LAUSR

In the article “Computed Tomography Perfusion is a Useful Adjunct to Computed Tomography Angiography in the Diagnosis of Brain Death”, Sawicki et al. reported computed tomography perfusion (CTP) findings in 50 patients with the clinical diagnosis of brain death [1]. The gold standard of the study was the clinical diagnosis of brain death based on the following criteria: unresponsiveness, absent brainstem reflexes, and apnea after the exclusion of reversible confounding factors [1]. The assumption of the study was that CTP findings of cerebral blood flow (CBF) <10ml/100g/min and cerebral blood volume (CBV) <1.0ml/100g was “consistent with threshold of neuronal necrosis” [1]. The above CBF and CBV thresholds were chosen as the cut-off for a positive CTP study and the authors reported that CTP had 100% sensitivity for brain death diagnosis [1]. The authors also reported that, based on CTP findings, neither CBF nor CBV were zero in the study patients with the clinical diagnosis of brain death [1]. Sawicki et al. implicitly assumed that any residual CBF detected on CTP at <10ml/100g/min was inadequate to prevent neuronal necrosis and irreversible cessation of functions of the whole brain including the brainstem. The irreversible cessation of the functions of the whole brain, including the brainstem, is the necessary criterion in death determination by neurological criteria [2]. There are several concerns with the study’s interpretations.