Analgesic effect and adverse events of dexmedetomidine as additive for pediatric caudal anesthesia: a meta-analysis

Melatonin vs. dexmedetomidine for sleep induction in children before electroencephalography

Background and objectives

In children requiring electroencephalography (EEG), sleep recording can provide crucial information. As EEG recordings during spontaneous sleep are not always possible, pharmacological sleep-inducing agents are sometimes required. The aim of the study was to evaluate safety and efficacy of melatonin (Mel) and dexmedetomidine (Dex; intranasal and sublingual application) for sleep induction prior to EEG.

Methods

In this prospective randomized study, 156 consecutive patients aged 1-19 years were enrolled and randomized by draw into melatonin group (Mel; n = 54; dose: 0.1 mg/kg), dexmedetomidine (Dex) sublingual group (DexL; n = 51; dose: 3 mcg/kg) or dexmedetomidine intranasal group (DexN; n = 51; dose: 3 mcg/kg). We compared the groups in several parameters regarding efficacy and safety and also carried out a separate analysis for a subgroup of patients with complex behavioral problems.

Results

Sleep was achieved in 93.6% of participants after the first application of the drug and in 99.4% after the application of another if needed. Mel was effective as the first drug in 83.3% and Dex in 99.0% (p < 0.001); in the subgroup of patients with complex developmental problems Mel was effective in 73.4% and Dex in 100% (p < 0.001). The patients fell asleep faster after intranasal application of Dex than after sublingual application (p = 0.006). None of the patients had respiratory depression, bradycardia, desaturation, or hypotension.

Conclusions

Mel and Dex are both safe for sleep induction prior to EEG recording in children. Dex is more effective compared to Mel in inducing sleep, also in the subgroup of children with complex behavioral problems.

Clinical Trial Registration

Dexmedetomidine and Melatonin for Sleep Induction for EEG in Children, NCT04665453.

Intranasal dexmedetomidine for transthoracic echocardiography in infants with shunt-dependent single ventricle heart disease

OBJECTIVES

We investigated the efficacy and complication profile of intranasal dexmedetomidine for transthoracic echocardiography sedation in patients with single ventricle physiology and shunt-dependent pulmonary blood flow during the high-risk interstage period.

METHODS

A single-centre, retrospective review identified interstage infants who received dexmedetomidine for echocardiography sedation. Baseline and procedural vitals were reported. Significant adverse events related to sedation were defined as an escalation in care or need for any additional/increased inotropic support to maintain pre-procedural haemodynamics. Minor adverse events were defined as changes from baseline haemodynamics that resolved without intervention. To assess whether sedation was adequate, echocardiogram reports were reviewed for completeness.

RESULTS

From September to December 2020, five interstage patients (age 29-69 days) were sedated with 3 mcg/kg intranasal dexmedetomidine. The median sedation onset time and duration time was 24 minutes (range 12-43 minutes) and 60 minutes (range 33-60 minutes), respectively. Sedation was deemed adequate in all patients as complete echocardiograms were accomplished without a rescue dose. When compared to baseline, three (60%) patients had a >10% reduction in heart rate, one (20%) patient had a >10% reduction in oxygen saturations, and one (20%) patient had a >30% decrease in blood pressure. Amongst all patients, no significant complications occurred and haemodynamic changes from baseline did not result in need for intervention or interruption of study.

CONCLUSIONS

Intranasal dexmedetomidine may be a reasonable option for echocardiography sedation in infants with shunt-dependent single ventricle heart disease, and further investigation is warranted to ensure efficacy and safety in an outpatient setting.

A comprehensive overview of clinical research on dexmedetomidine in the past 2 decades: A bibliometric analysis

Introduction: Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist with sedative, analgesic, anxiolytic, and opioid-sparing properties. A large number of dexmedetomidine-related publications have sprung out in the last 2 decades. However, no bibliometric analysis for clinical research on dexmedetomidine has been published to analyze hot spots, trends, and frontiers in this field. Methods: The clinical articles and reviews related to dexmedetomidine, published from 2002 to 2021 in the Web of Science Core Collection, were retrieved on 19 May 2022, using relevant search terms. VOSviewer and CiteSpace were used to conduct this bibliometric study. Results: The results showed that a total of 2,299 publications were retrieved from 656 academic journals with 48,549 co-cited references by 2,335 institutions from 65 countries/regions. The United States had the most publications among all the countries (n = 870, 37.8%) and the Harvard University contributed the most among all institutions (n = 57, 2.48%). The most productive academic journal on dexmedetomidine was Pediatric Anesthesia and the first co-cited journal was Anesthesiology. Mika Scheinin is the most productive author and Pratik P Pandharipande is the most co-cited author. Co-cited reference analysis and keyword analysis illustrated hot spots in the dexmedetomidine field including pharmacokinetics and pharmacodynamics, intensive care unit sedation and outcome, pain management and nerve block, and premedication and use in children. The effect of dexmedetomidine sedation on the outcomes of critically ill patients, the analgesic effect of dexmedetomidine, and its organ protective property are the frontiers in future research. Conclusion: This bibliometric analysis provided us with concise information about the development trend and provided an important reference for researchers to guide future research.

Dexmedetomidine and perioperative analgesia in children

Dexmedetomidine (DEX) is an anaesthetic agent that mimics natural deep sleep and produces minimal cardiorespiratory depression. As such, it is a very valuable option in the management of such a challenging population as paediatric patients. The main objective of this mini review was to evaluate the role of DEX as a perioperative analgesic in children receiving anaesthesia. We searched Google, Pubmed, Embase and the Cochrane Library for articles published between 2010 and 2021, and reviewed various of aspects of DEX, such as pharmacology, effectiveness, safety, and the most recent evidence on its clinical use as an analgesic in paediatric anaesthesia. We also include a cost estimate of perioperative analgesia with DEX.

Comparison of the Analgesic Effects of Intravenous Infusion of Dexmedetomidine Versus Bilateral Superficial Cervical Plexus Block After Thyroidectomy: A Randomized Controlled Trial

OBJECTIVES

Dexmedetomidine (DEX) is widely used in clinical practice because of its safety and effectiveness. Superficial cervical plexus block (SCPB) can reduce pain in thyroid surgery. The objective of this study was to investigated whether intravenous DEX has an equivalent analgesic effect and patients' satisfaction to SCPB for thyroid surgery.

