Effect of oral clonidine premedication on PR interval in patients undergoing rhinoplasty and functional endoscopic sinus surgery (FESS)

Background and aim: Clonidine, an alpha-2-agonist, plays a pivotal role in mitigating the sympathetic response during general anesthesia, thereby enhancing intraoperative hemodynamic stability. Despite its recognized benefits, reports of adverse cardiopulmonary effects have surfaced. This study investigates the impact of oral clonidine administered as premedication on patients undergoing rhinoplasty or Functional Endoscopic Sinus Surgery (FESS), with a focus on assessing alterations in the PR interval observed in postoperative electrocardiograms (ECG).Patients and method: A Randomized Clinical Trial (RCT) comprised fifty patients scheduled for rhinoplasty or FESS under general anesthesia. Each participant underwent a standard 12-lead ECG, followed by the administration of 300 mu g oral clonidine 30 min prior to entering the operating room. Anesthesia induction adhered to a uniform protocol for all subjects. Comprehensive ECG monitoring throughout the surgical procedure and recovery period facilitated the recording of any observed changes. Six hours post-clonidine administration, a second standard 12 lead ECG was obtained and juxtaposed with the initial recording.Findings: Analysis revealed a lengthening of the PR interval in 23 cases (46%). Within this cohort, 21 instances exhibited a prolongation falling within the normal range (0.12-0.2 sec), while the remaining two cases displayed abnormal prolongation (> 0.2 sec) (P-value < 0.001).Conclusion: This investigation suggests that premedication with oral clonidine has the potential to extend the PR interval.