (36).
Hemodynamics
Potential organ donors should have a mean arterial pressure
≥
65 mm Hg
and a urine output
≥
1 mL/kg per hour, and fluids and vasopressors
should be used, if necessary, to achieve these goals. Circulatory support
for the potential organ donor should follow the same principles of circu-
latory support used for other critically ill patients (see pages 270 – 272).
Pituitary Failure
More than half of patients with brain death will develop pituitary failure
with
diabetes insipidus and secondary adrenal insufficiency
(37). Both condi-
tions can lead to profound hypovolemia (with reduced organ perfusion)
and hypertonic hypernatremia (with cell dehydration). If there is evi-
dence of central diabetes insipidus (i.e., spontaneous diuresis with a
urine osmolality below 200 mOsm/L), treatment with
desmopressin
, a
vasopressin analog that does not cause vasoconstriction, is advised (38).
The usual dose of desmopressin is 0.5 – 2.0 µg IV every 2 – 3 hours, with
dose titration to maintain a urine output of 100 – 200 mL/hr.
A FINALWORD
Family Care
In the care of the patient with persistent coma or a persistent vegetative
state, spending time with the patient’s family (or other intimates) is as
important as patient care. These people will look to you for guidance,
and avoiding the
conspiracy of silence
(39) is one of the greatest services
you can perform as a physician.
REFERENCES
Altered Consciousness
1. León-Carrión J, van Eeckhout P, Dominguez-Morales Mdel R. The locked-in
syndrome: a syndrome looking for a therapy. Brain Inj 2002; 16:555–569.
2. The Multi-Society Task Force on PVS. Medical aspects of the persistent veg-
etative state (Part 1). N Engl J Med 1994; 330:1499–1508.
3. Bleck TP, Smith MC, Pierre-Louis SJ, et al. Neurologic complications of criti-
cal medical illnesses. Crit Care Med 1993; 21:98–103.
4. Papadopoulos M, Davies D, Moss R, et al. Pathophysiology of septic
encephalopathy: a review. Crit Care Med 2000; 28:3019–3024.
Disorders of Consciousness
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