MATERIALS AND METHODS

Ninety patients who had been scheduled for thyroidectomy under general anesthesia with endotracheal intubation were randomly divided into 3 groups. Group D: DEX was administered intravenously at an initial dose of 1 µg/kg over 10 minutes; then induction and endotracheal intubation performed, and then a continuous intravenous infusion of DEX was administered at a rate of 0.4 μg/kg/h until 30 minutes before the end of surgery. Group B: ultrasound-guided bilateral SCPB was performed, with 10 mL of 0.375% ropivacaine injected on each side. Group C: intravenous saline was administered at the same rate and dose as in group D. Patients' perioperative status, visual analog scale scores, complications and patients' satisfaction were recorded.

RESULTS

The pain at rest at 1 hour after extubation and the movement-evoked pain within 24 hours after extubation were significantly lower in groups D and B than in group C. Patients' satisfaction was significantly higher in groups D and B than in group C. There was no difference in pain at rest, movement-evoked pain and patients' satisfaction between group D and B.

CONCLUSIONS

Perioperative intravenous infusion of DEX can effectively reduce wound pain after thyroidectomy, and the analgesic effect is equivalent to that of bilateral SCPB.

Dexmedetomidine & perioperative analgesia in children

Dexmedetomidine (DEX) is an anaesthetic agent that mimics natural deep sleep and produces minimal cardiorespiratory depression. As such, it is a very valuable option in the management of such a challenging population as paediatric patients. The main objective of this mini review was to evaluate the role of DEX as a perioperative analgesic in children receiving anaesthesia. We searched Google, Pubmed, Embase and the Cochrane Library for articles published between 2010 and 2021, and reviewed various of aspects of DEX, such as pharmacology, effectiveness, safety, and the most recent evidence on its clinical use as an analgesic in paediatric anaesthesia. We also include a cost estimate of perioperative analgesia with DEX.

Efficacy of Dexmedetomidine Versus Morphine as an Adjunct to Bupivacaine in Caudal Anesthesia for Pediatric Thoracic Surgeries: A Randomized Controlled Trial

Background

Caudal anesthesia is an effective method of pain management, which can be successfully employed to minimize post-thoracotomy pain in pediatric patients. However, its main disadvantage is the short postoperative analgesic period, which can be prolonged by the concurrent administration of one of many adjuvants.

Objectives

This prospective randomized, blinded study aimed to compare the efficacy of dexmedetomidine versus morphine as adjuvants to bupivacaine in caudal anesthesia for thoracic surgeries in pediatric patients.

Methods

Fifty patients were randomly allocated into two equal groups. To achieve caudal epidural block anesthesia, the patients in group M (n = 25) were administered morphine and bupivacaine, while group D (n = 25) received a mixture of dexmedetomidine and bupivacaine. The primary outcome of this study was the postoperative analgesic duration achieved. The secondary outcomes included morphine administration in the first 24 hours following caudal block anesthesia, the face, legs, activity, cry, consolability (FLACC) scale scores, and adverse effects, including vomiting, itching, bradycardia, hypotension, and respiratory depression.

Results

The results showed that patients who had received dexmedetomidine achieved a longer postoperative analgesia as compared to those who had received morphine (P < 0.001). Postoperatively, the heart rate, blood pressure, pain score, and mean consumption of morphine were lower in group D as compared to the group M. There was no significant difference in the adverse effects between the two groups.

Conclusions

The use of dexmedetomidine as an adjuvant to bupivacaine for caudal anesthesia during pediatric thoracic surgeries induced better and prolonged postoperative analgesia as compared to morphine.

Efficacy and safety of caudal dexmedetomidine in pediatric infra-umbilical surgery: a meta-analysis and trial-sequential analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine is used as a local-anesthetics adjuvant in caudal block to prolong analgesia in pediatric infra-umbilical surgery.

OBJECTIVE

We evaluated the analgesic efficacy and safety of the addition of caudal dexmedetomidine to local anesthetics (vs local anesthetics alone) in pediatric infra-umbilical surgery.

EVIDENCE REVIEW

We searched 10 databases for randomized controlled trials (RCTs) of pediatric patients undergoing infra-umbilical surgery, comparing caudal block with and without dexmedetomidine as local anesthetic adjuvant. We performed a frequentist random-effects meta-analysis (R statistical package). We analyzed continuous outcomes as a ratio of means (ROM) and dichotomous data as relative risk (RR), along with 95% CI. We included 19 RCTs (n=1190 pediatric patients) in the meta-analysis. The primary outcome was duration of analgesia (defined as 'the time from caudal injection to the time at which the study-specific pain score was greater than a cut-off threshold').

FINDINGS

Data from 19 included RCTs (n=1190) suggested that compared with control (mean duration 346 min), the addition of caudal dexmedetomidine significantly prolonged the duration of analgesia (ratio of means 2.14, 95% CI 1.83 to 2.49, p<0.001; 'moderate' evidence). Trial-sequential analysis showed adequate 'information size' for the primary outcome. Caudal dexmedetomidine also reduced the number of analgesic administrations ('low' evidence), total acetaminophen dose ('moderate' evidence) and the risk of emergence delirium ('moderate' evidence). There were no significant differences in adverse effects such as hypotension, bradycardia, post-operative nausea and vomiting, urinary retention and respiratory depression.

CONCLUSIONS

Our results suggest that the addition of dexmedetomidine to local anesthetic in caudal block significantly improves the duration of analgesia and reduces the analgesic requirements, while maintaining a similar risk-profile compared with local anesthetic alone. Further data on neurological safety are needed.

Efficacy of caudal vs intravenous administration of α2 adrenoceptor agonists to prolong analgesia in pediatric caudal block: A systematic review and meta-analysis

BACKGROUND

α₂ adrenoceptor agonists have been proposed as adjuncts to prolong analgesia in pediatric caudal block. The aim of this meta-analysis was to compare the analgesic efficacy of caudal vs intravenous α₂ adrenoceptor agonists during pediatric caudal block.

