Comparative Effects of Remimazolam Tosylate and Dexmedetomidine on Postoperative Delirium in Elderly Patients Undergoing Thoracoscopic Surgery.

Postoperative delirium (POD) is a common acute brain dysfunction in the perioperative period, characterized by acute fluctuations in attention, consciousness, and cognition, typically occurring early after surgery. POD is closely associated with prolonged hospital stay, increased complications, delayed recovery, and higher mortality .

POD has multifactorial risk factors spanning preoperative, intraoperative, and postoperative phases. Its pathophysiology involves neuroinflammation, oxidative stress, blood-brain barrier dysfunction, and neurotransmitter imbalance . Advanced age, baseline cognitive impairment, infection, and malnutrition increase POD risk . Intraoperative hypotension, benzodiazepine exposure, and other anesthetic factors may also contribute .

Elderly patients have higher anesthesia risk due to age-related physiological decline. Cardiovascular reserve decreases with age, causing hemodynamic instability, especially during one-lung ventilation in thoracoscopic surgery . Among patients over 70 undergoing thoracoscopic lobectomy, 35.7% develop pulmonary complications; ASA grade ≥III, one-lung ventilation time, smoking history, and COPD are independent risk factors . Additionally, reduced hepatic and renal function slow anesthetic metabolism, increasing drug accumulation and delayed emergence .

Video-assisted thoracoscopic surgery (VATS) offers reduced trauma, faster recovery, and lower complication rates compared to open surgery . VATS shows clinical value in lung cancer and mediastinal tumors . Uniportal VATS allows faster recovery of pulmonary function (VC, FVC, TLC) and lower inflammatory markers (CRP, PCT, TNF-α) . However, caution is needed in elderly patients .

Despite reduced surgical trauma, elderly VATS patients may still develop POD. Anesthetic drugs, surgical stress, poor pain management, and neuroinflammation are key contributing factors . Therefore, optimizing perioperative anesthesia, maintaining hemodynamic stability, and reducing unnecessary sedative-analgesic loads are important strategies to lower POD risk.

Dexmedetomidine is a highly selective α2-adrenergic receptor agonist with advantages in sedation, analgesia, and neuroprotection . It activates central α2-receptors, causing hyperpolarization of noradrenergic neurons and reducing norepinephrine release, producing sympatholytic effects without significant respiratory depression . It also has anti-inflammatory properties that may help prevent POD . Perioperative dexmedetomidine may reduce POD risk by alleviating stress, improving sleep-like sedation, and reducing opioid requirements . However, it can cause hypotension and bradycardia, requiring careful dosing in elderly patients .

Remimazolam tosilate is a newer ultra-short-acting benzodiazepine with rapid onset, fast metabolism, and mild circulatory depression. Its potential advantages in elderly and hemodynamically compromised patients are increasingly recognized, but its effect on POD remains inconclusive.

In summary, elderly VATS patients are at high risk for POD. Dexmedetomidine has preventive evidence but is limited by hypotension and bradycardia. Remimazolam may offer a smoother sedation alternative, but direct comparative evidence is lacking. This study aims to compare remimazolam versus dexmedetomidine on POD and perioperative recovery, providing evidence for individualized anesthesia management in elderly VATS patients.