Ultrasound-guided rectus sheath block or wound infiltration in children: a randomized blinded study of analgesia and bupivacaine absorption

Rectus sheath block added to parasternal block may improve postoperative pain control and respiratory performance after cardiac surgery: a superiority single-blinded randomized controlled clinical trial

BACKGROUND

The population undergoing cardiac surgery confronts challenges from uncontrolled post-sternotomy pain, with possible adverse effects on outcome. While the parasternal block can improve analgesia, its coverage may be insufficient to cover epigastric area. In this non-blinded randomized controlled study, we evaluated the analgesic and respiratory effect of adding a rectus sheath block to a parasternal block.

METHODS

58 patients undergoing cardiac surgery via median sternotomy were randomly assigned to receive parasternal block with rectus sheath block (experimental) or parasternal block with epigastric exit sites of chest drains receiving surgical infiltration of local anesthetic (control). The primary outcome of this study was pain at rest at extubation. We also assessed pain scores at rest and during respiratory exercises, opiate consumption and respiratory performance during the first 24 hours after extubation.

RESULTS

The median (IQR) maximum pain scores (on a 0-10 Numeric Rate Scale (NRS)) at extubation were 4 (4, 4) in the rectus sheath group and 5 (4, 5) in the control group (difference 1, p value=0.03). Rectus sheath block reduced opioid utilization by 2 mg over 24 hours (IC 95% 0.0 to 2.0; p<0.01), reduced NRS scores at other time points, and improved respiratory performance at 6, 12, and 24 hours after extubation.

CONCLUSION

The addition of a rectus sheath block with a parasternal block improves analgesia for cardiac surgery requiring chest drains emerging in the epigastric area.

TRIAL REGISTRATION NUMBER

NCT05764616.

The Spread Distance of Local Anesthetics in the Rectus Sheath Block in Children Aged 0-8 Years: A Retrospective Study

Background The spread distance of local anesthetic (LA) in the rectus sheath block (RSB) should cover the planned surgical incision. However, there is limited data regarding the spread distance that can be covered by a certain volume in children. In this study, we aimed to investigate the spread distance of a particular volume of LA from a single injection point. Methodology This study included children aged 0-8 years (n = 41) who underwent umbilical or epigastric hernia repair, laparoscopic surgery, and surgeries via small midline incisions. The spread distances, which were measured via ultrasound guidance immediately after the block to ensure coverage of the entire planned surgical incision, were obtained from prospectively collected data about RSB. The spread distances in the craniocaudal direction on the right and left sides were compared and assessed for correlations with age, weight, LA volume, and sex. The need for a supplemental dose of LA in case of an incision exceeding the spread distance was also obtained from the records. Results The spread distances in the cranial and caudal directions from the injection point were 3.28 ± 1.04 cm and 3.74 ± 1.35 cm on the right (p = 0.066) and 3.44 ± 1.02 cm and 3.44 ± 1.33 cm on the left (p > 0.999), respectively. The total spread distances in the craniocaudal direction on the right and left were 5.55 ± 0.95 cm and 5.72 ± 1.28 cm in patients aged 0-2 years and 7.25 ± 1.92 cm and 7.39 ± 1.81 cm in patients aged at 2-8 years, respectively. The increase in the spread distance correlated with age, weight, and LA volume. None of the patients required a supplemental dose of LA, as the single-point injections covered the planned surgical incisions in all patients. Conclusions Similar spread distances in the cranial and caudal directions from a single injection point can be obtained with 0.5 mL/kg of the LA in 0-8-year-old children. The total spread distance in the craniocaudal direction was approximately 5 cm and 7 cm in children aged 0-2 years and 2-8 years, respectively.

Fascial plane blocks in children-Scientifically supported or not?

Since the introduction of Fascial Plane Blocks in 2007 there has been an enormous interest and application of Fascial Plane Blocks, evidenced by substantially more than 1000 PubMed items. Despite this gigantic number of publications, also including randomized controlled trials and meta-analyses in children, there is still no clear-cut insight into how much of the purported effect is in fact due to the blockade of nerve structures and how much is merely adding the well-known analgesic and anti-inflammatory effects of the plasma levels of local anesthetics that are achieved with these techniques. Furthermore, Fascial Plane Blocks appear useful only if compared to conventional multi-modal analgesia (no block or placebo) and Fascial Plane Blocks lack the potency to provide surgical anesthesia on their own and appear only to be of value when used for minor-moderate surgery. Despite the huge literature, there has so far not emerged any clinical situations where Fascial Plane Blocks have definitively been shown to be the block of choice, being decisively more effective than other established regional blocks. Lastly, Fascial Plane Blocks may appear as virtually free of complications, but case reports are emerging that point to a real risk for causing local anesthetic systemic toxicity when using Fascial Plane Blocks. This text aims to synthesize the current knowledge base regarding the Fascial Plane Blocks that are relevant to use in the pediatric context. In summary, there does currently not exist any convincing scientific evidence for the continued support for the use of Fascial Plane Blocks in children, except for the rectus sheath block and possibly also the transmuscular quadratus lumborum block.

The Ropivacaine Concentration Required for Ultrasound-Guided Rectus Sheath Block in Pediatric Patients Undergoing Single-Incision Laparoscopic Hernia Repair: A Sequential Allocation Dose-Finding Study

BACKGROUND

The local anesthetic concentration required for ultrasound-guided rectus sheath block (RSB) in children remains unknown. Knowledge of appropriate ropivacaine concentration can help clinicians reduce local anesthetic toxicity risk when performing ultrasound-guided RSB in children. This study aimed to determine the appropriate ropivacaine concentration for ultrasound-guided RSB in children undergoing laparoscopic inguinal hernia repair.

METHODS

In this single-arm prospective study with an up-down sequential allocation design of binary response variables, 18 consecutive children aged 11 months to 7 years undergoing single-incision laparoscopic percutaneous extraperitoneal closure were assessed. Orotracheal intubation was performed without intravenous anesthesia or a neuromuscular relaxant. After intubation, ultrasound-guided RSB was performed with a ropivacaine dose of 0.30 ml/kg (0.15 ml/kg per side). Dixon's up-and-down method was used to determine the concentration, starting from 0.25% in 0.05% increments. Surgery commenced ≥15 min following RSB. Body movement or a 20% increase in heart rate or systolic blood pressure within 1 min of surgery initiation determined an unsuccessful RSB. The 95% effective concentration of ropivacaine needed for successful RSB was calculated using the probit test.

RESULTS

The 95% effective concentration of ropivacaine needed for successful ultrasound-guided RSB was 0.31% (95% confidence interval, 0.25-7.29). The highest concentration of ropivacaine required for successful ultrasound-guided RSB in the group of patients in this study was 0.3%.

CONCLUSION

The 95% effective concentration of ropivacaine (0.30 ml/kg total, 0.15 ml/kg per side) for ultrasound-guided RSB was 0.31% in children undergoing single-incision laparoscopic surgery under general anesthesia.

