Intrathecal Dexmedetomidine and Fentanyl as Adjuvant to Bupivacaine on Duration of Spinal Block in Addicted Patients

Intrathecal Dexmedetomidine Combined With Ropivacaine in Cesarean Section: A Prospective Randomized Double-Blind Controlled Study

Objective

This study aimed to find the best dose of dexmedetomidine in spinal anesthesia for cesarean section.

Methods

120 American Society of Anesthesiologists (ASA) Class I and II parturients undergoing elective cesarean delivery under spinal anesthesia were randomly allocated into four groups treated with intrathecal ropivacaine (12 mg) alone (Group R) or in combination with dexmedetomidine 5 μg (Group RD1), 7.5 μg (Group RD2) and 10 μg (Group RD3). Characteristics of spinal anesthesia, hemodynamic changes, adverse effects, stress reactions and neonatal outcomes were recorded in the four groups.

Results

Patients in Group RD1, RD2, and RD3 had significantly longer sustained sensory and motor block time than patients in Group R. All four groups had comparable onset times of sensory and motor block. The time for the level of sensory block to lower to S1 was longer in Group RD1 (411.07 ± 106.66 min), Group RD2 (397.03 ± 125.39 min) and Group RD3 (468.63 ± 116.43 min) than in Group R (273.60 ± 88.34 min) (p < 0.001). The time to recover from motor block to a Bromage score of IV was longer in Group RD1 (353.60.07 ± 137.28 min), Group RD2 (350.57 ± 118.01 min) and Group RD3 (404.67 ± 112.83 min) than in Group R (232.70 ± 93.29) (p < 0.01). The incidence of chills was significantly lower in the Group RD1, RD2, and RD3 than in the Group R (p < 0.001). There was no significant difference in the incidence of adverse effects such as hypotension, bradycardia, nausea, vomiting, hypoxemia and pruritus in the four groups (p > 0.05). There was no statistically significant visceral traction response or fentanyl use in the four groups (p > 0.05). Phenylephrine dosing was significantly higher in Group RD2 and RD3 than in Group R (p < 0.05), and there was no significant difference in phenylephrine dosing between Group RD1 and Group R (p > 0.05). There were no statistical differences in postnatal Apgar scores (1 min, 5 min after birth) (p > 0.05). The postoperative concentrations of β-endorphin (β-EP), cortisol (Cor) and tumor necrosis factor-α (TNF-α) in the Group RD1, RD2, and RD3 were lower than that in Group R (p < 0.05).

Conclusion

Intrathecal 5μg of dexmedetomidine as an adjuvant to ropivacaine relieved intraoperative chills, did not increase intraoperative and postoperative adverse effects, did not increase the amount of intraoperative vasoconstrictor used, and reduced intraoperative stress reactions as well as prolonged the duration of maternal sensory and motor block, so this dose is appropriate for cesarean section.

Clinical Trial Registration

[www.chictr.org.cn/], identifier [ChiCTR2200056052].

The Comparison of the Efficacy of Early versus Late Administration of Dexmedetomidine on Postoperative Emergence Agitation in Children Undergoing Oral Surgeries: A Randomized Clinical Trial

BACKGROUND

Emergence Agitation (EA) is a dissociated state of consciousness characterized by irritability, uncompromising stance, and inconsolability. The etiology of EA is not completely understood. Dexmedetomidine is a highly selective α₂-adrenoreceptor agonist with sedative and analgesic properties, which has been used to reduce the incidence of EA. We aimed to assess the efficacy of early versus late administration of dexmedetomidine on EA in children undergoing oral surgery.

