Are peripheral and neuraxial blocks with ultrasound guidance more effective and safe in children?

Background and aims:  The efficacy and safety of ultrasound guided (USG) pediatric peripheral nerve and neuraxial blocks in children have not been evaluated. In this review, we have looked at the success rate, efficacy and complications with USG peripheral nerve blocks and compared with nerve stimulation or anatomical landmark based techniques in children.
Methods:  All suitable studies in MEDLINE, EMBASE Drugs and Cochrane Evidence Based Medicine Reviews: Cochrane Database of Systemic Reviews databases were identified. In addition, citation review and hand search of recent pediatric anesthesia and surgical journals were done. All three authors read all selected articles independently and a consensus was achieved. All randomized controlled trials (RCTs) comparing USG peripheral and neuraxial blocks with other techniques in children were included.
Results:  Ultrasound guidance has been demonstrated to improve block characteristics in children including shorter block performance time, higher success rates, shorter onset time, longer block duration, less volume of local anesthetic agents and visibility of neuraxial structures.
Conclusion:  Clinical studies in children suggest that US guidance has some advantages over more traditional nerve stimulation–based techniques for regional block. However, the advantage of US guidance on safety over traditional has not been adequately demonstrated in children except ilio-inguinal blocks.     

Peripheral and local anaesthetic techniques for paediatric surgery

Peripheral nerves blocks provide intraoperative and postoperative analgesia and are usually used as adjuncts to general anaesthesia in paediatric patients. For children in the UK, most of these blocks are performed under general anaesthesia. In older cooperative children, some are performed awake, providing the correct environment and reassurances are available to minimize stress and anxiety. Peripheral nerve blocks provide good quality analgesia without the adverse effects associated with systemic medications. Good pain management reduces morbidity and aids patient recovery, resulting in better patient and family satisfaction and earlier discharge. These factors are essential for successful and efficient paediatric surgery. Failure to achieve good pain control is obviously unpleasant, but has also been identified in the occurrence of sleep and behavioural disturbances in children following surgery. Delayed recovery and discharge can have significant disruptive and economic effects on the family and hospital. Despite these benefits, peripheral nerve blocks, like all invasive techniques, are associated with complications and adverse effects. They should only be performed after careful analysis of the risk:benefit ratio. This article discusses a general approach to common, predominantly, ultrasound-guided peripheral nerve blocks in children and role of peripheral catheters.     

Peripheral and local anaesthetic techniques for paediatric surgery

Peripheral nerve blocks provide intraoperative and postoperative analgesia and are usually used as adjuncts to general anaesthesia in paediatric patients. For children in the UK, most of these blocks are performed under general anaesthesia. In older cooperative children, some are performed awake, providing the correct environment and reassurances are available to minimize stress and anxiety. Peripheral nerve blocks provide good-quality analgesia without the adverse effects associated with systemic medications. Good pain management reduces morbidity and aids patient recovery, resulting in better patient and family satisfaction and earlier discharge. These factors are essential for successful and efficient paediatric surgery. Failure to achieve good pain control is obviously unpleasant, but has also been identified in the occurrence of sleep and behavioural disturbances in children following surgery. Delayed recovery and discharge can have significant disruptive and economic effects on the family and hospital. Despite these benefits, peripheral nerve blocks, like all invasive techniques, are associated with complications and adverse effects. They should only be performed after careful analysis of the risk:benefit ratio. This article discusses a general approach to peripheral nerve blocks in children, along with the benefits of a predominately ultrasound-based approach and the role of peripheral catheters.     