METHODS

A systematic search, data extraction, bias risk assessment, and pooled data analysis were performed following the PRISMA guidelines. All randomized controlled trials comparing caudal with intravenous α₂ adrenoceptor agonists in pediatric caudal block were included. Relative risk and weighted mean differences (the corresponding 95% confidence intervals) were calculated for dichotomous and continuous data, respectively. Trial sequential analyses were performed to evaluate the credibility of the meta-analysis.

RESULTS

A total of 244 patients in five trials were identified. Compared with the intravenous group (9.56 ± 4.23 hours), the time to the first rescue analgesia was prolonged in the caudal α₂ adrenoceptor agonists group (12.72 ± 5.99 hours) by a weighted mean difference of 2.98 hours [95% confidence interval: 0.59-5.36 hours; P = .01]. The number of children requiring rescue analgesia in the caudal group (64, 66.67%) was lower than that in the intravenous group (80, 81.63%) [relative risk = 0.82; 95% confidence interval: 0.69-0.97; P = .02]. These findings were also verified by trial sequential analysis. There were no significant differences in the side effects.

CONCLUSION

Caudal α₂ adrenoceptor agonists as adjuncts to local anesthetic during pediatric caudal block are more effective than intravenous injection. However, the results were affected by small sample size and significant heterogeneity.

Caudal dexmedetomidine in pediatric caudal anesthesia: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To evaluate the efficacy and safety of caudal dexmedetomidine in pediatric caudal anesthesia (CA).

METHODS

We searched PubMed, Embased, and Cochrane Library (from inception to June 2019) for eligible studies. The primary outcomes were the time to first analgesia, time of postoperative eye opening, intraoperative endtidal sevoflurane concentration, and postoperative sedation score. We calculated pooled risk ratios (RR) and 95% CIs using random- or fixed-effects models.

RESULTS

Thirteen trials involving 793 patients were found. Meta-analysis showed that the time to first rescue pain medication and the time from the end of anesthesia to eye opening in the CA+dexmedetomidine group were significantly longer than in the CA group (P < .00001). The intraoperative end-tidal sevoflurane concentration in the CA+dexmedetomidine group was significantly decreased (P < .00001). Dexmedetomidine appeared to increase the rate of bradycardia in the CA+dexmedetomidine group (P = .04). Additionally, the sedation score in the CA+ dexmedetomidine group was significantly higher at 2 hours after the operation compared with the CA group (P < .00001 at 2 hours).

CONCLUSIONS

Caudally administered dexmedetomidine is a good alternative for prolonging postoperative analgesia with less pain, decreased intraoperative end-tidal sevoflurane concentration, and full postoperative sedation.

Regional Anesthesia for Pediatric Ophthalmic Surgery: A Review of the Literature

Ophthalmic pediatric regional anesthesia has been widely described, but infrequently used. This review summarizes the available evidence supporting the use of conduction anesthesia in pediatric ophthalmic surgery. Key anatomic differences in axial length, intraocular pressure, and available orbital space between young children and adults impact conduct of ophthalmic regional anesthesia. The eye is near adult size at birth and completes its growth rapidly while the orbit does not. This results in significantly diminished extraocular orbital volumes for local anesthetic deposition. Needle-based blocks are categorized by relation of the needle to the extraocular muscle cone (ie, intraconal or extraconal) and in the cannula-based block, by description of the potential space deep to the Tenon capsule. In children, blocks are placed after induction of anesthesia by a pediatric anesthesiologist or ophthalmologist, via anatomic landmarks or under ultrasonography. Ocular conduction anesthesia confers several advantages for eye surgery including analgesia, akinesia, ablation of the oculocardiac reflex, and reduction of postoperative nausea and vomiting. Short (16 mm), blunt-tip needles are preferred because of altered globe-to-orbit ratios in children. Soft-tip cannulae of varying length have been demonstrated as safe in sub-Tenon blockade. Ultrasound technology facilitates direct, real-time visualization of needle position and local anesthetic spread and reduces inadvertent intraconal needle placement. The developing eye is vulnerable to thermal and mechanical insults, so ocular-rated transducers are mandated. The adjuvant hyaluronidase improves ocular akinesia, decreases local anesthetic dosage requirements, and improves initial block success; meanwhile, dexmedetomidine increases local anesthetic potency and prolongs duration of analgesia without an increase in adverse events. Intraconal blockade is a relative contraindication in neonates and infants, retinoblastoma surgery, and in the presence of posterior staphylomas and buphthalmos. Specific considerations include pertinent pediatric ophthalmologic topics, block placement in the syndromic child, and potential adverse effects associated with each technique. Recommendations based on our experience at a busy academic ophthalmologic tertiary referral center are provided.

Intranasal dexmedetomidine is an effective sedative agent for electroencephalography in children

BACKGROUND

Intranasal dexmedetomidine (DEX), as a novel sedation method, has been used in many clinical examinations of infants and children. However, the safety and efficacy of this method for electroencephalography (EEG) in children is limited. In this study, we performed a large-scale clinical case analysis of patients who received this sedation method. The purpose of this study was to evaluate the safety and efficacy of intranasal DEX for sedation in children during EEG.

METHODS

This was a retrospective study. The inclusion criteria were children who underwent EEG from October 2016 to October 2018 at the Children's Hospital affiliated with Chongqing Medical University. All the children received 2.5 μg·kg^- 1 of intranasal DEX for sedation during the procedure. We used the Modified Observer Assessment of Alertness/Sedation Scale (MOAA/S) and the Modified Aldrete score (MAS) to evaluate the effects of the treatment on sedation and resuscitation. The sex, age, weight, American Society of Anesthesiologists physical status (ASAPS), vital signs, sedation onset and recovery times, sedation success rate, and adverse patient events were recorded.

RESULTS

A total of 3475 cases were collected and analysed in this study. The success rate of the initial dose was 87.0% (3024/3475 cases), and the success rate of intranasal sedation rescue was 60.8% (274/451 cases). The median sedation onset time was 19 mins (IQR: 17-22 min), and the sedation recovery time was 41 mins (IQR: 36-47 min). The total incidence of adverse events was 0.95% (33/3475 cases), and no serious adverse events occurred.

CONCLUSIONS

Intranasal DEX (2.5 μg·kg^- 1) can be safely and effectively used for EEG sedation in children.

