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

Back to the Future: Historic Insights and Recent Innovations in Pediatric Regional Anesthesia

Pediatric regional anesthesia is evolving with new peripheral nerve blocks and techniques aimed at improving perioperative pain management. While caudal blocks have long been standard due to their simplicity and low complication rates, newer fascial plane blocks offer comparable efficacy with enhanced nerve coverage tailored to specific surgeries. Moreover, adjuncts like dexmedetomidine and dexamethasone have shown promise in prolonging block duration and enhancing post-operative pain relief and patient satisfaction. The integration of these advancements into clinical practice has yielded significant benefits, including reduced intraoperative fluid requirements, decreased reliance on opioids postoperatively, earlier initiation of enteral nutrition, lower readmission rates, shorter hospital stays, and decreased overall hospital costs. Our review underscores the technical progress and expanding literature supporting the rapid adoption of these impactful regional anesthesia techniques in pediatric care.

Transversus abdominis plane block with different bupivacaine concentrations in children undergoing unilateral inguinal hernia repair: a single-blind randomized clinical trial

BACKGROUND

Current knowledge on the ideal local anesthetic concentration for the ultrasound-guided transversus abdominis plane block (TAPB) in pediatrics is scarce. The purpose of this study is to compare the efficacy of US-guided TAPB at two different concentrations of bupivacaine in pediatrics undergoing unilateral inguinal hernia repair.

METHODS

After random allocation, 74 children aged 1-8 were randomized to receive US-guided TAPB by using 1 mg.kg^- 1 bupivacaine as either 0,25% (0,4 ml.kg^- 1) (Group 1) or 0,125% (0,8 ml.kg^- 1) (Group 2) concentration. All blocks were performed under general anesthesia, immediately after the induction, unilaterally with a lateral approach. All subjects received intravenous 15 mg/kg paracetamol 0.15 mg/kg dexamethasone and 0.1 mg/kg ondansetron intraoperatively. The primary outcome was the efficacy which is assessed by postoperative FLACC behavioral pain assessment score at 15', 30', 45', 1 h, 2 h, 6 h, and 24 h. The secondary outcomes were to assess the total dose of rescue analgesic consumption, length of hospital stay, the incidence of side effects, complications and satisfaction levels of the patients' parents and the surgeons.

RESULTS

Sixty-four children were recruited for the study. Postoperative pain scores were equal between the two groups. There was no need for a rescue analgesic in any group after the postoperative 6^thhour. No local or systemic complication or side effect related to anesthesia or surgery was reported.

CONCLUSION

TAPB using 1 mg.kg^- 1 bupivacaine administered as either high volume/low concentration or low volume/high concentration was providing both adequate analgesia and no side effects.

TRIAL REGISTRATION

This trial was retrospectively registered at Clinicaltrals.gov , NCT04202367 .

Pharmacokinetics of Bupivacaine Following Administration by an Ultrasound-Guided Transversus Abdominis Plane Block in Cats Undergoing Ovariohysterectomy

Bupivacaine is commonly used for peripheral nerve block in veterinary medicine. This study described the pharmacokinetics of two doses of bupivacaine following administration by an ultrasound-guided transversus abdominis plane (TAP) block in cats undergoing ovariohysterectomy. Twelve healthy female adult cats were included in a randomized, prospective, blinded clinical trial. Anaesthetic protocol included acepromazine–buprenorphine–propofol–isoflurane–meloxicam. Each cat received 1 mL/kg of bupivacaine 0.2% or 0.25% (BUPI-2 and BUPI-2.5, respectively) via bilateral two-point TAP block before surgery (n = 6/group). Plasma concentrations of bupivacaine were detected using liquid chromatography-mass spectrometry. A one-compartment model and non-compartmental analysis described the pharmacokinetic parameters. Bupivacaine was detected up to 480 min (335 ± 76 in BUPI-2 and 485 ± 198 ng/mL in BUPI-2.5). For BUPI-2 and BUPI-2.5, maximum plasma concentrations were 1166 ± 511 and 1810 ± 536 ng/mL at 33 ± 14 and 47 ± 22 min, clearance was 5.3 ± 1.8 and 4.9 ± 1.5 mL/min/kg, and elimination half-life were 253 ± 55 and 217 ± 52 min, respectively. The two doses of bupivacaine via TAP block produced concentrations below toxic levels in cats. A dose of 2.5 mg/kg bupivacaine was safe to be administered using this block in healthy cats.

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.

