Efficacy of Intravenous Nefopam, Dexmedetomidine, and Meperidine in Preventing Postspinal Anesthesia Shivering in Adult Patients Undergoing Lower Abdominal and Lower Limb Surgeries: A Double‐Blind Comparative Study

Spinal anaesthesia is a routinely used anaesthetic technique in elderly patients (> 60 years) undergoing operations involving the lower limbs, lower abdomen, pelvis and the perineum. Spinal anaesthesia has several advantages over general anaesthesia including stable haemodynamic variables, less blood loss, less post-operative pain, faster recovery time and less post-operative confusion. Despite these advantages, the sympathetic blockade induced by spinal anaesthesia can result in hypotension, bradycardia, dysrhythmias and cardiac arrests. Conventionally, spinal anaesthesia is performed at the level of L3,4 interspace; with a reported incidence of hypotension in the elderly ranging between 65% and 69%. A possible strategy for reducing spinal induced hypotension would be to minimize the peak block height to as low as possible for the planned procedure. To determine the difference in haemodynamic stability between elderly patients undergoing spinal anaesthesia at L5, S1 interspace compared to those at L3, 4. Thirty two elderly patients scheduled for lower limb or pelvic surgery under spinal anaesthesia were randomized into 2 groups (control group and intervention group) using a computer generated table of numbers. Control group; received 2.5 mls 0.5% hyperbaric bupivacaine injected intrathecally at the L3, 4 interspace and Intervention group; 2.5mls 0.5% hyperbaric bupivacaine injected intrathecally at the L5, S1 interspace. The two groups had similar baseline characteristics in age, sex, body mass index and use of anti-hypertensive medications. There was 68.8% proportion of hypotension in the control group and 75% in the intervention group. The difference was not found to be statistically significant (p= 0.694). During the study period, there were 106 episodes of hypotension, out of which, 65 were in the control group and 41 in the intervention group (p=0.004).. Linear regression analysis of the decrease in mean arterial pressures (MAP) showed a higher decrease in MAP in the control group (p 0.018). There were more crystalloids used in the control group (1006mls ± 374) than in the intervention group (606mls ±211) with a p< 0.0001. There was no difference in the amounts of vasopressors used between the two groups (p=0.288). There was no difference in the change in heart rates, conversion to general anaesthesia, use of supplementary intravenous fentanyl and the peak maximum block level achieved. The time to peak maximum sensory block level was 9.06min and 13.07min in the control group and intervention groups, respectively (p<0.0001). Among this population, there was no difference in the proportion of those with hypotension between the elderly patients who received their spinal anaesthesia at L3,4 and those who received spinal anaesthesia at L5,S1. The intervention group had better outcomes with significantly less episodes of hypotension. It took a longer time to achieve a maximum peak sensory block in the intervention group. Performing spinal anaesthesia at the level of L5,S1 was found to provide an adequate sensory block for a wide range of pelvic, perineal and lower limb surgeries.

BackgroundRegional anesthesia, like general anesthesia, influences the thermoregulatory process. In this study, we aimed to compare the efficacy, hemodynamic stability, and adverse effects of dexmedetomidine (DEX), ketamine, and the combination between them when used for control of shivering that occurs during spinal anesthesia.Patients and methodsIn this double-blind study, 90 male and female patients of ASA status I and II with age 18 up to 60 years old scheduled to undergo elective lower extraperitoneal abdominal and lower limb surgery using spinal anesthesia were included. This study was done from January 2017 to July 2017.ResultsThere was no significant difference in shivering control among the three groups, which was complete (when post-treatment shivering score declined to score 0) in 28 (93.3%) patients in DEX group, 27 (90%) patients in ketamine group, and 25 (83.33%) patients in combination group (P = 0.321), whereas incomplete (when the scores decreased but did not abolish the shivering completely) in two (6.67%) patients in DEX group, three (10%) patients in ketamine group, and five (16.67%) patients in combination group (P = 0.234).ConclusionWe concluded that intravenous DEX 0.4 mcg/kg, intravenous ketamine 0.3 mg/kg, or combination between DEX 0.25 mcg/kg and ketamine 0.25 mg/kg significantly controlled the shivering that occurred during spinal anesthesia. However, DEX is superior to ketamine and the combination in prevention of shivering.

