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.     

Neuraxial anaesthesia in paediatrics

Neuraxial anaesthesia is a valuable tool in the practice of paediatric anaesthesia. Spinal and epidural blockade are used for a variety of surgical cases as the sole anaesthetic or as an adjunct to general anaesthesia, and 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. The potential complications associated with neuraxial anaesthesia can be minimized by prudent technique and careful management. The use of the ultrasound for real-time visualization during paediatric neuraxial blocks may improve safety, success rate, and pain control after surgery.     

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.     

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.     

Multicentre clinical simulation evaluation of the ISO 80369-6 neuraxial non-Luer connector

To avoid potentially fatal wrong-route neuraxial drug errors, international standard ISO 80369-6 specifying a non-Luer neuraxial connector design was published in 2016. We describe usability studies used in development of the design. Thirty-eight doctors and 17 nurses performed simulated procedures on manikins, using devices fitted with Luer connectors or draft ISO 80369-6 ‘non-Luer’ connectors. The procedures included spinal anaesthesia; intrathecal chemotherapy; lumbar puncture, cerebrospinal fluid collection and pressure measurement; epidural catheter placement with bolus injection and critical care use. Participants attempted cross connection between neuraxial connectors and a range of other medical device connectors, including those from the ISO 80369 small-bore connector series. Video recording analysis was used for all assessments. Participants subjectively assessed performance of the draft non-Luer connector, including suitability for routine clinical use. Participants performed 198 procedures. The connector achieved easy, leak-free connections. The willingness of participants to use the non-Luer connectors were: spinal anaesthesia 100%; intrathecal chemotherapy 88%; lumbar puncture, cerebrospinal fluid collection and pressure measurement 93%; epidural catheter placement with bolus injection 78%; critical care use 100%. Concerns raised were generally device related, rather than connector related. Most cross-connection attempts failed, even using above clinical forces and, when successful, were judged of low clinical risk potential; the exception was a malaligned connection between the non-Luer slip and female Luer connectors. This led to revision of the dimensional tolerances of the non-Luer connector to reduce this risk, before publication of the final specification in 2016. We conclude that the ISO 80369-6 neuraxial non-Luer connector is suitable for clinical use.     

Epidural catheter placement in children: comparing a novel approach using ultrasound guidance and a standard loss-of-resistance technique

Background. We report a prospective, randomized study to evaluateultrasound guidance for epidural catheter placement in children0–6 yr of age. Methods. Epidural catheters were placed at lumbar or thoraciccord levels in 64 children undergoing major surgery, using eitherultrasonography or loss-of-resistance (LOR) for guidance. Usinga 5–10 MHz linear ultrasound probe, the neuraxial structureswere identified, the skin-epidural depth and epidural spacewas measured, the advancing epidural catheter visualized, andthe spread of local anaesthetic verifying catheter positionwas confirmed. Epidural placement procedures were analysed forbone contacts and speed of execution. Children under 6 monthswere analysed separately. Results. Epidural placement involved bone contacts in 17% ofchildren in the ultrasound group and 71% of children in theLOR group (P<0.0001). Epidurals were executed more swiftlyin the ultrasound group [162 (75) s vs 234 (138) s; P<0.01].Children under 6 months revealed a 0.9 correlation between skin-epiduraldepth and body weight. Conclusions. Ultrasonography is a useful aid to verify epiduralplacement of local anaesthetic agents and epidural cathetersin children. Advantages include a reduction in bone contacts,faster epidural placement, direct visualization of neuraxialstructures and the spread of local anaesthetic inside the epiduralspace. Ultrasound guidance requires additional training andgood manual skills, and should only be used once experiencein ultrasound-guided techniques of regional anaesthesia hasbeen acquired.     

Some vagaries of neonatal lumbar epidural anaesthesia.

Regional anaesthesia and analgesia offer unique advantages of reduction in general anaesthesia requirements and the demands on NICU resources while improving the general outcome. We assessed the feasibility of continuous lumbar epidural analgesia in 20 neonates for various major surgical procedures lasting from 60-260 min. The babies were aged 18 h to 34 days. They were born at a gestational age of 31-40 weeks. We had difficulty in passing the epidural catheter from the lumbar route in two patients, so we had to resort to the caudal route. The problems associated with the placement of the catheter from the lumbar route are discussed. The analgesia was provided for up to 72 h. Nineteen of the babies could be extubated in the operating theatre. They were awake but comfortable at the time of extubation. There were no complications due to the technique. Subsequent to this study, epidural analgesia either by lumbar or caudal route has become the routine in our hospital for all major thoraco-abdominal surgical procedures in neonates.     

