Benefit and risks of local anesthetics in infants and children

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

BACKGROUND

Dexmedetomidine has become a popular additive for regional anesthesia. Aim of this meta-analysis was to assess the effect of this additive on the duration of postoperative analgesia and possible adverse events in pediatrics undergoing orchidopexy or lower abdominal surgery.

METHODS

The literature databases of PubMed, Google Scholar, and Cochrane Library were searched for randomized, controlled trials (RCTs). Odds ratio (OR), weighted mean difference (WMD), and the corresponding 95% confidence intervals (CIs) were calculated using the RevMan software, version 5.2, for data synthesis and statistical analysis, which in accordance with the PRISMA statement.

RESULTS

Six RCTs were selected for this meta-analysis, involving a total of 328 pediatric patients. There was a significant longer duration of caudal analgesia (time to first analgesic requirements) in patients receiving dexmedetomidine with CA compared with CA alone (WMD: -8.21 h; 95% CI: -11.40 to -5.02; P < 0.00001). Side effects in these two groups were comparable (OR: 1.02; 95% CI: 0.51-2.04; P = 0.95). Subgroup analysis indicated there was no significant difference in hemodynamic changes during operation (WMD: 1.78; 95% CI: -3.20 to 6.77; P = 0.48) and the emergence time (time from the end of surgery to opening the eyes on calling) after surgery (WMD: 0.47 min; 95% CI: -5.27 to 6.22; P = 0.87).

CONCLUSIONS

Dexmedetomidine as an additive to local anesthetic provides a significantly longer postoperative analgesia with comparable adverse effects and hemodynamic changes, when compared to local anesthetics alone. There were insufficient data of the effects of different concentrations of dexmedetomidine; further studies are required to explore this issue.

Thoracic epidural infusion with chloroprocaine for postoperative analgesia following epicardial pacemaker placement in an infant

In critically ill neonates and infants, major interventions, including thoracotomy, may result in significant postoperative respiratory insufficiency and pain leading to the need for postoperative mechanical ventilation. Although there are many potential options for providing postoperative analgesia, there continues to be expanding use of regional anesthesia in this population. One of the many reported advantages is the provision of postoperative analgesia while avoiding the deleterious effects on respiratory function that may be seen with systemic opioids. We report the use of thoracic epidural anesthesia using a continuous infusion of chloroprocaine to provide analgesia following thoracotomy and epicardial pacemaker placement in an infant. The perioperative plan was complicated by comorbid conditions including congenital complete heart block, recent rhinovirus infection with residual respiratory involvement, and prematurity.

Evaluation of spinal toxicity and long-term spinal reflex function after intrathecal levobupivaciane in the neonatal rat

BACKGROUND

Neuraxial anesthesia is utilized in children of all ages. Local anesthetics produce dose-dependent toxicity in certain adult models, but the developing spinal cord may also be susceptible to drug-induced apoptosis. In postnatal rodents, we examined the effects of intrathecal levobupivacaine on neuropathology and long-term sensorimotor outcomes.

METHODS

Postnatal day 3 (P3) or P7 rat pups received intrathecal levobupivacaine 2.5 mg/kg (0.5%) or saline. Mechanical withdrawal thresholds and motor block were assessed. Spinal cord tissue analysis included apoptosis counts (activated caspase-3, Fluoro-Jade C) at 24 h, glial reactivity at 7 days, and histopathology in cord and cauda equina at 24 h and 7 days. Long-term spinal function in young adults (P35) was assessed by hind limb withdrawal thresholds, electromyography responses to suprathreshold stimuli, and gait analysis.

RESULTS

Intrathecal levobupivacaine produced spinal anesthesia at P3 and P7. No increase in apoptosis or histopathological change was seen in the cord or cauda equina. In the P3 saline group, activated caspase-3 (mean±SEM per lumbar cord section 6.1±0.3) and Fluoro-Jade C (12.1±1.2) counts were higher than at P7, but were not altered by levobupivacaine (P=0.62 and P=0.11, two-tailed Mann-Whitney test). At P35, mechanical withdrawal thresholds, thermal withdrawal latency, and electromyographic reflex responses did not differ across P3 or P7 levobupivacaine or saline groups (one way ANOVA with Bonferroni comparisons). Intrathecal bupivacaine at P3 did not alter gait.

CONCLUSION

Single dose intrathecal levobupivacaine 0.5% did not increase apoptosis or produce spinal toxicity in neonatal rat pups. This study provides preclinical safety data relevant to neonatal use of neuraxial local anesthesia.

Comparison of ropivacaine, bupivacaine and lidocaine in the management of post-tonsillectomy pain

OBJECTIVES

To compare the efficacy of preoperative peritonsillar injection of ropivacaine, bupivacaine and lidocaine for pediatric tonsillectomy.

PATIENTS AND METHODS

Between March 2009 and April 2012, 120 patients (66 males and 54 females) between ages of 4 and 13 years were included to the study. After informed consent was obtained from the parents, the patients were randomized into four groups. In Group 1 (31 patients, mean age 8.40 ± 4.05 years) received topical lidocaine hydrochloride with 1:100,000 epinephrine was applied to surgical bed following tonsillectomy. Group 2 (29 patients, mean age 8.15 ± 4.20 years) and group 3 (31 patients, mean age 7.75 ± 3.95 years) were administered 0.25% bupivacaine hydrochloride with 1:200,000 epinephrine and 0.5% ropivacaine respectively. In Group 4 (29 patients, mean age 8.15 ± 4.20 years) topical 0.9% saline was used. The operation time, postoperative pain, amount of intraoperative blood loss, postoperative hemorrhage and complications were assessed. The intensity of pain was scored on a visual analogue scale. The patients were followed up for 3 weeks after surgery.

RESULTS

The difference between mean operative time of the three groups against saline injected group was statistically significant (p<0.001). The difference between mean intraoperative blood loss of the lidocaine group against three groups was statistically significant (p<0.001). None of the patients in four groups experienced primary and secondary hemorrhage. The difference between mean pain score between ropovacaine and bupivacaine groups was not statistically significant (p>0.001). The difference between mean pain score of the two groups against lidocaine and saline groups was statistically significant (p<0.001).

