Vertical infraclavicular brachial plexus block in children: a preliminary study

The extent of blockade following axillary and infraclavicular approaches of brachial plexus block in uremic patients

INTRODUCTION

This study was aimed to compare the axillary approach performed through multiple injection method and vertical infraclavicular approach performed through single injection method in terms of the sensory and motor block onset, quality, and extent of blocks of brachial plexus in uremic patients who underwent arteriovenous fistula surgery.

METHODS

Forty patients scheduled for creation of arteriovenous fistula with axillary brachial plexus block (group AX, n = 20) or infraclavicular brachial plexus block (IC group, n = 20) were examined. The median, radial, ulnar, and musculocutaneous nerves were selectively localized by nerve stimulation. The volume of the local anesthetics was calculated based on the height of each patient, and the volume determined was prepared by mixing 2% lidocaine and 0.5% bupivacaine in equal proportions. Sensory and motor block were assessed at 3, 6, 9, 12, 15, 18, and 30th min and their durations were measured.

RESULTS

While the adequate sensory and motor block rate with axillary approach was 100% in musculocutaneous, median, radial, ulnar and medial antebrachial cutaneous nerves, it was 65% in axillary nerve, 80% in intercostobrachial nerve and 95% in medial brachial cutaneous nerve. This rate was found to be 100% for all the nerves with infraclavicular approach.

CONCLUSION

For arteriovenous fistula surgeries in uremic patients, both axillary approach performed through multiple injection method and vertical infraclavicular approach performed through single injection method can be used successfully; however, for the short performance of the procedure, infraclavicular block may be preferred.

KEYWORDS

Brachial plexus block; Axillary; Infraclavicular; Uremic patients.

[Ultrasound guidance in pediatric regional anesthesia]

Ultrasound imaging is being used to guide pediatric nerve block procedures. Difficulties that arise because of the smaller anatomical structures in children can be compensated for by the greater aqueous consistency and reduced calcification. Given the shorter distance between the surface of the skin and nerves, it is advisable to use a linear array transducer working at a high frequency (7-10 MHz). Like adults, children benefit when ultrasound guidance is used in the performance of neuraxial nerve trunk blocks, particularly of the umbilical and ilioinguinal nerves, and in greater measure in spinal blocks. Ultrasound guidance enhances efficacy and also affords the important advantage of greater safety. The main disadvantages are the cost of equipment and the necessary learning curve.

Ultrasound-guided supraclavicular vs infraclavicular brachial plexus blocks in children

BACKGROUND

Supraclavicular brachial plexus blocks are not common in children because of risk of pneumothorax. However, infraclavicular brachial plexus blocks have been described in paediatric patients both with nerve stimulation and ultrasound (US)-guidance. US-guidance reduces the risk of complications in supraclavicular brachial plexus blocks in adults.

OBJECTIVE

To compare the success rate, complications and time of performance of US-guided supraclavicular vs infraclavicular brachial plexus blocks in children.

MATERIAL AND METHODS

Eighty children, 5-15 years old, scheduled for upper limb surgery were divided into two randomized groups: group S (supraclavicular), n = 40, and group I (infraclavicular), n = 40. All blocks performed were exclusively US-guided, by a senior anaesthesiologist with at least 6 months of experience in US-guided blocks. For supraclavicular blocks the probe was placed in coronal-oblique-plane in the supraclavicular fossa and the puncture was in-plane (IP) from lateral to medial. For infraclavicular blocks the probe was placed parallel and below the clavicle and the puncture was out-of-plane. Ropivacaine 0.5% was administered up to a maximum of 0.5 ml x kg(-1) until appropriate US-guided-spread was achieved. Block duration and volumes of ropivacaine used (mean+/-1SD) in the supraclavicular approach were recorded. Success rate (mean +/- 1 SD, 95%confidence interval), complications rate and time to perform the block (two-tailed Student's test) were recorded both for supraclavicular and infraclavicular approaches.

RESULTS

In the US-guided supraclavicular brachial plexus blocks, the duration of the sensory block was 6.5 +/- 2 h and of the motor block was 4 +/- 1 h. The volume of ropivacaine used in this group was 6 +/- 2 ml. In group I, 88% of blocks achieved surgical anaesthesia without any supplemental analgesia compared with 95% in group S (P = 0.39; difference=7%; 95% CI: -10% to 24%). Failures in group I were because of arterial puncture and insufficient ulnar or radial sensory block. Failures in group S were because of insufficient ulnar sensory block. No pneumothorax or Horner's syndrome was recorded in either group. The mean time (SD) to perform the block was in group I: 13 min (range 5-16) and in group S: 9 min (range 7-12); the 95% CI for this difference was 2-6 min and was statistically significant (P < 0.05).

CONCLUSIONS

(i) Ultrasound-guided supraclavicular and infraclavicular brachial plexus blocks are effective in children. (ii) There has been no pneumothorax in 40 US-guided supraclavicular brachial plexus blocks performed by anaesthesiologists already trained in US-guided regional anaesthesia using an IP technique in children > or =5 years old. (iii) In this study, the supraclavicular approach of the brachial plexus was faster to perform than the infraclavicular one.

Continuous infraclavicular brachial plexus block in a child

Continuous regional anesthesia for both intra- and postoperative use in adults is becoming more common. As with many new anesthesia techniques, however, there is often a lag time before the same techniques are utilized in children. Our patient was a 10-year-old child requiring reoperation on her fifth digit with planned 48-h admission for range of motion exercises. We wanted to have a continuous regional blockade to control the patient's pain during the postoperative manipulations of the digit. A search of the literature from the last 10 years did not show any reports of the placements of a continuous brachial plexus block in children. In this case report, we present the successful placement and use of a continuous infraclavicular catheter in a child undergoing upper extremity surgery.

New local anesthetics for pediatric anesthesia

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Intraarticular Bupivacaine-Clonidine-Morphine Versus Femoral-Sciatic Nerve Block in Pediatric Patients Undergoing Anterior Cruciate Ligament Reconstruction

We hypothesized that combined femoral-sciatic nerve block (FSNB) offers better analgesia with fewer side effects than intraarticular infiltration (IA) in children undergoing anterior cruciate ligament (ACL) reconstruction. Thirty-six children undergoing ACL reconstruction were randomized to FSNB or IA. FSNB patients had FSNB with bupivacaine (0.125%)-clonidine (2 microg/kg), whereas IA patients received bupivacaine (0.25%)-clonidine (1 microg/kg)-morphine (5 mg). Postoperatively, analgesia was provided with patient-controlled analgesia and rescue morphine. Patient demographics were similar. FSNB patients required less intraoperative fentanyl (50 +/- 40 microg versus 80 +/- 50 microg; P = 0.04). Visual analog scale score for FSNB was smaller than IA in the recovery room (1.8 +/- 3 versus 5.4 +/- 3; P = 0.0002) and during the first 24 h (1.6 +/- 1 versus 2.9 +/- 2; P = 0.01)). FSNB morphine use in the first 18 h was less (7 +/- 13 mg versus 21 +/- 21 mg; P = 0.03). Fewer FSNB patients vomited (11% versus 50%; P = 0.03). IA patients required morphine patient-controlled analgesia sooner. After ACL reconstruction in children, FSNB with bupivacaine-clonidine provides better analgesia with fewer side effects than IA with bupivacaine-clonidine-morphine.