Ultrasound Verification of Laparoscopic-Assisted Transversus Abdominis Plane Blocks in Children Undergoing Laparoscopic Procedures

Purpose: Ultrasound-guided transversus abdominis plane (TAP) blocks have been demonstrated to decrease postoperative pain; however, laparoscopic-assisted TAP (L-TAP) blocks have not been well studied in children. Our study utilized intraoperative ultrasound to verify whether surgeon-administered blocks using only laparoscopic visualization were reliably delivered into the correct plane. Materials and Methods: Patients undergoing laparoscopic procedures were enrolled to receive L-TAP blocks. Preblock and postblock ultrasounds were performed to document the plane of local anesthetic delivery. Ultrasound images were reviewed by two blinded anesthesiologists to determine whether the L-TAP block was administered into the desired plane. Results: Fifty-one patients were enrolled. The average age was 5.9 years (range: 2 days to 17 years) and the mean weight was 25.4 kg (range: 2.64-118.8 kg). The most common procedures were inguinal hernia repair (n = 19), appendectomy (n = 10), and gastrostomy-tube placements (n = 13). Nine surgeons performed 93 L-TAP blocks (average: 10.3 blocks/surgeon). Ultrasound confirmed distribution in the correct plane in 53.5/93 blocks (57.5%; 58.0% for attending surgeons), with 77.4% concurrence between the anesthesiologist reviewers. Conclusion: L-TAP achieves delivery of local anesthetic into the correct tissue plane in over half the cases with minimal training. Further studies are needed to examine the effect of L-TAP blocks on reducing postoperative pain in pediatric patients.

Guidelines for Opioid Prescribing in Children and Adolescents After Surgery: An Expert Panel Opinion

IMPORTANCE

Opioids are frequently prescribed to children and adolescents after surgery. Prescription opioid misuse is associated with high-risk behavior in youth. Evidence-based guidelines for opioid prescribing practices in children are lacking.

OBJECTIVE

To assemble a multidisciplinary team of health care experts and leaders in opioid stewardship, review current literature regarding opioid use and risks unique to pediatric populations, and develop a broad framework for evidence-based opioid prescribing guidelines for children who require surgery.

EVIDENCE REVIEW

Reviews of relevant literature were performed including all English-language articles published from January 1, 1988, to February 28, 2019, found via searches of the PubMed (MEDLINE), CINAHL, Embase, and Cochrane databases. Pediatric was defined as children younger than 18 years. Animal and experimental studies, case reports, review articles, and editorials were excluded. Selected articles were graded using tools from the Oxford Centre for Evidence-based Medicine 2011 levels of evidence. The Appraisal of Guidelines for Research & Evaluation (AGREE) II instrument was applied throughout guideline creation. Consensus was determined using a modified Delphi technique.

FINDINGS

Overall, 14 574 articles were screened for inclusion, with 217 unique articles included for qualitative synthesis. Twenty guideline statements were generated from a 2-day in-person meeting and subsequently reviewed, edited, and endorsed externally by pediatric surgical specialists, the American Pediatric Surgery Association Board of Governors, the American Academy of Pediatrics Section on Surgery Executive Committee, and the American College of Surgeons Board of Regents. Review of the literature and guideline statements underscored 3 primary themes: (1) health care professionals caring for children who require surgery must recognize the risks of opioid misuse associated with prescription opioids, (2) nonopioid analgesic use should be optimized in the perioperative period, and (3) patient and family education regarding perioperative pain management and safe opioid use practices must occur both before and after surgery.

CONCLUSIONS AND RELEVANCE

These are the first opioid-prescribing guidelines to address the unique needs of children who require surgery. Health care professionals caring for children and adolescents in the perioperative period should optimize pain management and minimize risks associated with opioid use by engaging patients and families in opioid stewardship efforts.

The Role of Interfascial Plane Blocks in Paediatric Regional Anaesthesia: A Narrative Review of Current Perspectives and Updates

Regional anaesthesia has been increasingly used for analgesia in the perioperative period in paediatric anaesthesia for better pain control and improved patient outcomes. Interfascial plane blocks are considered as a subgroup of peripheral nerve blocks. The advent of ultrasound in modern regional anaesthesia practice has led to the evolution of various interfascial plane blocks. The ease of their performance and the low complication rates, compared with neuraxial anaesthesia, have led to their increased use in the perioperative period. Interfascial plane blocks are often incorporated in the multimodal analgesia regimen in the early recovery and ambulation after surgery protocols for various chest wall and abdominal surgeries. This achieves better pain control and decreases the requirements of opioids in the perioperative period, thereby facilitating early mobilization and discharge. This narrative review focuses on the relevant anatomic considerations, technique for the performance of each block along with its current applications and limitations, and includes a review of the current literature on various interfascial plane blocks in paediatric regional anaesthesia.