METHODS

A randomized, parallel, double-blind clinical trial was conducted at Mofid Children's Hospital affiliated to Shahid Beheshti University of Medical Sciences (Tehran, Iran) from November 2016 to March 2017. A total of 81 children, who underwent adenotonsillectomy or cleft palate repair surgery were enrolled in the study. Based on simple randomization, the children were assigned to two groups, namely early (group A, n=41) and late (group B, n=40) administration of dexmedetomidine. Intra-operative and postoperative hemodynamic variables, extubation time, post-anesthesia care unit (PACU) length of stay, and the scores on Ramsay sedation scale and FLACC pain scale were measured and compared. The data were analyzed using SPSS software (version 20.0), and P<0.05 were considered statistically significant.

RESULTS

The mean FLACC score was lower in the late group than in the early group (2.0±1.5 vs. 4.2±1.6, P<0.001). The mean Ramsay sedation score was higher in the late group than in the early group (3.5±1.4 vs. 1.8±0.8, P<0.001).

CONCLUSION

Late administration of dexmedetomidine 1 µg/kg reduced the incidence of EA and PACU length of stay and improved postoperative pain management.

TRIAL REGISTRATION NUMBER

IRCT 2016122031497N1.

Comparative study between 2-chloroprocaine and combination of 2-chloroprocaine with fentanyl for spinal anaesthesia

Using fentanyl as an adjuvant in spinal anesthesia has well been documented. Fentanyl being an opioid additive prolongs the duration of neuroaxial blockade without significantly increasing the time to ambulation. Aim: To assess the effect of fentanyl as an adjuvant used with 2-chloroprocaine on sensory and motor onset and offset block time, time for ambulation and complication rate. Methodology: A randomized comparative study was conducted for a period of 6 months in the department of anesthesiology at Kirupananda Variyar medical college and hospital, Salem. A total of 100 patients (50 in each group) posted for elective surgeries in the age group between 20 and 60 were enrolled as our study subjects. Group A patients received intrathecal injection of 3 mL of 1% 2-Chloroprocaine (30 mg) mixed with 0.5 mL of Normal saline and Group B patients received 3 mL of 1% 2-Chloroprocaine (30 mg) mixed with 0.5 mL of Fentanyl solution containing 50 micrograms per mL (25 mcg). Bilateral sensory and motor block onset and regression time was monitored. Results: Time for regression of sensory block, recovery of motor block and time to void urine was comparatively more among group B (2-chloroprocaine with fentanyl) than group A (2-chloroprocaine) and the difference was found to be statistically significant (p < .05). The length of stay in post-anesthesia ICU and the patient satisfaction score did not show a statistical significant difference between the two groups. Similarly no change was noted in hemodynamic parameters and in the incidence of adverse events. Conclusion: We conclude that the addition of fentayl to 2 chloroprocaine has a significant synergistic effect in prolonging postoperative analgesia without prolonging the time for ambulation.

Impacts of intrathecal fentanyl on the incidence of postoperative nausea/vomiting: Systematic review and meta-analysis of randomized studies

Post-operative nausea and vomiting (PONV) is an event of multifactorial origin with an incidence of 30% in the general population. Opioids such as fentanyl are being used as adjuvant to local anesthetic for its antiemetic effect. In this context, with this study we aimed to evaluate the impact of spinal fentanyl as an adjuvant on the incidence of PONV compared with a placebo, and shivering. A systematic search of randomized controlled trials that evaluated the use of spinal fentanyl in the prevention of PONV and shivering was conducted in different databases, of which 32 studies met the inclusion criteria. A total of 2116 patients scheduled for various surgeries, including cesarean section, orthopedic surgery in the lower limb, hysterectomy, and transurethral resection of the prostate, were included in the final analysis. The meta-analysis estimated the relative risk of incidence of PONV in the first 24 hours after surgery and secondary outcomes included the shivering symptom. The use of intrathecal fentanyl was associated with lower incidence of PONV, but not statistically significant when compared to the placebo (RR: 0.74 CI95%: 0.55-1.01 P = 0.06). Subgroup analysis showed a statistically significant reduction in PONV incidences with lower doses between 10 and 15 μg (RR: 0.44 CI95%: 0.35-0.55 P < 0.00001, I² = 0%) but not with higher doses 20-25 μg. Secondary outcomes showed a decrease in incidence with the use of fentanyl vs the placebo (RR: 0.49, CI95% 0.33-0.72 P = 0.0003). Current evidence shows that the use of spinal fentanyl decreases the incidence of PONV, an effect favored using low doses.

