Outcomes of patients referred for confirmation of brain death by 99mTc-exametazime scintigraphy.

OBJECTIVE: To review clinical outcomes in patients referred for confirmation of brain death by (99m)Tc-labelled exametazime scintigraphy and to assess any tangible benefit. DESIGN AND
SETTING: A retrospective casenote review in the intensive care unit and nuclear medicine department of a tertiary-level acute care hospital. PATIENTS AND PARTICIPANTS: 66 consecutive patients, in whom a clinical diagnosis of brain death was not possible, undergoing (99m)Tc-labelled exametazime scintigraphy from February 1993 to March 2002, and for 56 of whom casenotes were available for review. MEASUREMENTS AND
RESULTS: Brain death was confirmed in 77% on the basis of absent supratentorial and infratentorial uptake. Where brain death was not confirmed, a normal scan was seen in 30%, the remainder showing patchy reduced infratentorial and/or supratentorial uptake. All patients with the scintigraphic appearance of brain death subsequently died. Even when brain death could not be confirmed, 11 of 13 patients died soon afterwards. Two patients with normal brain scintigraphy regained consciousness and survived for an extended period. When brain death was not confirmed by scintigraphy, elapsed time to certification of death was longer (44.7 vs. 7 h) and organ donation was less common even when a subsequent clinical diagnosis was made.
CONCLUSIONS: The results indicate that patient prognosis remains poor regardless of the findings on (99m)Tc-labelled exametazime scintigraphy, but that the scan result influences the elapsed time to withdrawal of therapy or organ donation, providing a significant cost benefit, and occasionally a long-term survivor is seen.