Could adding magnesium as adjuvant to ropivacaine in caudal anaesthesia improve postoperative pain control?

The Effect of Adding Magnesium Sulfate to Local Anesthetic in Patients Undergoing Middle Ear Surgery

Background:

The use of local anesthesia has been proved to be beneficial in ear surgeries.

Aims:

This study was conducted to compare between local anesthesia alone and in combination with magnesium sulphate as an adjuvant in ear operations.

Materials and Methods:

This prospective study included a total of 164 cases prepared for elective ear surgeries were included. They were divided into two equal groups, group C or control group included cases who received local anesthesia alone, and group M which included cases who received local anesthesia in addition to magnesium sulphate. Ear ring block was performed in all cases. Monitoring of blood pressure, heart rate, and oxygen saturation was performed. Post-operative pain was assessed by visual analogue score. The total analgesic time and total analgesic requirement were recorded.

Statistical Analysis:

IBM's SPSS statistics (Statistical Package for the Social Sciences) for windows (version 25, 2017) was used for statistical analysis of the collected data. Shapiro-Wilk test was used to check the normality of the data distribution. All tests were conducted with 95% confidence interval. P (probability) value < 0.05 was considered statistically significant. Charts were generated using SPSS’ chart builder and Microsoft Excel for windows 2019.

Results:

The onset of sensory blockade was significantly earlier in the Mg group. Mg group showed a significant decrease in intraoperative and post-operative analgesic consumption. In addition, the first request for analgesia after operation was markedly delayed in the Mg group compared to controls. Regarding intraoperative VAS, it was significantly lower in the Mg group compared to controls at 15-minute reading. Post-operative VAS was significantly lower in Mg group during the first two hours.

Conclusion:

Addition of magnesium to local anesthesia causes early onset of sensory blockade, delayed call first for analgesia, and better VAS scores during the early post-operative period.

Effect of magnesium added to local anesthetics for caudal anesthesia on postoperative pain in pediatric surgical patients: A systematic review and meta-analysis with Trial Sequential Analysis

BACKGROUND

Magnesium has been investigated as an adjuvant for neuraxial anesthesia, but the effect of caudal magnesium on postoperative pain is inconsistent. The aim of this systematic review and meta-analysis was to evaluate the analgesic effect of caudal magnesium.

METHODS

We searched six databases, including trial registration sites. Randomized clinical trials reporting the effect of caudal magnesium on postoperative pain after general anesthesia were eligible. The risk ratio for use of rescue analgesics after surgery was combined using a random-effects model. We also assessed adverse events. The I2 statistic was used to assess heterogeneity. We assessed risk of bias with Cochrane domains. We controlled type I and II errors due to sparse data and repetitive testing with Trial Sequential Analysis. We assessed the quality of evidence with GRADE.

RESULTS

Four randomized controlled trials (247 patients) evaluated the need for rescue analgesics. In all four trials, 50 mg of magnesium was administered with caudal ropivacaine. The results suggested that the need for rescue analgesia was reduced significantly by caudal magnesium administration (risk ratio 0.45; 95% confidence interval 0.24-0.86). There was considerable heterogeneity as indicated by an I2 value of 62.5%. The Trial Sequential Analysis-adjusted confidence interval was 0.04-5.55, indicating that further trials are required. The quality of evidence was very low. The rate of adverse events was comparable between treatment groups.

CONCLUSION

Caudal magnesium may reduce the need for rescue analgesia after surgery, but further randomized clinical trials with a low risk of bias and a low risk of random errors are necessary to assess the effect of caudal magnesium on postoperative pain and adverse events.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry UMIN000025344.

Pharmacologic Properties of Novel Local Anesthetic Agents in Anesthesia Practice

Therapeutic duration of traditional local anesthetics when used in peripheral nerve blocks is normally limited. This article describes novel approaches to extend the duration of peripheral nerve blocks currently available or in development. Three newer approaches on extending the duration of peripheral nerve blocks include site-1 sodium channel blockers, novel local anesthetics delivery systems, and novel adjuvants of local anesthetics. Compared with plain amide-based and ester-based local anesthetics, alternative approaches show significant promise in decreasing postoperative pain, rescue opioid requirement, hospital length-of-stay, and overall health care cost, without compromising the established safety profile of traditional local anesthetics.

Nonopioid (Dexmedetomidine, Dexamethasone, Magnesium) Adjuvant to Ropivacaine Caudal Anesthesia in Pediatric Patients Undergoing Infraumbilical Surgeries: A Comparative Study

Background:

Desirable adjuvants to caudal ropivacaine are the one which prolongs analgesia and free of side effects. We compared nonopioid drugs dexmedetomidine, dexamethasone, and magnesium as adjuvants to ropivacaine caudal analgesia in pediatric patients undergoing infraumbilical surgeries.

