A randomized control study on effects of Dexmedetomidine, Magnesium sulphate and Propofol in middle ear surgeries

This is a randomized control study and aims to compare the effects of  Propofol , Dexmedetomidine and Magnesium sulphate in middle  ear surgeries .Primary objectives of the study is to compare the efficacy of intraoperative use of Propofol , Dexmedetomidine and Magnesium sulphate for controlled hypotension (MAP of 55-65 mmHg) in middle ear surgeries. The secondary objective is to assess oligemic field during the surgery , to compare the anaesthetic  agent consumption (oxygen, air and isoflurane) at the end of the surgery , to compare the degree of postoperative pain and postoperative nausea and vomiting.The recruited patients will be randomized and allocated into one of the three groups-Group P(Propofol),Group M(Magnesium sulphate) and Group D(Dexmedetomidine) by a computer generated table.The study drugs will be given as a boluses over 15 minutes(Propofol 6mg/kg/hr, Dexmedetomidine 1mcg/kg in 100mL NS, Magnesium sulphate 30mg/kg in 100 mL NS) before the time of incision, followed by and infusion( Propofol 4mg/kg,Dexmedetomidine 0.3mcg/kg/hr,Magnesium sulphate 10mg/kg/hr) till the microscope used for surgery is taken off.

The outcome variables and their measures:

1)Intraoperative haemodynamics at 5,10,15,20,30,45,60,78,90,105 and 120 minutes respectively

2)Oligemic field as assessed by the surgeon at the end of the surgery

3. Anaesthetic agent consumption at the end of the surgery

4)Post operative nausea and vomiting, Post operative pain – Early ( 5 minutes, 30 minutes, 1 hour ) and late ( 2 hours and 8 hours)

Descriptive and inferential statistical analysis will be done .Results on continuous measurements are presented as Mean +/- SD.Results on categorical measurements are presented as number %.Analysis of variance (ANOVA) will be used to find the significance of study parameters between three groups of patients. Student t test will be used to find the significance of study parameters within each group.Chi square/ Fisher exact test will be used to find the significance of study parameters on categorical scale between two groups.