Comparing the efficacy and safety of Dexmedetomidine/Ketamine with Propofol/Fentanyl for sedation in colonoscopy patients: A double-blinded randomized clinical trial

BACKGROUND

In this double-blinded randomized clinical trial, we aimed to compare the safety and efficacy of a combination of dexmedetomidine and ketamine [DK] with propofol and fentanyl [PF] for sedation in colonoscopy patients.

METHODS

In this study, 64 patients who underwent colonoscopy were randomized into two groups: 1) A, which received PF, and 2) B, which received DK for sedation. Among 64 patients, 31 patients were included in PF, and 33 patients were included in the DK group. Both groups were similar in terms of demographics. Patients' sedation score (based on Ramsay sedation scale) and vital signs were recorded at 2, 5, 10, and 15 minutes. Complications including apnea, hypotension, hypoxia, nausea, and vomiting, along with gastroenterologist satisfaction and patients' pain score (based on Wong-Baker faces pain assessment scale), were recorded by a checklist. Data were analyzed by SPSS v.18 software, using chi-square, independent t-tests, and repeated measures analysis with p<0.05 as the criterion for significant differences.

RESULTS

The mean score of sedation was 4.82±0.49 in the DK group and 5.22±0.45 in the PF group [p value=0.001]. Serious complications, including hypotension [p value=0.005] and apnea [p value=0.10] were significantly higher in the PF group. Satisfaction of gastroenterologist [p value= 0.400] and patients' pain score [p value = 0.900] were similar among groups.

CONCLUSION

Combination of DK provides sufficient sedation with fewer complications in comparison with PF in colonoscopy patients.

A Comprehensive Review and Update of the Use of Dexmedetomidine for Regional Blocks

PURPOSE OF REVIEW

This evidence-based systematic review will focus on the use of dexmedetomidine and its role as adjuvant anesthetics in regional blocks to help better guide physicians in their practice. This review will cover background and mechanism of dexmedetomidine as well as the use in various regional blocks.

RECENT FINDINGS

Local anesthetics are preferred for nerve blocks over opioids; however, both due come with its own side effects. Local anesthetics may be toxic as they disrupt cell membrane and proteins, but by using adjuvants such as dexmedetomidine, that can prolong sensory and motor blocks can reduce total amount of local anesthetics needed. Dexmedetomidine is an alpha-2-adrenergic agonist used as additive for regional nerve block. It has a relatively low side effect profile and have been researched in various regional blocks (intrathecal, paravertebral, axillary, infraclavicular brachial plexus, interscalene). Dexmedetomidine shows promising results as adjuvant anesthetics in most regional blocks.

SUMMARY

Many studies have been done and many show promising results for the use of dexmedetomidine in regional blocks. It may significantly increase in duration of sensory and motor blocks that correlates with lower pain scores and less need of morphine in various regional blocks.

Effect of 5-μg Dose of Dexmedetomidine in Combination With Intrathecal Bupivacaine on Spinal Anesthesia: A Systematic Review and Meta-analysis

PURPOSE

Intrathecal dexmedetomidine (DEX) has been used to improve the quality and duration of spinal anesthesia. The aim of this meta-analysis is to evaluate whether intrathecal DEX could prolong the duration of sensory and motor block during spinal anesthesia.

METHODS

We searched PubMed, EMBASE, Web of Science, and the Cochrane Library for randomized controlled trials that investigated the facilitatory effects of intrathecal administration of DEX compared with those of a placebo on spinal anesthesia from inception to April 2019. Sensory and motor block durations, sensory and motor block onset times, time to first analgesic request, and DEX-related adverse effects were evaluated. Results were combined using fixed-effects or random effects modeling when appropriate.