Tramadol for pain relief in children undergoing herniotomy: a comparison with ilioinguinal and iliohypogastric blocks

BACKGROUND: Prevention of postoperative pain in children is one of the most important objectives of the anesthesiologist. Preoperative ilioinguinal and iliohypogastric nerve blocks have been widely used to provide analgesia in children undergoing herniorrhaphy. Tramadol is an analgesic with micro-opioid and nonopioid activity. In this study we compared the usage of intravenous tramadol with ilioinguinal and iliohypogastric nerve blocks for control of post-herniorrhaphy pain in children aged 2-7 years. METHODS: Sixty patients were randomly allocated to two groups of thirty. One group received tramadol 1.5 mg.kg(-1) i.v. before induction of general anesthesia and the other had an ilioinguinal and iliohypogastric nerve block with 0.5% bupivacaine (0.25 ml.kg(-1)) before skin incision. We assessed pain using the Children's Hospital of Eastern Ontario Pain Scale and the Categorical Pain Scale. RESULTS: At 1, 4 and 24 h after surgery the two groups had identical pain scores. At 2 and 3 h after surgery the tramadol group experienced significantly less pain (P < 0.05). The rescue drug for residual pain, was used equally in the two groups. None of the 60 patients had respiratory depression but the tramadol group patients were found to have more episodes of nausea and vomiting (P < 0.05). CONCLUSIONS: We concluded that tramadol can have at least the same analgesic effect as that of ilioinguinal and iliohypogastric nerve blocks for post-herniorrhaphy pain in children, with even a superior effect at the time of maximal analgesia. We also highlight the troublesome side-effect of nausea and vomiting which brings into question the benefits of using this opioid that seems to lack respiratory depression.     

Regional anesthesia for sternotomy and bypass—Beyond the epidural

Systemic opioids have been the main stay for the management of perioperative pain in children undergoing cardiac surgery with sternotomy. The location, distribution, and duration of pain in these children have not been studied as extensively as in adults. Currently, there is no consensus to the dose of opioids required to provide optimum analgesia and attenuate the stress response while minimizing their unwanted side effects. At present there is a tendency to use lower dose aiming for early extubation and minimize opioid‐related side effects, but this may not obtund the stress response in all children. The development of chronic pain although rare when compared to adults is still a risk that needs further investigation. Regional anesthetic techniques, by blocking the afferent impulses, have been shown to be advantageous in reducing the stress response to surgery as well as pain and opioid requirements in children up to 24 hours after cardiac surgery. Central neuraxial blockades have not gained wide spread acceptance in these procedures due to the worry of hematoma, although rare, leading to catastrophic neurological outcomes. This review focuses on blocks outside the vertebral column, ie, peripheral nerve blocks, performed either in the front or the back of the chest wall to target the thoracic intercostal nerves. Techniques of ultrasound‐guided bilateral single shot paravertebral block and erector spinae block posteriorly and transversus thoracic plane block anteriorly are discussed. In addition, parasternal block and wound infiltration by surgeon as well as continuous local anesthetic infusion via catheters placed at end of procedures are summarized. Current evidence available for use of these techniques in children undergoing cardiac surgery are reviewed. These are based on small studies and case series and further studies are required to evaluate the risks and benefits of local anesthetic blocks in children undergoing cardiac surgery.     

‘Small blocks’ in paediatric patients

Regional anaesthetic techniques are now extensively used in paediatric anaesthesia. A better understanding and conceptualization of them has led us to define a new category of blocks, termed compartment blocks, in which the structure that has to be identified is a fascial plane, not the nerve to be blocked itself. Some of these compartment blocks, most of which have been described decades ago but fell into disuse, have now been rediscovered as they offer many advantages in terms of safety, efficiency and simplicity. These ‘small blocks’ share the same high benefit/risk ratio and, basically, the same technique of fascial plane localization; this makes them look very similar even though they involve various structures and nerves with no real anatomical link. In this category are included the peri-umbilical, ilioinguinal/iliohypogastric, pudendal, penile, fascia iliaca, saphenous nerve, metacarpal and laryngeal nerve blocks. These small blocks provide adequate analgesia for a number of very common procedures in paediatric patients; they do not require special skills, training, complicated or expensive devices. Their success rate is extremely high and they have no true contraindications or significant adverse effects. They are effective with only small amounts of local anaesthetics and thus, due to their many advantages, should be used extensively in children.     