Materials and Methods:

This study was done on 128 pediatric patients (3–12-year olds) undergoing infraumbilical surgeries; they were randomly allocated to four groups to receive normal saline, dexmedetomidine 1 μg/kg, dexamethasone 0.1 mg/kg, and magnesium sulfate 50 mg with injection ropivacaine 0.2% in the dose 0.5 ml/kg caudally. Modified Objective Pain Score and Ramsay Sedation Score, duration of analgesia, hemodynamic changes, and side effects were assessed. ANOVA test was used for numerical values as data were expressed in mean and standard deviation. Kruskal–Wallis test was used for postoperative pain and sedation score as data were expressed as median and range.

Results:

The demographic data and hemodynamics were comparable. There was a significant prolongation of duration of analgesia in all study groups, dexmedetomidine (406.2 ± 45.5 min), dexamethasone (450.0 ± 72.6 min), and magnesium (325.0 ± 45.8 min) as compared to ropivacaine (285.9 ± 52.7 min) group. None of the adjuvants resulted in either excess or prolonged sedation. No side effects were encountered.

Conclusion:

The adjuvants dexmedetomidine, dexamethasone, and magnesium added to ropivacaine prolong caudal analgesic duration without any sedation or side effect.

Efficacy of dexmedetomidine as an adjuvant to ropivacaine in pediatric caudal epidural block

Context:

Caudal analgesia is a reliable and an easy method to provide intraoperative and postoperative analgesia for infraumbilical surgeries in pediatric population but with the disadvantage of short duration of action after single injection. Many additives were used in combination with local anesthetics in the caudal block to prolong the postoperative analgesia.

Aim:

We compared the analgesic effects and side effects of dexmedetomidine added to ropivacaine in pediatric patients undergoing lower abdominal surgeries.

Settings and Design:

Double-blinded randomized controlled trial.

Materials and Methods:

Sixty patients (2-10 years) were evenly and randomly assigned into two groups in a double-blinded manner. After sevoflurane in oxygen anesthesia, each patient received a single caudal dose of ropivacaine 0.25% (1 ml/kg) combined with either dexmedetomidine 2 μg/kg in normal saline 0.5 ml, or corresponding volume of normal saline according to group assignment. Hemodynamic variables, end-tidal sevoflurane, and emergence time were monitored. Postoperative analgesia, requirement of additional analgesic, sedation, and side effects were assessed during the first 24 h.

Results:

The duration of postoperative analgesia was significantly longer (P = 0.001) and total consumption of rescue analgesic was significantly lower in Group RD compared with Group R (P < 0.05). Group RD have better quality of sleep and prolonged duration of sedation (P = 0.001). No significant difference was observed in the incidence of hemodynamic changes or side effects.

Conclusion:

Addition of dexmedetomidine to caudal ropivacaine significantly prolongs analgesia in children undergoing lower abdominal surgeries without an increase in the incidence of side effects.

A comparative study of dexmedetomidine and fentanyl as adjuvants to levobupivacaine for caudal analgesia in children undergoing lower limb orthopedic surgery

Background:

Levobupivacaine is an effective local anesthetic agent with less systemic toxicity than racemic bupivacaine, but it has short postoperative analgesic duration. Dexmedetomidine and fentanyl are promising adjuncts to provide excellent and prolonged postoperative caudal analgesia. This study compared the effects of caudal levobupivacaine plus dexmedetomidine and levobupivacaine plus fentanyl for postoperative analgesia and sedation in children undergoing lower limb orthopedic surgery.

Patients and Methods:

Ninety children, whose age ranged from 1 to 7 years, American Society of Anesthesiologists I-II, undergoing orthopedic lower limb surgery under general anesthesia received caudal block for postoperative analgesia. The children were randomly allocated into three groups: Group L (control) received 0.75 ml/kg levobupivacaine 0.25% diluted in saline; Group LD received 0.75 ml/kg levobupivacaine 0.25% with dexmedetomidine 1 μg/kg; and Group LF received 0.75 ml/kg levobupivacaine 0.25% with fentanyl 1 μg/kg. Following the administration of the drugs; hemodynamic variables, the total anesthesia time, sedation score, Face, Legs, Activity, Cry, Consolability score, duration of analgesia, and side effects were recorded.

Results:

Demographically, all the groups were comparable, both the baseline and the intraoperative hemodynamic profile were similar in all groups. The mean duration of analgesia and the mean sedation score in the Group LD were significantly greater as compared to both the other groups.

Conclusion:

Dexmedetomidine may be a better additive to levobupivacaine than fentanyl for caudal postoperative analgesia, arousable sedation with comparable hemodynamic and side effect profile in children.

Magnesium as an adjuvant for caudal analgesia in children

BACKGROUND

There is a need for an adjuvant agent of caudal block that prolongs its duration and improves the analgesic efficacy to fasten functional recovery. Magnesium is an N-methyl-D-aspartate receptor antagonist that functions as an analgesic. This study was aimed to evaluate whether magnesium as an adjuvant for caudal block in children can improve postoperative analgesia and functional recovery.