CONCLUSION

Ropivacaine infiltration is as effective as bupivacaine for post-tonsillectomy pain management in children. In view of potential side effects of bupivacaine-epinephrin combination, ropivacaine is a safer choice, for post-tonsillectomy pain relief.

Neuraxial analgesia in neonates and infants: a review of clinical and preclinical strategies for the development of safety and efficacy data

Neuraxial drugs provide robust pain control, have the potential to improve outcomes, and are an important component of the perioperative care of children. Opioids or clonidine improves analgesia when added to perioperative epidural infusions; analgesia is significantly prolonged by the addition of clonidine, ketamine, neostigmine, or tramadol to single-shot caudal injections of local anesthetic; and neonatal intrathecal anesthesia/analgesia is increasing in some centers. However, it is difficult to determine the relative risk-benefit of different techniques and drugs without detailed and sensitive data related to analgesia requirements, side effects, and follow-up. Current data related to benefits and complications in neonates and infants are summarized, but variability in current neuraxial drug use reflects the relative lack of high-quality evidence. Recent preclinical reports of adverse effects of general anesthetics on the developing brain have increased awareness of the potential benefit of neuraxial anesthesia/analgesia to avoid or reduce general anesthetic dose requirements. However, the developing spinal cord is also vulnerable to drug-related toxicity, and although there are well-established preclinical models and criteria for assessing spinal cord toxicity in adult animals, until recently there had been no systematic evaluation during early life. Therefore, in the second half of this review, we present preclinical data evaluating age-dependent changes in the pharmacodynamic response to different spinal analgesics, and recent studies evaluating spinal toxicity in specific developmental models. Finally, we advocate use of neuraxial drugs with the widest demonstrable safety margin and suggest minimum standards for preclinical evaluation before adoption of new analgesics or preparations into routine clinical practice.

Effects of suppository acetaminophen, bupivacaine wound infiltration, and caudal block with bupivacaine on postoperative pain in pediatric inguinal herniorrhaphy

Background:

The control of postoperative pain is important in children, and poor pain control leads to organ dysfunction and behavioral problems.

Objectives:

We compared the analgesic effects of suppository acetaminophen, bupivacaine wound infiltration, and caudal block with bupivacaine on postoperative pain in pediatric inguinal herniorrhaphy.

Patients and Methods:

In this double-blinded, randomized controlled clinical trial, 90 children of American Society of Anesthesiologists (ASA) grade I-II, aged between 3 months and 7 years, and scheduled for elective unilateral inguinal herniorrhaphy under general anesthesia were assigned to three equal groups. Patients in the first group received 20 mg/kg of suppository acetaminophen. In the second group, 2 mg/kg of 0.5% bupivacaine was infiltrated in the incisional site, and in the third group, a caudal block was performed with 0.75 mL/kg of 0.25% bupivacaine. The Face, Legs, Activity, Cry, Consolability (FLACC) pain scale was applied 30 minutes after operation. Thereafter, the FLACC score was obtained every hour during the next 6 hours. If the FLACC score was 4 or over, we administered 0.5 mg/kg of intravenous meperidine. The data was transferred to SPSS-10 software and analyzed statistically with chi-square and analysis of variance tests. P < 0.05 was considered significant.

Results:

The mean analgesic duration in the acetaminophen, bupivacaine infiltration, and caudal block groups was 4.07, 5.40, and 5.37 hours, respectively. Significant differences were not observed between the bupivacaine infiltration and caudal block groups (P = 0.9), but the differences between the bupivacaine infiltration and acetaminophen groups (P = 0.034) and the caudal block and acetaminophen groups (P = 0.039) were significant. With regard to meperidine administration, significant differences were not observed between the bupivacaine infiltration and caudal block groups (P = 0.848), but significant differences were observed between these two groups and the acetaminophen group (P < 0.05).

Conclusions:

Patients in the bupivacaine infiltration and caudal block groups had less postoperative pain than those in the acetaminophen group and received lower amount of meperidine. We concluded that in children, bupivacaine infiltration and caudal block with bupivacaine produce better analgesia than suppository acetaminophen. It seems that bupivacaine infiltration is better than caudal block because of its simplicity, lower incidence of complications, and failure rate.

Audit of extrapleural local anaesthetic infusion in neonates following repair of tracheo-oesophageal fistulae and oesophageal atresia via thoracotomy

In order to reduce postoperative opioid requirement, extrapleural local anaesthetic infusion dosing recommendations and guidelines for extrapleural catheter insertion were developed in our institution for 'extubatable' neonates requiring short-gap neonatal tracheo-oesophageal fistula/oesophageal atresia repair (via thoracotomy) and audited prospectively. Data audited included patient characteristics, analgesia details and ventilation duration. We divided patients into two groups: group 1 - term patients (=36 weeks gestational age) with birth-weights =2.5 kg; group 2 - pre-term patients (<36 weeks gestational age), with birth weights <2.5 kg and those with co-morbidities. There were 26 neonates in group 1 and 11 in group 2. All received extrapleural infusions of bupivacaine or levobupivacaine: the majority (90%) =300 µg.kg(-1).hour(-1) (median duration 43 hours, range 1.5 to 72 hours); 36% required morphine infusion and 39% were ventilated (median duration 34 hours, range 3 to 140 hours). In group 1, 24% required morphine infusion compared with 64% in group 2. Most group 1 patients (77%) were extubated immediately postoperatively; 20% had short duration ventilation (median 15 hours, range 11 to 37 hours); one required longer-term ventilation (231 hours). 82% of group 2 were ventilated for a median of 72 hours (range 3 to 140 hours). Review of patients' co-morbidities facilitated guideline revision. These now specify use in neonates requiring short-gap tracheo-oesophageal fistula/oesophageal atresia repair who are term at =36 weeks gestational age and =2.5 kg birth-weight, anticipated as ready for extubation either immediately or shortly after surgery.

