Neuraxial anaesthesia in paediatrics

Neuraxial anaesthesia is a valuable aid in the practice of paediatric anaesthesia. Spinal and epidural blockade are used as either the sole anaesthetic or as an adjunct to general anaesthesia, and often confer significant postoperative analgesia. Caudal epidural anaesthesia is used extensively for lower abdominal, urological and orthopaedic procedures in the setting of outpatient surgery. Lumbar and thoracic epidural infusions via a catheter can provide analgesia for chest and upper abdominal procedures. Major complications related to neuraxial catheter placement are uncommon in paediatric anaesthesia, even though block placement is typically after the patient is anesthetized. The use of the ultrasound for real-time visualization during paediatric neuraxial blocks provides an opportunity for observing final catheter position or confirming successful injection into the epidural space.     

Neuraxial anaesthesia in paediatrics

Neuraxial anaesthesia is a valuable aid in the practice of paediatric anaesthesia. Spinal and epidural blockade are used as either the sole anaesthetic or as an adjunct to general anaesthesia, and often confer significant postoperative analgesia. Caudal epidural anaesthesia is used extensively for lower abdominal, urological and orthopaedic procedures in the setting of outpatient surgery. Lumbar and thoracic epidural infusions via a catheter can provide analgesia for chest and upper abdominal procedures. Thoracic paravertebral blocks provide analgesia equivalent to thoracic epidurals but with fewer side effects. Their use in thoracic surgery have helped reduce the incidence of chronic thoracotomy pain. Major complications related to neuraxial catheter placement are uncommon in paediatric anaesthesia, even though block placement is typically after the patient is anaesthetized to ensure immobility during puncture. Available evidence suggest that it is safe to place regional blocks in children during general anaesthesia. Ultrasound is an excellent imaging modality for identifying the dura mater as the dura appears highly echogenic on ultrasound scans. Ultrasound imaging help estimate the location and level of spinous interspaces and may be useful in children with obesity, prior surgical instrumentation or scoliosis. The use of the ultrasound for real-time visualization during paediatric neuraxial blocks provides an opportunity for observing final catheter position or confirming successful injection into the epidural space.     

Lumbar and thoracic epidural anaesthesia in children

Epidural anaesthetic techniques are an established part of paediatric anaesthesia. Their positive effects on general anaesthetic requirements, stay in the recovery unit, efficient perioperative pain relief and blunting of the perioperative stress response promote the routine use of regional anaesthetic techniques in children.With increasing knowledge of the anatomy and physiology of children, refinements in equipment and increased knowledge of the pharmacology of the agents used, continuous epidural catheter techniques are considered to be safe. There is some evidence that an epidural approach via the caudal and trans-sacral route is a low-risk procedure, even if the catheter is advanced to higher levels. Despite its positive effects the direct puncture at thoracic levels will probably never reach the level of routine practice. Because of its potential risks, the use of thoracic epidural anaesthesia (TEA) should be restricted to experienced paediatric anaesthetists and specialized centres.     

Thoracic epidural anaesthesia and analgesia: United Kingdom practice

BACKGROUND: Thoracic epidural analgesia has become increasingly practised in recent years. Complications are rare but potentially serious and, consequently, careful evaluation is required before undertaking this technique. The practice surrounding this procedure varies widely amongst anaesthetists. METHODS: A postal survey to examine the practice of thoracic epidural analgesia was sent to all Royal College of Anaesthetists tutors in the United Kingdom. RESULTS: Responses were received from 240 tutors, representing a return rate of 83%. When obtaining consent for thoracic epidural cannulation, 42% of respondents mentioned risk of a dural tap complication and 11% mentioned neurological damage. Fifty percent of respondents performed epidural cannulation following induction of general anaesthesia. The practice of epidural insertion in patients with abnormal coagulation varied, although over 80% of respondents did not consider concurrent treatment with either aspirin or non-steroidal anti-inflammatory drugs a contraindication. Sterile precautions for epidural insertion also varied between anaesthetists. Postoperatively, 95% of respondents used an opioid-based bupivacaine solution for epidural infusions, and these were most commonly nursed on general surgical wards (63%). Seventy-eight percent of hospitals provided an acute pain team to review epidural analgesia. CONCLUSION: In the United Kingdom, there is little consensus in the practice of thoracic epidural analgesia relating to the issues of informed consent, epidural cannulation in patients with deranged clotting and the sterile precautions taken prior to performing epidural insertion. Most respondents use an opioid-based bupivacaine solution to provide postoperative epidural analgesia. Most hospitals in the UK now provide an acute pain service for thoracic epidural follow-up.     