Analgesic efficacy and impact of caudal block on surgical complications of hypospadias repair: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

is commonly used for children undergoing hypospadias repair. However, the safety of caudal block for hypospadias repair in children is controversial in terms of surgical complications such as urethrocutaneous fistula and glans dehiscence. We sought to perform a meta-analysis to estimate the analgesic efficacy and relative complications of caudal block for hypospadias repair in children.

METHODS

We identified comparative studies of caudal block versus peripheral nerve block or no caudal block; studies were published or presented through 1 January 2018, and reports of analgesic efficacy or surgical complications of hypospadias repair in children were identified. Peripheral nerve block includes dorsal nerve penile block and pudendal nerve block. Data were abstracted from studies comparing caudal block with peripheral nerve block or no caudal block; original source data were used when available. We prespecified separate assessments of randomized controlled trials (RCTs) and observational studies given the inherent differences between types of study designs. Data from 298 patients in four RCTs and from 1726 patients in seven observational studies were included. RCT and observational data were analyzed separately.

RESULTS

In RCTs, caudal blocks (compared with peripheral nerve blocks) showed no detectable differences in terms of need for additional analgesia within 24 hours after the surgery (OR 10.49; 95% CI 0.32 to 343.24; p=0.19), but limited data showed lower pain scores 24 hours after the surgery (standardized mean difference (SMD) 1.57; 95% CI 0.29 to 2.84; p=0.02), a significantly shorter duration of analgesia (SMD -3.33; 95% CI -4.18 to -2.48; p<0.0001) and analgesics consumption. No significant differences were observed in terms of postoperative nausea and vomiting (OR 3.08; 95% CI 0.12 to 77.80; p=0.50) or motor weakness (OR 0.01; 95% CI -0.03 to 0.05; p=0.56). Only one randomized study showed that caudal blocks (compared with peripheral nerve blocks) were associated with detectable differences in urethrocutaneous fistula rate (OR 25.27; 95% CI 1.37 to 465.01; p=0.03) and parental satisfaction rate (OR 0.07; 95% CI 0.02 to 0.21; p<0.00001). In observational studies, caudal block was not associated with surgical complications in all types of primary hypospadias repair (OR 1.83; 95% CI 0.80 to 4.16; p=0.15). To adjust for confounding factors and to eliminate potential selection bias involving caudal block indication, we performed subgroup analysis including only patients with distal hypospadias. This analysis revealed similar complication rates in children who received a caudal block and in children not receiving caudal block (OR 1.02; 95% CI, 0.39 to 2.65; p=0.96). This result further confirmed that caudal block was not a risk factor for surgical complications in hypospadias repair. The direction of outcomes in all the other subgroup analyses did not change, suggesting stability of our results.

CONCLUSIONS

In RCTs, only limited data showed peripheral nerve blocks providing better analgesic quality compared with caudal blocks. In real-world non-randomized observational studies with greater number of patients (but with admitted the potential for a presence of selection bias and residual confounders), caudal blocks were not associated with postoperative complications including urethrocutaneous fistula and glans dehiscence.

Effect of Intravenous Dexmedetomidine During General Anesthesia on Acute Postoperative Pain in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Dexmedetomidine has been shown to have an analgesic effect. However, no consensus was reached in previous studies.

METHODS

Electronic databases such as PubMed, Embase, and Cochrane Central were searched for relevant randomized controlled trials. The relative risk and weighted mean difference (WMD) were used to analyze the outcomes. Random-effects model was used for meta-analysis.

RESULTS

Compared with the normal saline group, patients using DEX showed a significantly decreased pain intensity within 6 hours [WMD=-0.93; 95% confidence interval (CI), -1.34 to -0.53) and at 24 hours after surgery (WMD=-0.47; 95% CI, -0.83 to -0.11). DEX usage significantly reduced the cumulative opioids consumption at 24 hours after surgery (WMD=-6.76; 95% CI, -10.16 to -3.35), decreased the rescue opioids consumption in postanesthesia care unit (WMD=-3.11; 95% CI, -5.20 to -1.03), reduced the risk of rescue analgesics (relative risk=0.49; 95% CI, 0.33-0.71), and the interval to first rescue analgesia was prolonged (WMD=34.93; 95% CI, 20.27-49.59).

CONCLUSIONS

Intravenous DEX effectively relieved the pain intensity, extended the pain-free period, and decreased the consumption of opioids during postoperative recovery of adults in general anesthesia.

Comparison of Dexmedetomidine and Morphine as Adjuvants to Bupivacaine for Epidural Anesthesia in Leg Fracture Surgery: A Randomized Clinical Trial

Background

Epidural block approach and drugs are common options for improving the sensory and motor block duration and postoperative pain management.

Objectives

The study aimed to compare the analgesic effects of dexmedetomidine and morphine as adjuvants to bupivacaine for epidural anesthesia in leg fracture surgery.

Methods

This prospective clinical trial was conducted on patients (n = 80, age range: 18 - 60 years) categorized as ASA class I or II. After a clinical examination, the patients were allocated to receive either lumbar epidural bupivacaine + morphine (BM) (12 mL bupivacaine 0.5% + morphine 2 mg) or bupivacaine + dexmedetomidine (BD) (12 mL bupivacaine 0.5% + dexmedetomidine 1 µg/kg). After drug administration, the sensory block level was assessed at 2-min intervals using the Cold Swab method until it reached the T12 level. At the T12 level of sensory block, the surgery began when motor block reached grade 3 of the modified Bromage scale.

Results

The BD group had a significantly shorter time to reach the sensory and motor block than the BM group (P < 0.001). The duration of sensory and motor block was significantly longer in the group BD than in the BM group (P < 0.001). Moreover, the BD group showed lower VAS scores (P < 0.0001) and longer time to first analgesia demand than the BM group.

Conclusions

Combined bupivacaine + dexmedetomidine prolongs the sensory and motor block duration and controls postoperative pain more effectively, indicating that it is an appropriate combination for epidural anesthesia.