Rectus sheath block versus local anesthetic infiltration in pediatric laparoscopic inguinal hernia repair: a randomized controlled trial

BACKGROUND

Rectus sheath block (RSB) and local anesthetic infiltration (LAI) are used for postoperative analgesia in pediatric laparoscopic inguinal hernia repair. However, whether the analgesic effect of RSB is superior to LAI remains unclear. The authors hypothesized that RSB would reduce opioid consumption in patients.

METHODS

Patients aged 3-14 years scheduled for laparoscopic inguinal hernia repair were randomly allocated to the RSB, local anesthetic infiltration high concentration (LAIHC), local anesthetic infiltration low concentration (LAILC), or control groups. Preoperatively, they received 0.4 ml/kg of 0.25% ropivacaine (RSB), 0.4 ml/kg of 0.25% ropivacaine (LAILC), or 0.2 ml/kg of 0.5% ropivacaine(LAIHC), and 0.2 ml/kg of normal saline (control). The primary outcome was equivalent morphine consumption.

RESULTS

The authors analyzed 136 patients (RSB, 33; LAIHC, 34; LAILC, 35; control, 34). Intraoperative morphine equivalent consumption was lower in the RSB group [0.115 (0.107-0.123)] than in the LAIHC [0.144 (0.137-0.151)], LAILC [0.141 (0.134-0.149)], and control [0.160 (0.151-0.170)] groups ( P <0.001). In the post-anesthesia care unit, morphine equivalent consumption differed between the RSB [0.018 (0.010-0.027)], LAIHC [0.038 (0.028-0.049)], LAILC [0.056 (0.044-0.067)], and control [0.074 (0.063-0.084)] groups ( P <0.001). The rescue morphine equivalent consumption did not differ significantly between the RSB [0.015 (0.007-0.023)] and LAIHC [0.019 (0.010-0.029)] groups, which were lower than that in the control group [0.037 (0.029-0.045)] ( P =0.001).

CONCLUSIONS

RSB can provide effective analgesia for pediatric laparoscopic inguinal hernia repair, with better effectiveness than that of LAI at the same dose.

Evaluating Patterns of Injectate Spread After Rectus Sheath Block: A Cadaveric Dissection Study

INTRODUCTION

This cadaveric dye study assesses the effect of volume and number of injections on the spread of solution after ultrasound-guided rectus sheath injections. In addition, this study evaluates the impact of the arcuate line on solution spread.

MATERIALS AND METHODS

Ultrasound-guided rectus sheath injections were performed on seven cadavers on both sides of the abdomen, for a total of 14 injections. Three cadavers received one injection of 30 mL of a solution consisting of bupivacaine and methylene blue at the level of the umbilicus. Four cadavers received two injections of 15 mL of the same solution, one midway between the xiphoid process and umbilicus and one midway between the umbilicus and pubis.

RESULTS

Six cadavers were successfully dissected and analyzed for a total of 12 injections, while one cadaver was excluded due to poor tissue quality that was inadequate for dissection and analysis. There was a significant spread of solution with all injections caudally to the pubis without limitation by the arcuate line. However, a single 30 mL injection showed inconsistent spread to the subcostal margin in four of six injections, including in a cadaver with an ostomy. A double injection of 15 mL showed consistent spread from xiphoid to pubis in five of six injections, except in a cadaver with a hernia.

CONCLUSIONS

Injections deep to the rectus abdominis muscle, using the same technique as an ultrasound-guided rectus sheath block, achieve spread along a large and continuous fascial plane without limitation by the arcuate line and may provide coverage of the entire anterior abdomen. A large volume is necessary for complete coverage and spread is improved with multiple injections. We suggest that two injections with a total volume of at least 30 mL per side may be needed to achieve adequate coverage in the absence of preexisting abdominal abnormalities.

Systematic review and meta-analysis of the effect of nerve block under ultrasound in ilioinguinal/iliohypogastric in children

BACKGROUND

Ilioinguinal/iliohypogastric nerve block (IINB) is a common operation in pediatric surgery. Nerve block under contrast-enhanced ultrasound (CEUS) has the advantages of visualization and noninvasiveness, which creates conditions for its application in nerve block. It can significantly improve the success rate of nerve block and reduce the complications of nerve block. At present, few studies in China have analyzed the effect of nerve block guided by ultrasound technology compared with ordinary treatment.

METHODS

With "ilioinguinal/iliohypogastric nerve block", "ultrasonic examination of the children", and "ultrasonography for ilioinguinal/iliohypogastric" as the keywords, the related literature published before 2022 was searched. RevMan 5.3 and Stata provided by the Cochrane Collaboration were employed for analysis and evaluation. Begg's risk of bias was utilized to assess the risk bias of the included references. Heterogeneity among studies was evaluated using the Q test and heterogeneity (I²).

RESULTS

Six studies were included, with a total of 391 cases. The overall risk (OR) of ilioinguinal/iliosubabdominal complications in children treated with nerve block after ultrasound examination was 0.49, and the complications of ilioventral/iliosubabdominal complications in children treated with nerve block after ultrasound examination were reduced. The OR of inhibiting pain events was 0.35, and the ilioinguinal/iliosubabdominal pain events were reduced after nerve block treatment by ultrasound examination. The OR of inhibiting adverse reactions was 0.45. After ultrasound examination, the adverse reactions of ilioinguinal/iliosubabdominal nerve block treatment were reduced, and there was no heterogeneity among the study groups (I²=0.00%).

CONCLUSIONS

The results of the meta-analysis confirmed that the complications of nerve block treatment after ultrasound examination were less than those of ordinary treatment. The incidence of pain events and adverse reactions in nerve block treatment were reduced after ultrasonography. Moreover, in terms of pain events, the effect of ultrasound guidance was significant. In short, in clinical studies, CEUS can be used to accurately evaluate complex situations and provide a more accurate reference for subsequent treatment.

Comparison of rectus sheath block and local anesthetic for analgesia in pediatric umbilical hernia repair: A systematic review and meta-analysis

BACKGROUND

Pediatric umbilical hernia repair could cause considerable postoperative discomfort. This study aimed to compare the analgesia between rectus sheath block and local anesthetic infiltration in child pediatric umbilical hernia repair.

METHODS

The relevant randomized controlled trials were searched from PubMed, Embase, Web of Science, EBSCO, and Cochrane library databases from its inception to October 2020. The random-effects model was used for meta-analysis.

RESULTS

Four randomized controlled trials were included in the meta-analysis. The 4 studies were published between 2006 and 2017, with sample sizes ranging from 13 to 52 and a total of 143 individuals across the 4 studies. The Jadad scores of the 4 included studies ranged from 4 to 5, and all 4 studies were considered high quality based on quality assessment. There was no difference in analgesic effect at 10 minutes (standardized mean difference [SMD] = -0.19; 95% confidence interval [CI] = -1.52 to 1.16; P = .78), 30 minutes (SMD = -0.37; 95% CI = -1.53 to 0.78; P = .52), 1 hour (SMD = -0.73; 95% CI = -2.00 to 0.53; P = .26) after surgery. Besides, there was no significant difference in postoperative nausea (risk ratio = 0.95; 95% CI = 0.18 to 5.02; P = .95) and postoperative morphine use in morphine equivalents (mean difference = -0.95; 95% CI = -0.06 to 0.01; P = .12).