Diagnostic nerve blocks in chronic pain

Diagnostic blocks are used to obtain information about the source of a patient's pain. As such they differ in principle and in practice from regional anaesthetic blocks. In order to be valid, diagnostic blocks must be precise and target-specific. They must be controlled in order to exclude false-positive responses. Sympathetic blocks have traditionally been performed without pharmacological controls, but studies have shown that the features of complex regional pain syndromes can be relieved equally well when normal saline is administered as when local anaesthetic is used. This warns that sympathetic blocks must be controlled in each and every case lest false conclusions be drawn about the response. Medial branch blocks of the lumbar and of the cervical dorsal rami have been extensively investigated in order to establish their validity, diagnostic utility and therapeutic utility. They provide an example and benchmark for how diagnostic blocks can and should be validated.     

Clinical implications of the transversus abdominis plane block in pediatric anesthesia

Optimal perioperative analgesia for infants and children after major abdominal surgery poses a challenge when central neuraxial techniques are contraindicated. As a regional anesthesia technique, the transversus abdominis plane (TAP) block has been shown to reduce opioid consumption and improve pain scores compared to traditional perioperative pain strategies. Accordingly, TAP blocks may be considered as an alternative to central neuraxial analgesia to optimize perioperative pain control. Advancements in ultrasound technology have further improved the reliability and safety profile of this technique. Despite growing recognition of the diverse clinical scenarios where TAP blocks may be of benefit, its use among pediatric anesthesiologists remains limited. This article describes the history, anatomy, and a review of the current literature on TAP blocks with an emphasis on outcomes in pediatric patients.     

Ultrasound guidance characteristics and efficiency of suprazygomatic maxillary nerve blocks in infants: a descriptive prospective study

Background: Bilateral suprazygomatic maxillary nerve blocks approach improves pain relief after palate surgery. We report the feasibility and efficiency of ultrasound‐guided suprazygomatic maxillary nerve blocks in cleft palate repair in children. Methods: Twenty‐five children scheduled to undergo surgical cleft palate repair were included. Ultrasound‐guided suprazygomatic maxillary blocks were performed according to landmarks previously defined. The ultrasound probe was located optimally over the maxilla and under the zygomatic bone to visualize the pterygopalatine fossa. 0.15·ml·kg^?1 of 0.2% ropivacaine was injected bilaterally. Feasibility of block, spread of local anesthetic, pain scores and side effects were noted. Results: Fifty ultrasound‐guided suprazygomatic maxillary nerve blocks were performed in 25 children. The needle movement was seen in all cases using an out‐of‐plane approach. The spread of LA was clearly observed in 94% (47/50) of cases. A poor ultrasound imaging was found in 4% (2/50), and the spread of LA was not identified in 2% of case (1/50). The median time to perform the block was 56 s (35–120 s). The median pain scores and consumption of nalbuphine were low during the study period. 80% of patients did not require continuous opioid infusion. No complication related to maxillary blocks was reported. Conclusion: With a very low technical failure rate and a good clinical success rate, ultrasound appears to be a useful and simple tool to aid suprazygomatic maxillary nerve block in children.     

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.     

A new formula of age-related anatomical landmarks for blockade of the sciatic nerve in the popliteal fossa in children using the posterior approach

Background:  Anatomical landmarks for sciatic nerve blockade are poorly described in children. In adults, the site of puncture of the high approach is located at least 10 cm above the popliteal skin crease.
Methods:  We hypothesized that correcting the adult landmarks (10 cm) by the ratio of the calculated child femoral shaft length over the adult femoral shaft length would provide adequate landmarks for needle introduction for popliteal nerve block in children.
Results:  The theoretical landmarks were calculated and tested in 21 infants and children. In all cases, the sciatic nerve was easily located using the nerve stimulator when the needle was inserted at the calculated place and 29 catheters were successfully placed in these 21 children.
Conclusion:  These simple landmarks adapted to children age are expected to help the clinicians to perform safely sciatic blocks at the popliteal fossa in young patients.     

