Dexmedetomidine vs. Morphine and Midazolam in Prevention and Treatment of Delirium after Adult Cardiac Surgery

Abstract

Delirium is defined as an acute cognitive disorder that presents with fluctuation in cognition,apathy and non-organized thinking.It may increases morbidity,mortality,Intensive Care Unit (ICU) stay and cost. Cognitive impairment after recovery from delirium may be long-lasting and the functional ability and quality of patient life may be affected.The reported incidence of delirium for patients after cardiac surgery ranged from 3% to 52% and may increase post-operative complications such as respiratory insufficiency,sternum instability and need for reoperating the sternum. The exact pathophysiology and etiology of delirium are unknown and the onset of delirium in each individual patient is caused by an interaction of predisposing and precipitating factors. Factors that have previously been identified as key independent predictors of delirium after cardiac surgery include advanced age,pre-operative cognitive decline,atrial fibrillation,previous delirium as well as measurable list of other conditions and co-morbidities. Given that many of these risk factors are non-modifiable,emphasis recently has been on identifying risk factors that can be modified like medications that cardiac surgery patients consume before,during and after surgery. Different scales have been published that allow the non-psychiatrically trained ICU stuff to diagnose delirium. The Confusion Assessment Method for the ICU (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) are the most reliable and valid screening tools for the adult critically ill patients. The CAM-ICU has been validated in many different ICU patient populations (medical ICU,surgical ICU,trauma patients,coronary unit,pediatric ICU) and based on clinical assessments of patient symptoms,which are defined by the Diagnostic and Statistical Manual fourth,text-revised (DSM-IV TR) edition that allows a relatively easy and fast evaluation of all critically ill patients,mechanically ventilated or not. Among ICU patients who develop delirium and who require continuous sedation therapy,the Pain,Anxiety and Delirium guidelines recommend that either propofol or dexmedetomidine should be considered as a replacement for benzodiazepine therapy. The study was done on 60 patients in order to compare dexmedetomidine versus morphin