Donor Optimisation in DBD

Once brain stem death is confirmed and the decision to proceed to organ donation has been made, the focus of ICU management shifts from treating the patient to optimising the function of the organs to be donated. This is an active and important phase of care — the quality of organs retrieved depends significantly on how well the donor is managed in the hours preceding retrieval.

Brain stem death causes a cascade of physiological disturbances. The sudden loss of hypothalamic and pituitary function causes central diabetes insipidus (massive polyuria and hypernatraemia), haemodynamic instability from loss of central autonomic control, hypothyroidism (acute loss of TSH stimulation), and adrenal insufficiency. These must be actively managed.

ProblemCauseTreatment
Haemodynamic instabilityLoss of autonomic tone; relative vasodilationVasopressin 0.5–2.4 units/hour (first-line vasopressor in donor management); noradrenaline as second agent
Diabetes insipidusLoss of ADH (vasopressin) from posterior pituitaryVasopressin infusion (dual role: vasopressor + ADH replacement); DDAVP if vasopressin insufficient to control urine output
HypernatraemiaConsequence of diabetes insipidusFluid replacement with 5% dextrose or 0.45% saline; target sodium 130–150 mmol/L
HypothyroidismLoss of TSH stimulationT3 (tri-iodothyronine) infusion: 4 mcg bolus then 3 mcg/hour (part of hormonal resuscitation bundle)
HyperglycaemiaInsulin resistance post-brain deathInsulin infusion; target blood glucose 4–10 mmol/L
HypothermiaLoss of hypothalamic thermoregulationActive warming; heated humidifier; warm blankets; target 36–37.5°C
Lung deteriorationNeurogenic pulmonary oedema; aspiration; atelectasisLung-protective ventilation; regular recruitment manoeuvres; tidal volume 6–8 mL/kg PBW; PEEP 8–10; target PaO2/FiO2 >300

The NHSBT Donor Optimisation Extended Care Bundle provides a standardised framework for donor management and specifies targets for all major physiological parameters. Following this bundle is associated with more organs retrieved per donor and better graft function after transplantation.