Background: Surgical processes can be associated with a stress and anxiety in the patient triggering changes in blood pressure and heart rate adversely effecting the induction and recovery process from anesthesia. These effects are more pronounced in setting of regional anesthesia where the patient is awake intraoperatively. A calm and quite environment maintained during surgery can be helpful in blunting the stressful response of the patient. Hence, we studied the effect of music therapy on hemodynamic parameters in patients undergoing spinal anesthesia for abdominal and lower limb surgeries and its effect on the visual analog scale (VAS), patient satisfaction, and Spielberger State-Trait Anxiety Inventory (SSTAI) score. Materials and Methods: This was a prospective, randomized, and comparative study where 60 patients of either gender between 18 and 65 years were divided into two groups of 30 patients each. The patients belonged to American Society of Anesthesiologists Grade I or II. The patients were randomized into Group M (those who listened to music) and Group C (those who did not listen to music). After the induction of spinal anesthesia, headphones were applied to all the patients and music was started in Group M. The intraoperative parameters such as heart rate, blood pressure, the VAS, and the SSTAI scale were recorded and compared in both the groups. Patient satisfaction was also recorded. Results: Patients who listened to music during surgery had significantly better VAS score, SSTAI score, and patient satisfaction. The hemodynamic parameters in both groups were comparable. Conclusion: Music therapy intraoperatively in patients undergoing lower limb and abdominal surgeries under spinal anesthesia can have better patient outcomes with a higher patient satisfaction.

Introduction: For administering Spinal Anesthesia (SA) 0.5% bupivacaine is employed with Dexmedetomidine (DMT) as an adjuvant. Literature review reveals that either intrathecal or lowdose intravenous DMT can enhance the characteristics of SA with bupivacaine Aim: To evaluate the effect of a single bolus intravenous (i.v.) DMT 0.5 µg/kg given either before or after the SA in combination with intrathecal 0.5% bupivacaine compared with intrathecal bupivacaine plus DMT. Materials and Methods: A randomised, triple-blind, singlecentre and placebo-controlled study was conducted at Gayatri Vidyaparishad Institute of Health care and medical technology, Marikavalasa, Visakhapatnam, Andhra Pradesh, India, from April 2020 to December 2021. Eighty patients were allocated to four study groups of 20 each. Patients of group Intrathecal DMT (ITD) were given SA with 0.5% bupivacaine heavy 3.4 mL+5µg DMT, patients of group Before Spinal DMT (BSD) were given intravenous DMT before administering the SA with bupivacaine, patients of group After Spinal DMT (ASD) were given intravenous DMT after administering the SA with bupivacaine, and the patients of group Nil DMT (ND) or control group, were given SA with 0.5% bupivacaine heavy 3.4 mL. The primary outcome variable was the difference in the duration of analgesia. The secondary outcome variables were the differences in the onset and duration of the block both motor and sensory. Differences of the parametric data were analyzed using Analysis of Variance (ANOVA) and Tukey’s Post Hoc test HSD Beta (Honestly significant difference). For analysis of non parametric data Chisquare test was used and a p-value of ≤0.05 was considered as statistically significant. Results: Patients in the ITD group had a longer duration of analgesia of 280.7±5.0 min (vis-a-vis 215±9.34, 210.7±12.0 and 97.9±7.12 min in BSD,ASD and ND, respectively) with a statistically significant difference at a p-value &lt;0.00001. They had a shorter duration of onset of motor block of 3.4±0.49 (visa-vis 4.6±0.53, 6.09±0.44 and 6.3±0.65 in BSD, ASD and ND groups, respectively) with a statistically significant difference at a p-value &lt;0.00001. Duration of onset of the sensory block was 2.2±0.37 min in the patients of ITD group (vis-a-vis 3.2±4.76, 3.5±6.71 and 4±0.40 in BSD,ASD and ND groups, respectively) with a statistically significant difference at a p-value &lt;0.00001. Conclusion: Dexmedetomidine used as an adjuvant to intrathecal bupivacaine produces greater augmentation of duration of analgesia, earlier onset of sensory and motor block, more haemodynamic stability and fewer overall side effects compared to its intravenous bolus administration.