Audit of epidural analgesia in children undergoing thoracotomy for decortication of empyema

Background: Uncertainty remains over the risk of epidural space infectionafter neuraxial blockade in the presence of systemic sepsis.For many years, we have provided epidural analgesia to childrenundergoing thoracotomy for the decortication of parapneumonicempyemas. Following recent publications asserting that epiduralanalgesia is absolutely contraindicated in this situation, weaudited our management. The purpose of this audit was to documentthe effectiveness and the incidence of complications after epiduralinsertion in children with active sepsis from empyemas. Methods: This is a retrospective single-centre audit over a 10-yr period. Results: Forty-six epidurals were performed in children with empyema,and three children were treated with systemic opioids. We foundno infective complications of the epidural space or insertionsites. The epidurals provided excellent analgesia. The incidenceof moderate–severe pain was 18%, and 2% for severe painin the first 24 h after surgery. Minor complications of epiduralanalgesia were uncommon. Two children receiving systemic opioidsfor pain relief suffered respiratory complications, one of whichresulted in a prolonged admission to the intensive care unit. Conclusions: Epidural analgesia provides excellent pain relief after thoracotomyin children with empyema, with a low complication rate. Untilevidence to the contrary emerges, it remains our technique ofchoice for thoracotomy, even in the presence of empyema.     

A national survey of neurological monitoring practice after obstetric regional anaesthesia in the UK

Neuraxial anaesthesia is widely used in obstetrics and neurological complications are rare. However, when they occur, subsequent investigation and management are time‐critical and correlate with the extent of neurological recovery. The Third National Audit Project recommended the implementation of guidelines in obstetric epidural management, including advice on monitoring for early signs of problems and acting upon concerns. However, no national guideline exists for postoperative management in the obstetric population. We conducted a national survey of monitoring after obstetric neuraxial blockade and the management of an abnormally prolonged block. We received responses from 112/189 (59.3%) obstetric anaesthetic leads invited to participate. We determined that post‐neuraxial blockade monitoring in the UK is highly variable: only 63/112 (56.3%) respondents’ units had a monitoring policy in place, although most of these did not undertake formal neurological monitoring, and a range of different monitoring methods and schedules were employed. In 12/63 (19%) local policies, the first review of neurology was performed at the standard postoperative visit the following day, and 66/112 (58.9%) units had no protocol in place to address emergency management of abnormally prolonged neuraxial blockade. Where a policy was in place, the initial recommended action and the type of imaging used were variable.     

Neuraxial analgesia in labour – induction and maintenance

Since the introduction of epidurals for labour analgesia in 1946 it has become the gold standard on delivery units throughout the world. Controversy remains as to the effects of neuraxial block upon the fetus; however, it is now widely accepted that there are beneficial and not just detrimental effects. With the introduction of low-dose anaesthetic solutions the major cardiovascular effects and concerns with toxicity have become much less prominent and the lack of profound motor block associated with traditional dosing has resulted in greater maternal satisfaction, although not the mobile revolution which was once anticipated. As research continues to search for the ideal labour analgesia, newer technologies are evolving making epidurals ever safer, individualized and tailored to the modern women in the delivery suite, as they demand greater control and autonomy over their deliveries. No current method has been able to emulate these ideals, but in the mean time women can enjoy safe and effective analgesia with minimal risks to either themselves or their babies.     