Comparison between Post-Operative Analgesic Efficacy of Low-Concentration High-Volume and High-Concentration Low-Volume Combinations of Ropivacaine for Transverse Abdominis Plane Block in Pediatric Open Inguinal Hernia Repair

Transverse abdominis plane (TAP) block can provide post-operative analgesia in children undergoing open inguinal hernia repair. However, the optimal anesthetic dose, and concentration for TAP block in the pediatric population, is not well defined. This study compared the post-operative analgesic effect of TAP block between low-concentration, with high-volume (LCHV) and high-concentration, with low-volume (HCLV) combinations of local anesthetic. Forty-four patients who underwent open inguinal hernia repair were randomly assigned to two groups. The patients in the LCHV group received 0.67 mL/kg of 0.15% ropivacaine. Whereas, those in the HCLV group received 0.4 mL/kg of 0.25% ropivacaine. Both groups received the same amount of ropivacaine (1 mg/kg). The primary outcome measure was the face, leg, activity, cry, consolability (FLACC) scale score at post-anesthetic care unit (PACU; T1). FLACC scale score at T1 was significantly lower in the HCLV group (2.91 versus 1.43; mean difference, −1.49; 95% confidence interval, −0.0245 to −2.936; p = 0.0464). FLACC scale scores one hour and six hours after the surgery were not different between the two groups. This study reports better post-operative analgesic effects after unilateral open inguinal hernia repair with 1 mg/kg of 0.25% ropivacaine than 1 mg/kg of 0.15% ropivacaine at PACU.

A Retrospective Study Evaluating the Effect of Low Doses of Perineural Dexamethasone on Ropivacaine Brachial Plexus Peripheral Nerve Block Analgesic Duration

Objective

Examination of the effectiveness of perineural dexamethasone administered in very low and low doses on ropivacaine brachial plexus block duration.

Design

Retrospective evaluation of brachial plexus block duration in a large cohort of patients receiving peripheral nerve blocks with and without perineural dexamethasone in a prospectively collected quality assurance database.

Setting

A single academic medical center.

Methods

A total of 1,942 brachial plexus blocks placed over a 16-month period were reviewed. Demographics, nerve block location, and perineural dexamethasone utilization and dose were examined in relation to block duration. Perineural dexamethasone was examined as none (0 mg), very low dose (2 mg or less), and low dose (greater than 2 mg to 4 mg). Continuous catheter techniques, local anesthetics other than ropivacaine, and block locations with fewer than 15 subjects were excluded. Associations between block duration and predictors of interest were examined using multivariable regression models. A subgroup analysis of the impact of receiving dexamethasone on block duration within each block type was also conducted using a univariate linear regression approach.

Results

A total of 1,027 subjects were evaluated. More than 90% of brachial plexus blocks contained perineural dexamethasone (≤4 mg), with a median dose of 2 mg. Increased block duration was associated with receiving any dose of perineural dexamethasone (P < 0.0001), female gender (P = 0.022), increased age (P = 0.048), and increased local anesthetic dose (P = 0.01). In a multivariable model, block duration did not differ with very low- or low-dose perineural dexamethasone after controlling for other factors (P = 0.420).

Conclusion

Perineural dexamethasone prolonged block duration compared with ropivacaine alone; however, duration was not greater with low-dose compared with very low-dose perineural dexamethasone.

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.

An Evaluation of the Adding Magnesium Sulfate to Ropivacaine on Ultrasound-Guided Transverse Abdominis Plane Block After Abdominal Hysterectomy

Background

Post-hysterectomy pain is extremely annoying and using transverse abdominis plane (TAP) block can be a useful method to manage postoperative pain, but its duration of effect is challenging. Magnesium sulfate increases, in some cases, the effects of local anesthetics on the peripheral nerve blocks.

Objectives

The current study aimed at investigating the effects of adding magnesium sulfate to ropivacaine in the transverse abdominis plane block after hysterectomy.