Background and Aims: This study aims to investigate the effect of intrathecal administration of dexmedetomidine on the duration of sensory and motor block and postoperative analgesic requirements produced by spinal bupivacaine. Materials and Methods: Ninety patients scheduled for major surgeries under spinal anaesthesia were chosen for the study. All patients received drug volume of 3.5ml containing 3 ml of hyperbaric bupivacine (15 mg). The study groups received dexmedetomidine 5 μg (group B,n = 30) or 10 μg (group C,n =30) diluted to 0.5 ml with 0.9% saline, added to bupivacaine in the same syringe, the control group (group A, n= 30) received an identical volume of 0.9% saline added to bupivacaine. Heart rate, arterial blood pressure, sensory level, motor block, pain and level of sedation were assessed intraoperatively and upto 24 hrs after spinal anaesthesia. The incidence of adverse effects were recorded. Result: Dexmedetomidine significantly prolonged time to two segment regression, sensory regression, regression of motor block to modified Bromage 0 and time to first rescue analgesic. In addition, it significantly decreased postoperative pain scores. The effects were greater in group C than in group B. In addition, group C patients had higher sedation scores and lower postoperative analgesic requirements than group B or A. Hemodynamic stability was maintained in all the groups. Conclusion: Intrathecal dexmedetomidine in dose of 5 μg and 10 μg significantly prolonged the anesthetic and analgesic effects of spinal hyperbaric bupivacaine in a dose dependent manner. A 10 μg dose may be benefit for prolonged surgical procedure.

Background &amp; objective: Spinal anesthesia is commonly used for lower limb and abdominal surgeries, but its effectiveness is limited by the duration of action of local anesthetics. To prolong analgesia and improve intraoperative conditions, adjuvants such as clonidine and fentanyl are added to local anesthetics. This study aims to compare the efficacy and safety of clonidine and fentanyl as adjuvants to ropivacaine in spinal anesthesia, focusing on sensory and motor blockade duration, postoperative analgesia, hemodynamic changes, and adverse effects. Methodology: A randomized, double-blind, controlled trial was conducted on 75 patients undergoing elective lower abdominal and lower limb surgeries. Patients were randomly assigned to three groups: Group A: ropivacaine 0.25%, Group B: ropivacaine + clonidine 5 µg, and Group C: ropivacaine + fentanyl 15 µg. The onset and duration of sensory and motor blockade were assessed using the pinprick method and Modified Bromage Scale. Hemodynamic parameters (heart rate, systolic and diastolic blood pressure) were monitored at regular intraoperative intervals. The time to first rescue analgesia and VAS pain scores were recorded at 1, 6, 12, and 24 hours. Adverse effects, including sedation, nausea, hypotension, and bradycardia, were recorded. Statistical analysis was performed using ANOVA and Chi-square tests in SPSS version [X]. P &lt; 0.05 was considered significant. Results: Group B (clonidine group) had the longest sensory and motor blockade duration, followed by Group C (Fentanyl), with Group A showing the shortest duration (p &lt; 0.0001). Time to first rescue analgesia was significantly prolonged in Group B (528.8 ± 12.2 min) compared to Group C (422.1 ± 13.9 min) and Group A (203.3 ± 16.4 min) (P &lt; 0.0001). Hemodynamic instability was more pronounced in Group B, with a higher incidence of hypotension and bradycardia, whereas Group C had a greater incidence of mild sedation and bradycardia. Sedation was significantly higher in Group B (P = 0.0033), while nausea and pruritus were more frequent in Group A. Group A required significantly more rescue analgesia doses compared to Groups B and C (P &lt; 0.0001). Conclusions: Clonidine as an adjuvant to ropivacaine in spinal anesthesia significantly prolongs sensory and motor blockade and enhances postoperative analgesia, but is associated with greater sedation and hemodynamic instability. Fentanyl also improves analgesia with a lower risk of hypotension but increases bradycardia incidence. Abbreviations: DBP: diastolic blood pressure, HR: heart rate, SA: Spinal anesthesia, SBP: systolic blood pressure, Keywords: Spinal Anesthesia; Ropivacaine; Clonidine; Fentanyl; Postoperative Analgesia; Hemodynamic Stability; Adverse Effects; Regional Anesthesia Citation: Ambali L, Thilaak P, Priya MR, Brindha R, Sabapathy VA, Periasamy P, Choudhary AK. Comparative study of clonidine and fentanyl as adjuvants to ropivacaine in spinal anesthesia: impact on analgesic efficacy, hemodynamic stability, and adverse effects. Anaesth. pain intensive care 2025;29(6):528-534; DOI: 10.35975/apic.v29i6.2903 Received: March 05, 2025; Revised: May 06, 2025; Accepted: May 15, 2025