Inadequate neuraxial anaesthesia in patients undergoing elective caesarean section: a systematic review

Neuraxial anaesthesia is widely utilised for elective caesarean section, but the prevalence of inadequate intra-operative anaesthesia is unclear. We aimed to determine the prevalence of inadequate neuraxial anaesthesia for elective caesarean section; prevalence of conversion from neuraxial anaesthesia to general anaesthesia following inadequate neuraxial anaesthesia; and the effect of mode of anaesthesia. We searched studies reporting inadequate neuraxial anaesthesia that used ≥ ED95 doses (effective dose in 95% of the population) of neuraxial local anaesthetic agents. Our primary outcome was the prevalence of inadequate neuraxial anaesthesia, defined as the need to convert to general anaesthesia; the need to repeat or abandon a planned primary neuraxial technique following incision; unplanned administration of intra-operative analgesia (excluding sedatives); or unplanned epidural drug supplementation. Fifty-four randomised controlled trials were included (3497 patients). The overall prevalence of requirement for supplemental analgesia or anaesthesia was 14.6% (95%CI 13.3–15.9%); 510 out of 3497 patients. The prevalence of general anaesthesia conversion was 2 out of 3497 patients (0.06% (95%CI 0.0–0.2%)). Spinal/combined spinal–epidural anaesthesia was associated with a lower overall prevalence of inadequate neuraxial anaesthesia than epidural anaesthesia (10.2% (95%CI 9.0–11.4%), 278 out of 2732 patients vs. 30.3% (95%CI 26.5–34.5%), 232 out of 765 patients). Further studies are needed to identify risk factors, optimise detection and management strategies and to determine long-term effects of inadequate neuraxial anaesthesia.     

Regional anaesthesia for caesarean section (and what to do when it fails)

Regional anaesthesia is the technique of choice for caesarean sections, with single-shot spinal most commonly used. Preoperative assessment must be undertaken in all women, and informed consent is mandatory. Antacid premedication should be given to both elective and emergency cases. Maternal obesity is a risk factor for failed regional anaesthesia. Light-touch is the most reliable way of assessing the block, and the level should be documented prior to surgery. Inadequate block is a frequent cause of litigation, and all women should be offered general anaesthesia. Good communication with the parturient and the obstetricians and detailed documentation are essential if this occurs. Management options include repeating or supplementing the block, nitrous oxide, opiates, ketamine or resorting to general anaesthesia. All caesarean sections require follow-up postoperatively.     

Neuraxial analgesia in labour – induction and maintenance

Epidurals were introduced for labour analgesia in the 1940s, and since then they have become the gold standard for analgesia in delivery units globally. Although some controversy remains with regards to the effect of neuraxial blockade on the fetus, it is now established that the benefits are significant. As a result of the introduction of low-dose concentration local anaesthetic mixtures, issues surrounding cardiovascular effects and toxicity have become much less of a concern. The profound motor block found with traditional regimens is much less of a problem resulting in improved maternal satisfaction, although the advent of mobile epidurals has not yet been fully established. Research continues to develop new technologies to provide safer and more individualized neuraxial analgesia tailored to the labouring parturient that seek more control and autonomy over their delivery. No modern technique can emulate the theoretical ideal; however, women can experience safe and effective analgesia with minimal risk to both themselves and their babies.     

Haemodynamic changes during high spinal anaesthesia in children having open heart surgery

