Regional anaesthesia of the lower extremity in infants and children

A randomised study comparing the extent of block produced by spinal column height and body weight-based formulae for paediatric caudal analgesia

Background and Aims:

Height and weight-based formulae are used for calculation of dose of medications for caudal analgesia but these have not been compared. We compared spinal column height-based Spiegel and weight-based Takasaki and Armitage formulae for achieving maximum height of sensory neuraxial block after caudal epidural analgesia in paediatric patients.

Methods:

In this double-blind randomised study, children aged between 1 and 6 years and planned for infra-umbilical surgery were randomly allocated to receive caudal epidural block (targeting T₁₀level block) with 0.25% bupivacaine, using a volume calculated by modified Spiegel formula (group I), Takasaki formula (group II), and Armitage formula (group III). The Institute ethics committee reviewed and approved the study protocol. The primary endpoint of the study was the difference in the number of spinal segments blocked as assessed by pinprick method. The secondary endpoint was the difference in volume of 0.25% bupivacaine used among the groups. The groups were compared using one-way ANOVA.

Results:

Seventy-five patients (25 in each group) completed the study as per protocol. The mean number of spinal segments blocked was significantly different among groups (P < 0.001) with patients in group I (13.8 ± 0.83) showing significantly lower number of spinal segments blocked as compared to that in group II (15.8 ± 1.06; P < 0.001), and group III (16.8 ± 1.28; P < 0.001). The mean volume of 0.25% bupivacaine used in group I was significantly lower (P < 0.001) than that in group II and group III.

Conclusion:

Dose calculation in caudal epidural analgesia as per spinal column height-based modified Spiegel formula was more precise than bodyweight-based Takasaki and Armitage formulae.

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.

Neonatal pain management

The past 2-3 decades have seen dramatic changes in the approach to pain management in the neonate. These practices started with refuting previously held misconceptions regarding nociception in preterm infants. Although neonates were initially thought to have limited response to painful stimuli, it was demonstrated that the developmental immaturity of the central nervous system makes the neonate more likely to feel pain. It was further demonstrated that untreated pain can have long-lasting physiologic and neurodevelopmental consequences. These concerns have resulted in a significant emphasis on improving and optimizing the techniques of analgesia for neonates and infants. The following article will review techniques for pain assessment, prevention, and treatment in this population with a specific focus on acute pain related to medical and surgical conditions.

Postoperative analgesia for the surgical correction of congenital clubfoot: comparison between peripheral nerve block and caudal epidural block

BACKGROUND AND OBJECTIVES

Correction of congenital clubfoot (CCF) is associated with severe postoperative pain. Caudal epidural block associated with general anesthesia is the anesthetic technique used more often in children, but it is limited by the short duration of the postoperative analgesia. Peripheral nerve blocks are associated with a low incidence of complications and prolonged analgesia. The objective of this study was to compare the duration of analgesia in peripheral nerve blocks and caudal block, as well as morphine consumption in the first 24 hours after correction of CCF in children.

METHODS

This is a randomized, double-blind study with children undergoing surgeries for posteromedial release of CCF, who were divided in four groups according to the anesthetic technique: caudal (ACa), sciatic and femoral block (IF), sciatic and saphenous block (IS), and sciatic block and local anesthesia (IL), associated with general anesthesia. In the first 24 hours, patients received oral dypirone and acetaminophen, and they were evaluated by anesthesiologists who were unaware of the technique used. Oral morphine (0.19 mg x kg(1) per day) was administered according to the scores of the CHIPPS (Children's and infants' postoperative pain scale) scale.

RESULTS

One hundred and eighteen children separated into four groups: ACa (30), IF (32), IS (28), and IL (28) participated in this study. The mean time between the blockade and the first dose of morphine was 6.16 hours in group ACa, 7.05 hours in group IF, 7.58 in IS, and 8.18 hours in IL. Morphine consumption was 0.3 mg.kg-1 per day in all four groups. Significant differences were not observed among the groups.

CONCLUSIONS

peripheral nerve blocks did not promote longer lasting analgesia or a decrease in morphine consumption in the first 24 hours in children undergoing CCF correction when compared to caudal epidural block.

Continuous sciatic block for leg and foot surgery in 160 children

BACKGROUND

The aim of this study was to assess the safety and efficacy of continuous sciatic block for lower limb surgery in children.

