Effect of intravenous clonidine premedication for the bloodless surgical field in patients undergoing middle ear or nasal surgery: A comparison of three different doses.

Aim: To evaluate the effect of intravenous (IV) clonidine premedication for the bloodless surgical field in patients undergoing middle ear or nasal surgery comparing three different doses.

Subjects And Methods: This prospective randomized, clinical trial was performed on 90 normotensive patients belonging to American Society of Anesthesiologists grade I/II, aged 18-60 years, of either sex, undergoing routine middle ear or nasal surgery. These patients were divided into three Groups A, B, and C with 30 patients in each according to the dose of IV clonidine used as premedicant that is 3, 4, and 5 µg/kg, respectively. The hypotensive period commenced 10 min after the start of surgery till the surgeon's request for no hypotension required any longer. The target mean blood pressure for producing bloodless surgical field was 60-70 mmHg. During the hypotensive period, the surgeons were asked to rate the bleeding severity score on a six-point scale from 0 (no bleeding) to 5 (severe bleeding).

Statistical Analysis Used: ANOVA, Chi-square test, Z-test, standard deviation and P value.

Results: IV clonidine premedication in a dose of 4 and 5 µg/kg reduces bleeding and provides a clear field for surgery. It also reduces the requirement of isoflurane, fentanyl, and metoprolol for controlled hypotension. However, clonidine 5 µg/kg was not more effective than clonidine 4 µg/kg in producing these effects rather was associated with some side effects.

Conclusion: IV clonidine premedication in a dose of 4 µg/kg is safe and effective for producing a bloodless surgical field in the middle ear and nasal surgery.