Dexmedetomidine in cardiac surgery: current evidence and clinical perspectives in adult and pediatric patients.

Cardiac surgery is frequently associated with significant perioperative morbidity resulting from hemodynamic in- stability, postoperative atrial fibrillation (POAF), acute kidney injury (AKI), systemic inflammatory response, postoperative delirium (POD), and prolonged intensive care unit (ICU) stay. Dexmedetomidine, a highly selec- tive α2-adrenergic receptor agonist, has emerged as an important adjunct in contemporary cardiac anesthesia and critical care because of its unique combination of sedative, sympatholytic, analgesic-sparing, anti-inflam- matory, and organ-protective properties. The purpose of this review is to summarize current evi- dence regarding the use of dexmedetomidine in adult and pediatric cardiac surgery. Recent randomized controlled trials, systematic reviews, and meta-analyses demon- strate that dexmedetomidine contributes to improved perioperative hemodynamic stability through attenuation of sympathetic activation, reduction of circulating cate- cholamines, and preservation of myocardial oxygen bal- ance. These effects appear to reduce the incidence of postoperative atrial fibrillation and improve cardiovascu- lar recovery following cardiac surgery. In addition to its cardiovascular benefits, dexmedetomi- dine has demonstrated significant neuroprotective poten- tial. Contemporary evidence supports its role in reducing postoperative delirium, particularly among elderly patients undergoing procedures involving cardiopulmo- nary bypass. Furthermore, emerging data suggest favora- ble effects on postoperative cognitive recovery through anti-inflammatory, antioxidant, and sleep-preserving mechanisms. Dexmedetomidine also exhibits clinically relevant cardi- oprotective, renoprotective, and anti-inflammatory ef- fects. Experimental and clinical studies have shown re- ductions in myocardial injury biomarkers, inflammatory cytokine release, and the incidence of acute kidney injury following cardiac surgery. In pediatric patients undergo- ing surgery for congenital heart disease, dexmedetomi- dine has been associated with improved hemodynamic stability, reduced opioid requirements, effective postop- erative sedation, and decreased incidence of junctional ectopic tachycardia. Current evidence supports dexmedetomidine as a valua- ble component of modern perioperative cardiac care. However, further large-scale multicenter randomized tri- als are needed to establish optimal dosing strategies and identify patient populations most likely to benefit from dexmedetomidine-based protocols.