Comparison of caudal ropivacaine, ropivacaine plus ketamine and ropivacaine plus tramadol administration for postoperative analgesia in children

Comparison of adjuvant pharmaceuticals for caudal block in pediatric lower abdominal and urological surgeries: A network meta-analysis

STUDY OBJECTIVE

Caudal block helps relieve pain after sub-umbilical surgery in pediatric patients; however, the duration for which it exerts its analgesic effect is limited. The addition of certain adjuvant agents to local anesthetics (LAs) that are used to administer caudal block can prolong postoperative analgesia. Therefore, we aimed to compare the efficiencies and side effects of caudal adjuvants in the settings of pediatric lower abdominal and urological surgeries.

DESIGN

A network meta-analysis (NMA).

PATIENTS

One hundred and twelve randomized controlled trials (RCTs) involving 6800 pediatric patients were included in the final analysis.

INTERVENTIONS

Different adjuvant agents, namely clonidine, dexamethasone, dexmedetomidine, fentanyl, ketamine, magnesium, midazolam, morphine, neostigmine, and tramadol.

MEASUREMENTS

The primary outcome was the duration of analgesia. The secondary outcomes included the requirement for additional analgesia, analgesic consumption, and postoperative complications. The effects and rankings were evaluated using NMA and the surface under the cumulative ranking curve scores, respectively.

RESULTS

Neostigmine, dexmedetomidine, and dexamethasone were found to be the three most effective adjuvants that prolong the duration of analgesia for caudal block, and these adjuvants extended this duration by 8.9 h (95% confidence interval [CI], 7.1-10.7), 7.3 h (95% CI, 6.0-8.6), and 5.9 h (95% CI, 4.0-7.7), respectively. Caudal neostigmine was associated with an increase in the incidence of postoperative nausea and vomiting, whereas dexmedetomidine and dexamethasone showed no postoperative complications.

CONCLUSIONS

This NMA provided evidence and suggested that dexmedetomidine and dexamethasone may be the most beneficial adjuvant pharmaceutics adding to LAs for caudal block in children. However, given the off-label status of caudal dexmedetomidine and dexamethasone, further high-quality RCTs are still warranted, especially to determine whether delayed neurological complications will occur.

Postoperative Pain Management: Efficacy of Caudal Tramadol in Pediatric Lower Abdominal Surgery: A Randomized Clinical Study

BACKGROUND

One of the methods of pain control after pediatric surgical procedures is regional techniques, including caudal block, despite their limitations.

OBJECTIVES

In this study, the pain score and complications of caudal tramadol were evaluated in pediatrics following lower abdominal surgery.

METHODS

In this study, 46 children aged 3 to 10 years were allocated into two equal groups (R and TR) for performing caudal analgesia after lower abdominal surgery. The injectate contained 0.2% ropivacaine 1 mL/kg in the R group (control group) and tramadol (2 mg/kg) and ropivacaine in the TR group. The pain score, duration of pain relief, amount of paracetamol consumption, hemodynamic alterations, and possible complications at specific times (1, 2, and 6 hours) were evaluated in both groups.

RESULTS

No considerable difference was observed in the pain score between the groups in the first and second hours (P > 0.05). However, in the sixth hour, the TR group had a significantly lower pain score than the R group (P < 0.05). Compared to the R group, the TR group had a longer period of analgesia and lower consumption of analgesic drugs (P < 0.05). Heart rate and blood pressure differences were not significant between the two groups (P > 0.05). Similarly, the duration of operation and recovery time were not remarkably different between the two groups (P > 0.05). Complications had no apparent differences between these two groups, as well (P > 0.05).

CONCLUSIONS

In this study, the addition of tramadol to caudal ropivacaine in pediatric lower abdominal surgery promoted pain relief without complications.

Comparison of Analgesic Efficacy of Dexamethasone versus Tramadol in Combination with Ropivacaine in Caudal Anesthesia for Children Undergoing Lower Abdominal Surgeries

Background:

Caudal anesthesia has emerged as a reliable and effective anesthetic technique in the pediatric age group. However, the limited duration of action of the local anesthetic drugs proves to one of the major hindrances in the complete utilization of caudal block as an effective analgesic technique. To overcome this shortcoming, adjuvant drugs were introduced into clinical practice.