Caudal epidural blocks in paediatric patients: a review and practical considerations

Caudal epidural blockade in children is one of the most widely administered techniques of regional anaesthesia. Recent clinical studies have answered major pharmacodynamic and pharmacokinetic questions, thus providing the scientific background for safe and effective blocks in daily clinical practice and demonstrating that patient selection can be expanded to range from extreme preterm births up to 50 kg of body weight. This narrative review discusses the main findings in the current literature with regard to patient selection (sub-umbilical vs mid-abdominal indications, contraindications, low-risk patients with spinal anomalies); anatomical considerations (access problems, age and body positioning, palpation for needle insertion); technical considerations (verification of needle position by ultrasound vs landmarks vs 'whoosh' or 'swoosh' testing); training and equipment requirements (learning curve, needle types, risk of tissue spreading); complications and safety (paediatric regional anaesthesia, caudal blocks); local anaesthetics (bupivacaine vs ropivacaine, risk of toxicity in children, management of toxic events); adjuvant drugs (clonidine, dexmedetomidine, opioids, ketamine); volume dosing (dermatomal reach, cranial rebound); caudally accessed lumbar or thoracic anaesthesia (contamination risk, verifying catheter placement); and postoperative pain. Caudal blocks are an efficient way to offer perioperative analgesia for painful sub-umbilical interventions. Performed on sedated children, they enable not only early ambulation, but also periprocedural haemodynamic stability and spontaneous breathing in patient groups at maximum risk of a difficult airway. These are important advantages over general anaesthesia, notably in preterm babies and in children with cardiopulmonary co-morbidities. Compared with other techniques of regional anaesthesia, a case for caudal blocks can still be made.

The Efficacy and Safety of Dexmedetomidine Combined with Bupivacaine on Caudal Epidural Block in Children: A Meta-Analysis

BACKGROUND This meta-analysis was conducted to evaluate the analgesics effect and safety of dexmedetomidine (DEX) combined with bupivacaine (BU) on caudal epidural block. MATERIAL AND METHODS Published studies were identified using the PubMed, EMBASE, Web of Science, and the Cochrane Library from inception until October 2017. Relative risk (RR), the standardized mean difference (SMD), and the corresponding 95% confidence interval (CI) were calculated using the STATA 12.0. RESULTS Ten randomized controlled trials (RCTs) were selected for this meta-analysis, involving a total of 691 patients. There was a longer duration of postoperative analgesia in children receiving DEX (SMD=3.19, 95% CI: 2.16-4.22, P<0.001). Furthermore, there was a lower number of patients requiring rescue analgesics in the (BU) + (DEX) group (6 hours: RR=0.09, 95% CI: 0.05-0.17, P<0.001; 12 hours: RR=0.50, 95% CI: 0.32-0.79, P=0.003; 24 hours: RR=0.66, 95% CI: 0.51-0.85, P=0.002). Finally, the occurrence of adverse events, between BU and DEX + BU group, was not statistically significant (RR=0.96, 95% CI: 0.58-1.58, P>0.05). CONCLUSIONS DEX seems to be a promising adjuvant to BU increase duration of caudal analgesia without an increase in side effects in children. However, the result may be influenced by clinical heterogeneity. More large-scale, multicenter, approaching, double-blinded RCTs are required to confirm our results.

Caudal and intravenous dexamethasone as an adjuvant to pediatric caudal block: A systematic review and meta-analysis

BACKGROUND

Dexamethasone has become a popular additive for regional anesthesia. The aim of this meta-analysis was to assess the effectiveness of this additive on the duration of postoperative analgesia, postoperative vomiting, and possible adverse events in pediatrics.

METHODS

We searched databases, conference records, and registered trials for randomized controlled trials. The databases included the Cochrane Library, JBI Database of Systematic Reviews, PubMed, ISI Web of Knowledge, Science-Direct, and Embase. Odds ratio, weighted mean difference, and the corresponding 95% confidence intervals were calculated using the REVMAN software, version 5.3, for data synthesis and statistical analysis, which following the PRISMA statement. The main outcomes were duration of postoperative analgesia (time from the end of surgery to first administration of analgesics as evidenced by a pain score) and postoperative vomiting.

RESULTS

Seven studies were selected for this meta-analysis, involving 647 pediatric patients. All the patients were randomized to receive caudal or intravenous dexamethasone with caudal block (experimental group) or plain caudal block (control group). There was significantly longer duration of postoperative analgesia in the experimental group compared with control group (weighted mean difference: 238.40 minutes; 95% CI: 193.41-283.40; P < .00001). The experimental group had fewer patients who needed analgesics after surgery (odds ratio: 0.18 minutes; 95% CI: 0.05-0.66; P = .009). Additionally, the number of subjects who remained pain-free to 2, 6, 24, and 48 hours after operation was significantly greater in the experimental group than control group. Side effects in these 2 groups were comparable (odds ratio: 0.94; 95% CI: 0.34-2.56; P = .90). The incidence of postoperative vomiting was significantly decreased in the experimental group compared with control group (odds ratio: 0.29; 95% CI: 0.13-0.63; P = .002).

CONCLUSION

Caudal and intravenous dexamethasone could provide longer duration of postoperative analgesia and reduced the incidence of postoperative vomiting with comparable adverse effects than plain caudal block. However, any additive to the caudal space carries with it the potential for neurotoxicity and that caution should always be exercised when weighting the risks and benefits of any additive. The result was influenced by small numbers of participants and significant heterogeneity.

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.

Effect of an Intravenous Dexamethasone Added to Caudal Local Anesthetics to Improve Postoperative Pain: A Systematic Review and Meta-analysis With Trial Sequential Analysis

BACKGROUND

Caudal anesthesia has been used for postoperative pain control in pediatric surgical patients, but the duration of the analgesic effect is occasionally unsatisfactory. Intravenous steroids have been shown to be effective for postsurgical pain management after certain surgeries. The aim of this meta-analysis with trial sequential analysis (TSA) was to evaluate the analgesic effect of steroids in patients administered with caudal anesthesia.