Background: For lower abdomen and lower limb surgery, spinal anaesthesia is most common modality used in routine. This study was conducted on 50 ASA 1 and 2 planned for lower limb and lower abdomen surgery. Methods: 50 patients of ASA 1 and 2 scheduled for lower limb and lower abdominal surgery were selected. Each patient received 4 milliliter volume of 0.75% isobaric ropivacaine + 5 microgram dexmedetomidine. At the intervals of 1 minute, 2 minute, 5 minute, 10 minute, 20 minute, 30 minute and 1 hour, 2 hour and 3 hour reading of pulse rate and blood pressure were recorded. Postoperatively, pain scores were recorded by using Visual Analogue Scale. Results: There were no significant changes in systolic and diastolic blood pressure after induction. The combination of ropivacaine and dexmedetomidine provided better postoperative analgesia and reduced requirement of diclofenac injection in first 24 hour. Conclusions: The patients showed excellent hemodynamic stability and postoperative analgesia to ropivacaine + dexmedetomidine. Thus it is a safe modality for lower limb and lower abdomen surgery as far as haemodynamic effects and postoperative analgesia is concerned.

Background:Regional anesthesia is the preferred technique for most of lower abdominal and lower limb surgeries. For decades, lignocaine had been the local anesthetic of choice for spinal anesthesia. Recent studies show that intravenous clonidine and dexmedetomidine can prolong the duration of the spinal anesthesia. Dexmedetomidine is a more suitable adjuvant compared to clonidine due to its more selective α2A receptor agonist activity.Aim:The study was undertaken to evaluate the effects of intravenous administration of dexmedetomidine on spinal anesthesia with 0.5% hyperbaric bupivacaine in lower abdominal surgeries.Study Design:Prospective randomized, double-blind control study.Materials and Methods:Sixty patients of American Society of Anaesthesiologists Grades I and II, 20–60 years age, undergoing lower abdominal surgeries under spinal anesthesia were randomized into two groups by computer-generated table. Group 1: Bupivacaine and dexmedetomidine group; and Group 2: Bupivacaine and saline group. Spinal anesthesia was given with 15 mg of 0.5% bupivacaine. Patients in Group 1 received dexmedetomidine 1 μg/kg over 20 min followed by 0.5 μg/kg/h, intravenously till the end of surgery. Patients in Group 2 received normal saline. Observations were analyzed using Student's unpaired t-test.Results:The mean duration of analgesia in group 1 was 219.7 ± 2.55 minutes and in group 2 was 150.2 ± 5.7 minutes. The prolongation in duration of analgesia in dexmedetomidine group was statistically significant. The mean durations of motor blockade in Group 1 and Group 2 were 189.6 ± 2.14 and 158.2 ± 5.31 min, respectively.Conclusion:Intravenous dexmedetomidine is useful to maintain hemodynamic stability and prolong spinal analgesia.