Aim:

Our aim was to determine which of the two drugs – dexamethasone and tramadol – serves as a better adjuvant for caudal analgesia in pediatric patients.

Settings and Design:

This was a prospective, randomized, double-blind study that comprised 90 American Society of Anesthesiologist (ASA) physical status I and II pediatric patients posted for lower abdominal surgeries.

Materials and Methods:

Ninety ASA physical status I and II children aged 5–12 years posted for lower abdominal surgeries were chosen. They were randomly divided into three groups – Group R received 0.5 ml.kg⁻¹ of 0.2% ropivacaine plus 0.9% normal saline; Group T received 0.5 ml.kg⁻¹ of 0.2% ropivacaine plus 2 mg.kg⁻¹ tramadol; and Group D received 0.5 ml.kg⁻¹ of 0.2% ropivacaine plus 0.1 mg.kg⁻¹ dexamethasone. Postoperative pain was assessed using a modified objective pain score and time to first rescue analgesia (duration of sensory block) was recorded. Postoperative sedation and any other postoperative adverse effects were noted.

Statistical Analysis:

Student's independent t-test was employed for comparing continuous variables and Chi-square test for categorical variables. Kruskal–Wallis test was used for postoperative pain and sedation score data.

Results:

The duration of sensory block was significantly longer with dexamethasone than tramadol. No significant postoperative sedation or any other adverse effect was noted in any patient.

Conclusion:

Dexamethasone is superior to tramadol as an adjuvant to ropivacaine for pediatric lower abdominal surgeries.

Effect of morphine and a low dose of ketamine on the T cells of patients with refractory cancer pain in vitro

The combination of morphine and ketamine is considered safe and efficacious in many patients. However, a considerable number of immunomodulatory effects have been reported to be produced by both morphine and ketamine. The aim of the present study was to assess the direct effect of morphine and a low dose of ketamine on the T cells of patients with refractory cancer pain in vitro. Venous blood was obtained from patients with refractory cancer pain and peripheral blood mononuclear cells were isolated using the Ficoll-Hypaque density gradient method. Anti-CD3 beads were used to isolate T cells by positive selection. Subsequently, the T cells were treated with vehicle, 200 ng/ml of morphine or 200 ng/ml of morphine + 100 ng/ml ketamine for 24 h, following which the cells were stimulated with anti-CD3 and anti-CD28. Flow cytometric analysis of CD3⁺ T cells, and interleukin (IL)-2 and interferon (IFN)-γ in the supernatant, reverse transcription-quantitative PCR analysis for the detection of IL-2 and IFN-γ and western blotting for the detection of p65 nuclear factor (NF)-κB were performed. In vitro, the CD4⁺ and CD8⁺ T cell counts, CD4⁺/CD8⁺ ratio, secretion of IL-2 and IFN-γ in the supernatant, mRNA expression levels of IL-2 and IFN-γ and expression of p65 NF-κB were significantly decreased following treatment with morphine and morphine + ketamine, compared with results in the control group (all P<0.05). However, there was no significant difference between treatment with morphine and that with morphine + ketamine. Treatment with morphine + ketamine in vitro decreased the immune functions of patients with refractory cancer pain, although the effect of treatment with morphine and a low dose of ketamine did not differ significantly from that with morphine treatment alone.

Efficacy of Double Drug Impregnated Autologous Coagulum Patch versus Single Drug Impregnated Autologous Coagulum Patch in Postoperative Pain Management after Spinal Surgery

Background:

Postoperative pain and cerebrospinal fluid (CSF) leak are common known complications of spinal surgery, both having a synergistic effect on each other. Thus, both need to be dealt simultaneously. Double drug impregnated autologous coagulum patch (DDIAC) is a novel method which reduced both incidences of postoperative CSF leaks as well as pain.

Methodology:

Twenty-seven patients undergoing lumbar disc surgery without instrumentation were included and randomized into DDIAC and single drug impregnated autologous coagulum patch (SDIAC) group. The patients were assessed postoperatively with visual analog scale (VAS).