METHODS

This study was a systematic review and meta-analysis. A search of published literature was conducted in the MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases and in trial registration sites. Randomized controlled trials that compared intravenous steroids with a placebo in pediatric patients who had received caudal anesthesia for surgery were included in the study. The primary outcomes from the present meta-analysis were the analgesic duration and the number of patients who required rescue analgesics. The analgesic duration and incidence of rescue use were summarized using mean difference or risk ratio with a 97.5% confidence interval (CI), respectively. If the 97.5% CI of the mean difference or risk ratio included a value of 0 or 1, respectively, we considered the difference not to be significant. We used the random effects model to combine the results. Heterogeneity was quantified with the I statistic. The quality of the trials was evaluated using the Cochrane methodology. Moreover, a TSA with a risk of type 1 error of 2.5% and power of 90% was performed. We established the minimum clinically meaningful difference of analgesic duration as 3 hours. The target sample size for meta-analysis was also calculated in the TSA. We also assessed adverse events.

RESULTS

Six trials with 424 patients were included; 211 patients received intravenous steroids. All trials compared dexamethasone of at least 0.5 mg/kg dose with a placebo. Dexamethasone prolonged the duration of caudal analgesia (mean difference, 244 minutes; 97.5% CI, 188-300). Heterogeneity was considerable with an I value of 94.8%. Quality of evidence was very low. The TSA suggested that only 17.0% of the target sample size had been reached, but the cumulative Z score crossed the trial sequential monitoring boundary to indicate a benefit. Rescue use was reported in 4 studies with 260 patients. Rescue use was not significantly reduced in the dexamethasone group (risk ratio, 0.53; 97.5% CI, 0.09-3.30; I, 98.7%). No increase in adverse events was reported.

CONCLUSIONS

Intravenous dexamethasone prolongs the analgesic duration of caudal anesthesia. Trials to investigate the effectiveness of a lower dose of the dexamethasone in prolonging analgesic effects would be of interest. Further trials with a low risk of bias are necessary.

Interventions for postoperative pain in children: An overview of systematic reviews

The aim of this study was to conduct an overview of systematic reviews that summarizes the results about efficacy and safety from randomized controlled trials involving the various strategies used for postoperative pain management in children. We searched the Cochrane Database of Systematic Reviews, CINAHL, Database of Reviews of Effect, Embase, MEDLINE, and PsycINFO from the earliest date to January 24, 2016. This overview included 45 systematic reviews that evaluated interventions for postoperative pain in children. Out of 45 systematic reviews that investigated various interventions for postoperative pain in children, 19 systematic reviews (42%) presented conclusive evidence of efficacy. Positive conclusive evidence was reported in 18 systematic reviews (40%) for the efficacy of diclofenac, ketamine, caudal analgesia, dexmedetomidine, music therapy, corticosteroid, epidural analgesia, paracetamol, and/or nonsteroidal anti-inflammatory drugs and transversus abdominis plane block. Only one systematic review reported conclusive evidence of equal efficacy that involved a comparison of dexmedetomidine vs morphine and fentanyl. Safety of interventions was reported as conclusive in 14 systematic reviews (31%), with positive conclusive evidence for dexmedetomidine, corticosteroid, epidural analgesia, transversus abdominis plane block, and clonidine. Seven systematic reviews reported equal conclusive safety for epidural infusion, diclofenac intravenous vs ketamine added to opioid analgesia, bupivacaine, ketamine, paracetamol, and dexmedetomidine vs intravenous infusions of various opioid analgesics, oral suspension and suppository of diclofenac, only opioid, normal saline, no treatment, placebo, and midazolam. Negative conclusive statement for safety was reported in one systematic review for caudal analgesia vs noncaudal regional analgesia. More than half of systematic reviews included in this overview were rated as having medium methodological quality. Of 45 included systematic reviews, 10 were Cochrane reviews and they had higher methodological quality than non-Cochrane reviews. As evidence concerning efficacy and safety is inconclusive for most of the analyzed interventions, our review points out the need for more rigorous trials concerning pain management in children.

Comparison of Dexmedetomidine and Fentanyl as an Adjuvant to Ropivacaine for Postoperative Epidural Analgesia in Pediatric Orthopedic Surgery

PURPOSE

Opioids are commonly used as an epidural adjuvant to local anesthetics, but are associated with potentially serious side effects, such as respiratory depression. The aim of this study was to compare the efficacy and safety of dexmedetomidine with that of fentanyl as an adjuvant to epidural ropivacaine in pediatric orthopedic surgery.

MATERIALS AND METHODS

This study enrolled 60 children (3-12 years old) scheduled for orthopedic surgery of the lower extremities and lumbar epidural patient-controlled analgesia (PCA). Children received either dexmedetomidine (1 μg/kg) or fentanyl (1 μg/kg) along with 0.2% ropivacaine (0.2 mL/kg) via an epidural catheter at 30 minutes before the end of surgery. Postoperatively, the children were observed for ropivacaine consumption via epidural PCA, postoperative pain intensity, need for rescue analgesics, emergence agitation, and other adverse effects.

RESULTS

The mean dose of bolus epidural ropivacaine was significantly lower within the first 6 h after surgery in the dexmedetomidine group, compared with the fentanyl group (0.029±0.030 mg/kg/h vs. 0.053±0.039 mg/kg/h, p=0.012). The median pain score at postoperative 6 h was also lower in the dexmedetomidine group, compared to the fentanyl group [0 (0-1.0) vs. 1.0 (0-3.0), p=0.039]. However, there was no difference in the need for rescue analgesia throughout the study period between groups.

CONCLUSION

The use of dexmedetomidine as an epidural adjuvant had a significantly greater analgesic and local anesthetic-sparing effect, compared to fentanyl, in the early postoperative period in children undergoing major orthopedic lower extremity surgery.

