Clonidine as an adjuvant in monitored anesthesia care for ENT surgeries: A prospective, randomized, double blind placebo controlled study

Abstract

Objective: Alpha-2 adrenoceptors have recently been used perioperatively for their sedative, analgesic,
sympatholytic and cardiovascular stabilizing effects. The efficacy of clonidine as an adjuvant in providing
monitored anesthesia care (MAC) for ear, nose and throat (ENT) surgeries has not been much investigated,
so we conducted this study.
Methodology: In this prospective double blind randomized placebo controlled study, 90 patients posted
for elective ENT surgeries under local anesthesia with MAC were included and divided into 3 groups of 30
each. In Group CBI patients received clonidine 3 μg/kg intravenous bolus followed by clonidine infusion
at 0.3 μg/kg/hr. Patients of Group CB received clonidine 3 μg/kg bolus followed by placebo infusion and
in Group P patients received placebo bolus followed by placebo infusion. All three Groups received
similar premedication of intravenous midazolam 0.03 mg/kg and fentanyl 2 μg/kg. Demographic data,
intraoperative vital parameters, observer’s assessment and alertness scale (OAAS) score for sedation,
bleeding score, patient and surgeon satisfaction score, postoperative Aldrete score, visual analogue scale
(VAS) score for analgesia, rescue sedative and analgesic consumption and complications were noted.
Results: OAAS score (0-noresponse to 5-awake), 10 min after infusion of study drug was significantly
lower in Groups CBI (2.06 ± 0.61) and CB (2.83 ± 0.70) signifying superior sedation as compared to
placebo Group (4.80 ± 0.40), (p=0.000). Intraoperative rescue sedative and analgesic consumption were
significantly lower in Groups CBI and CB, as compared to placebo group (p = 0.000). Mean heart rate (HR)
and mean arterial pressure (MAP) were significantly lower in Groups CBI and CB as compared to Group
P (p = 0.000). Intraoperative bleeding score (0-Nolbleeding to 4-modearte bleeding) was significantly
lower in Group CBI (0.86 ± 0.68) and CB (1.36 ± 0.76) as compared to placebo (3.10 ± 0.54), p = 0.000.
Surgeons and patients were more satisfied in clonidine Groups CBI and CB, (p = 0.000). Patients of Group
CBI demonstrated better sedation profile, less bleeding score and higher satisfaction scores as compared
to Group CB (p<0.05).
Conclusion: Being a safe, well tolerated, cheap and effective regime, our study favors the use of clonidine
3 μg/kg IV bolus followed by infusion of 0.3 μg/kg/hr as an adjunct to conventional MAC regime of
midazolam and fentanyl in ENT surgeries as it provides effective sedation and bloodless surgical field.