CONTROLLED HYPOTENSION IN ENDOSCOPIC SINUS SURGERY: COMPARATIVE STUDY BETWEEN THE EFFICACY OF ESMOLOL , SODIUM NITROPRUSSIDE AND MAGNESIUM SULPHATE

Abstract

Background: This prospective study was designed to compare the efficacy of esmolol, sodium
nitroprusside (SNP) and magnesium sulphate (MgSO4) for producing controlled hypotension in
patients submitted for Endoscopic Sinus Surgery (ESS).
Methods: This study was conducted on sixty normotensive ASA I and II patients of either sex, aging
20-50 years, subjected to undergo elective ESS in Zagazig University Hospital during the period from
April 2010 to March 2011 after obtaing the ethics committee approval and the patients informed
consent. Patients with history of cardiovascular, renal, central nervous system, hepatic or pulmonary
dysfunction, or those receiving any medications known to interfere with autonomic control of
cardiovascular functions were excluded from the study. The patients were randomly allocated into
three groups. Group I: Patients received Esmolol as IV bolus application of 500 ug / kg, followed by
continuous infusion at a rate of 100-300 ug/ kg/ min. Group II: Patients received SNP as starting rate
of IV infusion of 1 ug/ kg/min, then, continuous IV infusion rate of 1-10 ug /kg/min. Group III:
Patients received MgSO4; 40 mg/ kg administered as a slow i.v bolus over a 10 min period before the
induction of anesthesia, then, 15 mg/ kg/ h by continuous IV infusion during the operation.
Results: The SBP, DBP and MAP were significantly decreased by the three different hypotensive
agents. In the SNP group, we found a significant increase in HR, while the hypotensive effects of both
esmolol and MgSO4 groups were associated with significant decreases in the HR. There was
statistically significant decrease of the blood loss in both esmolol and MgSO4 groups as compared to
SNP group. There was a statistically significant decrease in esmolol group than in SNP and MgSO4
groups as regards the average category scale (ACS) score. There were no significant differences
between the three groups regarding the duration of starvation, while there was statistically significant
increase of the duration of surgery in the SNP group when compared to the esmolol and MgSO4
groups.
In conclusion: The use of esmolol or MgSO4 was associated with a better quality of the operative
field and decreased operative time and blood loss than the use of SNP. Also, esmolol was superior to
MgSO4 as a hypotensive agent used in those patients undergoing ESS.
Key words: Controlled hypotension, ESS, Esmolol, SNP, MgSO4, SBP, DBP, MAP, ACS.