Efficacy and safety of clonidine as additive for caudal regional anesthesia: a quantitative systematic review of randomized controlled trials

BACKGROUND

Clonidine is still the most popular additive for caudal regional anesthesia. Aim of the present quantitative systematic review was to assess the efficacy and safety of the combined use of clonidine and local anesthetics in comparison with caudal local anesthetics alone.

METHODS

The systematic search, data extraction, critical appraisal and pooled analysis were performed according to the PRISMA statement. The systematic search included the Central register of controlled trials of the Cochrane Library (to present), MEDLINE (1966 to present), EMBASE (1980 to present) and CINAHL (1981 to present). Relative risk (RR), mean difference (MD) and the corresponding 95% confidence intervals (CI) were calculated using the Revman(®) statistical software for dichotomous and continuous outcomes.

RESULTS

Twenty randomized controlled trials (published between 1994 and 2010) including 993 patients met the inclusion criteria. There was a longer duration of postoperative analgesia in children receiving clonidine in addition to local anesthetic (MD: 3.98 h; 95% CI: 2.84-5.13; P < 0.00001). Furthermore, there was a lower number of patients requiring rescue analgesics in the clonidine group (RR: 0.72; 95% CI: 0.57-0.90; P = 0.003). The incidence of complications (e.g., respiratory depression) remained very low and was not different to caudal local anesthetics alone.

CONCLUSIONS

There is considerable evidence that caudally administered clonidine in addition to local anesthetics provides extended duration of analgesia with a decreased incidence for analgesic rescue requirement and little adverse effects compared to caudal local anesthetics alone.

Effects of levobupivacaine versus bupivacaine infiltration on postoperative analgesia in pediatric tonsillectomy patients: a randomized, double-blind, placebo-controlled study

OBJECTIVES

We compared the effects of levobupivacaine hydrochloride, bupivacaine hydrochloride, and saline injections in alleviating posttonsillectomy pain.

METHODS

Between November 2009 and April 2010, we recruited 60 patients (36 male and 24 female) between 2 and 12 years of age into the study. After informed consent was obtained from the parents, patients admitted for tonsillectomy were randomized into 3 groups by means of sealed envelopes. Group 1 (20 patients; mean age, 6.45+/-2.78 years) received 0.9% sodium chloride (saline solution), group 2 (20 patients; mean age, 5.60+/-2.70 years) received 0.25% levobupivacaine hydrochloride, and group 3 (20 patients; mean age, 5.85+/-2.43 years) received 0.5% bupivacaine hydrochloride infiltrated around each tonsil. Pain was evaluated with McGrath's face scale.

RESULTS

The postoperative pain scores at 1 and 5 hours were similar among the groups (p>0.05). The pain scores in the levobupivacaine group were lower than those in the saline group at 13 hours (p<0.017). The pain scores in the bupivacaine and levobupivacaine groups were significantly lower than those in the saline group from 17 to 21 hours until day 6 (p>0.017). There was no difference between the levobupivacaine and bupivacaine groups (p>0.017).

CONCLUSIONS

Local infiltration of levobupivacaine is a relatively safe and effective method and is equivalent to use of bupivacaine for posttonsillectomy pain.

Continuous Bupivacaine Infusion Post-Iliac Crest Bone Graft Harvesting in Pediatric Cleft Surgery: Role and Comparison with Ketorolac

Objective

To investigate the use of intravenous ketorolac and iliac crest bupivacaine infusion in the management of iliac crest donor-site pain in the pediatric cleft population. The null hypothesis was there is no difference with respect to pain scores between ketorolac and iliac crest bupivacaine infusion as analgesic adjuncts to intravenous opioids.

Method

A total of 54 children and adolescents (27 boys, 27 girls) undergoing alveolar cleft repair or Le Fort I osteotomy were assigned randomly in a prospective, single-blinded fashion to one of three groups: intravenous ketorolac plus iliac crest normal saline infusion, intravenous ketorolac plus iliac crest bupivacaine infusion, or iliac crest bupivacaine infusion alone. Iliac crest infusions and ketorolac were administered for 48 hours or until discharge, whichever occurred first. All patients received morphine via a patient-controlled analgesia device.

Main outcome Measure(s)

Primary outcome was pain score, and secondary outcomes were morphine consumption and satisfaction scores.

Results

Pain scores, morphine consumption, and satisfaction scores were not significantly different among groups. Estimated costs were significantly higher for bupivacaine infusion than intravenous ketorolac.

Conclusions

Iliac crest donor-site pain is well managed in this patient population. Intravenous ketorolac and iliac crest bupivacaine infusion provide comparable analgesia for iliac crest bone graft donor-site pain in children and adolescents.

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.

The influence of age on bupivacaine cardiotoxicity

BACKGROUND

The susceptibility of children and newborns to cardiotoxicity from racemic bupivacaine, RS(±)-bupivacaine, is controversial. Some studies indicate that newborns can sustain higher bupivacaine plasma levels than adults, without severe toxicity. In this study, we compared the influence of age on cardiotoxicity from RS(±)-bupivacaine and S(-)-bupivacaine in rats. The effects of these local anesthetics (LAs) on the regulation of intracellular Ca(2+) concentrations in cardiac fibers were also investigated.

METHODS

The lethal dose was determined in ventilated male Wistar rats at 2, 4, 8, and 16 weeks of age by monitoring when cardiac electrical activity stopped after infusion of RS(±)-bupivacaine and S(-)-bupivacaine (4 mg · kg(-1) · min(-1)). The effects on cardiac muscle contraction were investigated by in vitro measurement of papillary muscle twitches in the presence and absence of RS(±)-bupivacaine or S(-)-bupivacaine. Skinned ventricular fibers were used to investigate the intracellular effects on Ca(2+) regulation induced by both LAs.

