Pharmacological perioperative brain neuroprotection: a qualitative review of randomized clinical trials

Perioperative cerebral damage may be associated with surgery and anaesthesia. Pharmacological perioperative neuroprotection is associated with conflicting results. In this qualitative review of randomized controlled clinical trials on perioperative pharmacological brain neuroprotection, we report the effects of tested therapies on new postoperative neurological deficit, postoperative cognitive decline (POCD), and mortality rate. Studies were identified from Cochrane Central Register and MEDLINE and by hand-searching. Of 5904 retrieved studies, 25 randomized trials met our inclusion criteria. Tested therapies were: lidocaine, thiopental, S()-ketamine, propofol, nimodipine, GM1 ganglioside, lexipafant, glutamate/aspartate and xenon remacemide, atorvastatin, magnesium sulphate, erythropoietin, piracetam, rivastigmine, pegorgotein, and 17-estradiol. The use of atorvastatin and magnesium sulphate was associated with a lower incidence of new postoperative neurological deficit. The use of lidocaine, ketamine, and magnesium sulphate was associated with controversial results on POCD. The POCD did not differ between treated patients and control group for other tested drugs (thiopental, propofol, nimodipine, GM1 ganglioside, lexipafant, glutamate/aspartate, xenon, erythropoietin, remacemide, piracetam, rivastigmine, pegorgotein, and 17-estradiol). None of the tested drugs was associated with a reduction in mortality rate. Drugs with various mechanisms of action have been tested over time; current evidence suggests that pharmacological brain neuroprotection might reduce the incidence of new postoperative neurological deficits and POCD, while no benefits on perioperative mortality are described. Of importance from this review is the need for shared methodological approach when clinical studies on pharmacological neuroprotection are designed.