Local anaesthetic dosage of peripheral nerve blocks in children: analysis of 40 121 blocks from the Pediatric Regional Anesthesia Network database

Background

The knowledge regarding appropriate dosage of local anaesthetics for peripheral nerve blocks in children is very scarce. The main objective of the current investigation was to evaluate dosing patterns of local anaesthetics in children receiving peripheral nerve blocks across multiple paediatric hospitals in the USA. We also sought to estimate the incidence of local anaesthetic systemic toxicity.

Surface mapping of peripheral nerves in children with a nerve stimulator

Defining anatomical landmarks may be difficult in the growing child. With the aid of a peripheral nerve stimulator, the path of many superficial peripheral nerves can be 'mapped' prior to skin penetration by stimulating the motor component of the peripheral nerve percutaneously with a 2-3.5 mA output. The required current will vary and is dependent upon the depth of the nerve and the moistness of the overlying skin. This 'nerve mapping technique' has proved particularly useful for brachial plexus, axillary, ulna and median nerve blocks in the upper limb and femoral and popliteal nerve blocks in the lower limb. It is a useful teaching tool and improves the success rate of peripheral nerve blocks in children of all ages.     

An introduction to femoral nerve and associated lumbar plexus nerve blocks under ultrasonic guidance

Anesthesiologists need approaches to peripheral nerve blocks that will work in all patients. Because we take care of many patients with morbid obesity at UCSF, we have utilized ultrasound guidance to improve our block success rates with femoral neuroblockade. However, rather than reserve its use for procedures and patients in which we expect difficult placement of the nerve block, we have broadened our scope of practice to integrate the use of ultrasound into most routine peripheral nerve blocks to gain proficiency with this important technique. With experience we have been able to establish another important principle: one only needs to establish the correct needle tip to fascial plane relationship before the injection of local anesthetic solution. It is unnecessary to make direct contact between the block needle and the nerve to ensure block success. We believe the ultrasonic guided needle approaches that we have described in the previous paragraphs will play a crucial role in the future practice of regional anesthesia.     

超声引导下神经阻滞技术用于患儿腹部手术后镇痛的进展

区域神经阻滞是多模式镇痛的基础方案。与静脉镇痛比较,区域神经阻滞具有更强的针对性和有效性,神经阻滞麻醉镇痛可有效减少阿片类药物使用带来的不良反应。联合应用超声引导技术,能够提高神经阻滞的安全性和精确性。患儿腹部神经阻滞解剖结构以及局麻药物扩散途径、临床应用以及并发症的报道较少,药物浓度与剂量缺乏统一标准,需要进一步的临床研究。本文分别从患儿腰方肌阻滞（QLB）、腹横肌平面阻滞（TAPB）、腹直肌鞘阻滞（RSB）、竖脊肌平面阻滞（ESPB）和椎旁阻滞（PVB）的局麻药物扩散途径、浓度剂量、临床应用及相关并发症等方面进行综述,以期为患儿术后镇痛提供参考。     

Peripheral and local anaesthetic techniques for paediatric surgery

Peripheral nerve blocks (PNBs) in paediatric patients are usually used as an adjunct to general anaesthesia, providing intra- and postoperative analgesia. These blocks provide good-quality analgesia preventing morbidity related to pain and reducing adverse effects from systemic analgesics. PNBs aid early patient recovery and discharge, which is essential in day-case surgery. Like all invasive techniques, PNBs are associated with complications and adverse effects. They should therefore be performed only after careful analysis of the risk:benefit ratio for each child. This article discusses a general approach to PNBs in children. It covers a small selection of limb and trunk blocks, and discusses the benefit of ultrasound guidance.     

The road to success: a review of 1000 axillary brachial plexus blocks

The authors present their experience of > 1000 axillary brachial plexus blocks performed over 13 years (1990-2002). Using a technique that involves the location of individual nerves with a nerve stimulator, the overall success rate was 97.9%, ranging from 89.7% in 1990 to 98.4% in 1998. There have been no failures, defined as the need for conversion to general anaesthesia, in the last 500 blocks. Supplementary nerve blocks at the elbow were performed in 22.2% of patients. The first author, trained and supervised by the second author, achieved similar success rates in half the time taken by the second author. The authors conclude that technique and experience are the keys to success, but that high success rates can be achieved in a short time if anaesthetists are trained by experts in regional anaesthesia.     