RESULTS

The lethal dose for RS(±)-bupivacaine and S(-)-bupivacaine in 2-week-old animals (46.0 ± 5.2 and 91.3 ± 4.9 mg · kg(-1), respectively) was higher than in 16-week-old animals (22.7 ± 1.3 and 22.0 ± 2.7 mg · kg(-1), respectively). Papillary muscle twitches were reduced in a dose-dependent manner, with significant difference between young and adult hearts. In adults, the muscle twitches were reduced to 8.6% ± 0.8% of control by RS(±)-bupivacaine, and to 18.1% ± 2.7% of control by S(-)-bupivacaine (100 μM). S(-)-bupivacaine had a positive inotropic effect at <10 μM, but only in 2-week-old animals. In chemically skinned ventricular fibers, RS(±)-bupivacaine and S(-)-bupivacaine induced similar increases in Ca(2+) release from the sarcoplasmic reticulum (SR) preactivated with caffeine (1 mM), and this effect was greater in younger rats than adults. In 16-week-old rats, caffeine-induced tension was 53.9% ± 1.7% of the maximal fiber response with RS(±)-bupivacaine, and 54.1% ± 3.2% with S(-)-bupivacaine. The caffeine response in 2-week-old rats was 81.1% ± 3.7% of the maximal response with RS(±)-bupivacaine, and 78.1% ± 4.5% with S(-)-bupivacaine. The Ca(2+) sensitivity of contractile proteins was equally increased at both ages tested, with RS(±)-bupivacaine or S(-)-bupivacaine. Ca(2+) uptake from the SR was not altered by the LA or by age.

CONCLUSIONS

Differences in the mechanisms for regulating intracellular SR Ca(2+) may contribute to the decreased susceptibility of young animals to cardiodepression induced by RS(±)-bupivacaine and S(-)-bupivacaine.

Topical bupivacaine compared to lidocaine with epinephrine for post-tonsillectomy pain relief in children: a randomized controlled study

OBJECTIVE

To compare the topical administration of bupivacaine hydrochloride, lidocaine hydrochloride with epinephrine and saline in alleviating post tonsillectomy pain.

STUDY DESIGN

A double-blind prospective randomized controlled clinical study.

METHODS

Between November 2008 and March 2009, 60 patients (32 males and 28 females) between ages of 1.5 and 15 years were recruited into the study. After informed consent was obtained from the parents, patients, admitted for tonsillectomy, were randomized into three groups using sealed envelops. Group 1 (20 patients, mean age 5.2±1.7) received topical lidocaine hydrochloride (20 mg/ml) with 0.00125% epinephrine. Group 2 (20 patients, mean age 6±3.7) received topical 0.5% bupivacaine hydrochloride and group 3 (20 patients, mean age 6.7±3.6) received topical saline.

RESULTS

The post-operative pain scores at 1h were similar among the groups (p=0.29). Pain scores in bupivacaine hydrochloride group were significantly lesser than the saline group at 5th, 13th, 17th and 21st hours, until the sixth day (p<0.017). Moreover, pain scores of bupivacaine hydrochloride group were superior to lidocaine hydrochloride group starting at 17 h, until fourth day (p<0.017). Pain scores of lidocaine hydrochloride group were lesser than saline group in the first and fifth days (p<0.017), whereas, there was no significant difference at other times.

CONCLUSION

Topical administration of bupivacaine hydrochloride proved to provide more efficient pain control than both saline and lidocaine without any drug related complication.

Lidocaine toxicity secondary to local anesthesia administered in the community for elective circumcision

We report three previously healthy infants aged, respectively, 23 days, 6 weeks, and 3 months with systemic lidocaine toxicity following administration of subcutaneous lidocaine for regional anesthesia during an elective circumcision. The patients developed a generalized seizure requiring endotracheal intubation but recovered fully with supportive care. We report the clinical details of these cases as well as a review of lidocaine toxicity.

Successful resuscitation of bupivacaine-induced cardiotoxicity in a neonate

We report a case of bupivacaine-induced cardiotoxicity in a neonate following caudal epidural block under general anesthesia for urologic surgery. Prompt recognition of the complication allowed early intervention with both standard resuscitative measures and administration of 20% Intralipid(®) , resulting in a good outcome.

Acute pain management in children

The greatest advance in pediatric pain medicine is the recognition that untreated pain is a significant cause of morbidity and even mortality after surgical trauma. Accurate assessment of pain in different age groups and the effective treatment of postoperative pain is constantly being refined; with newer drugs being used alone or in combination with other drugs continues to be explored. Several advances in developmental neurobiology and pharmacology, knowledge of new analgesics and newer applications of old analgesics in the last two decades have helped the pediatric anesthesiologist in managing pain in children more efficiently. The latter include administering opioids via the skin and nasal mucosa and their addition into the neuraxial local anesthetics. Systemic opioids, nonsteroidal anti-inflammatory agents and regional analgesics alone or combined with additives are currently used to provide effective postoperative analgesia. These modalities are best utilized when combined as a multimodal approach to treat acute pain in the perioperative setting. The development of receptor specific drugs that can produce pain relief without the untoward side effects of respiratory depression will hasten the recovery and discharge of children after surgery. This review focuses on the overview of acute pain management in children, with an emphasis on pharmacological and regional anesthesia in achieving this goal.

Severe central nervous system and cardiovascular toxicity in a pediatric patient after ingestion of an over-the-counter local anesthetic

Dibucaine is considered one of the most potent and consequently toxic amide anesthetics available, and despite withdrawal from the US market as a spinal anesthetic, it remains accessible as an over-the-counter preparation in the United States. Dibucaine exposures in children are infrequently encountered, but to date, all reported consequential ingestions have resulted in death. We report the first case of a potentially fatal dibucaine-induced wide-complex arrhythmia in a child who survived her clinical course without sequelae. It is our hope that this report will highlight the toxicity of dibucaine and prompt a review of its over-the-counter status. The rationale and success of a new antidote, 20% lipid emulsion, for the management of local anesthetic toxicity is discussed.

The effectiveness of aerosolized intraperitoneal bupivacaine in reducing postoperative pain in children undergoing robotic-assisted laparoscopic pyeloplasty

OBJECTIVE

To assess the effectiveness of aerosolized intraperitoneal bupivacaine in reducing postoperative pain in children. Laparoscopic surgery has decreased the severity of postoperative pain in children. However, children often experience abdominal and shoulder pain requiring significant amounts of opioids, potentially prolonging their hospitalization.