Effects of dexmedetomidine versus midazolam for premedication in paediatric anaesthesia with sevoflurane: A meta-analysis

Background Dexmedetomidine (DEX), an α₂-adrenergic receptor agonist, produces ideal sedation and early postoperative recovery for premedication in paediatric surgery, reducing preoperative anxiety and facilitating smooth induction of anaesthesia. We performed a meta-analysis to compare the effects of DEX and midazolam (MDZ) in paediatric anaesthesia with sevoflurane. Methods PubMed, Ovid, Web of Science, and Public Health Management Corporation were searched through December 2016 for randomized controlled trials (RCTs) that compared DEX and MDZ in children undergoing sevoflurane anaesthesia. The risk ratio (RR) with 95% incidence interval (95%CI) was used for dichotomous variables. Results Twelve RCTs involving 422 patients in the DEX group and 448 patients in the MDZ group were included. Patients in the DEX group had a significantly lower incidence of unsatisfactory sedation (RR [95%CI] = 0.71 [0.57-0.89]), unsatisfactory parental separation (RR [95%CI] = 0.56 [0.35-0.87]), and rescue analgesia (RR [95%CI] = 0.52 [0.35-0.77]) than patients in the MDZ group. However, both groups had a similar incidence of unsatisfactory mask acceptance, emergence agitation, and postoperative nausea and vomiting. Conclusion Compared with MDZ, DEX is beneficial in paediatric anaesthesia with sevoflurane because of its lower incidence of unsatisfactory sedation, parental separation, and rescue analgesia.

Effect of dexmedetomidine as an adjuvant to bupivacaine in femoral nerve block for perioperative analgesia in patients undergoing total knee replacement arthroplasty: A dose-response study

Context:

Dexmedetomidine is being increasingly used in nerve blocks. However, there are only a few dose determination studies.

Aims:

To compare two doses of dexmedetomidine, in femoral nerve block, for postoperative analgesia after total knee arthroplasty (TKA).

Settings and Design:

A prospective, randomized, controlled trial was conducted in the Department of Anesthesia at AIIMS, a Tertiary Care Hospital.

Materials and Methods:

Sixty American Society of Anesthesiologists I–II patients undergoing TKA under subarachnoid block were randomized to three Groups A, B, and C. Control Group A received 20 ml (0.25%) of bupivacaine in femoral nerve block. Groups B and C received 1 and 2 μg/kg dexmedetomidine along with bupivacaine for the block, respectively. Outcomes measured were analgesic efficacy measured in terms of visual analog scale (VAS) score at rest and passive motion, duration of postoperative analgesia, and postoperative morphine consumption. Adverse effects of dexmedetomidine were also studied.

Statistical Analysis Used:

All qualitative data were analyzed using Chi-square test and VAS scores using Kruskal–Wallis test. Comparison of patient-controlled analgesia (PCA) morphine consumption and time to first use of PCA were done using ANOVA followed by Least Significant Difference test. A P < 0.05 was considered statistically significant.

Results:

The VAS score at rest was significantly lower in Group C compared to Groups A and B (P < 0.05). There was no difference in VAS score at motion between Groups B and C. The mean duration of analgesia was significantly longer in Group C (6.66 h) compared to Groups A (4.55 h) and B (5.70 h). Postoperative mean morphine consumption was significantly lower in Group C (22.85 mg) compared to Group A (32.15 mg) but was comparable to Group B (27.05 mg). There was no significant difference in adverse effects between the groups.

Conclusion:

The use of dexmedetomidine at 2 μg/kg dose in femoral nerve block is superior to 1 μg/kg for providing analgesia after TKA, although its role in facilitating early ambulation needs further evaluation.

Comparison between two doses of dexmedetomidine added to bupivacaine for caudal analgesia in paediatric infraumbilical surgeries

Background and Aims:

Caudal block (CB) with adjuvants is routinely used in children for anaesthesia. We evaluated the efficacy of the α2 adrenergic agonist, dexmedetomidine at two different doses as an adjuvant to bupivacaine in CB.

Methods:

This study was conducted on ninety children. Control group BD0 received 0.25% bupivacaine 1 ml/kg, whereas, the study groups BD1 and BD2 received 1 μg/kg and 2 μg/kg dexmedetomidine, respectively, with 0.25% bupivacaine 1 ml/kg as a single shot CB. Adequacy of the block, haemodynamic changes, duration of analgesia and side effects were compared. Analysis of Variance was used for between-group comparisons of numerical variables. Student's t-test and Mann–Whitney U-test were used for quantitative data.

Results:

The demography was comparable. Anal sphincter 5 min after administration of the CB was relaxed in 89.3%, 82.1% and 75% of cases in BD0, BD1 and BD2 groups, respectively. The sphincter was relaxed at the end of surgery in all the cases. Comparable haemodynamics was noted with significantly prolonged duration of analgesia in the groups BD1 (964.2 ± 309 min) and BD2 (1152.6 ± 380.4 min) compared to control (444.6 ± 179.4 min). While no complications were encountered in groups BD0 and BD1, bradycardia was observed in four cases of BD2 group with accompanied hypotension in one of them.

Conclusion:

Dexmedetomidine as an adjuvant to bupivacaine improves the quality of CB, provides good operating conditions and increases the duration of post-operative analgesia. We conclude that 1 μg/kg is as effective as 2 μg/kg of dexmedetomidine and with a better safety profile.

Dexmedetomidine as an adjuvant to bupivacaine in caudal analgesia in children

Context:

Postoperative pain management is becoming an integral part of anesthesia care. Various techniques of pediatric pain relief have been designed among which the most commonly practiced is caudal epidural block. Several adjuvants have been used to prolong the duration of caudal analgesia such as clonidine, neostigmine, ketamine, opioids, and ephedrine. We have designed the study using dexmedetomidine as an adjuvant to assess analgesic efficacy, duration of postoperative analgesia, hemodynamic stability, postoperative sedation, and any adverse effects in children.

Aims:

The aim is to study the effects of dexmedetomidine as an adjuvant to bupivacaine in caudal analgesia in pediatric patients posted for infraumbilical surgeries.

Settings and Design:

This is a randomized, double-blind study in which effect of dexmedetomidine is studied when added to bupivacaine in the caudal epidural block. The observations are made intraoperatively for hemodynamic stability and postoperatively for the duration of analgesia.

Subjects and Methods:

This study was conducted in 100 children of American Society of Anesthesiologists physical status I and II, aged 2–10 years, undergoing elective infraumbilical surgeries. They were divided into two groups as follows: Group A: (0.25%) bupivacaine 1 ml/kg + normal saline (NS) 1 ml. Group B: (0.25%) bupivacaine 1 ml/kg + 1 μg/kg dexmedetomidine in 1 ml NS. As this study was double-blind, patients were randomly assigned to receive either (bupivacaine + saline) or (bupivacaine + dexmedetomidine) in each group. The patients were observed for hemodynamic stability, respiratory depression, and postoperative pain using face, legs, activity, cry, consolability (FLACC) pain scale for 24 h postoperatively.