CONCLUSION

Rectus sheath block and local anesthetic are effective methods for analgesia in pediatric umbilical hernia repair.

Peak plasma concentration of total and free bupivacaine after erector spinae plane and pectointercostal fascial plane blocks

PURPOSE

Erector spinae plane blocks (ESPB) and pectointercostal fascial (PIFB) plane blocks are novel interfascial blocks for which local anesthetic (LA) doses and concentrations necessary to achieve safe and effective analgesia are unknown. The goal of this prospective observational study was to provide the timing (Tmax) and concentration (Cmax) of maximum total and free plasma bupivacaine after ESPB in breast surgery and after PIFB in cardiac surgery patients.

METHODS

Erector spinae plane blocks or PIFBs (18 patients per block; total, 36 patients) were performed with 2 mg⋅kg-1 of bupivacaine with epinephrine 5 μg⋅mL-1. Our principal outcomes were the mean or median Cmax of total and free plasma bupivacaine measured 10, 20, 30, 45, 60, 90, 180, and 240 min after LA injection using liquid chromatography with tandem mass spectrometry.

RESULTS

For ESPB, the mean (standard deviation [SD]) total bupivacaine Cmax was 0.37 (0.12) μg⋅mL-1 (range, 0.19 to 0.64), and the median [interquartile range (IQR)] Tmax was 30 [50] min (range, 10-180). For ESPB, the mean (SD) free bupivacaine Cmax was 0.015 (0.017) μg⋅mL-1 (range, 0.003-0.067), and the median [IQR] Tmax was 30 [20] min (range, 10-120). After PIFB, mean plasma concentrations plateaued at 60-240 min. For PIFB, the mean (SD) total bupivacaine Cmax was 0.32 (0.21) μg⋅mL-1 (range, 0.14-0.95), with a median [IQR] Tmax of 120 [150] min (range, 30-240). For PIFB, the mean (SD) free bupivacaine Cmax was 0.019 (0.010) μg⋅mL-1 (range, 0.005-0.048), and the median [IQR] Tmax was 180 [120] min (range, 30-240). For both ESPB and PIFB, we observed no correlations between pharmacokinetic and demographic parameters.

CONCLUSION

Total and free bupivacaine Cmax observed after ESPB and PIFB with 2 mg⋅kg-1 of bupivacaine with epinephrine 5 μg⋅mL-1 were five to twenty times lower than levels considered toxic in the literature.

Comparison of Single-Dermatome Laparoscopic Appendectomy With Standard Laparoscopic Appendectomy in Terms of Postoperative Pain and Patient Satisfaction: A Randomized Controlled Trial

BACKGROUND

Laparoscopic appendectomy (LA), used since 1980, is a common surgical technique for acute appendicitis (AA) treatment. Laparoscopic surgical techniques can achieve higher patient satisfaction than conventional open surgery techniques. However, many patients complain of severe pain after laparoscopic abdominal surgeries. In this study, we compared single-dermatome laparoscopic appendectomy (SDLA), wherein all trocars were placed at the same dermatome field, with standard laparoscopic appendectomy (SLA), wherein trocars were placed at multiple dermatome sites, in terms of postoperative pain and patient satisfaction.

MATERIALS AND METHODS

The study was designed as a double-blind randomized controlled trial. Patients who underwent LA for AA between May 2019 and December 2019 were included in the study and randomized into 2 groups, wherein patients were included sequentially. The first group was operated with SLA surgery, whereas the second group was operated with SDLA surgery. All patients were assessed in terms of visual analog scale (VAS) scores, hemodynamic parameters, and patient satisfaction at postoperative 1, 2, 4, 6, 12, and 24 hours.

RESULTS

In the SLA technique, VAS values at postoperative 1, 2, and 4 hours were significantly higher than in the SDLA ( P =0.009; P <0.05). No significant difference was observed between the surgical techniques in terms of VAS levels at postoperative 6, 12, and 24 hours ( P >0.05). In the SDLA group, patient satisfaction was significantly higher than in the SLA group ( P =0.024; P <0.05).

CONCLUSIONS

In our study, SDLA caused less pain in AA cases during postoperative period than SLA. Further, the SDLA method achieved higher patient satisfaction during the postoperative period than the SLA method.

Ambulatory Pain Management in the Pediatric Patient Population

PURPOSE OF REVIEW

Outpatient surgery in the pediatric population has become increasingly common. However, many patients still experience moderate to severe postoperative pain. A poor understanding of the extent of pain after pediatric ambulatory surgery and the lack of randomized control studies of pain management of the outpatient necessitate this review of scientific evidence and multimodal analgesia.

RECENT FINDINGS

A multimodal approach to pain management should be applied to the ambulatory setting to decrease postoperative pain. These include non-pharmacological techniques, multimodal pharmacologics, and neuraxial and peripheral nerve blocks. Postoperative pain management in pediatric ambulatory surgical patients remains suboptimal at most centers due to limited evidence-based approach to postoperative pain control. Pediatric ambulatory pain management requires a multipronged approach to address this inadequacy.

Fascial plane blocks: a narrative review of the literature

Fascial plane blocks (FPBs) are increasingly numerous and are often touted as effective solutions to many perioperative challenges facing anesthesiologists. As 'new' FPBs are being described, questions regarding their effectiveness remain unanswered as appropriate studies are lacking and publications are often limited to case discussions or technical reports. It is often unclear if newly named FPBs truly represent a novel intervention with new indications, or if these new publications describe mere ultrasound facilitated modifications of existing techniques. Here, we present broad concepts and potential mechanisms of FPB. In addition, we discuss major FPBs of (1) the extremities (2) the posterior torso and (3) the anterior torso. The characteristics, indications and a brief summary of the literature on these blocks is included. Finally, we provide an estimate of the overall level of evidence currently supporting individual approaches as FPBs continue to rapidly evolve.

Comparative Analgesic Efficacies of Ropivacaine and Bupivacaine for Postoperative Rectus Sheath Block in Paediatric Abdominal Surgery: A Meta-Analysis of Randomized Controlled Trial and Retrospective Cohort Studies

Background

The optimal dose and concentration of analgesic efficacy of ropivacaine (RPV) and bupivacaine (BPV) for postoperative pain relief in paediatric abdominal surgery patients is still unclear. Therefore, this meta-analysis compared the efficacy of these analgesics, their administered modes (ultrasound-guided RSB versus LAI) for postoperative pain relief, and side effects.