FINDINGS

A total of 1478 patients from 25 clinical studies were included in the analysis. Compared with placebo, intrathecal DEX significantly prolonged the durations of both sensory block (weighted mean difference [WMD] = 134.42 min; 95% CI, 109.71-159.13 min; P < 0.001) and motor block (WMD = 114.27 min; 95% CI, 93.18-135.35 min; P < 0.001). It also hastened the onset of sensory block (WMD = -0.80 min; 95% CI, -1.21 to -0.40; P < 0.001) and motor block (WMD = -1.03 min; 95% CI, -1.51 to -0.56 min; P < 0.001). Furthermore, it delayed the time to first analgesic request (WMD = 216.90 min; 95% CI, 178.90-254.90 min; P < 0.001) and reduced the incidence of shivering (risk ratio [RR] = 0.39; 95% CI, 0.27-0.55; P < 0.001). DEX was associated with increased risk of transient bradycardia (RR = 1.59; 95% CI, 1.07-2.37; P = 0.022) and hypotension (RR = 1.40; 95% CI, 1.04-1.89; P = 0.026) but did not increase the incidence of postoperative nausea and vomiting (RR = 0.87; 95% CI, 0.62-1.24; P = 0.45).

IMPLICATIONS

Intrathecal DEX can prolong the duration of sensory block, the duration of motor block, and the time to first analgesic request associated with spinal anesthesia.

Effect of Different Doses of Intrathecal Dexmedetomidine as an Adjuvant Combined With Hyperbaric Ropivacaine in Patients Undergoing Cesarean Section

Objective

In this study, we aim to investigate the effect of different doses of dexmedetomidine as an adjuvant to hyperbaric ropivacaine in spinal anesthesia for cesarean section.

Methods

Seventy-five parturients with American Society of Anesthesiologists (ASA) I or II were anesthetized with intrathecal ropivacaine (12.5 mg) alone (R group) or in combination with dexmedetomidine 3 μg (RD3 group) and 5 μg (RD5 group) to undergo a cesarean section. The anesthetic parameters, postoperative analgesia, stress responses and neonates outcomes were monitored.

Results

The onset time of sensory block to T10, T4, and peak level in the RD3 group and RD5 group were significantly shorter than those in the R group (p < 0.05). The time of the level of sensory block to descend two segments and to T10 in the RD3 group(57.28 ± 16.65 min, 3.87 ± 1.60 h) and RD5 group (71.92 ± 10.10 min, 3.99 ± 1.06 h) were longer than that in the R group (40.64 ± 12.06 min, 1.98 ± 1.01 h) (p < 0.05). The median time of motor blockade to both legs score 3 on the Bromage scale (B3B3) in the RD3 group and RD5 group was shorter than that in the R group (p < 0.001). The time of motor blockade recovery to both legs score 0 on the Bromage scale (B0B0) in the RD5 group (3.6 h) was longer than that in the R group (2 h) or RD3 group (2.2 h) (p < 0.001). Visceral traction response and abdominal muscle relaxation during the operation in the RD3 group and the RD5 group were better than that in the R group. The Visual Analogue Score (VAS) in the 12 h after the operation in the RD3 group (3.30 ± 1.17) and RD5 group (2.80 ± 0.87) was smaller than that in the R group (3.80 ± 1.47) (p < 0.05). The incidence of shivering in the RD3 group and RD5 group was significantly lower than that in the R group (p < 0.05). The postoperative concentrations of c-reactive protein (CRP), interleukin-6 (IL-6) and cortisol in the RD3 and RD5 groups were lower than that in the R group (p < 0.05).

Conclusion

3 µg intrathecal dexmedetomidine as an adjuvant to ropivacaine improved intraoperative somato-visceral sensory block characteristics and postoperative analgesia, alleviated shivering in parturients, and did not prolong the time of motor block or produce any side effects, which makes this dose appropriate for cesarean delivery.

