Tips and tricks to facilitate ultrasound-guided placement of peripheral nerve catheters in children.

AIM: To describe an approach to facilitate ultrasound (US)-guided placement of peripheral nerve catheters in children. BACKGROUND: Continuous peripheral nerve blocks (CPNB) provide excellent surgical anesthesia and postoperative analgesia. However, catheters can be difficult to place, especially in children. METHODS: Ten US-guided peripheral nerve catheters were placed and placement difficulties encountered were recorded. Four series of 15 consecutive US-guided CPNB were then performed, adding in each series one possible solution to each of the troubles previously encountered. Finally, all maneuvers were employed in the placement of 15 US-guided CPNB in children 3-10 years old and then followed clinically. RESULTS: Initial difficulties encountered were as follows: (i) introducing the catheter, (ii) catheter tip visualization, (iii) length of catheter to be introduced, and (iv) catheter fixation and appropriate long-lasting dressing. The proposed facilitating procedure that addresses each of these difficulties is as follows: (i) three-hand technique: an assistant's hand holds the US transducer, the proceduralist anesthetist slightly withdraws and rotates the needle tip with one hand and advances the catheter with the other, (ii) needle visualization in long axis (LAX) whenever possible with catheter placed inside the needle and US guidance of spread of local anesthetic (LA) through the catheter, (iii) catheter advanced until resistance is found or up to a maximum of 5 cm, and (iv) subcutaneous tunneling of the catheter, Dermabond glue, and careful transparent dressing. All catheters in the last series were 100% effective during surgery and provided complete analgesia for ≥3 days without complications. CONCLUSIONS: Continuous peripheral nerve blocks in children should be placed under US guidance in LAX whenever possible, with a three-hand technique and slightly withdrawing or rotating the needle tip to introduce the catheter, administering LA through the catheter, and performing subcutaneous tunneling and careful dressing.

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.

Study of the adjustment of the Ambu laryngeal mask under magnetic resonance imaging.

BACKGROUND: Our aim in this study was to analyze the adjustment of the laryngeal mask, Ambu AuraOnce, in pediatric patients during magnetic resonance imaging (MRI) and to look for a correlation between clinical parameters such as the sealing pressure and the ease of introduction with radiological parameters. METHODS: One-hundred and twenty-one pediatric patients from 4 months to 17 years who required a cranial MRI for other reasons were enrolled in the study. General anesthesia was induced with sevofluorane and no relaxant was used. Insertion attempts, sealing pressure, desaturation episodes and maintenance of anesthesia were recorded. Spontaneous ventilation was maintained throughout all procedures and no episodes of desaturation below 95% were seen. Patients without cough or pharyngeal pain were discharged after 1 h. Data were classified into three groups according to the size of the used laryngeal mask (group 1 for laryngeal mask number 1(1/2); group 2 for laryngeal mask number 2, and group 3 for laryngeal mask number 2(1/2)). Sagittal MRI cuts were reviewed to calculate neck flexion, laryngeal mask position and its relationship with the trachea. RESULTS: First-attempt introduction rate of the laryngeal mask was 96%, and it was 100% after a second attempt. Sealing pressure was 22.1+/-4.15 mmHg for group 1, 22.23+/-3.94 for group 2, and 23.83+/-3.28 for group 3. The angles between the laryngeal mask and the four first cervical vertebrae were calculated (group 1, 33.65+/-8.05; group 2, 28.09+/-6.65; group 3, 25.79+/-4.26). Distances between trachea and proximal and distal cuffs were measured to evaluate proper fitting of the laryngeal mask. Anomalous placement seen on MRI, using distances from proximal and distal cuff to trachea, occurred in 23.5% in group 1, 10.9% in group 2, and 13.8% in group 3. We found no correlation between this anomalous position of the laryngeal mask and sealing pressure or ease of introduction. CONCLUSIONS: The Ambu AuraOnce can be regarded as a safe product for airway maintenance in pediatric patients. No relationship was found between radiological measurements and sealing pressures.

Ultrasound-guided umbilical nerve block in children: a brief description of a new approach.

BACKGROUND: The most popular peripheral nerve blocks used in umbilical hernia repair are rectus sheath block and paraumbilical block. However, multiple anatomic variations have been described and some complications may occur. Ultrasonographic guidance of peripheral nerve blocks has reduced the number of complications and improved the quality of blocks. This case series describes a new ultrasound-guided puncture technique of the 10th intercostal nerve in pediatric umbilical surgery. METHODS: Ten children (age range: 2-5 years) scheduled for umbilical hernia repair were included. Following the induction of general anesthesia, the ultrasonographic anatomy of the umbilical region was studied with a 10-MHz linear probe. An ultrasound-guided peripheral block of the 10th intercostal nerve in the lateral edge of both rectus abdominis muscles (RMs) was performed (total of 20 punctures). Surgical conditions, intraoperative hemodynamic parameters, and postoperative analgesia by means of the modified CHEOPS scale were evaluated. RESULTS: Umbilical anatomy was clearly identified by ultrasound in all cases. The epigastric vessels were identified--above the umbilicus--within the depth of the muscular mass of the RM. The spread of local anesthetic was ultrasound-controlled in all cases. However, the intercostal nerve could not be visualized. All blocks were effective during the surgery. Postoperative analgesia was only required in two children in the second postoperative hour. There were no complications. CONCLUSIONS: Ultrasound guidance enables performance of an effective umbilical block in the lateral edge of RM. Further studies should be carried on to visualize the intercostal nerve and to compare this technique with the classical ones.

Vertical infraclavicular brachial plexus block in children: a preliminary study.

BACKGROUND: Brachial plexus blockade is a well-established technique in upper limb surgery. Among the infraclavicular approaches, the vertical infraclavicular brachial plexus (VIP) block is easy to perform and has a large spectrum of nerve blockade. The aim of this preliminary study was to determine the ease, effectiveness, safety, and duration of the VIP block in pediatric trauma surgery. METHODS: Fifty-five patients (ASA physical status I and II, age range 5-17 years old) scheduled for upper limb trauma surgery received a VIP block under light general anesthesia, using 0.5 ml x kg(-1) of ropivacaine 0.5%. The number of attempts and time to perform the block, the occurrence of a surgical response, the visual analogue score (VAS) scores, the incidence of complications and the duration of the block were evaluated. RESULTS: The brachial plexus was found easily at the first or second attempt in 85% (47 of 55) of the cases, in 15% (eight of 55) of the cases it was localized after three to four attempts. The mean time to perform the block was 3.35 +/- 3.37 min. Ninety-eight percentage (54 of 55) of the blockades were effective for surgery and in just one case was ineffective. The VAS scores at the end of the procedure in 100% (55 of 55) of the cases were <3. There were no cases with clinical signs of pneumothorax nor inadvertent puncture of major vessels. Two patients developed a Horner's syndrome and in one a mild superficial hematoma at the puncture site occurred. The mean sensory block duration was 8.45 +/- 1.71 h and the mean motor block duration was 6.52 +/- 2.50 h. CONCLUSIONS: In this preliminary study, the VIP block was easy to perform, effective and free of major complications for pediatric trauma surgery. With the doses of ropivacaine we used it was useful for intra- and postoperative analgesia.