Prolongation of subarachnoid block by intravenous dexmedetomidine for sub umbilical surgical procedures: A prospective control study

Abstract

Background:Intravenous dexmedetomidine is used as adjuvant during general anesthesia due to its sedative and analgesic effects. The present study was aimed to evaluate the effects of intravenous dexmedetomidine on sensory and motor block characteristics, hemodynamic parameters and sedation during subarachnoid block.Materials and Methods:In this double-blind randomized placebo control study, 60 patients of American Society of Anesthesiologist I and II were randomized into two groups by computer generated table. Patients of Group D administered intravenous dexmedetomidine 0.5 μg/kg and patients of Group C received similar volume of normal saline, administered after 20 min of subarachnoid block with 0.5% hyperbaric bupivacaine. The cephalic level of sensory block, total duration of sensory analgesia and motor block were recorded. Sedation scores using Ramsey Sedation Score (RSS) and hemodynamic changes were also assessed.Results:Demographic profile, duration of surgery and cephalic level of sensory block were comparable. The time for two segments regression was 142.35 ± 30.7 min in Group D, longer than Group C (98.54 ± 23.2 min). Duration of sensory blockade was 259.7 ± 46.8 min in the Group D versus 216.4 ± 31.4 min in Group C (P < 0.001). The mean duration of motor blockade showed no statistically significant difference between groups. There was clinically significant decrease in heart rate and blood pressure in patients of Group D. The RSS was higher (arousable sedation) in patients of Group D. No respiratory depression was observed.Conclusion:Intravenous dexmedetomidine in dosage of 0.5 μg/kg, administered after 20 min of subarachnoid block prolonged the duration of sensory and motor blockade with arousable sedation.

Effects of Continuous Intravenous Infusion of Dexmedetomidine on the Duration of Spinal Anesthesia: A Prospective, Double-Blind, Randomized, Controlled Trial

“…In the present study, no significant differences were observed in the percentage of patients administered the cardiovasoactive drugs between the two groups, and the loading dose set to 3 μg/kg/h in our protocol may have influenced this result. Nevertheless, previous studies indicated that bradycardia was transient and easily reversed with intravenous atropine [10] [11] [12] [20].…”

Role of Intravenous Dexmedetomidine in Prolonging Postoperative Analgesia and Quality of Block Following Spinal Anaesthesia. A Systemic Review and Update

“…Few studies have evaluated the onset time of sensory block after spinal anaesthesia, Readdy et al have compared intravenous dexmedetomidine with clonidine reported that dexmedetomidine shortened onset of sensory-motor block [41] but other studies are not supporting the faster onset of sensory/motor block [12,13,[27][28][29][30]. Few study have reported intravenous dexmedetomidine shortened the onset time by 30-60 sec, which might be clinically significant but it was insignificant statistically [11,33,35].…”

“…Sensory block duration -though there are too much variation in method and dose of intravenous dexmedetomidine and duration of sensory blockadebut most of the studies has reported significantly increased duration of sensory blockade by use of intravenous dexmedetomidine [11][12][13][28][29][30][31][32][33][34][35]37,38,42]. Only one study did not find any difference in block quality with the use of low dose dexmedetomidine infusion that was used solely for the purpose of intraoperative sedation [36].…”

“…The different potential role of intravenous dexmedetomidine in neuraxial anaesthesia has not been evaluated fully, few studies have shown that it prolong the sensory-motor blockade and provide better intraoperative and postoperative analgesia [12,13]. Apart from prolonging analgesia, it has been used for prevention and treatment of shivering [14][15][16][17][18][19][20][21][22][23].…”

Comparison of different regimens of intravenous dexmedetomidine on duration of subarachnoid block

“…[7] study showed a faster onset of sensory blockade with a time of 2.91 ± 1.16 min whereas Gupta et al . [9] study attained T10 sensory blockade at 3.1 ± 1 min. This difference from our study might be due to the difference in the dosage pattern in other studies when compared to our study.…”