Regional anaesthesia in the patient receiving antithrombotic and antiplatelet therapy

The actual incidence of neurological dysfunction resulting from haemorrhagic complications associated with neuraxial block is unknown. Although the incidence cited in the literature is estimated to be <1 in 150,000 epidural and <1 in 220,000 spinal anaesthetics, recent surveys suggest that the frequency is increasing and may be as high as 1 in 3000 in some patient populations. Overall, the risk of clinically significant bleeding increases with age, associated abnormalities of the spinal cord or vertebral column, the presence of an underlying coagulopathy, difficulty during needle placement, and an indwelling neuraxial catheter during sustained anticoagulation (particularly with standard unfractionated heparin or low molecular weight heparin). The decision to perform spinal or epidural anaesthesia/analgesia and the timing of catheter removal in a patient receiving antithrombotic therapy is made on an individual basis, weighing the small, although definite risk of spinal haematoma with the benefits of regional anaesthesia for a specific patient. Coagulation status should be optimized at the time of spinal or epidural needle/catheter placement, and the level of anticoagulation must be carefully monitored during the period of neuraxial catheterization. Indwelling catheters should not be removed in the presence of therapeutic anticoagulation, as this appears to significantly increase the risk of spinal haematoma. Vigilance in monitoring is critical to allow early evaluation of neurological dysfunction and prompt intervention. An understanding of the complexity of this issue is essential to patient management.     

Bloqueo del plano del músculo erector de la columna en 4 casos de cirugía torácica videoasistida

Multimodal anaesthesia, combining epidural catheter and general anaesthesia, is a common technique in thoracic surgery, however, epidural catheter placement is not always possible.Recently, erector spinae plane block has been described, which provides analgesia like that of the epidural block, although unilateral, and which has been used in various procedures at thoracic level. At present, there are no studies comparing the efficacy or safety of this block with those commonly used in thoracic surgery. However, its safety profile and contraindications seem different from those of the epidural catheter, since its placement is done under ultrasound view, the needle introduction is done in plane and the ultrasound target, the transverse process, is easily identifiable and is relatively remote from major neural or vascular structures and the pleura. Unlike other blockages made by anatomical references, erector spinae plane block can be done with the patient in different positions.We describe our experience with erector spinae plane block as part of a multimodal anaesthetic approach in thoracic surgery.     

Anaesthetic management in children with metachromatic leukodystrophy

We present a case of metachromatic leukodystrophy in a child who required surgery for gastro-oesophageal reflux. In spite of his demyelinating disease, we used a lumbar epidural technique with general anaesthesia; the epidural catheter allowed us to continue the analgesia postoperatively and to avoid opioids in this high risk patient.     

Epidural treatment of pain in burn patients by subcutaneous port access

Summary This study was undertaken to analyze and, by that means, to try to relieve the considerable suffering that burned patients experience as a result of the pain of the burn and that of the treatment by bathing and debridement. Pain relief was attempted by the administration of epidural analgesia and anaesthesia at the lumbar and cervical levels by catheter placement and by the implantation of monodose systems of infusion in patients with leg and arm involvement. When the patients were bathed or debrided or other painful maneuvers were performed, they were given epidural analgesia and anaesthesia (10Occ of bupivacaine to 0.25 %) or surgical epidural anaesthesia.     

Spinal haematoma after removal of a thoracic epidural catheter in a patient with coagulopathy resulting from unexpected vitamin K deficiency

Postoperative epidural analgesia is effective and widely utilised after major abdominal surgery. Spinal haematoma is a rare and devastating complication after epidural analgesia. Well‐established risk factors for the development of spinal haematoma after neuraxial procedures have been documented. We present the case of a patient with normal pre‐operative coagulation parameters who developed a spinal haematoma more than 24 h after removal of an epidural catheter; she had been without oral intake for only 4 days during which time she developed vitamin K‐deficient coagulopathy. Clinicians should consider pre‐operative screening of coagulation (International Normalised Ratio), or giving vitamin K supplementation, before performing neuraxial procedures in patients who are at risk of developing vitamin K deficiency or coagulopathy in the peri‐operative period.     

Failed epidural: causes and management

Failed epidural anaesthesia or analgesia is more frequent than generally recognized. We review the factors known to influence the success rate of epidural anaesthesia. Reasons for an inadequate epidural block include incorrect primary placement, secondary migration of a catheter after correct placement, and suboptimal dosing of local anaesthetic drugs. For catheter placement, the loss of resistance using saline has become the most widely used method. Patient positioning, the use of a midline or paramedian approach, and the method used for catheter fixation can all influence the success rate. When using equipotent doses, the difference in clinical effect between bupivacaine and the newer isoforms levobupivacaine and ropivacaine appears minimal. With continuous infusion, dose is the primary determinant of epidural anaesthesia quality, with volume and concentration playing a lesser role. Addition of adjuvants, especially opioids and epinephrine, may substantially increase the success rate of epidural analgesia. Adjuvant opioids may have a spinal or supraspinal action. The use of patient-controlled epidural analgesia with background infusion appears to be the best method for postoperative analgesia.     