Cinical Trial Registration

ChiCTR, identifier ChiCTR1800014454. Registered 15 January 2018, http://www.chictr.org.cn/edit.aspx?pid=24613&htm=4

Outcomes of intrathecal analgesia in multiparous women undergoing normal vaginal delivery: A randomised controlled trial

Background and Aims

Although intrathecal analgesia is an effective option during labour, there is a need to establish sustainable and assured analgesia during the entire labour process. We aimed to assess the effect of adding dexmedetomidine, fentanyl or morphine to low-dose bupivacaine-dexamethasone for intrathecal labour analgesia in multiparous women.

Methods

This was a triple-blind, randomised controlled trial that included 140 multiparous women. Eligible women were randomly allocated to have intrathecal bupivacaine-dexamethasone with dexmedetomidine (group D), fentanyl (group F), morphine (group M) or saline (placebo) (group C). The duration of analgesia, intrathecal block characteristics and maternal and foetal outcomes were assessed and analysed.

Results

The longest analgesia duration and S1 regression time was recorded in group D followed by groups M, F and C, respectively, with statistical significance between all of them (P < 0.001). The shortest analgesia onset time and the highest sensory levels were recorded in group D followed by group F then group M with statistical significance between all of them (P < 0.001 and 0.003, respectively). Visual analogue scale values were comparable among groups M, F and D (P > 0.05) at most of the measurement time points and at the peak of the last uterine contraction before delivery while being significantly lower than those in group C (P < 0.001). However, there were similar motor block characteristics and normal neonatal outcomes in all groups.

Conclusion

In comparison to morphine and fentanyl, dexmedetomidine addition to intrathecal bupivacaine-dexamethasone significantly prolonged the duration and accelerated the onset of labour analgesia, with a good maternal and neonatal outcome.

Change in saturation oxygen and hemodynamic responses by adding intrathecal dexmedetomidine vs. sufentanil to bupivacaine in patients undergoing dynamic hip screw operation: a randomized clinical trial

Sufentanil (SUF) and dexmedetomidine (DEX) are used as bupivacaine in the spinal technique that providing stable hemodynamic conditions with least side effects. This study aimed to compare the change in saturation oxygen and hemodynamic responses after intrathecal DEX and SUF as adjuvants to bupivacaine in patients undergoing dynamic hip screw. This clinical trial was conducted with 80 patients referring to Valiasr Hospital, Arak, Iran, who were randomly assigned to two groups (n = 40): DEX group (8 mg bupivacaine with 5 μg DEX) and SUF group (8 mg bupivacaine with 2.5 μg SUF). The pain severity was lower in DEX group at different hours and the systolic pressure and diastolic blood pressure were lower in DEX group than in SUF group after surgery. Saturation oxygen was generally lower and more stable in DEX group but there was no significant difference between two groups. The incidence of sensory and motor block was lower in DEX group than in SUF group, but the duration of assessment of sensory block was lower in SUF group than in DEX group. DEX relieves pain up to 24 hours postoperatively. Nevertheless, Care should be taken to avoid the DEX induced shivering in patients. The study was approved by Ethical Committee of Arak University of Medical Sciences by IR.ARAKMU.REC.1395.32 code on April 25, 2016 and was registered in Iranian Registry of Clinical Trials by code number: IRCT2017050220258N45 on August 4, 2017.

[Comparison of fentanyl and dexmedetomidine as an adjuvant to bupivacaine for unilateral spinal anesthesia in lower limb surgery: a randomized trial]

BACKGROUND AND OBJECTIVES

One of the disadvantages of unilateral spinal anesthesia is the short duration of post-operative analgesia, which can be addressed by adding adjuvants to local anesthetics. The aim of current study was to compare the effects of adding dexmedetomidine, fentanyl, or saline to bupivacaine on the properties of unilateral spinal anesthesia in patients undergoing calf surgery.