Dexmedetomidine (DEX) can prolong duration of anesthesia and shorten onset of sensory and motor block relative to clonidine. This study attempted to compare the efficacy of intravenous DEX and clonidine for hemodynamic changes and block after spinal anesthesia with ropivacaine in lower limb orthopedic surgery. In a double-blind randomized clinical trial, 120 patients undergoing spinal anesthesia in lower limb orthopedic surgery were recruited and divided into three groups using balanced block randomization: DEX group (n = 40; intravenous DEX 0.2 µg/kg), clonidine group (n = 40; intravenous clonidine 0.4 µg/kg), and placebo group (n = 40; intravenous normal saline 10 mL) in which pain scores were assessed using visual analogue scales (at recovery, and 2, 4, 6, and 12 hours after surgery) and time to achieve and onset of sensory and motor block. Statistically significant differences were found in mean arterial pressure among the groups at all times except baseline (P = 0.001), with a less mean arterial pressure and a prolonged duration of sensory and motor block (P = 0.001) in the DEX group where pain relieved in patients immediately after surgery and at above mentioned time points (P = 0.001). Simultaneous administration of intravenous DEX with ropivacaine for spinal anesthesia prolongs the duration of sensory and motor block and relieves postoperative pain, and however, can decrease blood pressure. Although intravenous DEX as an adjuvant can be helpful during spinal anesthesia with ropivacaine, it should be taken with caution owing to a lowering of mean arterial pressure in patients especially in the older adults. This study was approved by Ethical Committee of Arak University of Medical Sciences (No. IR.Arakmu.Rec.1395.450) in March, 2017, and the trial was registered and approved by the Iranian Registry of Clinical Trials (IRCT No. IRCT2017092020258N60) in 2017.

Objective: To study the effects of intravenous dexmedetomidine infusion and compare it with intravenous midazolam infusion during spinal anaesthesia (S/A) with regards to effect on psychomotor performance, memory and any side effect. Materials Methods: A prospective randomized double blind study was conducted on 60 patients of ASA I to III, scheduled for lower abdominal or lower limb surgery under S/A. All patients were randomly divided into two groups of 30 each; randomization was done by computer generated random numbers. In Group D, dexmedetomidine 1 μg/kg and In Group M, midazolam 0.04 mg/kg basal infusion for 10 min then S/A was given with hyperbaric bupivacaine (0.5%). After achieving required level of S/A; position given and then infusion of inj. Dexmedetomidine 0.5µg/kg/hr in group D and Inj. Midazolam 0.04mg/kg/hr by infusion started. Both psychomotor and memory test were performed before study drug infusion and after 1 and 4 hour of stoppage of infusion. Results: Thus, in both the groups, psychomotor performance was not significantly changed as compared to baseline at 1 hour and 4 hour after stoppage of infusion. There was significantly decreased in recall of picture, after 1 hour of study drug infusion in both the groups (anterograde amnesia); which was regained at 1 hour after stoppage of infusion. The mean time required to achieved sedation score (RSS) of 3 were statistically significant shorter in group D as compared to in group M (P 0.05). Conclusion: Thus, we conclude that, Dexmedetomidine provide rapid onset of arousable sedation without causing respiratory and cardiovascular depression. It provides anterograde amnesia with rapid recovery of psychomotor function.

Background: Modern technology has produced better equipment than was available hitherto with the result that spinal anaesthesia is undoubtedly simpler, cheaper and above all, safer than it used to be. These notwithstanding, it is used infrequently. The aim of the study was to evaluate the safety, benefits and applicability of subarachnoid spinal anaesthesia in a tertiary referral centre in a developing country.Methods: This was a prospective analysis involving 200 patients requiring anaesthesia for lower abdominal and limb surgery at the Jos University Teaching Hospital, Jos. Subarachnoid spinal anaesthesia was performed through the L2/L3 or L3/L4 interspace employing either 0.5% bupivacaine hydrochloride in 8% glucose monohydrate (Marcain heavy Astra) 2-4mls or 5% lignocaine (heavy xylocaine Astra) 1-2mls. Patients with uncorrected or undercorrected hypovolaemia, uncorrected anaemia or heart disease, local sepsis and those on anticoagulant therapy or who had bleeding disorders were excluded. Also excluded were children. Results: A total of 200 patients with age range of 15-90 years and a mean age of 34.48 years were studied. The male to female ratio was 1:1.74. Eighty of them underwent caesarean section (38 emergency and 42 electives), 26 prostatectomy, 24 appendicectomy, 19 herniorraphy, 11 haemorrhoidectomy, 9 fissurectomy, 7 total abdominal hysterectomy, 5 Manchester operation, 4 myomectomy, while the remaining 15 were for other procedures involving the lower abdomen or limb. Complications noted were: nausea (17.50%) and vomiting (3.5%), pain at injection site (15.5%), chills/shivering (15.0%), post-spinal headache (0.5%) and hypotension (3.0%). Subarachnoid anaesthesia was non-fatal. One hundred and ninety patients (95%) were satisfied with spinal anaesthesia. Conclusion: Spinal anaesthesia though safe is not without hazards. Spinal anaesthesia may be used for most operations in the lower abdomen (including caesarean section), perineum or leg. Nigerian Journal of Surgical Research Vol. 7(1&2) 2005: 226-230