BACKGROUND: This prospective series examined the haemodynamic effects of high spinal anaesthesia in combination with light general anaesthesia in infants and children undergoing open heart surgery who were candidates for immediate or early postoperative extubation. METHODS: After midazolam premedication and sevoflurane inhalation induction, 30 patients, aged 7 months to 13 years, who were undergoing open heart surgery, received spinal anaesthetics with 0.5% tetracaine D10 mixed with morphine. The spinal blocks were placed at the L2,3 or L3,4 interspace with cephalad spread being promoted by positioning the patient in 30 degrees of Trendelenburg for a minimum of 10 min. Maintenance of anaesthesia was with isoflurane 0.2-0.5% in 70% nitrous oxide to maintain heart rate and blood pressure within 20% of postinduction baseline values. Haemodynamic values were recorded at predetermined timed intervals and intraoperative events up to and including aortic cannulation. For analysis of the data, patients were divided into four age groups (< 1 years, 1-3 years, 4-6 years and > 7 years). RESULTS: Haemodynamic stability was demonstrated in all four age groups. Statistically significant slowing of the heart rate did occur in the groups older than 1 year at 25 min, although clinically significant bradycardia requiring treatment never occurred. Hypotension did occur during specific surgical manipulations but recovered spontaneously. Atropine, fluid boluses and vasopressors were never used. At the conclusion of surgery, all patients met extubation criteria and could move all four extremities. CONCLUSIONS: High spinal anaesthesia with hyperbaric tetracaine and morphine in combination with light general anaesthesia is well tolerated haemodynamically by the paediatric population studied.     

The role of regional anaesthesia and multimodal analgesia in the prevention of chronic postoperative pain: a narrative review

Effective prevention of chronic postoperative pain is an important clinical goal, informed by a growing body of studies. Peri-operative regional anaesthesia remains one of the most important tools in the multimodal analgesic toolbox, blocking injury-induced activation and sensitisation of both the peripheral and central nervous system. We review the definition and taxonomy of chronic postoperative pain, its mechanistic basis and the most recent evidence for the preventative potential of multimodal analgesia, with a special focus on regional anaesthesia. While regional anaesthesia targets several important aspects of the mechanistic pathway leading to chronic postoperative pain, evidence for its efficacy is still mixed, possibly owing to the heterogeneity of risk profiles within the surgical patient, but also to variation in techniques and medications reported in the literature.     

Fundamentals and innovations in regional anaesthesia for infants and children

Regional anaesthesia in children has evolved rapidly in the last decade. Although it previously consisted of primarily neuraxial techniques, the practice now incorporates advanced peripheral nerve blocks, which were only recently described in adults. These novel blocks provide new avenues for providing opioid-sparing analgesia while minimising invasiveness, and perhaps risk, associated with older techniques. At the same time, established methods, such as infant spinal anaesthesia, under-utilised in the last 20 years, are experiencing a revival. The impetus has been the concern regarding the potential long-term neurocognitive effects of general anaesthesia in the young child. These techniques have expanded from single shot spinal anaesthesia to combined spinal/epidural techniques, which can now effectively provide surgical anaesthesia for procedures below the umbilicus for a prolonged period of time, thereby avoiding the need for general anaesthesia. Continuous 2-chloroprocaine infusions, previously only described for intra-operative regional anaesthesia, have gained popularity as a means of providing prolonged postoperative analgesia in epidural and continuous nerve block techniques. The rapid, liver-independent metabolism of 2-chloroprocaine makes it ideal for prolonged local anaesthetic infusions in neonates and small infants, obviating the increased risk of local anaesthetic systemic toxicity that occurs with amide local anaesthetics. Debate continues over certain practices in paediatric regional anaesthesia. While the rarity of complications makes comparative analyses difficult, data from large prospective registries indicate that providing regional anaesthesia to children while under general anaesthesia appears to be at least as safe as in the sedated or awake patient. In addition, the estimated frequency of serious adverse events demonstrates that regional blocks in children under general anaesthesia are no less safe than in awake adults. In infants, the techniques of direct thoracic epidural placement or caudal placement with cephalad threading each have distinct advantages and disadvantages. As the data cannot support the safety of one technique over the other, the site of epidural insertion remains largely a matter of anaesthetist discretion.     