METHODS

In this double-blind clinical trial, 90 patients who underwent elective calf surgery were randomly divided into three groups. The spinal anesthetic rate in each of the three groups was 1mL bupivacaine 0.5% (5mg). In groups BD, BF and BS, 5μg of dexmedetomidine, 25μg of fentanyl and 0.5mL saline were added, respectively. The duration of the motor and sensory blocks in both limbs and the rate of pain during 24h after surgery were calculated. Hemodynamic changes were also measured during anesthesia for up to 90min.

RESULTS

The duration of both of motor and sensory block was significantly longer in dependent limb in the BF (96 and 169min) and BD (92 and 166min) groups than the BS (84 and 157min) group. Visual Analog Scale was significantly lower in the two groups of BF (1.4) and BD (1.3), within 24h after surgery, than the BS (1.6) group.

CONCLUSIONS

The addition of fentanyl and dexmedetomidine to bupivacaine in unilateral spinal anesthesia can increase the duration of the motor and sensory block in dependent limb and prolong the duration of postoperative pain. However, fentanyl is more effective than dexmedetomidine.

Comparison of fentanyl and dexmedetomidine as an adjuvant to bupivacaine for unilateral spinal anesthesia in lower limb surgery: a randomized trial

Background and objectives

One of the disadvantages of unilateral spinal anesthesia is the short duration of post-operative analgesia, which can be addressed by adding adjuvants to local anesthetics. The aim of current study was to compare the effects of adding dexmedetomidine, fentanyl, or saline to bupivacaine on the properties of unilateral spinal anesthesia in patients undergoing calf surgery.

Methods

In this double-blind clinical trial, 90 patients who underwent elective calf surgery were randomly divided into three groups. The spinal anesthetic rate in each of the three groups was 1 mL bupivacaine 0.5% (5 mg). In groups BD, BF and BS, 5 μg of dexmedetomidine, 25 μg of fentanyl and 0.5 mL saline were added, respectively. The duration of the motor and sensory blocks in both limbs and the rate of pain during 24 h after surgery were calculated. Hemodynamic changes were also measured during anesthesia for up to 90 min.

Results

The duration of both of motor and sensory block was significantly longer in dependent limb in the BF (96 and 169 min) and BD (92 and 166 min) groups than the BS (84 and 157 min) group. Visual Analog Scale was significantly lower in the two groups of BF (1.4) and BD (1.3), within 24 h after surgery, than the BS (1.6) group.

Conclusions

The addition of fentanyl and dexmedetomidine to bupivacaine in unilateral spinal anesthesia can increase the duration of the motor and sensory block in dependent limb and prolong the duration of postoperative pain. However, fentanyl is more effective than dexmedetomidine.

The Effect of Dexmedetomidine Prescription on Shivering during Operation in the Spinal Anesthesia Procedures of Selective Orthopedic Surgery of the Lower Limb in Addicted Patients

Background

Shivering during a surgery is common. Recently, Alpha-D-agonist dexmedetomidine has been used to control and prevent shivering during and after surgery. However, the anti-shivering effects of this drug in people are unknown with substance abuse. The purpose of this study was to investigate the anti-shivering effect of this drug in addicted individuals.

Methods

After obtaining the required criteria, the criteria were randomized in 2 groups, dexmedetomidine and normal saline (each group n = 30), and were matched in age and sex. The dexmedetomidine 0.5 mg/kg/h was given to one group and normal saline infusion was given to the other group as a placebo immediately after induction of anesthesia and before surgery for lower limb lesions. During the operation, patients were monitored for shivering as well as vital signs and arterial oxygen saturation. In addition, after surgery, patients were evaluated for clinical side effects.