Methods

The current randomized, double blind, clinical trial, to manage postoperative pain, was conducted on a total of 60 patients, 30 - 60 years old, ASA (American Society of Anesthesiologists) class I-II undergone elective abdominal hysterectomy candidates to receive ultrasound-guided bilateral transverse abdominis abdominis plane (TAP) blocks. Patients with coagulation disorders, infection, history of any addiction, sensitivity to the local anesthetics and magnesium sulfate were excluded. The subjects were equally allocated into two groups, the control group, ropivacaine plus normal saline (R), and the study group, ropivacaine plus magnesium sulfate (RM). The injection contained 19 mL ropivacaine 0.2% plus 1 mL normal saline in the group R, and 19 mL ropivacaine 0.2% plus 1 mL magnesium sulfate 50% in the RM group on each side. As well as the patients' characteristics, the level of pain score (visual analogue scale = VAS), rescue analgesic demand (diclofenac suppository), and possible adverse effects were evaluated at 1, 2, 6, 12, and 24 hours after the operation in the two groups.

Results

The mean pain scores of the patients at the first hour after surgery were 5.7 ± 0.9 and 5.9 ± 1.1 in R and RM groups, respectively. The scores reached 2.9 ± 0.5 and 2.7 ± 0.4 at the second hour after surgery (the first post-block measurement) and 3.1 ± 0.7 and 2.8 ± 0.7 within the next 24 hours, respectively. Although the pain scores were generally lower at all hours in the RM group, none was statistically significant. The rescue analgesic consumption gradually increased in the two groups, and it was less in the study group than in the control group in the first hours after the block (second hour after surgery); however, it was not statistically significant. No adverse effects were observed in the two groups.

Conclusions

Results of the current study suggested that the addition of magnesium sulfate to ropivacaine in TAP block does not affect the post-hysterectomy pain.

Ultrasound-guided lateral and subcostal transversus abdominis plane block in calves: a cadaveric study

OBJECTIVE

To describe and assess the ultrasound-guided transversus abdominis plane (TAP) block feasibility in calf cadavers, to compare two injection volumes and to evaluate possible undesired solution spreads.

STUDY DESIGN

Prospective, descriptive, anatomic study.

ANIMALS

A group of 15 bovine cadavers weighing 47±11 kg (mean±standard deviation).

METHODS

Lateral (n = 24) and subcostal (n = 12) TAP block approaches were assessed. For each approach, two volumes (0.2 or 0.4 mL kg^-1) of toluidine blue and contrast medium were injected using both sides of the animals. Nerve staining was assessed by anatomical dissection and spread of injectate by contrast-enhanced computed tomography. Objective and subjective technique feasibility was evaluated by a specific score (poor, good, excellent).

RESULTS

Using the lateral approach, 58%, 92% and 25% and 75%, 83% and 25% of the thirteenth thoracic, first and second lumbar nerves were stained by 0.2 and 0.4 mL kg^-1, respectively. Craniocaudal and dorsoventral solution spread and number of blocks that adequately stained an individual nerve were not significantly different between the volumes. Using the subcostal approach, 67%, 83%, 67%, 67% and 50%, and 83%, 100%, 83%, 83% and 50% of the eighth, ninth, tenth, eleventh, twelfth thoracic nerves were stained by 0.2 and 0.4 mL kg^-1, respectively. With both techniques, no intraspinal and one intraperitoneal spread were observed. Objective and subjective feasibility score was excellent for both approaches in the majority of the cases.

CONCLUSIONS AND CLINICAL RELEVANCE

TAP injections were easy to perform with both techniques in calf cadavers. The volume of injectate did not influence spread. The authors conclude that a combination of the two approaches is necessary, but perhaps not sufficient, to stain all of the nerves innervating the ventral abdominal wall. Further studies are required to refine the technique and evaluate its efficacy in preventing nociception in calves.

Femoral nerve blockade using various concentrations of local anesthetic for knee arthroscopy in the pediatric population

BACKGROUND

Femoral nerve blockade (FNB) provides effective postoperative analgesia in children undergoing arthroscopic knee surgery as evidenced by their opioid-sparing effects and decreased postoperative pain scores. Increasing the local anesthetic concentration in peripheral nerve blockade for adults undergoing orthopedic surgery has been shown to be beneficial, increasing block success rate, and providing a longer duration of analgesia. The effect of increasing the concentration of local anesthetic in extremity blocks in children remains largely unexplored.

METHODS

We retrospectively evaluated the effectiveness of FNB using three concentrations of local anesthetic (ropivacaine 0.2%, bupivacaine 0.25%, and ropivacaine 0.5%) in children and adolescents undergoing arthroscopic knee surgery. The primary outcome evaluated was postoperative opioid consumption before discharge. Secondary outcomes included post-anesthesia care unit (PACU) and hospital discharge times, first pain score in PACU, and the incidence of adverse events.