Results:

There were 21 males and 6 females in the study. Seventeen (63%) patients got randomized for DDIAC patch application and other 10 (37%) patients entered the control arm group (SDIAC) patch use. Preoperative VAS was 5 in both the groups. The average postoperative VAS was 3.01 in DDIAC arm and 4.29 in control arm. The average analgesic shot required in the DDIAC group was 0.41 in 24 h and SDIAC group was 4.1 in 24 h. In DDIAC group, none of these patients had CSF leak from the surgical wound till discharge from the hospital. In the SDIAC group, one (10%, n = 10) patient had CSF leak.

Conclusions:

DDIAC patch was effective in controlling pain in the postoperative period; however, few patients may require analgesic shots for pain management. SDIAC patch may control some pain in the immediate postoperative period; however, this was not sufficient for a longer postoperative period.

Comparison of analgesic efficacy of caudal dexmedetomidine versus caudal tramadol with ropivacaine in paediatric infraumbilical surgeries: A prospective, randomised, double-blinded clinical study

Background and Aims:

Caudal epidural analgesia is commonly practised regional block technique in children undergoing infraumbilical surgeries but has a short duration of action after single shot local anaesthetic injection. The aim of this study was to compare ropivacaine 0.25% with dexmedetomidine and tramadol in caudal anaesthesia in paediatric infraumbilical surgeries.

Methods:

In a randomised, prospective, double-blinded study, sixty children (1–8 years) belonging to American Society of Anesthesiologists’ physical status I or II scheduled for infraumbilical surgeries were included. They were randomly assigned into two groups: Group ropivacaine with tramadol (RT) (n = 30) received 0.25% ropivacaine 1 mL/kg with 2 mg/kg of tramadol, and Group ropivacaine with dexmedetomidine (RD) (n = 30) received 0.25% ropivacaine 1 mL/kg with dexmedetomidine 2 μg/kg. The primary outcome variable was the duration of analgesia, and the secondary outcome variables included motor block, sedation score, time from caudal block to skin incision, emergence time and adverse effects.

Results:

The mean duration of analgesia was 654.20 ± 78.38 min in Group RT, while in Group RD, it was 780.29 ± 71.21 min (P = 0.0001). The difference between the mean sedation score and mean emergence time between the two groups were statistically significant (P = 0.0001 and 0.0411, respectively). No significant difference was observed in the incidence of haemodynamic changes or side effects.

Conclusion:

Caudal dexmedetomidine with ropivacaine prolongs post-operative analgesia compared to caudal tramadol with ropivacaine.

Adjuvants in pediatric regional anesthesia

SUMMARY Local anesthetics have a limited duration of action. Adjuvants are used to prolong the duration of action and to augment analgesia allowing lower concentrations of local anesthetic to be used. Adjuvants have been used more extensively with neuraxial blocks, particularly caudal epidural blocks, but more recently to supplement peripheral nerve blocks. Intrathecal adjuvants are not covered in this review since spinal anesthesia is not widely used in children except in ex-premature infants. Morphine is the historical gold-standard with which other adjuvants are compared. Clonidine is most useful and is becoming increasingly popular, while the side-effect profile of other agents reduces their utility. Concerns with regard to the neurotoxicity of ketamine in animal models has led to its withdrawal in some countries.

Bayesian enhanced meta-analysis of post-operative analgesic efficacy of additives for caudal analgesia in children

BACKGROUND

The authors calculated the effect size for post-operative analgesia of three additives, clonidine, neostigmine, and tramadol to bupivacaine, ropivacaine, or levobupivacaine used for single-dose caudal extradural blockade in children.

METHODS

A meta-analysis was performed for three end points of efficacy: the increase of time until administration of analgesic drugs, the proportion of patients requiring analgesic drugs during the initial 24 post-operative hours, and the amounts of post-operative analgesic drugs. A Bayesian inference supporting direct statements about the probability of the magnitude of an effect was used to compare the effects size.

RESULTS

Neostigmine increased the duration of analgesia by 9.96 h (95% confidence interval: 7.75 to 12.16), as compared with 3.68 h (2.65 to 4.7) with clonidine and 4.45 (2.84 to 6.07) with tramadol. There is a 95% probability that neostigmine increases the duration of post-operative analgesia by more than 8 h, clonidine by more than 2.8 h, and tramadol by more than 3.25 h, as compared with local anesthetics alone. The odds ratios for the proportion of patients requiring analgesic drugs were 0.22 [0.13 to 0.37] for clonidine and 0.28 [0.10 to 0.75] for neostigmine. With tramadol, there was no statistically significant difference. All three additives reduced the amounts of post-operative analgesic drugs. Neostigmine and tramadol increase the probability for post-operative nausea or vomiting (PONV).