Ultrasound guided transversus abdominis plane block in infants, children and adolescents: a simple procedural guidance for their performance

The transversus abdominis plane block (TAP) has been described recently for pain management following abdominal surgery. Although many techniques have been described using anatomical landmarks, a simple ultrasound (US) guidance technique for the block has not been described in children. An article published by Hebbard and colleagues on the use of US-guidance for TAP blocks described the technique with the probe positioned at the midaxillary line with a needle insertion that is located further medial on the abdominal wall. This technique, although feasible in adults is not possible in children due to the need for obtaining a more thorough spread of the local anesthetic solution. We describe in this article, a user-friendly approach to the placement of a TAP block in infants, children and adolescents. Further pharmacokinetic data has to be obtained for actual dosing for these blocks in infants and children.     

Effect of ilioinguinal nerve block on the catecholamine plasma levels in orchidopexy: comparison with caudal epidural block

BACKGROUND: Both caudal epidural and ilioinguinal/iliohypogastric nerve blocks have been used to provide effective intra- and postoperative analgesia. Stress response hormone levels can be used as an objective method to assess the analgesic efficacy of the anaesthetic techniques used in infraumbilical surgery in children. In this study, we compared catecholamine blood levels in children undergoing these two different supplementary analgesic/anaesthetic techniques. METHODS: Thirty male paediatric patients undergoing orchidopexy, ASA I, received inhalation general anaesthesia, and were randomly allocated to one of two groups: a caudal group (n = 15) and an ilioinguinal/iliohypogastric nerve block group (n = 15). Plasma epinephrine and norepinephrine concentrations were measured at the induction time, at the end of surgery, and in the postanaesthesia care unit. Postoperative pain score was also assessed in the postanaesthesia care unit. Results: In both groups, there was a substantial decrease in the catecholamine blood levels; however, there were significantly higher levels of epinephrine in the ilioinguinal group at the end of surgery (P = 0.008) and in the recovery room (P = 0.02) and a significant higher level of norpinephrine in the recovery room (P = 0.008). CONCLUSIONS: The result of this study revealed that caudal epidural block was more effective than ilioinguinal block in suppressing the stress response as reflected in epinephrine and norepinephrine blood levels in orchidopexy patients.     

Peripheral nerve block in ankle fracture surgery: a qualitative study of patients’ experiences

Peripheral nerve blocks are popular as a mode of anaesthesia for limb surgery and their beneficial effects are well documented in elective surgery. However, concerns have been raised about potential rebound pain outweighing the benefits in acute ankle fracture surgery. Furthermore, pain scores and morphine consumption do not provide a full picture, as pain is subjective. To evaluate the clinical usefulness of peripheral nerve blocks, we explored patients’ expectations and experiences by means of semi‐structured interviews analysed with systematic text condensation. We obtained ethical approval and informed consent and sampled purposively among adult patients scheduled for ankle surgery with nerve blocks as the primary mode of anaesthesia. Patients were interviewed within 48 h postoperatively. Data saturation was reached after 13 interviews. We found that, despite pre‐emptive ibuprofen and paracetamol, some patients did experience excruciating rebound pain for up to 2 h, although most had little or no pain. The patients had doubts about what to do when the block wore off, which led to a risk of unnecessary pain levels or morphine overuse. Patients had difficulty understanding the effect and course of the nerve blocks. They had misunderstandings regarding the blocks’ effect on sensation, resulting in fear of feeling pain during surgery and of permanent nerve damage after surgery. However, patients valued the mental alertness, ability to ambulate and efficient pain relief provided by the blocks. We recommend that patients be given thorough and repeated information as we feel this is crucial in preventing undesirable responses from patients, and is likely to increase the overall clinical usefulness of nerve blocks in acute limb surgery.