Methods

Three databases, PubMed, Embase, and Cochrane Database of Systematic Reviews, were exhaustively searched with predefined keywords. Eight randomized clinical trials and retrospective studies were selected. Analgesic effect, postoperative pain score, level of side effect, applied dose, and concentration of drug were analysed.

Results

Drug dose ranged from 0.5–2.5 mL/kg of 0.2 to 0.5% concentrations. Male participant for RSB and LAI treatment groups varied from 40–62% and 25–83%, respectively. Mean age of RSB and LAI groups ranged from 3.8–11.65 years and 4.3–11.27 years, respectively. Our meta-analysis revealed that RSB could reduce total opioid use postoperatively (WMD = −0.02, 95% CI: −0.02, −0.02), with I² value of 15%. We found that the RPV (0.25%, 2.5 ml/kg) was optimal in suppressing the pain. Its lower concentration (0.2%) was ineffective, whereas higher one (0.375%) seems to increase risk of systemic toxicity. Similarly, BPV (0.25%, 2.5 mg/kg) efficaciously reduced the pain score, while its lower concentration was ineffective. The combined postoperative pain score in the RPV-treated group was found to be significantly reduced (p < 0.01) with I² value of 85% indicating high heterogeneity.

Conclusion

Both RPV and BPV were significantly effective in reducing postoperative pain score. It appears that RSB could be a preferred choice to deliver analgesia, due to reduced opiate dose requirement and improved clinical safety without significant postoperative adverse events.

Laparoscopic-guided versus transincisional rectus sheath block for pediatric single-incision laparoscopic cholecystectomy: A randomized controlled trial

PURPOSE

The purpose of our study was to compare the effectiveness of transincisional (TI) versus laparoscopic-guided (LG) rectus sheath block (RSB) for pain control following pediatric single-incision laparoscopic cholecystectomy (SILC).

METHODS

Forty-eight patients 10-21 years old presenting to a single institution for SILC from 2015 to 2018 were randomized to TI or LG RSB. Apart from RSB technique, perioperative care protocols were identical between groups. Pain scores were assessed with validated measures upon arrival in the postanesthesia care unit (PACU) and at regular intervals until discharge. The patients and those assessing them were blinded to RSB technique. The primary outcome was pain score 60 min after PACU arrival. Secondary outcomes included pain scores throughout the PACU stay, opioids (reported as morphine milligram equivalents (MME) per kg bodyweight) administered in PACU, length of stay, outpatient pain scores and opioid use, and adverse events. Groups were compared on outcomes using t test and generalized estimating equations for continuous variables and Fisher's exact test for categorical variables with significance at α = 0.05.

RESULTS

Mean age of the 48 subjects was 15 years (range = 11-20). The majority (79%) were female. Indications for surgery included symptomatic cholelithiasis (n = 41), acute cholecystitis (n = 4), gallstone pancreatitis (n = 2) and choledocholithiasis (n = 1). Mean (standard deviation) operative time was 61 (±23) min overall. No statistically significant differences in demographics, indication, operative time, or intraoperative analgesia were observed between TI (n = 24) and LG (n = 24) groups. The mean 60-min pain score was 3.4 (±2.6) in the LG group versus 3.8 (±2.1) in the TI group (p = 0.573). No significant differences were detected between groups in overall PACU or outpatient pain scores, PACU or outpatient opioid use, length of stay, or incidence of complications. Overall, mean opioid use was 0.1 MME/kg in the PACU and 0.5 MME/kg in the outpatient setting. Mean postoperative length of stay was 0.2 day. There were no major complications.

CONCLUSION

Laparoscopic-guided rectus sheath block is not superior to transincisional rectus sheath block for pain control following pediatric single-incision laparoscopic cholecystectomy. The single-incision laparoscopic approach combined with rectus sheath block resulted in effective pain control, low opioid use, and expedited length of stay with no major complications.

LEVEL OF EVIDENCE

Level I, treatment study, randomized controlled trial.

[Peripheral truncal blocks-Overview and assessment]

By implementation of sonography for regional anesthesia, truncal blocks became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety and helps to avoid complications during needle placement. Additionally, complex punctures are possible that were associated with higher risk using landmarks alone. Next to the blocking of specific nerve structures, interfascial and compartment blocks have also become established, whereby the visualization of individual nerves and plexus structures is not of relevance. The present review article describes published and clinically established puncture techniques with respect to the indications and procedures. The clinical value is reported according to the scientific evidence and the analgesic profile. Moreover, the authors explain potential risks, complications and dosing of local anesthetic agents.

Comparison between rectus sheath block with 0.25% ropivacaine and local anesthetic infiltration with 0.5% ropivacaine for laparoscopic inguinal hernia repair in children

This randomized, observer-blinded prospective study aimed to compare the postoperative analgesic effects of ultrasound-guided rectus sheath block with those of local anesthetic infiltration of the surgical field in children undergoing inguinal hernia repair. Children aged 2 to 14 years, scheduled for elective single-incision laparoscopic percutaneous extraperitoneal closure, were randomly allocated to receive ultrasound-guided rectus sheath block (group R) or local anesthetic infiltration of the surgical field (group L). In group R, 0.5 ml/kg of 0.25% ropivacaine (per side) was administered after intubation. In group L, 0.4 ml/kg of 0.5% ropivacaine was administered after peritoneal closure. Postoperative pain was assessed using the Face Scale and Face, Legs, Activity, Cry, Consolability scale at various time points, including the primary endpoint of 2 h after leaving the operation room. Additional analgesic drugs were used according to the Face Scale scores. Patient characteristics, the amount of additional drugs, and complication rate were evaluated in both groups. The patient and surgical characteristics were comparable between groups. The Face Scale and Face, Legs, Activity, Cry, Consolability scale scores were not significantly different between group R (n = 38) and group L (n = 38) at 2 h after leaving the operation room. The amount of additional drugs administered at 2 h after leaving the operation room were also comparable between groups. Our findings suggest that the postoperative analgesic efficacy of ultrasound-guided rectus sheath block is not superior to that of local anesthetic infiltration of the surgical field for pediatric single-incision laparoscopic percutaneous extraperitoneal closure.

Ultrasound-guided rectus sheath block: an anatomic study in dog cadavers

OBJECTIVES

To describe the ultrasound-guided rectus sheath block technique and the anatomical spread of two volumes of methylene blue injection in dog cadavers.

STUDY DESIGN

Blinded, prospective, experimental cadaveric study.

ANIMALS

A total of eight dog cadavers weighing 8.9 ± 1.6 kg.

METHODS

Ultrasound-guided rectus sheath injections were performed bilaterally 1 cm cranial to the umbilicus using 0.25 mL kg^-1 (low volume; LV) and 0.50 mL kg^-1 (high volume; HV) of 0.5% methylene blue dye. A total of 16 hemiabdomens were injected. The ultrasound image quality of the muscular and fascial plane landmarks and needle visualization were scored using a standardized scale. Cadavers were dissected to determine the distribution of the dye and to assess staining of ventral branches of the spinal nerves.