METHODS

Forty-one consecutive patients undergoing unilateral robotic-assisted pyeloplasty between December 2005 and December 2007 were retrospectively reviewed to assess perioperative opioid requirements and length of hospitalization.

RESULTS

In addition to standard-of-care perioperative analgesia, five patients received intraperitoneal aerosolized bupivacaine just prior to trocar removal, 17 patients received aerosolized bupivacaine just prior to incising the perirenal fascia, and 19 patients received no intervention. There was a significant reduction in postoperative opioid utilization when bupivacaine was administered at the beginning of the surgery (0.1mg/kg vs 0.4mg/kg, P=0.04), but not at the end (0.3mg/kg, P=0.25), as compared to controls. All patients receiving aerosolized bupivacaine had a significantly shorter time in hospital (2.4 vs 1.4 days, P=<0.01).

CONCLUSIONS

The administration of intraperitoneal aerosolized bupivacaine just prior to incising the perirenal fascia appears to be a simple, effective and low-cost method to reduce postoperative pain in children undergoing laparoscopic pyeloplasty.

Regional anesthesia for postoperative pain control in children: focus on continuous central and perineural infusions

Regional anesthesia is widely employed for postoperative pain control in both adults and children. Central or perineural approaches can be performed as a bolus injection or as a continuous infusion of local anesthetics. However, bolus injections, even with the addition of adjuvants, are inadequate for prolonged surgery and long-term pain control. Continuous infusion remains the technique of choice when there is a prolonged operation or intense postoperative pain. This article reviews the safety and efficacy of central and perineural continuous infusions for postoperative pain control in children. The literature confirms the very low rate of complications and adverse effects of regional anesthesia in children. However, clinicians need to be aware of the key points for performing a block and placing a catheter in children: good knowledge of anatomic and physiologic differences between adults and children is necessary; the use of newer local anesthetics, such as ropivacaine and levobupivacaine, increases the therapeutic window; and that it is mandatory to work with dedicated pediatric equipment. Through the use of new techniques such as nerve mapping and/or ultrasound the success of blocks can be improved and the risks reduced.

Clinically unrecognized intravascular placement of epidural catheter in a child--an argument for the use of radio-opaque contrast?

An epidural catheter was inserted after induction of anesthesia in a 28.2 kg 9-year-old boy scheduled to undergo bilateral femoral varus derotational osteotomies. There was no gravity free flow of blood down the catheter and there was no blood aspirated with a 2 ml syringe. After a negative test dose of a 4 ml solution of 0.25% levobupivacaine with epinephrine 1 : 200 000, a further 8 ml was administered via the epidural catheter. No significant increase in heart rate was noted. On surgical skin incision the heart rate increased from 94 to 116 b.min(-1) and blood pressure increased from 104/44 to 116/46 mmHg. A further 3 ml 0.25% levobupivacaine with epinephrine and clonidine 2 mug.kg(-1) were administered via the epidural catheter. The operation continued uneventfully although it was noted that the heart rate increased intermittently during the procedure. In view of the unexplained tachycardia and a history of cerebral palsy with the potential for postoperative muscle spasms, it was felt important to have a reliable epidural. To confirm placement, 2 ml of Isovue 300 (Iopamidol) was administered via the epidural catheter. X-ray screening demonstrated intravascular placement and the rapid disappearance of contrast. The catheter was removed and reinserted. Contrast demonstrated good spread in the epidural space. The merits of screening with contrast for epidural catheter placement in children are discussed.

Guidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: an update

The safe sedation of children for procedures requires a systematic approach that includes the following: no administration of sedating medication without the safety net of medical supervision; careful presedation evaluation for underlying medical or surgical conditions that would place the child at increased risk from sedating medications; appropriate fasting for elective procedures and a balance between depth of sedation and risk for those who are unable to fast because of the urgent nature of the procedure; a focused airway examination for large tonsils or anatomic airway abnormalities that might increase the potential for airway obstruction; a clear understanding of the pharmacokinetic and pharmacodynamic effects of the medications used for sedation, as well as an appreciation for drug interactions; appropriate training and skills in airway management to allow rescue of the patient; age- and size-appropriate equipment for airway management and venous access; appropriate medications and reversal agents; sufficient numbers of people to carry out the procedure and monitor the patient; appropriate physiologic monitoring during and after the procedure; a properly equipped and staffed recovery area; recovery to presedation level of consciousness before discharge from medical supervision; and appropriate discharge instructions. This report was developed through a collaborative effort of the American Academy of Pediatrics and the American Academy of Pediatric Dentistry to offer pediatric providers updated information and guidance in delivering safe sedation to children.

Contact dermatitis and bradycardia in a preterm infant given tetracaine 4% gel

The use of analgesics for procedural pain management in the newborn infant has been steadily increasing during the past decade. With this trend of increased analgesic utilization, there is the potential for infants to suffer from drug-induced side effects. There also is the potential to wrongfully blame drugs for all adverse events that occur during analgesic use. Two adverse events that occurred in a neonate exposed to tetracaine gel and the probability that the adverse events were caused by the drug are presented. During administration of the topical local anesthetic tetracaine for analgesia during percutaneous central venous catheter placement, a preterm infant experienced bradycardia. Several hours later, a local cutaneous reaction that progressed to skin desquamation occurred at the site. The authors assessed the probability that tetracaine caused 2 adverse events using a validated adverse drug reaction probability scale by Naranjo et al. According to the algorithm developed by Naranjo et al, it was determined that bradycardia was unlikely caused by the drug; however, the dermal reaction was probably the result of the drug.The authors determined that tetracaine caused a serious local skin reaction, but not bradycardia, in a preterm infant. This is the first report of a serious skin reaction in a neonate treated with tetracaine. Based on these findings, tetracaine gel can continue to be used to treat pain in neonates with careful evaluation of the skin.