CONCLUSIONS

Neostigmine provides the longest post-operative analgesia. With clonidine, the duration of analgesia is shorter and sedation is increased, but the probability for PONV could be decreased.

Percutaneous sciatic nerve block with tramadol induces analgesia and motor blockade in two animal pain models

Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics.

Efficacy and adverse effects of ketamine as an additive for paediatric caudal anaesthesia: a quantitative systematic review of randomized controlled trials

BACKGROUND

The aim of this quantitative systematic review was to assess the efficacy and adverse effects of ketamine added to caudal local anaesthetics in comparison with local anaesthetics alone in children undergoing urological, lower abdominal, or lower limb surgery.

METHODS

The systematic search, data extraction, critical appraisal, and pooled data analysis were performed according to the PRISMA statement. All randomized controlled trials (RCTs) were included in this meta-analysis and relative risk (RR), mean difference (MD), and the corresponding 95% confidence intervals (CIs) were calculated using the Revman(®) statistical software for dichotomous and continuous outcomes.

RESULTS

Thirteen RCTs (published between 1991 and 2008) including 584 patients met the inclusion criteria. There was a significant longer time to first analgesic requirements in patients receiving ketamine in addition to a local anaesthetic compared with a local anaesthetic alone (MD: 5.60 h; 95% CI: 5.45-5.76; P<0.00001). There was a lower RR for the need of rescue analgesia in children receiving a caudal regional anaesthesia with ketamine in addition to local anaesthetics (RR: 0.71; 95% CI: 0.44-1.15; P=0.16).

CONCLUSIONS

Caudally administered ketamine, in addition to a local anaesthetic, provides prolonged postoperative analgesia with few adverse effects compared with local anaesthetics alone. There is a clear benefit of caudal ketamine, but the uncertainties about neurotoxicity relating to the dose of ketamine, single vs repeated doses and the child's age, still need to be clarified for use in clinical practice.

Persistent hiccups associated with epidural ropivacaine in a newborn

OBJECTIVE

To report a case of persistent hiccups associated with epidural ropivacaine in a newborn infant.

CASE SUMMARY

A term female infant (3.05 kg) received epidural ropivacaine for pain control during and after an operative procedure to correct a tracheoesophageal fistula. Three intermittent doses of ropivacaine were administered during the operative period (total dose 2.29 mg/kg) followed by a continuous epidural (caudal) infusion (0.1% ropivacaine; initial dose 0.23 mg/kg/h plus fentanyl 0.46 μg/kg/h). The infant was extubated in the recovery area and transferred to the intensive care unit. Within hours of transfer, she developed persistent hiccups. The epidural infusion was titrated for pain control, up to 0.32 mg/kg/h (ropivacaine). The hiccup frequency increased to every 10-30 seconds, with the patient appearing hypotonic with lip trembling and intermittent tongue fasciculation. An electroencephalogram did not show any epileptiform activity or focal features consistent with seizure activity. The epidural infusion was reduced to 0.26 mg/kg/h (ropivacaine), with dramatic improvement in hiccups and tone. The infusion was discontinued and complete resolution of hiccups was observed.

DISCUSSION

Ropivacaine is commonly used for infiltration anesthesia and peripheral and epidural block anesthesia. Use of the Naranjo probability scale determined that our patient's hiccups were probably caused by ropivacaine. To our knowledge, this is the first report of persistent hiccups associated with epidural ropivacaine.

CONCLUSIONS

Clinicians should consider the potential of neurotoxicity, manifested as persistent hiccups, when epidural ropivacaine is administered to young infants.

Ketamine for perioperative pain management in children: a meta-analysis of published studies

INTRODUCTION

Balanced analgesia, using both opioid and nonopioids agents, has become the standard care for postoperative pain management. Ketamine, a compound with analgesic and antihyperalgesic properties, has been shown to decrease postoperative pain and opioid requirements in adults. The goal of the present meta-analysis was to investigate postoperative analgesic properties of ketamine in pediatric patients.

