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.

Inclusion Criteria:

1. Patients aged ≥65 years.
2. Patients who will have stage 2 hypertension as per ACC/AHA guidelines (Systolic BP > 140 and Diastolic BP> 90 mmHg)
3. Elective cataract surgery under local anesthesia.
4. American Society of Anesthesiologists (ASA) physical status II or III.

Exclusion Criteria:

1. Allergy or contraindication to dexmedetomidine.
2. Significant baseline bradycardia (<50 bpm) or arrhythmias.
3. Use of sedative or anxiolytic medications.
4. History of severe hepatic, renal, or cerebrovascular diseases.