RESULTS

Fewer ventral spinal nerve branches were stained in the LV group than in the HV group, at 2.00 ± 0 and 2.90 ± 0.83, respectively (p < 0.01). Ventral branches of thoracic (T) and lumbar (L) spinal nerves (T10, T11, T12, T13 and L1) were stained 25%, 100%, 75%, 25% and 0% of the time in LV group and 12.5%, 87.5%, 100.0%, 75.0% and 13.0% in HV group. A lesser extent of cranial-caudal dye distribution was observed in the LV group than in the HV group (7.1 ± 1.8 cm and 9.2 ± 1.8 cm, respectively; p = 0.03). There was no significant difference in medial-lateral spread of dye, number of test doses or ultrasound image quality scores between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The results of this study suggest that, on an anatomical basis, this easily performed block has the potential to provide effective abdominal wall analgesia for the ventral midline. This study supports the potential of the rectus sheath block for abdominal procedures, and further investigations on its clinical efficacy are warranted.

Rectus sheath single-injection blocks: a study to quantify local anaesthetic absorption using serial ultrasound measurements and lidocaine serum concentrations

Objectives

Rectus sheath blocks are an established option for analgesia following abdominal surgery, but pharmacokinetic data are limited. This study sought to characterise the absorption of lidocaine injectate and the pharmacokinetics of lidocaine after rectus sheath injection.

Methods

Bilateral rectus sheath single-injection blocks were given to 10 patients undergoing general or urological surgery. Afterwards, serial lidocaine serum levels and ultrasound measurements of the rectus sheath injectate reservoir were collected.

Key findings

Injectate within the rectus sheath was visible with ultrasound up to 12 h after injection. However, the rate of drug absorption exceeded that of injectate disappearance. Peak serum concentration occurred within 30 min with average peak concentrations of 1.65 μg/ml. Lidocaine clearance was lower than reported in young healthy subjects. The body mass index positively correlated with lidocaine terminal phase half-life, and clearance negatively correlated with age.

Conclusions

The study provides the first data describing lidocaine pharmacokinetics after rectus sheath injection. Peak serum concentrations transiently achieved systemic levels associated with pain relief after a single bolus injection. The data from this study could be used to develop a regime using single shot rectus sheath blockade with a bolus of lidocaine followed by infusion using bilateral rectus sheath catheters.

Single injection ultrasound-guided rectus sheath blocks for children: Distribution of injected anesthetic

BACKGROUND

Single injection ultrasound-guided rectus sheath blocks are used for postoperative analgesia after midline abdominal incisions, but the ultrasonographic spread of medication posterior to the rectus muscle has not been investigated.

AIMS

The primary goal of this study was to determine the ultrasound-measured medication spread superiorly and inferiorly after single injection ultrasound-guided rectus sheath blocks and to calculate the incidence of cases with spread up to the subcostal margin and below of umbilicus. The secondary goals were to correlate the spread with the volume of medication administered and with the patient's age, weight, height, sex, and body mass index.

METHODS

Pediatric patients who underwent single injection ultrasound-guided rectus sheath blocks and underwent data collection of ultrasonographic information on medication spread along the plane of the posterior rectus sheath were identified retrospectively from an acute pain service database at UPMC Children's Hospital of Pittsburgh.

RESULTS

Sixty-eight children, 10.2 ± 4.2 (mean ± SD) years old, 41.7 ± 17.9 kg, 140 ± 24.6 cm, had complete data collection. Mean injected volume of ropivacaine was 8.3 ± 2.8 mL (right) and 8.2 ± 2.8 mL (left). The average spread was measured as 3.9 ± 1.4 cm (right) and 3.4 ± 1.3 cm (left) cranial to the umbilicus, and 1.5 ± 1.6 cm (right) and 1.6 ± 1.4 cm (left) caudal to the umbilicus. Complete spread up to the level of the subcostal margin was observed in 52.9% (n = 36; right) and 36.8% (n = 25; left) of cases. The spread correlated closely with the volume of injected ropivacaine (right: 0.556, P < 0.001; left: 0.541, P < 0.001). The spread below umbilicus was 70.6% (n = 48, right) and 80.9% (n = 55, left). There was a positive strong correlation (P < 0.001) between total medication spread and age (right: 0.608; left: 0.538), weight (right: 0.600; left: 0.540), and height (right: 0.593; left: 0.526).

CONCLUSION

After single injection ultrasound-guided rectus sheath blocks, incomplete cephalocaudal medication spread can be expected within the posterior rectus sheath.

The use of ultrasound guidance for perioperative neuraxial and peripheral nerve blocks in children

BACKGROUND

The use of ultrasound guidance for regional anaesthesia has become popular over the past two decades. However, it is not recognized by all experts as an essential tool, perhaps because it is unclear whether ultrasound reduces the risk of severe neurological complications, and the cost of an ultrasound machine (USD 22,000) is substantially higher than the cost of other tools. This review was published in 2016 and updated in 2019.

OBJECTIVES

To determine whether ultrasound guidance offers any clinical advantage when neuraxial and peripheral nerve blocks are performed in children in terms of decreasing failure rate or the rate of complications.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trial registers up to March 2018 together with reference checking to identify additional studies and contacted study authors to obtain additional trial information.