Complications related to thoracic epidural analgesia: a prospective study in 1071 surgical patients

In a prospective study, the complications of 1071 patients scheduled for thoracic epidural catheterization for postoperative analgesia (TEA) were studied. All catheters were inserted preoperatively between segment Th 2/3 and Th 11/12 under local anesthesia. Balanced anesthesia with endotracheal intubation and TEA were combined. Postoperatively 389 patients (36.9%) were monitored on a normal surgical ward. Buprenorphine, 0.15 to 0.3 mg, and if needed bupivacaine 0.375% 3–5 ml h^-1 were given epidurally. Primary perforation of the dura occurred in 13 patients (1.23%). Radicular pain syndromes were observed in six patients (0.56%). In one patient (0.09%) respiratory depression was seen in close connection with the epidural administration of 0.3 mg buprenorphine. Although 116 patients (10.83%) showed one abnormal clotting parameter but no clinical signs of hemorrhage, there was no complication related to this group. No persisting neurological sequelae caused by the thoracic epidural catheters were found. In conclusion, continuous TEA with buprenorphine for postoperative pain relief after major abdominal surgery is a safe method without too high a risk of catheter-related or drug-induced complications, even on a normal surgical ward and when one clotting parameter is abnormal.     

Effects of thoracic paravertebral block with bupivacaine versus combined thoracic epidural block with bupivacaine and morphine on pain and pulmonary function after cholecystectomy

Twenty patients undergoing elective cholecystectomy via a subcostal incision were randomized in a double-blind study to either thoracic paravertebral blockade with bupivacaine 0.5% (15 ml followed by 5 ml/h) or thoracic epidural blockade with bupivacaine 7 ml 0.5% + morphine 2 mg followed by 5 ml/h + 0.2 mg/h, respectively for 8 h postoperatively. Mean initial spread of sensory analgesia on the right side was the same (Th3,4-Th11 versus Th2,6-Th11), but decreased (P less than 0.05) postoperatively in the paravertebral group. All patients in the epidural group had bilateral blockade, compared with three patients in the paravertebral group. In both groups only minor insignificant changes in blood pressure and pulse rate were seen postoperatively. Pain scores were significantly higher in the paravertebral group, as was the need for systemic morphine (P less than 0.05). Pulmonary function estimated by forced vital capacity, forced expiratory volume and peak expiratory flow rate decreased about 50% postoperatively in both groups. In conclusion, the continuous paravertebral bupivacaine infusion used here was insufficient as the only analgesic after cholecystectomy. In contrast, epidural blockade with combined bupivacaine and low dose morphine produced total pain relief in six of ten patients.     

Paediatric regional anaesthesia,a survey of practice in the United Kingdom

Background. A variety of techniques and drugs, many unlicensed,is used in paediatric regional anaesthesia. This study is thefirst to survey paediatric anaesthetists about the techniquesand drugs used in paediatric regional anaesthesia. The aim isto provide a record and benchmark of UK practice. Methods. A postal questionnaire was sent to all members of theAssociation of Paediatric Anaesthetists residing in the UK.Information was requested on the type of hospital worked in,years of practice, paediatric anaesthesia workload, regionalanaesthesia techniques used, and drugs used in regional anaesthesia. Results. A total of 220 responses from 264 questionnaires (83.3%)were received. Of these respondents, 155 (70%) practised paediatricanaesthesia as more than 50% of their workload, and 10 had retiredor returned blank forms. Two hundred and two of 210 (96%) usecaudal anaesthesia and 151 (72%) use caudal, epidural and peripheralblock. One hundred and ninety-two of 210 (91%) have no lowerage limit for using caudal anaesthesia. One hundred and twenty-threeof 210 anaesthetists (58%) used adjuvants with local anaestheticsin caudal block, the most common being fentanyl [44/210 (21%)],clonidine [55/210 (26%)], diamorphine [27/210 (13%)] and ketamine[67/210 (32%)]. Those working in specialist centres or teachinghospitals or who had a greater paediatric anaesthesia workloadwere more likely to use a greater variety of regional anaesthesiatechniques. Conclusions. Caudal anaesthesia is widely used for patientsof all ages by almost all practitioners. Most anaesthetistsat all hospital types and experience levels use adjuvants withlocal anaesthetics when performing caudal anaesthesia. Thosewith more experience in paediatric anaesthesia and those inspecialist centres commonly use other neuraxial and peripheralblock techniques. Br J Anaesth 2002; 89: 707–10