Aims:Intravenous (IV) dexmedetomidine with excellent sedative properties has been shown to reduce analgesic requirements during general anaesthesia. A study was conducted to assess the effects of IV dexmedetomidine on sensory, motor, haemodynamic parameters and sedation during subarachnoid block (SAB).Methods:A total of 50 patients undergoing infraumbilical and lower limb surgeries under SAB were selected. Group D received IV dexmedetomidine 0.5 mcg/kg bolus over 10 min prior to SAB, followed by an infusion of 0.5 mcg/kg/h for the duration of the surgery. Group C received similar volume of normal saline infusion. Time for the onset of sensory and motor blockade, cephalad level of analgesia and duration of analgesia were noted. Sedation scores using Ramsay Sedation Score (RSS) and haemodynamic parameters were assessed.Results:Demographic parameters, duration and type of surgery were comparable. Onset of sensory block was 66±44.14 s in Group D compared with 129.6±102.4 s in Group C. The time for two segment regression was 111.52±30.9 min in Group D and 53.6±18.22 min in Group C and duration of analgesia was 222.8±123.4 min in Group D and 138.36±21.62 min in Group C. The duration of motor blockade was prolonged in Group D compared with Group C. There was clinically and statistically significant decrease in heart rate and blood pressures in Group D. The mean intraoperative RSS was higher in Group D.Conclusion:Administration of IV dexmedetomidine during SAB hastens the onset of sensory block and prolongs the duration of sensory and motor block with satisfactory arousable sedation.

Background:Dexmedetomidine has been shown to blunt the stress response to surgery. Hence a study was designed to evaluate the effect of intravenous (IV) Dexmedetomidine infusion during general anesthesia for abdominal surgeries on blood glucose levels and on Sevoflurane requirements during anesthesia.Materials and Methods:Forty patients scheduled for abdominal surgery under general anesthesia were divided into Dexmedetomidine (D) group and Placebo (P) group of 20 each. Group D received a loading dose of Inj. Dexmedetomidine at 1 μg/kg/10 min diluted to 20 mL, followed by maintenance with 0.5 μg/kg/h., till the end of surgery. Group P received similar volume of IV normal saline. Anesthesia was maintained with nitrous oxide in oxygen and Sevoflurane keeping entropy between 40 and 60. Data were analyzed using students t test, chi square test and Fisher Exact test as applicable.Results:During the first postoperative hour, Dexmedetomidine group showed blood glucose levels of 118.2 ± 16.24 mg/dL, compared to placebo group which was 136.95 ± 19.76 mg/dL and it was statistically significant (P < 0.01). Mean hourly Sevoflurane requirement in Group D was 11.10 ± 2.17 mL, compared to 15.45 ± 3.97 mL in placebo group. In peri-operative period, the heart rate and MAP were significantly lower in Group D, when compared to placebo. Patients in Group D were better sedated and post-operative pain score was better in Group D compared to Group P.Conclusion:IV Dexmedetomidine was effective in blunting stress response to surgical trauma as indicated by lower blood glucose levels, and reduces Sevoflurane requirements during entropy guided general anesthesia without affecting time for extubation.

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BACKGROUND: This prospective randomized double blind study was conducted to evaluate the effect and safety of intrathecal dexmedetomidine added to isobaric ropivacaine. MATERIALS AND METHODS: 120 adult female patients, who underwent vaginal hysterectomies, were randomly allocated to receive intrathecally either 3 ml of 0.75% isobaric ropivacaine + 0.5 ml normal saline (Group R) or 3 ml of 0.75% isobaric ropivacaine +5 μg dexmedetomidine in 0.5 ml of normal saline (Group D). Following intrathecal administration, duration of onset of sensory and motor blockade, maximum dermatomal level achieved, duration of analgesia, hemodynamic parameters and incidence of side effects were observed. RESULTS: Duration of onset of sensory block upto T10, T8 and the highest level of block achieved i. e. T6 were similar in both the groups. The mean time of sensory regression to S2 was 297.71±34.11 min in group D and 221.35±22.70 min in group R. Time to achieve Bromage score 0 was significantly slower with the addition of dexmedetomidine (229.37±28.74 min in group R vs. 258.55±30.46 min in group D). Duration of postoperative analgesia was significantly greater in group D (270.00±38.75 min) as compared to group R (174.77±22.31 min). The maximum VAS score for pain was less in group D (4.42±0.69) as compared to group R (7.03±0.78). There were no significant difference in hemodynamic parameters and incidence of side effects in both the groups. CONCLUSION: The addition of dexmedetomidine to ropivacaine intrathecally produces significantly longer sensory and motor blockade along with better postoperative analgesia, and excellent hemodynamic stability without any significant side effects.

Background and Aims:Unanticipated difficult intubation or the failed intubation in operating room and in emergency department is an imperative source of anesthesia-related patient's mortality. The aim of this study is to compare the predictive value of upper lip bite test (ULBT) and ratio of height to thyromental distance (RHTMD) with other commonly used preoperative airway assessment tests for predicting difficult intubation in Indian population.Materials and Methods:In this prospective, single-blinded observational study, 260 adult patients of either sex, belonging to American Society of Anesthesiologists physical Status I and II undergoing elective surgical procedure under general anesthesia were included in the study. ULBT, RHTMD, inter-incisor gap, modified Mallampati grade, horizontal length of the mandible, head and neck movements, sternomental distance, and TMD were assessed preoperatively and correlated with Cormack and Lehane's grading during laryngoscopy under anesthesia. Statistical analysis was done by Chi-square and Fisher's exact test.Results:ULBT and RHTMD had highest sensitivity (66.7% and 63.3%), specificity (99.1% and 89.6%), positive predictive value (90.9% and 44.2%), and negative predictive value (96.9% and 95.0%), respectively, when compared to other parameters in predicting difficult airway.Conclusion:ULBT and RHTMD may be used as a simple bedside airway assessment tools for prediction of difficult intubation.