1. Intravenous clonidine for controlled hypotension in Functional Endoscopic Sinus Surgery under general anaesthesia
Professor. Subramani Kandasamy
Assoc Prof. Anita Joselyn and
Assistant Professor. Meghna David
Christian Medical College, Vellore, India
Results: Target MAP was achieved in 47% of patients in group C versus 7% in Group W with induction dose of fentanyl alone. 43% in group C versus 20% in group W needed ceiling dose of fentanyl. 10% in group C versus 73% in group W inrequired the ceiling dose of fentanyl and metoprolol to achieve target MAP. These are statistically significant. Group C had a statistically significant reduction in intraoperative blood loss, better surgical site scoring, and better pain control in the immediate post-operative period. The complication rates namely prolonged sedation, bradycardia and hypotension requiring treatment were similar in both the groups. There was no difference in the volatile anaesthetic requirement between the two groups.
Achieving Target blood pressure
Group C n = 30
Group W
n = 30
p Value
Induction dose of Fentanyl
14 (47%)
2 (7%)
<0.001
Ceiling dose of Fentanyl
13 (43%)
6 (20%)
<0.01
Additional Metoprolol
3 (10%)
22 (73%)
Introduction: Clonidine has been used with varying success for controlled hypotension in FESS under GA. Unlike previous studies, we have used clonidine intravenously in a body weight based dosage at a specific anaesthetic depth of 1.0 MAC of isoflurane.
Blood loss, pain and surgical field score
Group C
Group W
p Value
Blood loss (ml)
(Median and range)
63.5 (40-200)
180 (70-300)
0.0449
Surgical field score 11 3
0.05
Pain (VAS)
0-3
0-5
0.01
Methods: 60 ASA grade I and II patients scheduled to undergo FESS were randomly assigned to receive 3 mcg/kg of clonidine (group C) or an equal volume of sterile water (Group W) intravenously 30 minutes prior to induction of anaesthesia. Anaesthesia was induced with propofol and maintained with 1.0 MAC of Isoflurane in air and oxygen. Starting from 2.0 mcg/kg at induction, fentanyl was administered up to a total dose of 4.0 mcg/kg as necessary to achieve a mean arterial blood pressure (MAP) of 55-65mmHg. If target blood pressure was not achieved, incremental boluses of Metoprolol (0.5mg) were administered. Blood loss, quality of surgical field, bradycardia and hypotension needing treatment, sedation and pain were recorded.
Conclusion: In this first of its kind study (body weight based clonidine and MAC), 3 mcg/kg of clonidine is effective in achieving controlled hypotension and reducing intra-operative requirement of fentanyl and metoprolol. It effectively reduces intraoperative blood loss, improves surgical field and offers good analgesia in the immediate post-operative period. Its use does not reduce volatile anaesthetic requirement or increase side effects like hypotension, bradycardia and excessive sedation.
Side effects
Group C
n = 30
Group W
n=30
p Value
Excess Sedation
2 (7%)
3 (10%)
0.640
Hypotension
10 (33%)
9 (30%)
0.781
Bradycardia
1 (3%)
0.313