SELECTION CRITERIA

We included all parallel randomized controlled trials that evaluated the effects of ultrasound guidance used when a regional blockade technique was performed in children. We included studies performed in children (≤ 18 years of age) undergoing any type of surgical procedure (open or laparoscopic), for which a neuraxial (spinal, epidural, caudal, or combined spinal and epidural) or peripheral nerve block (any peripheral nerve block including fascial (fascia iliaca, transversus abdominis plane, rectus sheath blocks) or perivascular blocks), for surgical anaesthesia (alone or in combination with general anaesthesia) or for postoperative analgesia, was performed with ultrasound guidance. We excluded studies in which regional blockade was used to treat chronic pain.We included studies in which ultrasound guidance was used to perform the technique in real time (in-plane or out-of-plane), as pre-scanning before the procedure or to evaluate the spread of the local anaesthetic so the position of the needle could be adjusted or the block complemented. For control groups, any other technique used to perform the block including landmarks, loss of resistance (air or fluid), click, paraesthesia, nerve stimulator, transarterial, or infiltration was accepted.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcomes were failed blocks, pain scores at one hour after surgery, and block duration. Secondary outcomes included time to perform the block, number of needle passes, and minor and major complications. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included 33 trials with a total of 2293 participants from 0.9 to 12 (mean or median) years of age. Most trials were at low risk of selection, detection, attrition, and reporting bias, however the lack of blinding of participants and personnel caring for participants resulted in 25 trials being judged as at high or unclear risk of bias. We identified five ongoing trials.Ultrasound guidance probably reduces the risk of failed block (risk difference (RD) -0.16, 95% confidence interval (CI) -0.25 to -0.07; 22 trials; 1789 participants; moderate-quality evidence). When ultrasound guidance was used, there was a small to moderate reduction in pain one hour after surgery, equivalent to a reduction of 1.3 points on the revised Bieri FACES pain scale (scale; 0 = no pain, 10 = maximal pain) (standardized mean difference (SMD) -0.41, 95% CI -0.74 to -0.07 (medium effect size); 15 trials; 982 participants; moderate-quality evidence). Ultrasound guidance increases block duration by the equivalent of 42 minutes (SMD 1.24, 95% CI 0.72 to 1.75; 10 trials; 460 participants; high-quality evidence).There is probably little or no difference in the time taken to perform the block (SMD -0.46, 95% CI -1.06 to 0.13; 9 trials; 680 participants; moderate-quality evidence). It is uncertain whether the number of needle passes required is reduced with the use of ultrasound guidance (SMD -0.63, 95% CI -1.08 to -0.18; 3 trials; 256 participants; very low-quality evidence).There were no occurrences of major complications in either the intervention or control arms of the trials (cardiac arrest from local anaesthetic toxicity (22 trials; 1576 participants; moderate-quality evidence); lasting neurological injury (19 trials; 1250 participants; low-quality evidence)).There may be little of no difference in the risk of bloody puncture (RD -0.02, 95% CI -0.05 to 0.00; 13 trials; 896 participants; low-quality evidence) or transient neurological injury (RD -0.00, 95% CI -0.01 to 0.01; 18 trials; 1230 participants; low-quality evidence). There were no occurrences of seizure from local anaesthetic toxicity (22 trials; 1576 participants; moderate-quality evidence) or block infections without neurological injury (18 trials; 1238 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

Ultrasound guidance for regional blockade in children probably decreases the risk of failed block. It increases the duration of the block and probably decreases pain scores at one hour after surgery. There may be little or no difference in the risks of some minor complications. The five ongoing studies may alter the conclusions of the review once published and assessed.

Regional anesthesia to ameliorate postoperative analgesia outcomes in pediatric surgical patients: an updated systematic review of randomized controlled trials

Regional anesthesia is becoming increasingly popular among anesthesiologists in the management of postoperative analgesia following pediatric surgery. The main objective of this review was to systematically evaluate the last 5 years of randomized controlled trials on the role of regional anesthesia techniques in alleviating postoperative pain associated with various pediatric surgical procedures. Forty studies on 2,408 pediatric patients were evaluated. The majority of the articles published from 2013 to 2017 reported that the use of regional anesthesia minimized postoperative pain and reduced opioid consumption. Only a few surgical procedures (cholecystectomy, inguinal hernia repair, and non-laparoscopic major abdominal surgery) reported no significant difference in the postoperative pain relief compared with the standard anesthetic management. The growing number of randomized controlled trials in the pediatric literature is very promising; however, additional confirmation is needed to reinforce the use of specific regional anesthesia techniques to provide optimal postoperative pain relief for a few surgical procedures (reconstructive ear surgery, chest wall deformity, hypospadias, umbilical hernia, cleft palate repair) in pediatric patients. More randomized controlled trials are needed to establish regional anesthesia as an essential component of postoperative analgesia management in children.

Ultrasound-guided bilateral rectus sheath block vs. conventional local analgesia in single port laparoscopic appendectomy for children with nonperforated appendicitis

INTRODUCTION

Despite its minimally invasive approach, laparoscopic surgery can cause considerable pain. Regional analgesic techniques such as the rectus sheath block (RSB) offer improved pain management following elective umbilical hernia repair in the pediatric population. This effect has not been examined in laparoscopic single-incision surgery in children. We sought to compare the efficacy of bilateral ultrasound-guided RSB versus local anesthetic infiltration (LAI) in providing postoperative pain relief in pediatric single-incision transumbilical laparoscopic assisted appendectomy (TULA) with same-day discharge.

METHODS

We retrospectively reviewed 275 children, ages 4 to 17 years old, who underwent TULA for uncomplicated appendicitis in a single institution from August 2014 to July 2015. We compared those that received preincision bilateral RSB (n=136) with those who received LAI (n=139). The primary outcome was narcotic administration. Secondary outcomes included initial and mean scores, time from anesthesia induction to release, operative time, time to rescue dose of analgesic in the PACU and time to PACU discharge.

RESULTS

Total narcotic administration was significantly reduced in patients that underwent preincision RSB compared to those that received conventional LAI, with a mean of 0.112 mg/kg of morphine versus 0.290 mg/kg morphine (p<0.0001). Patients undergoing RSB reported lower initial (0.38 vs. 2.38; p<0.0001) and mean pain scores (1.26 vs. 1.77; p<0.015). Time to rescue analgesia was prolonged in patients undergoing RSB compared to LAI (58.93min vs. 41.56min; p=0.047).

CONCLUSION

Preincision RSB for TULA in uncomplicated appendicitis in children is associated with decreased opioid consumption and lower pain scores compared with LAI. As the addition of this procedure only added 6.67min to time under anesthesia, we feel that it is a viable option for postoperative pain control in pediatric single-incision laparoscopic surgery.

RETROSPECTIVE COMPARATIVE STUDY

LEVEL III EVIDENCE.

Ultrasound-guided rectus sheath block, caudal analgesia, or surgical site infiltration for pediatric umbilical herniorrhaphy: a prospective, double-blinded, randomized comparison of three regional anesthetic techniques

Background

Umbilical hernia repair is a common pediatric surgical procedure. While opioid analgesics are a feasible option and have long been a mainstay in the pharmacological intervention for pain, the effort to improve care and limit opioid-related adverse effects has led to the use of alternative techniques, including regional anesthesia. The current study prospectively compares the analgesic efficacy of three techniques, including caudal epidural blockade, peripheral nerve blockade, and local wound infiltration, in a double-blinded study.

Patients and methods

A total of 39 patients undergoing umbilical hernia repair were randomized to receive a caudal epidural block (CDL), ultrasound-guided bilateral rectus sheath blocks (RSB), or surgical site infiltration (SSI) with local anesthetic. Intraoperative anesthetic care was standardized, and treatment groups were otherwise blinded from the intraoperative anesthesiology team and recovery nurses. Postoperatively, the efficacy was evaluated using Hannallah pain scores, Aldrete recovery scores, the need for intravenous fentanyl, and the time to discharge.

Results

Each cohort was similar in terms of age, weight, premedication dosing, length of case, intraoperative and postoperative fentanyl requirements, and time to tracheal extubation. Among the three cohorts, there were no significant differences noted in terms of pain scores or time to recovery.

Conclusion

All the three techniques provided effective analgesia following umbilical hernia repair. Our findings offer effective and safe analgesic options as alternatives to the neuraxial (caudal) approach.

A prospective audit of pain profiles following general and urological surgery in children

BACKGROUND

Postoperative pain is frequently undertreated in children both in hospital and at home following discharge. Pain has both short- and long-term consequences for children, their families, and the healthcare system. A greater understanding of procedure-specific postoperative pain trajectories is required to improve pain management.