Results

The results showed that systolic blood pressure was significantly lower in the dexmedetomidine group at 30 minutes to 150 minutes after injection during the operation (P < 0.01). There was no significant difference between the 2 groups at the other times. In intra-group comparisons in both groups, diastolic pressure drop was significantly decreased to 90 minutes after surgery. In general, at other times in each group, diastolic pressure changes were not significant compared to preoperative. In between group comparisons, the mean heart rate was significantly lower in the dexmedetomidine group at 30 minutes and 60 minutes compared to the control group. In addition, at other times, its lower values were not significantly different with the control group. The 2 groups did not show significant differences in the number of breaths per minute or as the intra-group (P > 0.05), although, the average respiratory rate per minute in the dexmedetomidine group was lower. Decreased temperature of the tympanic curvature was significantly lower in the DEX group at 10 and 60 minutes after surgery than the control group (P < 0.001). Arterial oxygen saturation was more than 97% in both groups before and after operation, and no difference was observed between the 2 groups.

Conclusions

Prescribing dexmedetomidine during spinal anesthesia in patients with substance abuse can significantly decrease the incidence of shivering during surgery while not having adverse effects on hemodynamics of patients and can be used as a safe and effective drug for this purpose.

A Comparative Study between Intrathecal Isobaric Ropivacaine 0.75% Plus Dexmedetomidine and Isobaric Ropivacaine 0.75% Plus Fentanyl for Lower Limb Surgeries

Background:

Spinal anesthesia is used commonly intraoperatively. However, local anesthetics are associated with relatively short duration of action. A number of adjuvants have been used to prolong the postoperative analgesia.

Objectives:

To compare efficacy of dexmedetomidine and fentanyl when given intrathecally as an adjuvant to 2.5 ml of 0.75% isobaric ropivacaine.

Materials and Methods:

Sixty selected patients were randomized to receive 2.5 ml of 0.75% isobaric ropivacaine with dexmedetomidine 5 mcg (Group RD) or 20 mcg of fentanyl (Group RF) intrathecally for lower limb surgeries, block characteristics, hemodynamic changes, and adverse effects were compared.

Results:

Efficacy of both the drugs when given intrathecally was studied. Mean time needed for sensory blockade at T10 was 156.4667 ± 33.78 s in Group RD and 185.2000 ± 35.17 s in Group RF. The results are clinically and statistically significant (P - 0.002). The mean of total duration of sensory block in Group RD was 194.400 min while it was 139.9000 min in Group RF which was clinically and statistically significant (P - 0.0001). Time taken for onset of motor block was almost same in both groups. The mean of total duration of motor block in Group RD was 136.7333 min while it was 94.8667 min in Group RF which was clinically and statistically significant (P - 0.000).

Conclusion:

Dexmedetomidine at a dose of 5 μg added to 2.5 ml of ropivacaine provided earlier sensory blockade, prolonged duration of sensory and motor blockade for patients under intrathecal anesthesia for lower limb surgeries with no sedation.

Addition of dexmedetomidine to QX-314 enhances the onset and duration of sciatic nerve block in rats

An experimental set-up was designed to observe whether adding dexmedetomidine to QX-314 would enhance the onset and duration of sensory and motor function in a rat sciatic nerve block model. Fifty-six Sprague-Dawley rats received unilateral sciatic nerve blocks with 0.2 mL of 35 mmol/L QX-314 alone, dexmedetomidine (5.3 μmol/L (1 μg/kg), 26.4 μmol/L (5 μg/kg), 52.8 μmol/L (10 μg/kg)) alone, or a combination of the two. Thermal nociception and motor function were assessed by an investigator blinded to the drug treatment, and sciatic nerves and perineural tissues were harvested at 14 days after injection. In addition, we examined the effects of these solutions on compound action potentials in isolated frog sciatic nerves. Dexmedetomidine added to QX-314 enhanced the onset and duration of thermal nociception block and motor block (P < 0.05) without aggravating histopathological injuries. Furthermore, 52.8 μmol/L dexmedetomidine added to 35 mmol/L QX-314 showed less inflammation than QX-314 alone at 14 days (P = 0.003). Dexmedetomidine plus QX-314 was shown to dose-dependently reduce the compound action potentials relative to QX-314 alone (P < 0.05). It was concluded that co-administration of QX-314 with a clinical dose of dexmedetomidine produced a synergistic anesthetic effect to enhance the effect of sciatic nerve block.