Techniques of epidural block

Epidural blocks can be performed at any level from the high cervical spine down to the sacral hiatus. A lumbar epidural can provide surgical anaesthesia and postoperative analgesia for sub-umbilical surgery, whereas a thoracic epidural will provide effective analgesia but not anaesthesia for thoracic and upper abdominal surgery. A single-shot bolus has a duration of 2-4 hours, using a long-acting local anaesthetic, but in the majority of cases prolonged postoperative analgesia is achieved by inserting an epidural catheter and infusing a dilute local anaesthetic and opioid drug combination. Although a useful regional anaesthetic technique with significant patient benefits, an epidural is an invasive procedure, can be technically difficult, and has the potential to cause serious adverse events (direct needle trauma to the spinal cord or the spinal nerve roots, vertebral canal haematoma and meningitis or epidural abscess) if not done to a high standard and managed appropriately. Epidural and caudal blockade have a number of synonyms, which can be confusing. The terms ‘epidural’ (extradural, peridural) and ‘caudal’ (sacral epidural) are used throughout this article.     

Meningitis following cerebrospinal fluid-cutaneous fistula secondary to combined spinal-epidural anaesthesia for elective caesarean delivery

Cerebrospinal fluid-cutaneous fistula is a rare complication associated with neuraxial procedures. Here, we describe a case of fistula formation related to combined spinal-epidural anaesthesia for elective caesarean delivery, where the epidural catheter was removed only two hours later. The clear fluid leaking persistently from the site of the skin puncture associated with the epidural insertion site was confirmed to be cerebrospinal fluid with an increased beta-trace protein, and the fistula was closed with skin sutures. Subsequently, the patient presented with neurological signs and symptoms consistent with meningitis and was treated empirically with intravenous antibiotics. Cerebrospinal fluid-cutaneous fistula formation with secondary meningitis is an exceptionally rare event in obstetric anaesthesia.     

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     

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.     

Total spinal anaesthesia as a complication of local anaesthetic test-dose administration through an epidural catheter

We describe a case of total spinal anaesthesia, which occurred after a 3-ml lignocaine (20 mg ml(-1)) test dose was administered through an epidural catheter in a 79-year-old patient scheduled for gastrectomy under combined general and epidural anaesthesia. The surgery was postponed, and the patient required admission to the intensive therapy unit. Spinal MRI from the total spinal cord did not reveal any pathology. During the next 24 h the patient recovered and after 11 days was successfully operated on under general anaesthesia. No late complications followed. We presume that during placement, the epidural catheter had migrated to the spinal canal as a result of technical difficulties. Although controversial, we consider that administering a standard test dose of local anaesthetic via an epidural catheter is recommended, especially in high-risk patients and when epidural space identification or catheter placement poses technical difficulties. A test dose of local anaesthetic does not fully prevent complications.     

Postoperative nerve irritation syndrome after epidural analgesia in a six-year-old child

Morbidity after paediatric epidural anaesthesia is unusual.We report a case of transient nerve root irritation occurringafter epidural analgesia for radical nephrectomy in a 6-yr-oldboy who received a continuous infusion of bupivacaine 0.1%.The epidural catheter was inserted within the L2–L3 interspaceunder general anaesthesia. Several possible causes are discussed.Mechanical irritation of nerve roots by the epidural catheterin the epidural space is the most likely cause. Br J Anaesth 2004: 92: 146–8     

An observational study of factors leading to difficulty in resident anaesthesiologists identifying the epidural space in obstetric patients

Background

Multiple attempts at needle placement for neuraxial block may cause patient discomfort, a higher incidence of spinal haematomas, postdural puncture headache and nerve trauma. The aim of this study was to evaluate the factors predicting difficult epidural analgesia for inexperienced residents.

Methods

In this prospective observational study, conducted in a teaching hospital, four anaesthesiology residents without prior experience in obstetric anaesthesia performed all epidural procedures. A difficult epidural was defined as a need for more than one attempt at catheter placement. The following patient data were recorded: body mass index, abdominal circumference (classified as <105 or ?105 cm), ability to palpate anatomical landmarks and spinal abnormality.

Results

Four hundred and twelve pregnant women in labour were recruited. Residents achieved successful cannulation of the epidural space in 74% of attempts. Factors associated with difficult epidural placement in the univariate analysis were body mass index >30 kg/m², an abdominal circumference >105 cm, inability to palpate spinous processes and spinal abnormality. With the exception of abdominal circumference, all factors were independently predictive of difficult placement in the multivariate analysis with spinal abnormality being the most significant factor.

Conclusions

For residents with no prior experience in obstetric anaesthesia, the most reliable factor in predicting difficult epidural cannulation was spinal abnormality.