MATERIAL AND METHODS

A comprehensive literature search was conducted to identify clinical trials that used ketamine as a perioperative analgesic compound in children and infants. Outcomes measured were postoperative analgesic consumption, pain intensity and duration of sensory block (when ketamine was used by caudal route) during the postoperative care unit (PACU) stay and the early postoperative period (6-24 h after leaving the operative room). The data from each trial were combined to calculate the pooled odds ratios or standard mean differences and their 95% confidence intervals.

RESULTS

Thirty-five randomized, blinded controlled studies were retrieved from the literature. Systemic ketamine was effective in decreasing PACU pain intensity and analgesic requirement but failed to influence early (6-24 h) pain intensity and analgesic requirement. Ketamine administered locally during tonsillectomy, decreased PACU and early (6-24 h) pain intensity and PACU analgesic requirements. Used as an adjuvant for caudal analgesia, ketamine increased the duration of sensory block and PACU analgesic requirement without impacting PACU pain intensity. Ketamine failed to exhibit a postoperative opioid-sparing effect.

CONCLUSIONS

This meta-analysis found that administration of ketamine was associated with decreased PACU postoperative pain intensity and nonopioid analgesic requirement. However, ketamine failed to exhibit a postoperative opioid-sparing effect.

Epidural ropivacaine versus ropivacaine plus tramadol in postoperative analgesia in children undergoing major abdominal surgery: a comparison

PURPOSE

In this study, we aimed to compare the effects of ropivacaine alone and ropivacaine plus tramadol administered epidurally for postoperative analgesia in children.

METHODS

Following Ethics Committee approval and informed parent consent, 44 children aged between 2 and 12 years, with ASA physical status I or II, who were undergoing major abdominal surgery were included in the study. Following tracheal intubation, patients were placed into lateral decubitus position and an epidural catheter (22-24 G) was inserted by using a Tuohy needle. Patients were randomly divided into two groups to receive either ropivacaine alone (0.2%), 0.7 ml/kg, in group I, or ropivacaine (0.2%) plus tramadol (2 mg/kg), with total volume 0.7 ml/kg, in group II, epidurally in both groups. Hemodynamic variables, pain and sedation scores, duration of analgesia, and side effects were recorded postoperatively.

RESULTS

The duration of analgesia was significantly longer in group RT than in group R (298.6 ± 28 and 867.9 ± 106.8 min in group I and II, respectively) (P < 0.05). CHEOPS scores were significantly lower in group RT at 30 min, 45 min, and 3 h postoperatively than in group R (P < 0.05). However, sedation scores were similar between the two groups. Twenty-two patients (100%) in group R and 13 patients (59%) in group RT needed supplemental analgesia postoperatively. There were no significant differences in side effects between the groups.

CONCLUSION

In children undergoing major abdominal surgery, epidural tramadol, added to epidural ropivacaine, provided lower pain scores, longer duration of analgesia, and lower postoperative analgesic requirement.

Ketamine induces apoptosis via the mitochondrial pathway in human lymphocytes and neuronal cells

BACKGROUND

Ketamine has been shown to have neurotoxic properties, when administered neuraxially. The mechanism of this local toxicity is still unknown. Therefore, we investigated the mechanism of cytotoxicity in different human cell lines in vitro.

METHODS

We incubated the following cell types for 24 h with increasing concentrations of S(+)-ketamine and racemic ketamine: (i) human Jurkat T-lymphoma cells overexpressing the antiapoptotic B-cell lymphoma 2 protein, (ii) cells deficient of caspase-9, caspase-8, or Fas-associated protein with death domain and parental cells, and (iii) neuroblastoma cells (SHEP). N-Methyl-d-aspartate (NMDA) receptors and caspase-3 cleavage were identified by immunoblotting. Cell viability and apoptotic cell death were evaluated flowcytometrically by Annexin V and 7-aminoactinomycin D double staining. Mitochondrial metabolic activity and caspase-3 activation were measured.

RESULTS

Ketamine, in a concentration-dependent manner, induced apoptosis in lymphocytes and neuroblastoma cell lines. Cell lines with alterations of the mitochondrial pathway of apoptosis were protected against ketamine-induced apoptosis, whereas alterations of the death receptor pathway did not reduce apoptosis. S(+)-Ketamine and racemic ketamine induced the same percentage of cell death in Jurkat cells, whereas in neuroblastoma cells, S(+)-ketamine was slightly less toxic.