AIM

To determine the duration and severity of acute postoperative pain experienced by children undergoing 8 different general and urological procedures (primary outcomes). Behavioral disturbance rates, nausea and vomiting scores, and parental satisfaction were also examined during the follow-up period (secondary outcomes).

METHOD

Families of children (0-18 years) undergoing common general and urological procedures were invited to enroll in the study. Children's pain scores, measured using a parental proxy 0-10 numerical rating scale, were collected by telephone interview until pain was resolved. Analgesia prescribed and given, behavioral disturbance, nausea and vomiting scores, the method of medication education communication, and parental satisfaction were also measured.

RESULTS

Of 360 patients recruited, 326 complete datasets were available. Patients underwent laparoscopic appendicectomy (57), open appendicectomy (19), circumcision (50), cystoscopy (52), hypospadias repair (22), inguinal hernia repair (51), orchidopexy (51), or umbilical hernia repair (24). Postoperative pain peaked on the day of or the day after surgery in all groups, and decreased over time. Pain lasted a median duration of 5 postoperative days following open appendicectomy, and 0-2 postoperative days for other procedures. Behavioral disturbance rates closely followed pain scores. Analgesia administration at home varied widely between and within groups.

CONCLUSION

Pain management was inadequate in most of the groups studied, particularly after appendicectomy or umbilical hernia repair, with most children experiencing at least moderate pain on the day of and day after surgery. There was a need for a standardized management, with increased dual analgesia prescribing, to ensure that children receive adequate postoperative analgesia in hospital and at home.

Development of a novel technique for bilateral rectus sheath nerve blocks under laparoscopic-guidance

BACKGROUND

Bilateral rectus sheath blocks have proven to be superior to local anesthetic infiltration for umbilical incisions and have been gaining popularity for the treatment of perioperative pain in children. We aim to develop a technique of surgeon performed rectus sheath blocks under laparoscopic-guidance alone.

METHODS

In phase I, we observed the laparoscopic appearance of a rectus sheath block. The pain management team performed an ultrasound-guided rectus sheath nerve block as we visualized the posterior rectus sheath with the laparoscope. In phase II, after completion of the laparoscopic procedure, we performed a rectus sheath nerve block. Ultrasound was used to identify where the local anesthetic had been injected.

RESULTS

Nineteen patients were included in this study, accounting for 38 rectus sheath blocks. In phase I, we observed with the laparoscope the delivery of ten ultrasound-guided rectus sheath blocks. In phase II, 28 laparoscopic-guided rectus sheath blocks were completed with immediate ultrasound confirmation of correct placement.

CONCLUSIONS

We have demonstrated that the rectus sheath nerve block can be performed reliably under laparoscopic-guidance alone. The efficacy of the laparoscopic-guided nerve block compared to the ultrasound-guided approach will need further study in a prospective, randomized trial.

TYPE OF STUDY

Retrospective review.

LEVEL OF EVIDENCE

3.

Percutaneous ultrasound-guided vs. intraoperative rectus sheath block for pediatric umbilical hernia repair: A randomized clinical trial

BACKGROUND

Regional anesthesia is commonly used in children. Our hypothesis was that percutaneous ultrasound-guided (PERC) rectus sheath blocks would result in lower postoperative pain scores compared to intraoperative (IO) rectus sheath blocks following umbilical hernia repair.

METHODS

A single-institution randomized blinded trial was conducted in pediatric patients undergoing elective umbilical hernia repair. The primary outcome was mean postoperative Wong-Baker pain score. Secondary outcomes included narcotic requirements and length of postoperative stay.

RESULTS

Fifty-eight patients were included: 28 PERC and 30 IO. Operating room time was significantly longer in the PERC group (41 vs. 35min, p<0.01). Mean postoperative pain scores (PERC-2.6 vs. IO-3.3, p=0.11), morphine equivalents intraoperatively (PERC-0 vs. IO-0.04mg/kg, p=0.29) and postoperatively (PERC-0.04 vs. IO-0.09mg/kg, p=0.17), time to first postoperative narcotic dose (PERC-30 vs. IO-22min, p=0.33, log-rank test), and postoperative length of stay (PERC-76 vs. IO-80min, p=0.44) were similar.

CONCLUSION

Following umbilical hernia repair in children, percutaneous ultrasound-guided and intraoperative rectus sheath blocks resulted in similar mean postoperative pain scores. There were no differences in secondary outcomes such as time to first narcotic, narcotic requirements, and length of stay. The additional resources required to complete a percutaneous ultrasound-guided rectus sheath block may not be warranted.

TYPE OF STUDY

Randomized controlled trial.

LEVEL OF EVIDENCE

Level I.

Comparison of the analgesic efficacy of ultrasound-guided rectus sheath block and local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children

BACKGROUND

Ultrasound-guided rectus sheath block and local anesthetic infiltration are the standard options to improve postoperative pain for children undergoing surgery with a midline incision. However, there is no study comparing the effect of ultrasound-guided rectus sheath block with local anesthetic infiltration for children undergoing laparoscopic surgery.

AIMS

The aim of this trial was to compare the onset of ultrasound-guided rectus sheath block with that of local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children.

METHODS

We performed an observer-blinded, randomized, prospective trial. Enrolled patients were assigned to either an ultrasound-guided rectus sheath block group or a local anesthetic infiltration group. The ultrasound-guided rectus sheath block group (n = 17) received ultrasound-guided rectus sheath block with 0.2 ml·kg^-1 of 0.375% ropivacaine per side in the posterior rectus sheath compartment. The local anesthetic infiltration group (n = 17) received local anesthetic infiltration with 0.2 ml·kg^-1 of 0.75% ropivacaine. The Face, Legs, Activity, Cry, and Consolability (FLACC) pain scores were recorded at 0, 30, 60 min after arrival at the postanesthesia care unit.

RESULTS

Of the 37 patients enrolled in this study, 34 completed the study protocol. A significant difference in the pain scale between the ultrasound-guided rectus sheath block group and local anesthetic infiltration group was found at 0 min (median: 0, interquartile range [IQR]: 0-1.5, vs median: 1, IQR 0-5, confidence interval of median [95% CI]: 0-3, P = 0.048), but no significant difference was found at 30 min (median: 1, IQR: 0-4 vs median: 6, IQR: 0-7, 95% CI: 0-5, P = 0.061), or 60 min (median: 0, IQR: 0-2 vs median: 1, IQR: 0-3, 95% CI: -1 to 1, P = 0.310). No significant difference was found in anesthesia time between the ultrasound-guided rectus sheath block and local anesthetic infiltration groups. No procedure-related complications were observed in either group.

