Sedation and analgesia, which are universally used in intensive care units (ICUs), provide patients with comfort and safety. The current trends aim at light sedation; the objective is to ensure the minimal sedation level for improving patients' autonomy and enabling the professional staff to assess the patients' neurological status and cognitive functions. Reports in the literature have indicated that a sedative or an entire sedation procedure can affect cognitive processes, the duration of mechanical ventilation and treatment outcomes in critically ill patients. At present, special attention is given to post-sedation delirium. Although sedatives differ in their uptake points, which can influence the quality of sedation, their common characteristic is substantial impairment of cognitive functions, memory and respiration. Alpha 2-adrenergic receptor agonists, which comprise a novel group of agents, are used frequently for sedation. One of these medications is dexmedetomidine, which is designed to sedate adult ICU patients who exhibit a score ≥ -3 according to the Richmond Agitation-Sedation Scale. Recent studies comparing the use of dexmedetomidine and the other sedative agents that are most commonly administered in ICUs demonstrated that the former largely fulfils the expectations of intensivists.