Intravenöse Midazolam-Ketamin-Anästhesie zur geschlossenen Reposition der Vorderarmfraktur bei Kindern

BACKGROUND

The aim of this study was to compare ketamine requirements in children undergoing closed reduction of forearm fractures under midazolam-ketamine anaesthesia with or without axillary plexus anaesthesia.

METHODS

With hospital ethical committee approval, we retrospectively analyzed the records of children who received midazolam-ketamine anaesthesia in the years 2000-2001 (group A) and midazolam-ketamine anaesthesia combined with axillary plexus anaesthesia in the years 2002-2004 (group B) for closed reduction of forearm fractures. Requirements for ketamine and postoperative analgesics were noted. Groups were compared with the Mann-Whitney U-test or T-test and the chi2-test (p<0.05).

RESULTS

A total of 455 children (group A 225/group B 230) were included in this study. The total amounts of ketamine were not statistically different between the two groups (p=0.154). However, ketamine requirements became less if the time interval between start of axillary plexus anaesthesia and start of intervention became more than 15 min (p<0.05). Patients in group B requested fewer analgesics in the postoperative period (p<0.01).

CONCLUSIONS

In the clinical routine of an emergency department the combination of midazolam-ketamine anaesthesia with axillary plexus anesthesia for closed reduction of forearm fractures in children did not result in lower requirements of ketamine.

Lignocaine and chlorhexidine toxicity in children resulting from mouth paint ingestion: a bottling problem

BACKGROUND

A pharmaceutical product was marketed in Australia for 'teething' in an almost identical container to a popular paediatric paracetamol preparation. The product contained lignocaine and chlorhexidine. The similarity of the packaging resulted in large number of therapeutic errors in which the 'teething' preparation was given in error for paracetamol. As the exact dose of the erroneously administered mouth paint was known this provided an opportunity for outcome assessment of lignocaine ingestion.

METHODS

Calls to two state poison information centres regarding this product were prospectively followed up. Information collected included: demographics, type of exposure, details of the exposure and adverse effects. A systematic review of the literature was used to identify all previous reported cases of lignocaine and chlorhexidine ingestion.

RESULTS

There were 28 cases with complete follow up where the product was given in therapeutic errors (10 girls and 18 boys; median age 11 months; range 2 months-4 years). The mean ingested dose of lignocaine was 2.7 mg/kg (standard deviation 1.3 mg) and chlorhexidine was 0.06 mg/kg (standard deviation 0.03 mg). The largest ingested lignocaine dose was 5.9 mg/kg. Two children developed minor symptoms: one vomited twice and the other was reported to have increased salivation and difficulty with solid food for 20 min. No other adverse effects were reported. The literature review suggested that severe effects occurred with doses more than 15 mg/kg.

CONCLUSION

No major adverse effects occurred with lignocaine ingestions of less than 6 mg/kg and it would be appropriate to observe these patients at home. Chlorhexidine did not appear to cause clinical effects in this low concentration.

Current management of pediatric postoperative pain

Pain is a common complaint in children after surgery. Four out of five children require analgesia even after minor surgery, and after more extensive surgery, significant postoperative pain may last for weeks. Severe pain during, and after surgery may aggravate long-lasting negative effects to the body and mind. In order to prevent harmful effects, all children should be provided with effective analgesia. Pain management should be safe and easy to administer. Postoperative pain management in children has improved substantially during the last 5 years. Recent trials indicate that children may undergo major surgery with minimal untoward effects when effective proactive pain management is provided. This review will focus on new clinical strategies on pain management in children. Since most pediatric surgery is performed as a day-case or short-stay basic recommendations for parental guidance and pain management after discharge are also presented.

Caudal Regional Anesthesia, Ropivacaine Concentration, Postoperative Analgesia, and Infants

In this randomized, double-blind trial we evaluated the quality and duration of analgesia and motor effects after caudal block using 1 mL/kg of ropivacaine 0.1% (Group 1), 0.15% (Group 2), 0.175% (Group 3) compared to 0.2% (Group 4) in infants 1-12 mo old. Postoperatively, the number of infants who received pain medication differed among the groups (P < 0.0005). There were more infants in Groups 1 and 2 compared with Group 4 and there was no difference between Groups 3 and 4. In the postanesthesia care unit, infants in Groups 1 and 2 received more pain medication than did those in Group 4 (P = 0.0098). In the day surgery unit, there was a significant difference among the groups (P = 0.0326); infants in Groups 3 and 4 required no pain medication. The analgesia duration differed among the groups (P = 0.034). Infants in Groups 1 and 2 had a shorter duration, and there was no difference between Groups 3 and 4. Infants in Group 4 took longer to regain their motor power compared with those in Group 3 (P = 0.0347). We conclude that in infants, ropivacaine 0.175% provided postoperative analgesia and duration similar to that of ropivacaine 0.2%, whereas ropivacaine 0.1% and 0.15% did not, and it was associated with fewer motor effects.

Pharmacokinetics of levobupivacaine after caudal epidural administration in infants less than 3 months of age

BACKGROUND

There are few data describing levobupivacaine pharmacokinetics in infants (<3 months) after caudal administration.

METHODS

An open-label study was undertaken to examine the pharmacokinetics of levobupivacaine 2.5 mg ml(-1), 2 mg kg(-1) in children aged less than 3 months after single-shot caudal epidural administration. Plasma concentrations were determined at intervals from 0.5 to 4 h after injection. A population pharmacokinetic analysis of levobupivacaine time-concentration profiles (84 observations) from 22 infants with mean postnatal age (PNA) 2.0 (range 0.6-2.9) months was undertaken using non-linear mixed effects models (NONMEM). Time-concentration profiles were analysed using a one-compartment model with first-order input and first-order elimination. Estimates were standardized to a 70 kg adult using allometric size models.

