Neurological, psychological and cognitive sequelae of cardiac surgery

Abstract

Recovery from cardiac surgery is marred for many patients by the development of neurological, psychological or cognitive dysfunction. Whilst the incidence of overt neurological injury, such as stroke, is low, more subtle neurological and cognitive deficits frequently occur. Many patients also experience depression and anxiety following surgery but these psychological conditions are often pre-existing. Preoperative brain imaging and neurological examination have found pre-existing neurological abnormalities in many patients. In addition, macro- and micro-emboli, cerebral hypoperfusion, inflammation and excitotoxicity have all been implicated and the aetiology is likely to be multifactorial. Currently, careful anaesthetic, perfusion and surgical techniques are probably the most important means of preventing cerebral injury. In particular, cannulation and cross-clamping of an atheromatous aorta demands close attention and, perhaps, should be guided by epiaortic ultrasound. Pharmacological cerebral protection in the form of propofol is ineffective, but there may be a role for future NMDA receptor antagonists. Although our understanding of the mechanisms of cerebral injury has greatly increased in recent years, much more yet remains to be learnt about the neurological, psychological and cognitive sequelae of cardiac surgery.