Hemodynamic responses to surgical stimuli in brain-death organ donors.

Though spinal reflexes have been described in experimental brain-death animals, no documentation has been previously provided for human. The hemodynamic responses to surgical stimuli have been investigated here in eight brain-death organ donors. Baseline systolic blood pressure, diastolic blood pressure, and heart rate in observed patients were 99 +/- 15 mmHg, 61 +/- 13 mmHg, and 105 +/- 22 beats/min respectively. After skin incision, these parameters elevated maximally to 130 +/- 23 mmHg, 74 +/- 17 mmHg, and 119 +/- 18 beats/min (p <0.05). Either spinal reflex arcs or adrenal medullary stimulation, or both, have been speculated to possibly play the role in these hemodynamic responses. However, the existence of such responses should not invalidate the diagnosis of brain death.