RESULTS

Population parameter estimates (between-subject variability) for total levobupivacaine were clearance (CLt) 12.8 [coefficient of variation (CV) 50.6%] litre h(-1) 70 kg(-1), volume of distribution (Vt) 202 (CV 31.6%) litre 70 kg(-1), absorption half-life (Tabs) 0.323 (CV 18.6%) h 70 kg(-1). Estimates for the unbound drug were clearance (CLfree) 104 (CV 43.5%) litre h(-1) 70 kg(-1), volume of distribution (Vfree) 1700 (CV 44.9%) litre 70 kg(-1), absorption half-life (Tabsfree) 0.175 (CV 83.7%) h 70 kg(-1). There was no effect attributable to PNA on CL or V. Time to peak plasma concentration (Tmax) was 0.82 (CV 18%) h. Peak plasma concentration (Cmax) was 0.69 (CV 25%) microg ml(-1) for total levobupivacaine and 0.09 (CV 37%) microg ml(-1) for unbound levobupivacaine.

CONCLUSIONS

Clearance in infants is approximately half that described in adults, suggesting immaturity of P450 CYP3A4 and CYP1A2 enzyme isoforms that metabolize levobupivacaine in infants. This lower clearance delays Tmax, which was noted to occur approximately 50 min after administration of caudal epidural levobupivacaine.

Caudal analgesia and anesthesia techniques in children

PURPOSE OF REVIEW

Caudal epidural blockade remains the cornerstone of pediatric regional anesthesia. In this article we provide a comprehensive review of the recent developments in caudal anesthesia in infants and children.

RECENT FINDINGS

Research has focused on prolonging the duration of single-shot caudal blocks and accurately positioning continuous caudal catheters. New local anesthetics with similar potencies but less toxicity have been introduced. Opioids prolong the duration of analgesia of local anesthetic, but have also been associated with unacceptable side effects, particularly in pediatric outpatients. Various non-opioid adjuncts with more favorable side-effect profiles may increase the duration of analgesia. New ultrasound and nerve-stimulation techniques have been developed to accurately guide epidural catheters to a specific spinal level.

SUMMARY

The addition of ketamine or clonidine to a caudal local anesthetic prolong the duration of the block. However, a preservative-free preparation of ketamine that is suitable for neuraxial use is not widely available. Ultrasound imaging and electrical stimulation are promising options to accurately position a caudal needle. However, because ultrasound imaging is more difficult in older children, nerve stimulation is a more-suitable technique to accurately guide caudal catheters in this patient population. Although complications associated with caudal block are rare, the risks and benefits must be carefully considered on an individual basis.

Postoperative pain management in children

There is increased awareness of the need for effective postoperative analgesia in infants and young children. A multi-modal approach to preventing and treating pain usually is used. Mild analgesics, local and regional analgesia, and opioids when indicated, frequently are combined to minimize adverse effects of individual drugs or techniques.

Prevention and treatment of postoperative pain with particular reference to children

Pain therapy is an important aspect of medical practice for patients of all ages, to optimize care, to obtain an adequate quality of life and to improve their general conditions. Pain is among the most prevalent symptoms experienced by patients undergoing surgery. The success of postoperative pain therapy depends on the ability of the clinician to assess the presenting problems, identify and evaluate pain syndromes and formulate a plan for comprehensive continuing care. The prevalence of acute pain has led to the need to develop techniques for the assessment and management of this symptom in order to focus the attention on an interdisciplinary therapeutic approach (including pharmacologic, cognitive-behavioral, psychologic and physical treatment) and on the timing of different interventions (pre and postoperative). In this chapter we describe the principal therapeutic approaches to control pain in post-operative patients, such as non-opioid, opioid and adjuvant analgesics with particular attention in paediatric age. Moreover we report the principal scales to assess the pain intensity in the post-operative period. The need of a multidisciplinatory team and of a pre and postoperative pain management program represents an important goal in order to obtain effective pain relief and optimize pediatric care and rapid recovery. The introduction of a perioperative team service will improve the approach to pain management programs and it is considered the most important challenge for future.

Methemoglobinemia in children with acute lymphoblastic leukemia (ALL) receiving dapsone for pneumocystis carinii pneumonia (PCP) prophylaxis: a correlation with cytochrome b5 reductase (Cb5R) enzyme levels

BACKGROUND

Dapsone is commonly used for pneumocystis carinii pneumonia (PCP) prophylaxis in immunocompromised patients. Methemoglobinemia is a known complication of dapsone, but its true frequency and pathogenesis in childhood cancer patients are unknown. Additionally, practice guidelines for evaluation and management of dapsone-induced methemoglobinemia are not available.

PROCEDURE

We studied 15 children with acute lymphoblastic leukemia (ALL) receiving dapsone for PCP prophylaxis to determine the frequency of methemoglobinemia, and correlate its occurrence with cytochrome b5 reductase (Cb5R) enzyme levels. Ten children with ALL receiving trimethoprim-sulfamethaxazole (TMP-SMX) were studied as controls. All patients underwent physical examination, pulse oximetry, and methemoglobin (metHb) estimation. Commercially available assay was used to measure Cb5R levels.

RESULTS

Three (20%) patients receiving dapsone developed symptomatic methemoglobinemia. Average duration of dapsone prophylaxis prior to diagnosis was 6.6 weeks (range 3.5-10 weeks). Mean metHb level in symptomatic patients was 11.67%; 95% confidence interval (CI) 0-25.79 (range 7-18%), and 1.37%; 95% CI 0.6-2.14 (range 0.02-3%) in asymptomatic patients (P = 0.09), whereas the mean metHb level in the control group was 0.54%; 95% CI 0.35-0.73 (range 0.1-0.8%) (asymptomatic vs control P < 0.0001). Mean Cb5R level in symptomatic patients was 8.6 IU/g Hb; 95% CI 3.4-13.7 (range 6.9-10.9) compared to 12.5 IU/g Hb; 95% CI 11.1-13.9 (range 10.8-14.6) in asymptomatic patients (P = 0.06). Two symptomatic patients had Cb5R levels at or below 50% of normal, consistent with heterozygosity. Parental studies for Cb5R levels were suggestive of a carrier state in one of each patient's parents.