METHODS

A total of 160 pediatric patients aged 4 months to 12 years weighing 3.5-50 kg, were given continuous sciatic block plus single shot 3-in-1 block for leg and foot surgery. After general anesthesia, the sciatic nerve was located by using loss of resistance to saline by the mid-thigh approach. An 18 gauge epidural needle was introduced at the junction of the proximal two-third with the distal one-third of a line extending from the apex of popliteal triangle to the midpoint of the line joining the greater trochanter and the ischial tuberosity. A 20 g catheter was threaded through the needle for 5-10 cm and 0.25% bupivacaine 0.75 ml.kg(-1) was injected. A single shot 3-in-1 block was also given to facilitate the use of a tourniquet with 0.25% bupivacaine 0.25 ml. In 20 patients a nerve stimulator was used in addition to loss of resistance. The intraoperative sedation comprised propofol and ketamine infusions and 50% nitrous oxide in oxygen by LMA.

RESULTS

Eight-two percent of patients showed no response to surgery; 14% patients showed some response to the medial incision over the ankle and needed additional bolus doses of ketamine and propofol. Block was considered to have failed in 4% who required an increase in propofol and ketamine infusions. A total of 154 patients had good postoperative pain relief for 72 h with continuous infusion of 0.05% bupivacaine. The other six were given oral codeine and diclofenac. There were no complications attributable to sciatic block in any patient.

CONCLUSIONS

Sciatic block with a single shot 3-in-1 block for tourniquet pain and light general anesthesia provides good intraoperative conditions for leg and foot surgery and adequate postoperative pain relief. Additional sedation to minimize the discomfort of a cast may be a consideration in the first 24 h.

Continuous peripheral nerve blocks in children

In recent years, regional anaesthesia in children has generated increasing interest. Continuous peripheral nerve blocks have an important role in the anaesthetic arsenal, allowing effective, safe and prolonged postoperative pain management. Indications for continuous peripheral nerve blocks depend on benefits/risks analysis of each technique for each patient. The indications include surgery associated with intense postoperative pain, surgery requiring painful physical therapy, and complex regional pain syndrome. Continuous peripheral nerve blocks are usually performed under general anaesthesia or sedation, and require appropriate equipment in order to decrease the risk of nerve injury. New techniques, such as transcutaneous stimulation or ultrasound guidance, appear to facilitate nerve and plexus identification in paediatric patients. Nevertheless, continuous peripheral nerve block may mask compartment syndrome in certain surgical procedure or trauma. Finally, ropivacaine appears to be the best local anaesthetic for continuous peripheral nerve blocks in children, requiring low flow rate with low concentration of the local anaesthetic.

[The use of regional anesthesia in orthopedics]

Regional anesthesia has its place in the perioperative pain management of orthopedic patients. A reduction in postoperative mortality and morbidity with regional anesthesia is acknowledged for subsets of patient populations. Single shot and continuous applications are techniques for providing regional analgesia. Continuous infusion of local anesthetics with catheter techniques provides for uninterrupted postoperative analgesia. The combination of regional and general anesthesia reduces the consumption of systemic anesthetics. The side effects of opioid therapy are thereby reduced. The inhibition of intraoperative stress reaction, especially with epidural anesthesia, helps to prevent or lower unwanted metabolic changes. Patient contentment with analgesic quality differs with the technique with which the regional anesthesia is applied (PDA, PCEA, IVRA, peripheral block, i.a. injection), and the medication (LA, opioid) used.

Recent developments in paediatric regional anaesthesia

PURPOSE OF REVIEW

This review will focus on recently published data concerning side effects and complications of paediatric regional anaesthesia, putting into perspective the currently used techniques.

RECENT FINDINGS

Penile block is clearly a technique with a very large benefit and minimal side effects. Ilioinguinal nerve block, on the other hand, quite commonly leads to complications. Single-shot caudal anaesthesia is considered a safe and effective technique; however, even with this widely used block, complications such as sacral osteomyelitis can occur. Recent review articles have focussed on the role of additives for prolonging the duration of paediatric caudal anaesthesia. The use of ketamine or s-ketamine as an additive appears to be most promising for the future.

SUMMARY

Paediatric regional anaesthesia is now widely used for postoperative pain relief in children. However, a careful risk-benefit analysis is always mandatory before such medical interventions are undertaken.