Introduction: Postoperative pain management of high quality is important and in majority of post surgical cases pain is not treated adequately. We have evaluated the efficacy and safety of pregabalin and gabapentine as preemptive analgesic for post operative pain management in patients undergoing lower abdominal and lower limb surgery under spinal anesthesia. Materials and Methods: In a randomized double blind study, 90 patients were divided into three groups. Group G received tab gabapentin 900 mg, Group P received tab pregabalin 300 mg and Group C received placebo tablet orally 1 hour prior to surgery. All patients underwent surgery under spinal anesthesia using 0.5% Bupivacaine. Assessment of postoperative pain was made with visual Analogue Scale (VAS) score at 1, 2, 4, 6, 8, 12, 18, and 24 hours post operatively. Injection tramadol 100 mg was given as rescue analgesic intramuscularly when VAS score was > 7 in all the groups. Time to first rescue analgesics and number of rescue analgesics received were noted in all groups. The occurrences of side effects were noted in all groups. Results: The tramadol as rescue analgesia consumption was less in pregabalin and gabapentin groups compared to control and was statistically significant (P < 0.001). Initial VAS scores were lower in pregabalin (3.2 ± 0.4) and gabapentin (3.63 ± 0.32) groups compared to control (6.60 ± 0.77) and was statistically significant (P < 0.001). Time to first rescue analgesia was significantly longer for pregabalin (24.6 hours) followed by gabapentin (20.76 hours) and control (4.93 hours) groups. Conclusion: Pregabalin 300 mg single dose given 1 hour prior to surgery is superior to 900 mg gabapentin and placebo in attenuating post operative in patients undergoing lower abdominal and lower limb surgery. Both drugs are better than placebo.

Dexmedetomidine (DEX) has been reported to have synergistic action with local anesthetics. This prospective, randomized, double-blind clinical study was designed to observe the efficacy of intravenous DEX without loading dose on spinal blockade duration, postoperative sedation, patient-controlled analgesia and its morphine-sparing effect in lower limb surgeries.Seventy-five patients, scheduled for lower limb surgery under spinal anesthesia, were randomly allocated into 2 groups: group BS (received 15 mg of 0.5% of bupivacaine for subarachnoid anesthesia and continuous intravenous infusion of saline in Ringer solution) and BD group (received 15 mg of 0.5% of bupivacaine for subarachnoid anesthesia and continuous intravenous infusion of DEX in Ringer solution at a rate of 0.25 μg/kg/h). Intravenous infusion started 15 minutes before spinal anesthesia.The onset time of sensory and motor blockade was shorten, the duration of sensory and motor blockade was significantly prolonged in BD patients when compared to BS patients. The Ramsay sedation score measured immediately after surgery was greater in BD group than BS group. BD patients also shown increased time to the first request of postoperative morphine and decreased total morphine consumption as compared with BS patients.Collectively, intravenous administration of DEX without loading dose promoted the efficacy of spinal bupivacaine anesthesia and postoperative analgesia in patients undergoing lower limb surgery.