Comparison of intrathecal versus intra-articular dexmedetomidine as an adjuvant to bupivacaine on postoperative pain following knee arthroscopy: a randomized clinical trial

Background

Postoperative pain is a common, distressing symptom following arthroscopic knee surgery. The aim of this study was to compare the potential analgesic effect of dexmedetomidine after intrathecal versus intra-articular administration following arthroscopic knee surgery.

Methods

Ninety patients undergoing unilateral elective arthroscopic knee surgery were randomly assigned into three groups in a double-blind placebo controlled study. The intrathecal dexmedetomidine group (IT) received an intrathecal block with intrathecal dexmedetomidine, the intra-articular group (IA) received an intrathecal block and intra-articular dexmedetomidine, and the control group received an intrathecal block and intra-articular saline. The primary outcome of our study was postoperative pain as assessed by the visual analogue scale of pain (VAS). Secondary outcomes included the effect of dexmedetomidine on total postoperative analgesic use and time to the first analgesic request, hemodynamics, sedation, postoperative nausea and vomiting, patient satisfaction, and postoperative C-reactive protein (CRP) levels.

Results

Dexmedetomidine administration decreased pain scores for 4 h in both the intrathecal and intra-articular groups, compared to only 2 h in the control patient group. Furthermore, there was a significant reduction in pain scores for 6 h in the intra-articular group. The time to the first postoperative analgesia request was longer in the intra-articular group compared to the intrathecal and control groups. The total meperidine requirement was significantly lower in the intra-articular and intrathecal groups than in the control group.

Conclusions

Both intrathecal and intra-articular dexmedetomidine enhanced postoperative analgesia after arthroscopic knee surgery. Less total meperidine was required with intra-articular administration to extend postoperative analgesia to 6 h with hemodynamic stability.

Treatment of Postoperative Pain in Pediatric Operations: Comparing the Efficiency of Bupivacaine, Bupivacaine-Dexmedetomidine and Bupivacaine-Fentanyl for Caudal Block

BACKGROUND

Caudal analgesia is a common method for postoperative pain management in pediatric patients. Additive agents such as opioids and α₂ agonists have been used to enhance the analgesic effects of local anesthetics for caudal block.

OBJECTIVES

The aim of this study was to compare the additive effects of dexmedetomidine and fentanyl on bupivacaine-induced caudal analgesia in pediatric patients who had undergone elective inguinal hernia repair.

METHODS

This randomized, double-blind clinical trial included children aged 1 - 5 years who were divided into three groups: the bupivacaine group (Group B) received 0.25% bupivacaine (1 ml/kg), the bupivacaine-dexmedetomidine group (Group BD) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg dexmedetomidine, and the bupivacaine-fentanyl group (Group BF) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg fentanyl. The hemodynamic variables (heart rate, systolic blood pressure, respiratory rate, and peripheral arterial oxygen saturation) were measured perioperatively. Pain, sedation and motor block scores and adverse events (nausea and vomiting, pruritis, hypotension, bradycardia, urinary retention and respiratory depression) were documented at 30 and 60 minutes, and the 1st, 2nd, 4th, 6th, 12th and 24th hours after the operation. The other recordings include the duration of surgery and analgesic requirement.

RESULTS

A total of 61 patients were analyzed. The lowest pain scores were found in the BD group at all time points (P < 0.001). The sedation scores were higher in the BD group than in the other two groups at all time points (P < 0.001). No motor block was observed after the operation. Only three patients required analgesic administration 2 to 6 hours after the operation in group B. No side effects were observed in any of the groups, and there was no significant difference in the duration of surgery among the three groups.

CONCLUSIONS

The results show that the analgesic and sedative effects were better when dexmedetomidine was added to bupivacaine than when fentanyl was added or bupivacaine alone was administered in the pediatric population studied here that underwent elective inguinal hernia repair.