Effect of Intraoperative Dexmedetomidine on Early Postoperative Cognitive Dysfunction

Effect of Intraoperative Dexmedetomidine Infusion on Early Postoperative Cognitive Dysfunction (POCD) in Geriatric Patients Undergoing Hip Surgery Under Spinal Anaesthesia

This study will aim to identify the impact of Intraoperative dexmedetomidine infusion on POCD assessed by the Montreal Cognitive Assessment (MoCA) in geriatric patients above 60 years undergoing hip surgery under spinal anaesthesia.

Postoperative cognitive dysfunction (POCD) is a common postoperative neurological complication in elderly. POCD is a subtle impairment of memory, concentration and information processing with clinical manifestations of delirium, anxiety, personality changes and impaired memory, which is associated with prolonged hospitalization, a reduced quality of life and an increase in morbidity and mortality. Dexmedetomidine is a highly selective α-2 adrenergic receptor agonist with a dose-dependent sedative hypnotic effect. It has also been reported that dexmedetomidine has a potential role in preventing POCD due to its neuroprotective effects both in vitro and in vivo. Till date very few studies have analysed the impact of dexmedetomidine on early POCD. Even in the few available studies compared assessment of POCD using the Mini-Mental State Examination (MMSE) scores and found that MMSE have lower sensitivity for identifying Cognitive Dysfunction as compared to Montreal Cognitive Assessment (MoCA). The study would analyze the impact of Intraoperative Dexmedetomidine infusion on early Postoperative Cognitive Dysfunction (POCD) in geriatric patients above 60 years undergoing hip surgery under spinal anesthesia. So this study will aim to identify the impact of Intraoperative dexmedetomidine infusion on POCD assessed by the Montreal Cognitive Assessment (MoCA) in geriatric patients above 60 years undergoing hip surgery under spinal anaesthesia.

This will be a prospective, randomized, placebo-controlled, double-blind clinical trial. The patients will be recruited according to the inclusion criteria and will be distributed to one of the groups according to computer-generated random assignment. The personnel involved in the study, including statisticians, investigators, anaesthetists, surgeons and the patients will be blinded to the specific experimental scheme implementation Patients will be randomized into one of the two groups using a computer based random number generator. https://www.randomizer.org. All recordings would be performed by an anaesthesiologist blinded to the group allocation.

Receiving Dexmedetomidine injection at a dose of 1 mcg/kg over 10 min, after Spinal Anaesthesia and before start of surgery, followed by a continuous infusion at a rate of 0.4 mcg/kg/h until the end of surgery.

Dexmedetomidine Injection at a dose of 1 mcg/kg over 10 min, after Spinal Anaesthesia and before start of surgery, followed by a continuous infusion at a rate of 0.4 mcg/kg/h until the end of surgery.

Number of cases developing POCD in the Dexmedetomidine Group as compared to the placebo group using the Montreal Cognitive Assessment (MoCA) test. The "Montreal Cognitive Assessment" (MoCA) test is a free assessment available at http://www.mocatest.org tool designed for quick screening for mild cognitive impairment. It is a one page, 30 point test done in approximately 10 min for assessment of attention, memory, abstraction, delayed recall and orientation, with total score of 30. MoCA range from zero to 30, with a score of 26 and higher generally considered normal. Scores below 26 were considered as Postoperative Cognitive Dysfunction.

Inclusion Criteria: American society of Anesthesiology (ASA) status of I-III Age between 60-75 years scheduled for elective hip surgery under spinal anesthesia Exclusion Criteria: Patient not willing to be a part of the study Patients were aged <60 or >75 years Patients with accompanying medical conditions that may affect the level of consciousness, such as stroke, stupor or dementia, or patients with abnormalities in hepatic or renal function, electrolyte imbalance Patients suffering from preoperative bradycardia [heart rate (HR) <60 bpm] or hypotension [mean arterial blood pressure (MAP) <70 mmHg] Patients who had recently received a sedative or opioid drug Patients with a MoCA (Montreal Cognitive Assessment) score <26 Patients with persistent hypotension and bradycardia intra-operatively even after giving Mephentermine will be excluded from the study