CONCLUSION

Ultrasound-guided rectus sheath block is a quicker way to control postoperative pain for pediatric patients undergoing laparoscopic extraperitoneal closure than local anesthetic infiltration, and thus may provide a clinical benefit.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Rectus sheath and transversus abdominis plane blocks in children: a systematic review and meta-analysis of randomized trials

INTRODUCTION

The role of rectus sheath blocks (RSB) and transversus abdominis plane (TAP) blocks in pediatric surgery has not been well established.

OBJECTIVE

We aimed to determine if RSB and TAP blocks decrease postoperative pain and improve recovery in children.

DATA SOURCES

Duplicate searching of MEDLINE, EMBASE, Cochrane, Web of Science, and trial registries databases by two reviewers.

STUDY SELECTION

Included were randomized trials in children on RSB or TAP block in abdominal operations, excluding inguinal procedures.

DATA EXTRACTION

Independent duplicate data extraction and quality assessment using a standardized form.

RESULTS

Ten trials met inclusion criteria (n = 599), RSB in five and TAP block in five. A linear mixed effects model on patient level data from three trials showed nerve blocks lowered morphine requirements 6-8 h after surgery, -0.03 mg · kg(-1) (95% CI -0.05, -0.002). Pooled analysis of summary data showed nerve blocks lowered 0-10 scale pain scores immediately after the operation, -0.7 (95% CI -1.3, -0.1); lowered 4-16 scale pain scores, -2.0 (95% CI -2.3, -1.7); and delayed the time to first rescue analgesia, 17 min (95% CI 1.3, 33). Quality assessment showed some studies at moderate to high risk of bias.

CONCLUSION

Abdominal wall blocks reduce pain and opiate use in children. We advise cautious interpretation of the results given the heterogeneity of studies.

The use of ultrasound guidance for perioperative neuraxial and peripheral nerve blocks in children

BACKGROUND

The use of ultrasound guidance for regional anaesthesia has become popular over the past two decades. However, it is not recognized by all experts as an essential tool. The cost of an ultrasound machine is substantially higher than the cost of other tools such as a nerve stimulator.

OBJECTIVES

To determine whether ultrasound guidance offers any clinical advantage when neuraxial and peripheral nerve blocks are performed in children in terms of increasing the success rate or decreasing the rate of complications.

SEARCH METHODS

We searched the following databases to March 2015: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OvidSP), EMBASE (OvidSP) and Scopus (from inception to 27 January 2015).

SELECTION CRITERIA

We included all parallel randomized controlled trials (RCTs) that evaluated the effects of ultrasound guidance used when a regional blockade technique was performed in children, and that included any of our selected outcomes.

DATA COLLECTION AND ANALYSIS

We assessed selected studies for risk of bias by using the assessment tool of The Cochrane Collaboration. Two review authors independently extracted data. We graded the level of evidence for each outcome according to the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) Working Group scale.

MAIN RESULTS

We included 20 studies (1241 participants) for which the source of funding was a government organization (two studies), a charitable organization (one study), an institutional department (four studies) or an unspecified source (11 studies); two studies declared that they received help from the industry (equipment loan). In 14 studies (939 participants), ultrasound guidance increased the success rate by decreasing the occurrence of a failed block: risk difference (RD) -0.11 (95% confidence interval (CI) -0.17 to -0.05); I(2) = 64%; number needed for additional beneficial outcome for a peripheral nerve block (NNTB) 6 (95% CI 5 to 8). Blocks were performed under general anaesthesia (usual clinical practice in this population); therefore, haemodynamic changes to the surgical stimulus (rather than classic sensory/motor blockade evaluation) were used to define success. For peripheral nerve blocks, the younger the child, the greater was the benefit. In eight studies (414 participants), pain scores at one hour in the post-anaesthesia care unit were reduced when ultrasound guidance was used; however, the clinical relevance of the difference was unclear (equivalent to -0.2 on a scale from 0 to 10). In eight studies (358 participants), block duration was longer when ultrasound guidance was used: standardized mean difference (SMD) 1.21 (95% CI 0.76 to 1.65; I(2) = 73%; equivalent to 62 minutes). Here again, younger children benefited most from ultrasound guidance. Time to perform the procedure was reduced when ultrasound guidance was used for pre-scanning before a neuraxial block (SMD -1.97, 95% CI -2.41 to -1.54; I(2) = 0%; equivalent to 2.4 minutes; two studies with 122 participants) or as an out-of-plane technique (SMD -0.68, 95% CI -0.96 to -0.40; I(2) = 0%; equivalent to 94 seconds; two studies with 204 participants). In two studies (122 participants), ultrasound guidance reduced the number of needle passes required to perform the block (SMD -0.90, 95% CI -1.27 to -0.52; I(2) = 0%; equivalent to 0.6 needle pass per participant). For two studies (204 participants), we could not demonstrate a difference in the incidence of bloody puncture when ultrasound guidance was used for neuraxial blockade, but we found that the number of participants was well below the optimal information size (RD -0.07, 95% CI -0.19 to 0.04). No major complications were reported for any of the 1241 participants. We rated the quality of evidence as high for success, pain scores at one hour, block duration, time to perform the block and number of needle passes. We rated the quality of evidence as low for bloody punctures.

AUTHORS' CONCLUSIONS

Ultrasound guidance seems advantageous, particularly in young children, for whom it improves the success rate and increases the block duration. Additional data are required before conclusions can be drawn on the effect of ultrasound guidance in reducing the rate of bloody puncture.

Dose effect of local anesthetics on analgesic outcomes for the transversus abdominis plane (TAP) block in children: a randomized, double-blinded, clinical trial

BACKGROUND

Current knowledge on local anesthetic dosage for the TAP block in pediatric patients is very limited.

OBJECTIVE

To evaluate the effect of two escalating local anesthetic doses on postsurgical analgesic outcomes in children receiving a TAP block.

METHODS

The study was a prospective, randomized, double-blinded, clinical trial. Children (<8 years) were randomized to one of the two intervention groups: TAP block with bupivacaine at a dose of 2.5 mg · kg(-1) or 1.25 mg · kg(-1). Analgesic outcomes included pain scores in the postanesthesia care unit (PACU), time to analgesic requirement and total number of analgesic requirements.

RESULTS

Thirty-six patients were recruited in the study. Pain scores in PACU were not different between study groups. The total number of analgesic dosage required in 24 h after surgery was higher in the lower dose group, median (IQR) of 4 (3 to 5) compared to 2.5 (1.5 to 3) in the greater dose group, P = 0.03. There was a clinically but not statistically significant difference in the time to first analgesic requirement in the 2.5 mg · kg(-1) group, median (IQR) of 248 (130 to 367) minutes compared to 146 (95 to 261) minutes in the 1.25 mg · kg(-1) dose group, P = 0.15.

CONCLUSIONS

The use of higher local anesthetic doses for the TAP block in children does not provide benefits on early pain scores but seems to improve analgesic duration and decrease the need for additional analgesics over 24 h after surgery. The use of higher, but yet safe, local anesthetic dosages for TAP blocks is a viable strategy to improve analgesia in children.