METHODS

Eighty children, 2-6 years of age, undergoing inguinal herniorrhaphy, were included in this prospective, randomized, double-blinded study. For caudal block, Group R received ropivacaine 1.5 mg·ml(-1), 1 ml·kg(-1) and Group RM received the same dose of ropivacaine mixed with 50 mg of magnesium. The Parents' Postoperative Pain Measure (PPPM) score, analgesic consumption, functional recovery, and adverse effects were evaluated at 6, 24, 48, and 72 h after surgery, as well as daily thereafter until the child showed full functional recovery.

RESULTS

The PPPM score after hospital discharge was significantly lower for Group RM than for Group R at all times (P < 0.05). Children in Group RM required less fentanyl for rescue analgesia in the recovery area (16.2% vs 39.5%, P = 0.034) and less oral analgesics after discharge (20.5% vs 52.6%, P = 0.007). The time to return of normal functional activity was shorter in Group RM (P < 0.05). The incidence of adverse effects did not differ between groups.

CONCLUSIONS

As an adjuvant for caudal analgesia, 50 mg magnesium provided superior quality of analgesia and faster return of normal functional activity than local anesthetic alone in children.

Enhancement of ropivacaine caudal analgesia using dexamethasone or magnesium in children undergoing inguinal hernia repair

BACKGROUND

Caudal analgesia is the most commonly used technique providing intra- and postoperative analgesia for various pediatric infraumbilical surgical procedures but with the disadvantage of short duration of action after single injection. Caudal dexamethasone and magnesium could offer significant analgesic benefits. We compared the analgesic effects and side-effects of dexamethasone or magnesium added to caudal ropivacaine in pediatric patients undergoing inguinal hernia repair.

MATERIALS AND METHODS

A total of 105 (1-6 years) were randomly assigned into three groups in a double-blinded manner. After a standardized sevoflurane in oxygen anesthesia, each patient received a single caudal dose of ropivacaine 0.15% 1.5 mL/kg combined with either magnesium 50 mg in normal saline 1 mL (group RM), dexamethasone 0.1 mg/kg in normal saline 1 mL (group RD), or corresponding volume of normal saline (group R) according to group assignment. Postoperative analgesia, use of analgesics, and side-effects were assessed during the first 24 h.

RESULTS

Addition of magnesium or dexamethasone to caudal ropivacaine significantly prolonged analgesia duration 8 (5-11) h and 12 (8-16) h, respectively compared with 4 (3-5) h with the use of ropivacaine alone. The incidence of postoperative rescue analgesia was significantly higher in group R compared with groups RM and RD. The time to 1(st) analgesic dose was significantly longer in groups RM and RD (500 ± 190 and 730 ± 260 min) respectively compared with group R (260 ± 65 min). Group R patients achieved significantly higher Children's Hospital of Eastern Ontario Pain Scale and Faces Legs Activity Cry Consolability scores (4(th) hourly) compared with groups RM and RD patients (8(th) and 12(th) hourly, respectively).

CONCLUSION

The addition of dexamethasone or magnesium to caudal ropivacaine significantly prolonged the duration of postoperative analgesia in children undergoing inguinal hernia repair. Also the time to 1(st) analgesic dose was longer and the need for rescue postoperative analgesic was reduced and without increase in incidence of side effects.

Effects of dexmedetomidine added to caudal ropivacaine in paediatric lower abdominal surgeries

Purpose:

The objectives of this study were to compare the effects of caudal dexmedetomidine combined with ropivacaine to provide postoperative analgesia in children and also to establish its safety in the paediatric population.

Methods:

In a randomised, prospective, parallel group, double-blinded study, 60 children were recruited and allocated into two groups: Group RD (n=30) received 0.25% ropivacaine 1 ml/kg with dexmedetomidine 2 μg/kg, making the volume to 0.5 ml and Group R (n=30) received 0.25% ropivacaine 1 ml/kg + 0.5 ml normal saline. Induction of anaesthesia was achieved with 50% N₂O and 8% sevoflurane in oxygen in spontaneous ventilation. An appropriate-sized LMA was then inserted and a caudal block performed in all patients. Behaviour during emergence was rated with a 4-point scale, sedation with Ramsay's sedation scale, and pain assessed with face, legs, activity, cry, consolability (FLACC) pain score.

Results:

The duration of postoperative analgesia recorded a median of 5.5 hours in Group R compared with 14.5 hours in Group RD, with a P value of <0.001. Group R patients achieved a statistically significant higher FLACC score compared with Group RD patients. The difference between the means of mean sedation score, emergence behaviour score, mean emergence time was statistically highly significant (P<0.001). The peri-operative haemodynamics were stable among both the groups.

Conclusion:

Caudal dexmedetomidine (2 μg/kg) with 0.25% ropivacaine (1 ml/kg) for paediatric lower abdominal surgeries achieved significant postoperative pain relief that resulted in a better quality of sleep and a prolonged duration of arousable sedation and produced less incidence of emergence agitation following sevoflurane anaesthesia.