Effect of intranasal Dexmedetomidine on optic nerve sheath diameter (ONSD) during suspension laryngoscopy in adult patients undergoing airway surgery: A randomised, placebo-controlled trial

This randomized, placebo-controlled trial aims to evaluate the effect of intranasal Dexmedetomidine on optic nerve sheath diameter (ONSD)—an indirect marker of intracranial pressure—during suspension laryngoscopy in adult patients undergoing elective airway surgery under general anesthesia.

Participants:

60 adults aged 18–60 years, classified as ASA I–III, scheduled for elective airway surgery, and who have provided informed consent. Exclusions include eye diseases, history of raised intracranial pressure, certain medications, severe systemic disease, pregnancy, and known allergy to Dexmedetomidine.

Design:

Participants will be randomly assigned to receive either intranasal Dexmedetomidine (1 mcg/kg) or normal saline spray 30 minutes before surgery. The trial is triple-blind—neither the patients, investigators, nor data analysts will know group assignments.

Outcomes:

Primary Outcome: Optic nerve sheath diameter (ONSD) at four key time points using ultrasound.

Secondary Outcomes: Blood pressure responses, sedation level, and cough response during extubation.

Analysis:

Statistical methods include t-tests, chi-square tests, and repeated measures ANOVA, with significance set at p<0.05.

Ethics & Timeline:

Ethical clearance and clinical trial registration will be obtained. The study will run over 18 months, with 12 months for recruitment and 6 months for follow-up and data analysis.

Expected Impact:

The study will help determine whether intranasal Dexmedetomidine effectively controls increases in intracranial pressure and cardiovascular responses during airway surgery, potentially improving anesthetic safety and patient comfort.