CONCLUSIONS

Ketamine at millimolar concentrations induces apoptosis via the mitochondrial pathway, independent of death receptor signalling. At higher concentrations necrosis is the predominant mechanism. Less toxicity of S(+)-ketamine was observed in neuroblastoma cells, but this difference was minor and therefore unlikely to be mediated via the NMDA receptor.

The evolution of ketamine applications in children

Ketamine has found many applications in pediatric anesthetic practice. Insights into the mechanism of action and the pharmacokinetics and pharmacodynamics of its isomers have led to a re-evaluation of this drug, expanding the range of applications in children. Ketamine is a remarkably versatile drug that can be administered through almost any route. It can also be used for different purposes. The aim of this review is to look at the possible applications of this drug in children.

The effect of intraarticular combinations of tramadol and ropivacaine with ketamine on postoperative pain after arthroscopic meniscectomy

INTRODUCTION

The purpose of this prospective randomized study was to evaluate the effects of intraarticular combinations of tramadol and ropivacaine with ketamine in postoperative pain control of patients undergoing arthroscopic meniscectomy.

MATERIALS AND METHODS

We randomly divided 80 patients into four groups to receive intraarticular 50 mg tramadol (Group T), 50 mg tramadol with 0.5 mg kg(-1) ketamine (Group TK), 75 mg ropivacaine (Group R), 75 mg ropivacaine with 0.5 mg kg(-1) ketamine (Group RK) in 20 ml normal saline at the end of surgery. Postoperative analgesia was provided with patient-controlled analgesia with morphine. Postoperative pain scores, total morphine consumption amount and side effects were recorded at intervals of 0, 1, 2, 4, 8, 12 and 24 h after the operation.

RESULTS

Pain scores were higher in Group T when compared with Group R and Group RK at second and fourth hours, also compared with Group RK at zeroth, first, second, fourth and eighth hours. Total morphine consumption amount was found to be higher in Group T when compared to Group TK at eighth and twelfth hours and Group RK at eighth hours (P < 0.05). Total morphine consumption was lowest in Group TK (P < 0.05). There were no significant differences among the study groups regarding side effects.

CONCLUSIONS

Administration of intraarticular tramadol-ketamine combination was found to be more effective in decreasing postoperative daily analgesic consumption.

[Special features of procedures in paediatric orthopaedics]

To get good to excellent results in paediatric orthopaedics perioperative pain treatment is essential. Guidelines are in general similar to those for adults. Some special features should be taken into account. Differences are reduced possibilities of communication in the early years, different pharmacokinetics and a different perception of pain itself. A multimodal approach has proven to be very effective: workflow tailored to children's needs, ambiance appropriate for children and pharmacological analgesia. Children and parents have to be informed carefully about procedures, hospital setting and pain therapy in the first session. Pain therapy is orientated to the reversed WHO pain treatment scheme completed by surface and regional anaesthesia. After discharge pain treatment has to be administered. This article presents concepts of perioperative analgesia.

Recent developments in the pharmacological management of pain in children

PURPOSE OF REVIEW

This review explores progress in developmental pharmacokinetics, pharmacogenomics and formulations of analgesic agents, and discusses potential implications for pain therapy.

RECENT FINDINGS

Characterization of the developmental pharmacokinetics of morphine, tramadol, paracetamol and nonsteroidal anti-inflammatory drugs has improved dosing in children. Oral sugar solutions have replaced the brandy/sugar pacifier and are effective for single painful events in neonates. Intravenous paracetamol offers increased dosing accuracy, and avoids absorption and bioavailability variability. New nitric-oxide-releasing versions of paracetamol and nonsteroidal anti-inflammatory drugs offer safer alternatives to their parent drugs with enhanced potency. Ketamine has come under a cloud for its possible effects on the neonatal developing brain, but it is being used increasingly in children to supplement opioids for pain after major surgery. Hopes that morphine analgesia may improve neurological outcome in premature babies have not materialized. Reports concerning chronic pain are generally case series and controlled trials are rare and nearly nonexistent in children.