Midazolam and dexmedetomidine both being sedatives, but the latter with additional analgesic properties is expected to prolong the duration of sensory and motor block obtained with spinal anaesthesia. To compare intravenous dexmedetomidine with midazolam and placebo with respect to sensory and motor block duration, analgesia, and sedation in patients undergoing lower limb and lower abdominal surgeries with intrathecal ropivacaine anaesthesia. In this single blind placebo controlled trial, 60 patients, classified as American Society of Anaesthesiologists' (ASA) physical status I-II, were randomized into three groups (n=20 per group). All patients were administered ropivacaine (15 mg) for spinal anaesthesia. Intravenous dexmedetomidine was administered in Group D (1 μg/kg loading dose over 10 minutes, followed by a continuous infusion (0.5 μg/kg/hr), intravenous midazolam was administered in Group M (0.05 mg/kg) loading dose, followed by a continuous infusion (0.02 mg/kg/hr) and normal saline was infused in Group C. Intraoperative haemodynamic changes, onset, level and duration of sensory block, onset and duration of motor block, level of sedation, postoperative analgesia and side effects were recorded. Heart rate was seen to fall significantly in Group D patients for the first 15 minutes. Measurements of mean blood pressure revealed significant decrease in Group D after 40 minutes, whereas the fall in Group C occurred after 15 minutes. Duration of sensory block was significantly longer in Group D patients (208±19.358 mins) as compared to Group M and C where the duration was (177±15.252 mins) and (177±17.800 mins) respectively. Higher levels of sedation were achieved in Group D and M where sedation score was 3 (fully asleep but arousable), 90% cases in Group D and 100% cases in Group M. The time at which first analgesic was given to patients (VAS score 4) was (271.50±21.831) in Group D and (202±25.047) in M and (218.50±38.013) in Group C. Dexmedetomidine significantly prolongs duration of analgesia providing pain relief in intraoperative and postoperative period. Injection of diclofenac sodium 75 mg intramuscular was used as rescue analgesic. The VAS score reached a value of 4 earlier in the midazolam and saline group than dexmedetomidine group. Intravenous dexmedetomidine prolonged spinal anaesthesia, though midazolam did not. It also provided sedation and additional analgesia. Therefore, dexmedetomidine is appropriate during spinal anaesthesia, although heart rate needs to be monitored cautiously.

Introduction Spinal block is a preferred technique for most lower abdominal and lower limb surgeries. Lignocaine had been the local anesthetic of choice for decades in such surgeries. With the advent of adjuvants, now it has become possible to enhance the duration of spinal anesthesia. These adjuvants can be given intravenously or intrathecally. Intravenous clonidine and dexmedetomidine have been used in recent studies as adjuvant in spinal anesthesia with promising results. Dexmedetomidine is a more suitable adjuvant compared with clonidine due to its more selective alpha-2A receptor agonist activity. Aims and objectives To evaluate the effect of intravenous dexmedetomidine on spinal anesthesia with 0.5% bupivacaine in lower abdominal surgeries in terms of onset and duration of sensory and motor blockade and sensory regression. Materials and methods Sixty patients of American Society of Anesthesiologists grades I and II, 25 to 60 years of age, posted for elective lower abdominal surgeries under spinal anesthesia were included in the study and randomly allocated into computer-generated two groups. Group IV received intrathecal 0.5% bupivacaine heavy and intravenous infusion of dexmedetomidine 1 μg/kg over 20 minutes followed by 0.5 μg/kg/hour till the end of surgery. Patients in group III (control group) received intrathecal 0.5% bupivacaine heavy and intravenous normal saline as placebo. Results In groups IV and III, mean duration of analgesia was 209 ± 29.93 and 150.20 ± 3.46 minutes respectively. This increase in duration of analgesia in dexmedetomidine group was statistically significant. The mean duration of motor blockade was 189.48 ± 1.34 and 158.18 ± 3.27 minutes respectively. Injection diclofenac sodium 75 mg intramuscularly was used as rescue analgesic. How to cite this article Sharma YK, Agrawal M. Intravenous Dexmedetomidine enhances the Duration of Spinal Anesthesia with 0.5% Hyperbaric Bupivacaine in Lower Abdominal Surgeries. Int J Adv Integ Med Sci 2017;2(3):144-148.