RESULTS

Two hundred and sixty-nine children and adolescents who received a FNB for arthroscopic knee surgery from January 2010 to December 2013 were included for analysis. Local anesthetic used in FNB was ropivacaine 0.2% in 116 (43%) cases, ropivacaine 0.5% in 75 (28%) cases, and bupivacaine 0.25% in 78 (29%) cases. Median postoperative opioid consumption (mg/kg intravenous morphine equivalents) in the ropivacaine 0.5% group was 0 mg/kg (interquartile ranges [IQR]: 0 mg, 0.03 mg/kg) compared to 0.02 mg/kg (IQR: 0, 0.08 mg/kg) in the ropivacaine 0.2% group and 0.01 mg/kg (IQR: 0, 0.08 mg/kg) in the bupivacaine 0.25% group (p=0.009). Median PACU time was shortest in the ropivacaine 0.5% group (47 min; IQR: 36, 68 min) compared to the ropivacaine 0.2% (58 min; IQR: 41, 77) and bupivacaine 0.25% (54 min; IQR: 35, 75 min) groups (p=0.040). Among groups, there were no significant differences in first postoperative pain scores or incidence of nausea and vomiting. No patient in any group experienced a serious adverse event.

CONCLUSION

The results suggest that ropivacaine 0.5% for FNB offers superior postoperative analgesia in the form of decreased postoperative opioid consumption and earlier PACU/hospital discharge, when compared to ropivacaine 0.2% and bupivacaine 0.25% in the pediatric population.

LEVEL OF EVIDENCE

III, Retrospective Comparative Study.

Truncal blocks for perioperative pain management: a review of the literature and evolving techniques

As the American healthcare system continues to evolve and reimbursement becomes tied to value-based incentive programs, perioperative pain management will become increasingly important. Regional anesthetic techniques are only one component of a successful multimodal pain regimen. In recent years, the use of peripheral and paraneuraxial blocks to provide chest wall and abdominal analgesia has gained popularity. When used within a multimodal regimen, truncal blocks may provide similar analgesia when compared with other regional anesthetic techniques. While there are other reviews that cover this topic, our review will also highlight the emerging role for serratus plane blocks, pectoral nerve blocks and quadratus lumborum blocks in providing thoracic and abdominal analgesia.

Paediatric regional anaesthesia: a current perspective

PURPOSE OF REVIEW

Effective analgesia is necessary for optimal recovery after surgery, but children often do not attain adequate postoperative pain control. This review examines the current trends in paediatric regional anaesthesia.

RECENT FINDINGS

Better pain assessment and therapeutic regimens are needed for our patients. Trunk blocks such as paravertebral, transversus abdominis plane, rectus sheath and ilioinguinal/iliohypogastric are becoming a popular means of providing analgesia for thoracic and abdominal procedures. The introduction of ultrasound guidance improves accuracy, efficacy, and safety of regional anaesthesia, and also decreases the amount of local anaesthetic injected. Single injection nerve blocks have a limited duration and the patients can benefit from adding an adjunct to local anaesthetic or placing a catheter. The use of adjuncts is reasonable, but it is difficult to find a medication with both minimal side-effects and the ability to combat pain for extended periods of time. More peripheral nerve block catheters are used in the paediatric inpatient and outpatient settings and recent data support the feasibility and efficacy of ambulatory peripheral nerve catheters.

SUMMARY

By using a multimodal approach that includes regional anaesthesia, paediatric pain management should aim to reduce patients' pain to an acceptable level without compromising their degree of mobilization. Undoubtedly, peripheral nerve blocks improve analgesia, but future large prospective studies should be conducted to further delineate their effectiveness, duration and safety.

Comparative Effectiveness of Two Ultrasound-Guided Regional Block Techniques for Surgical Anesthesia in Open Unilateral Inguinal Hernia Repair

Transversus abdominis plane (TAP) and ilioinguinal/iliohypogastric (II/IH) nerve blocks have been described as analgesic adjuncts for inguinal hernia repair, but the efficacy of these techniques in providing intraoperative anesthesia, either individually or together, is not known. We designed this retrospective cohort study to test the hypothesis that combining TAP and II/IH nerve blocks ("double TAP" technique) results in greater accordance between the preoperative anesthetic plan and actual anesthetic technique provided when compared to TAP alone. Based on this study, double TAP may be preferred for patients undergoing open inguinal hernia repair who wish to avoid general anesthesia.