Statistical Analysis Used:

Unpaired Student's t-test.

Results:

The mean duration of effective analgesia in Group A patients was 4.33 ± 0.98 h versus 9.88 ± 0.90 h in Group B patients. Likewise, the difference in mean FLACC score of both the groups was also statistically significant, 7.21 ± 0.76 and 6.49 ± 1.72 in Group A and Group B, respectively.

Conclusion:

Dexmedetomidine as adjuvant to Bupivacaine increases duration of caudal analgesia and improves hemodynamic stability without an increase in adverse effects in children undergoing infraumbilical surgeries.

Alpha-2 adrenoceptor agonists as adjuncts to peripheral nerve blocks in children: a meta-analysis

BACKGROUND

Adult meta-analyses have verified that adjunct use of alpha-2 adrenoceptor agonists (A2AA) together with local anesthetics (LA) will prolong the duration of peripheral nerve blocks. The standard use of A2AAs for peripheral nerve blockade has recently been recommended also in children, but the evidence base in support of this suggestion has to date been equivocal. The purpose of this meta-analysis was to produce evidence-based data regarding the effect in children.

METHODS

Following a thorough literature search, five randomized controlled trials were included in a meta-analysis. Raw data from all studies were gathered and aggregated into patients randomized to receive plain LA (Group PLA) or LA mixed with either adjunct clonidine or dexmedetomidine (Group ADJ). The main outcome parameter was block duration (time to first administration of supplemental analgesic based on predetermined pain scores) analyzed by survival statistics. The total number of supplemental analgesic doses during the first 24 postoperative hours and serious side effects were included as secondary outcomes.

RESULTS

Pooling of the study data generated 141 patients in Group PLA and 142 patients in Group ADJ (overall n = 283; age: 0.8-13 years; weight 8-47 kg). Block duration was significantly prolonged (9.75 h vs 3.75 h) compared to the use of plain LA. Survival statistics verified a beneficial effect of using adjunct A2AAs [the log rank (Mantel-Cox) test (P = 0.0078), Gehan-Breslow-Wilcoxon test (P = 0.0027), and hazard ratio (1.653; 95% CI: 1.142 to 2.395)]. The number of patients that needed ≥ 2 doses of supplemental analgesics was higher in Group PLA (n = 19) compared to Group ADJ (n = 6) (P = 0.0088). No serious side effects were reported.

CONCLUSION

This meta-analysis provides evidence-based support for the use of adjunct alpha-2 adrenoceptor agonists when performing peripheral nerve blocks in children.

Single Shot Adductor Canal Block for Postoperative Analgesia of Pediatric Patellar Dislocation Surgery: A Case-Series Report

Postoperative analgesia for the knee surgery in children can be challenging. Meanwhile acute pain management in pediatric patients is still often undertreated due to inadequate pain assessment or management. We reported the ultrasound-guided single-injection adductor canal block (ACB) with 0.2% ropivacaine and dexmedetomidine (0.5 μg/kg) in addition in a series of 6 children. Patients' age was range from 7 to 15 years old with right or left habitual patellar dislocation needing an open reduction and internal refixation. Pain assessments using Numeric Rating Scale scores on the operative limb were made preoperatively and at 12, 24, 36, and 48 h postoperatively at rest. Medication consumption was calculated as well. The possible complications, such as hemodynamic changes, nausea, vomiting, and dysesthesia, were also recorded at 12, 24, 36, and 48 h postoperatively at rest. The pain scores were low, and analgesic medication consumption was minimal. Meanwhile, no adverse events were recorded in any of the subject. Single-injection ACB might be an optimal analgesia strategy for patellar dislocation surgery in pediatric patients.

Comparison of caudal bupivacaine alone with bupivacaine plus two doses of dexmedetomidine for postoperative analgesia in pediatric patients undergoing infra-umbilical surgery: a randomized controlled double-blinded study

BACKGROUND

Data are still insufficient about the effects of different concentrations of caudal dexmedetomidine when used to prolong postoperative analgesia in children. The aim of this study was to assess the analgesic efficacy and side effects of two doses of caudal dexmedetomidine (1 and 2 μg·kg(-1)) co-administered with bupivacaine in terms of postoperative pain scores and requirement of postoperative analgesia over 24 h in children undergoing infra-umbilical surgery.

METHODS

Ninety-one children, aged 1-6 years, undergoing infra-umbilical surgery were included and randomly allocated into three groups of caudal block. Group B received 0.25% bupivacaine 2 mg·kg(-1) (0.8 ml·kg(-1)). Groups BD1 and BD2 received dexmedetomidine 1 and 2 μg·kg(-1), respectively along with bupivacaine 2 mg·kg(-1) in a total volume of 0.8 ml·kg(-1). Anesthesia was induced and maintained with sevoflurane in 100% oxygen. Hemodynamic and other routine intraoperative monitoring was carried out in addition to endtidal sevoflurane concentration. Time to spontaneous eye opening and postoperative pain and sedation scores were recorded in addition to time to first analgesia, paracetamol analgesic requirements, and any side effects during the first 24 postoperative hours.

RESULTS

Time to first analgesia requirement was significantly longer in BD1 and BD2 groups compared to B group with mean values (95% CI) of 809 min (652-965), 880 (733-1026), and 396 (343-448), respectively, P < 0.001. Postoperative paracetamol analgesic requirements over 24 h were higher in group B compared to BD1 and BD2 groups (Mean (95% CI): 3.2 (2.9-3.5) doses, 1.9 (1.5-2.3), and 1.6 (1.3-1.9), respectively), P < 0.001. The dexmedetomidine groups had significantly higher postoperative sedation scores compared to plain bupivacaine group that were dose dependent and for longer time in BD2 group. Two patients in BD2 group developed bradycardia and hypotension, and one developed urine retention compared to none in other groups.

CONCLUSION

A 1 μg·kg(-1) dose of caudal dexmedetomidine achieved comparable prolongation of postoperative analgesia to 2 μg·kg(-1) dose, with shorter duration of postoperative sedation and lower incidence of other side effects.