Intranasal Dexmedetomidine on Blood Pressure in Elderly Hypertensive Patients Undergoing Cataract Surgery

Overview

Cataract surgery in elderly patients with controlled hypertension carries a risk of hemodynamic instability, particularly fluctuations in mean arterial blood pressure (MAP). Dexmedetomidine, a selective α2-adrenergic agonist, offers hemodynamic stabilization and sedation when administered intranasally and provides a simple and non-invasive premedication option. This study evaluates the effects of intranasal dexmedetomidine on perioperative mean arterial blood pressure in patients undergoing cataract surgeries. Research Question: Does intranasal dexmedetomidine premedication control blood pressure in elderly hypertensive patients undergoing cataract surgery? Research Hypothesis: Intranasal dexmedetomidine significantly reduces MAP and improves secondary outcomes compared to placebo. Primary Objective: To evaluate the efficacy of intranasal Dexmedetomidine as a premedication to control hypertension in elderly patients scheduled for cataract surgery. Secondary Objectives: 1. To assess surgery cancellation rates. 2. To evaluate satisfaction levels among patients, anesthesiologists, and surgeons using the Modified Observer's assessment of alertness/sedation scale (MOAA/S). 3- To evaluate the effect of intranasal dexmedetomidine on HR multiple readings starting from preoperative hold area till 2 hours postoperatively. This randomized, double-blinded clinical trial will include 126 elderly hypertensive patients (≥65 years) undergoing cataract surgery under local anesthesia. Inclusion Criteria will consist of patients aged ≥65 years, ASA II or III, stage 2 hypertension as per ACC / AHA guidelines (SBP\>140 and DBP\> 90 mmHg), undergoing elective cataract surgery under local anesthesia. Exclusion Criteria will include allergy or contraindication to dexmedetomidine, significant baseline bradycardia (\<50 bpm) or arrhythmia, use of sedative or anxiolytic medications, history of severe hepatic, renal, or cerebrovascular disease. Participants will be randomly assigned to receive either intranasal dexmedetomidine (1 mcg/kg ideal body weight) or a placebo (normal saline) 30 minutes before surgery. MAP, HR, and SpO₂ will be recorded at multiple perioperative intervals, and surgical cancellation rates, satisfaction levels will be noted, surgical duration, and hospital stay will be documented.

Intranasal Administration Technique: 1. Intranasal dexmedetomidine (1 mcg/kg ideal body weight) will be diluted to a total volume of 1 ml. 2. A mucosal atomization device (MAD) will be used for administration. 3. The dose will be divided evenly, with 0.5 mL sprayed into each nostril while the patient is in a semi-recumbent position. 4. The control group will receive an equivalent volume of 0.9% saline using the same method. Local Anesthesia A peribulbar block will be administered with a mixture of lidocaine 2% and bupivacaine 0.5% (total volume: 5 mL). The block will be performed under aseptic conditions by an experienced anesthesiologist.