Delirium in Intensive Care Unit

Delirium is an acute, fluctuating disturbance in attention and cognition that commonly complicates the course of critically ill patients, particularly those admitted with acute heart failure (AHF). Its occurrence in the intensive care unit (ICU) is associated with prolonged mechanical ventilation, longer ICU and hospital stays, increased morbidity and mortality, and substantial healthcare costs. In patients with AHF, the risk of delirium is amplified by factors such as cerebral hypoperfusion, systemic inflammation, sedative exposure, and multi-organ dysfunction. Therefore, effective prevention and early management of delirium in this population are critical to improving outcomes. Dexmedetomidine, a selective α2-adrenoceptor agonist, has gained wide use in ICU sedation due to its anxiolytic and analgesic properties and minimal respiratory depression. Several randomized controlled trials and meta-analyses have demonstrated that dexmedetomidine-based sedation reduces the incidence and duration of delirium compared with traditional sedatives such as benzodiazepines or propofol. However, its use in AHF patients may be limited by dose-dependent bradycardia and hypotension, potentially compromising hemodynamic stability in an already fragile population. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, possesses unique properties that may offer an alternative approach to delirium prevention. At subanesthetic (low) doses, ketamine provides analgesia, maintains respiratory drive, and exerts sympathomimetic effects that support blood pressure and cardiac output-features that may be advantageous in AHF. Emerging evidence from cardiac surgery and critical care studies suggests that low-dose ketamine infusion might reduce delirium incidence through anti-inflammatory and neuroprotective mechanisms, although data remain limited and heterogeneous. Given the hemodynamic fragility of AHF patients and the need for sedatives that balance safety and delirium treatment, a direct comparison between low-dose ketamine and dexmedetomidine is warranted. This study aims to evaluate and compare the efficacy and safety of these two agents in treating delirium among AHF patients admitted to the ICU. By addressing this gap, the study seeks to identify a sedation strategy that optimizes cognitive and hemodynamic outcomes in this high-risk population.