CONCLUSIONS

Heterozygosity for Cb5R deficiency may pre-dispose to methemoglobinemia even on a thrice-weekly regimen of dapsone. Such individuals should avoid subsequent exposure to oxidant agents, if possible. Children with ALL tend to be symptomatic at low levels of metHb and may have delayed detection of methemoglobinemia. Hence, frequent monitoring of patients receiving dapsone is recommended. Monitoring guidelines for dapsone prophylaxis are proposed.

Isobaric Ropivacaine 5 mg/mL for Spinal Anesthesia in Children

In this clinical trial, we evaluated the clinical effects of ropivacaine for spinal anesthesia in children. An open, prospective study was performed on 93 children, aged 1-17 yr, undergoing elective lower abdominal or lower limb surgery. A plain solution of ropivacaine 5 mg/mL at a dose of 0.5 mg/kg body weight (up to 20 mg) was administered via the L3-4 or L4-5 interspace with the patient in the lateral decubitus position. After injection, the patients were placed supine. The spread and duration of sensory analgesia and the degree of motor block were recorded. Satisfactory surgical anesthesia was achieved in 92 of the 93 children. Three children received general anesthesia; in one child spinal anesthesia failed, and in two cases surgery outlasted the duration of the sensory block. Four children received supplemental analgesia for skin incision. The mean highest level of sensory block was T6 (range, T2 to T12), and the mean time to the regression of sensory block to T10 was 96 min (range, 34-210 min). One child developed transient bradycardia and one hypotension. After discharge four children developed mild transient radiating neurologic symptoms and one epidural blood patch was performed for persistent position-dependent headache. We conclude that the block performance of intrathecal isobaric ropivacaine in children (>1 yr) is similar to that obtained in adults but the safety of the larger dose used in children warrants further studies.

Randomized, double-blind, phase III, controlled trial comparing levobupivacaine 0.25%, ropivacaine 0.25% and bupivacaine 0.25% by the caudal route in children

BACKGROUND

The rationale for replacing racemic bupivacaine with the s-enantiomers levobupivacaine and ropivacaine is to provide a wider margin of safety with the same analgesic efficacy and less postoperative motor block. In a randomized, double-blind, phase III, controlled trial we compared the caudal administration of levobupivacaine 0.25% and ropivacaine 0.25% with bupivacaine 0.25% in children.

METHODS

Ninety-nine ASA I-II children less than 10 yr old scheduled for elective sub-umbilical surgery were randomized to receive caudal block with bupivacaine 0.25%, ropivacaine 0.25% or levobupivacaine 0.25%. The primary outcome of the study was the clinical efficacy of the caudal block during the operation. Secondary outcome measures were analgesic onset time, pain relief after the operation and residual motor blockade.

RESULTS

The proportion of children with effective analgesia during the operation was similar among groups. There were no significant differences in the analgesic onset time of the caudal block. Bupivacaine produced a significant incidence of residual motor block compared with levobupivacaine or ropivacaine at wake-up (P<0.01). There were no significant differences in the number of patients receiving rescue analgesia after surgery. However, analgesic block lasted significantly longer in patients receiving bupivacaine (P=0.03).

CONCLUSION

During sub-umbilical surgery, caudal levobupivacaine, ropivacaine and bupivacaine provided comparable analgesic efficacy. Bupivacaine produced a higher incidence of residual motor blockade and a longer analgesic block than ropivacaine and levobupivacaine.

Lipophilicity affects the pharmacokinetics and toxicity of local anaesthetic agents administered by caudal block

1. Drugs administered into the epidural space by caudal block are cleared by means of a process potentially affected by the lipophilic character of the compounds. 2. In the present study, we examined the relationship between the octanol-water partition coefficient (log Poct) and the time to reach the maximum plasma drug concentration (tmax) of lignocaine, bupivacaine and ropivacaine administered by caudal block in paediatric patients. We also examined the relationship between log Poct and the toxicity of these local anaesthetic agents in experimental models. The tmax and toxicity data were obtained from the literature. 3. Ropivacaine, with a log Poct of 2.9, exhibited a tmax of 61.6 min. The tmax of lignocaine, with a log Poct of 2.4, and bupivacaine, with a log Poct of with 3.4, were approximately 50% shorter than ropivacaine. At log Poct of approximately 3.0, the toxicity of these local anaesthetic agents was substantially increased. The relationship between log Poct and the convulsive effect in dogs was similar to the relationship between log Poct and the lethal dose in sheep. 4. With local anaesthetic agents, it appears that the relationship between log Poct and drug transfer from the epidural space to the blood stream is parabolic, being the slowest rate of transference at log Poct 3.0. Toxicity, due to plasma availability of these local anaesthetic agents, seems to be increased at log Poct equal or higher than 3.0 secondary to the highest transfer from plasma into the central nervous system.

Postoperative analgesia in infants and children

PURPOSE OF REVIEW

Although postoperative analgesia in infants and children should be an integral part of the perioperative management, undertreatment of pain is not rare in clinical practice and may influence outcome and long term behaviour. Therefore, this review summarizes results of recent papers and discusses actual trends and future perspectives concerning postoperative pharmacologic pain therapy in infants and children.

RECENT FINDINGS

A multimodal approach using locoregional anesthesia and systemic analgesics is a widely accepted technique. New developments include new local anesthetics with a wider margin of safety and more experience with adjuvants, catheter techniques and systemic analgesics. Replacement of bupivacaine with ropivacaine may be prudent especially for prolonged epidural infusion, use in neonates, impaired hepatic metabolic function, and anesthetic techniques requiring large dosage of local anesthetic. The limited duration of analgesia after single blocks can be prolonged by use of adjuvants (clonidine, ketamine), catheter techniques or early use of systemic analgesics. Non-opioids (acetaminophen, non-steroidal anti-inflammatory drugs) are appropriate for patients with mild to moderate pain or as a component of multimodal pain therapy. Patient- and nurse-controlled analgesia are convenient ways for opioid administration in infants and children.

SUMMARY

The reviewed studies suggest that there are many reliable agents and techniques available to provide a safe and effective postoperative analgesia even in neonates and small infants.