SUMMARY

Unlicensed drug use in the very young will increase as familiarity increases. Pharmacogenomic studies have the potential to tailor drug therapy to the individual and decrease between-patient variability. Unfortunately, the pharmacodynamic knowledge in children of analgesic agents remains neglected and is usually extrapolated from adult data.

New local anesthetics for pediatric anesthesia

PURPOSE OF REVIEW

To evaluate the relevance of new local anesthetics in pediatric regional anesthesia.

RECENT FINDINGS

Several studies evaluate the pharmacokinetics of new local anesthetics, like ropivacaine and levobupivacaine, and compare their safety and efficacy with the old but widely used bupivacaine.

SUMMARY

The goal of anesthetists using regional anesthesia is to use local anesthestics that are as safe and effective as possible, with a rapid onset and a long duration. Even though adequate dose guidelines are available, several toxic effects are reported with the use of bupivacaine in children due to inadvertent intravenous injection, long-term infusion (> 48 h) or administration in newborn babies and infants with reduced metabolism. Ropivacaine and levobupivacaine are new local anesthetics with a wider safety margin that have similar characteristics: both of them are pure S-(-)-enantiomers whose main pharmacological features are less cardio- and neuro-affinity and -toxicity in comparison with the racemic formulae and R-isomers, and a differential neural blockade with less motor than sensory block. Several clinical studies in children compare ropivacaine and levobupivacaine with bupivacaine.

Ropivacaine: a review of its use in regional anaesthesia and acute pain management

Ropivacaine (Naropin) is the pure S(-)-enantiomer of propivacaine, and is a long-acting amide local anaesthetic agent, eliciting nerve block via reversible inhibition of sodium ion influx in nerve fibres. Ropivacaine is a well tolerated regional anaesthetic effective for surgical anaesthesia as well as the relief of postoperative and labour pain. The efficacy of ropivacaine is similar to that of bupivacaine and levobupivacaine for peripheral nerve blocks and, although it may be slightly less potent than bupivacaine when administered epidurally or intrathecally, equi-effective doses have been established. Clinically adequate doses of ropivacaine appear to be associated with a lower incidence or grade of motor block than bupivacaine. Thus ropivacaine, with its efficacy, lower propensity for motor block and reduced potential for CNS toxicity and cardiotoxicity, appears to be an important option for regional anaesthesia and for the management of postoperative and labour pain.

Comparison of caudal ketamine with lidocaine or tramadol administration for postoperative analgesia of hypospadias surgery in children

BACKGROUND

This study was designed to investigate whether the addition of tramadol or lidocaine to ketamine would enhance the quality of intra- and postoperative analgesia for hypospadias surgery in children.

METHODS

Sixty-two ASA PS I or II children, between 1 and 10 years of age, scheduled for hypospadias surgery were recruited. Anesthesia was induced with 6-8% sevoflurane and maintained with 0.5-2.5% sevoflurane-50% N2O in oxygen. Children were allocated randomly to receive one of two study drugs. Children in group KL received caudal ketamine (0.25 mg.kg(-1)) plus lidocaine (2%, 2 mg.kg(-1)) and in group KT ketamine (0.25 mg.kg(-1)) plus tramadol (1 mg.kg(-1)). Systemic blood pressure, heart rate, peripheral O2 saturation, sedation, and pain scores (CHEOPS) were recorded at 1, 5, 10, 15, 30, 45 min and 1, 2, 3 h following recovery from anesthesia.

RESULTS

Duration of analgesia was similar in the two groups (P > 0.05). CHEOPS in group KL was lower than in group KT during the study period, except at first 15 min. Sedation scores were higher in group KL than group KT in the first 10 min (P < 0.05). Incidence of postoperative nausea and vomiting was similar in the two groups (P > 0.05) Sevoflurane concentration required was significantly lower in group KL than group KT peroperatively (P < 0.001).

CONCLUSIONS

Caudal ketamine (0.25 mg.kg(-1)), plus lidocaine (2% 2 mg.kg(-1)) significantly reduced sevoflurane concentration compared with ketamine (0.25 mg.kg(-1)) + tramadol (1 mg.kg(-1)). We suggested that both ketamine + lidocaine and ketamine + tramadol provided very effective and long duration of analgesia, similarly. However, analgesia quality is superior in the ketamine-lidocaine group postoperatively.