Ultrasound assessment of caudal catheter position in infants

Postoperative Apnea in a Neonate Following an Epidural Bolus Dose Through a High Thoracic Epidural Catheter

Regional anesthesia is being used more frequently in the practice of pediatric anesthesia including neonates and infants. While generally safe and effective, adverse effects may occur related to catheter placement or its subsequent use. We present the rare occurrence of high motor blockade with apnea following the administration of a bolus dose of the local anesthetic agent, 2-chloroprocaine, into the thoracic epidural catheter of a 4-week-old, 2.2-kg former premature neonate. The patient had an epidural catheter that had been threaded from the caudal space to the thoracic level to provide analgesia following an abdominal surgical procedure. Subsequent investigation with a standard chest radiograph revealed a higher than intended placement of the epidural catheter (T4 instead of T8-10) which resulted in a transient high motor blockade with apnea. The epidural infusion was discontinued and assisted ventilation was provided by bag-valve-mask ventilation. Immediately, the heart rate and oxygen saturation returned to baseline values, and within 5 min the patient became more active, spontaneous ventilation resumed, and a strong cry was noted. The epidural catheter was removed and the remainder of the postoperative course was unremarkable. Adverse effects of epidural anesthesia in neonates are discussed and options for identifying the correct placement of a thoracic epidural catheter are reviewed.

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.

The Migration of Caudally Threaded Thoracic Epidural Catheters in Neonates and Infants

BACKGROUND

The migration of pediatric thoracic epidural catheters via a thoracic insertion site has been described. We assessed the migration of caudally threaded thoracic epidural catheters in neonates and infants at our institution.

METHODS

The anesthesia records and diagnostic imaging studies of neonates and infants who had caudal epidural catheters placed during a 26-month period at our hospital were analyzed. Imaging studies were reviewed for changes in epidural catheter tip position.

RESULTS

Eighty-five patients 1-325 days of age (median, 51 days; interquartile range, 39-78 days) and weights of 2.5-9.5 kg (median, 5 kg; interquartile range, 4.3-5.8 kg) met the study criteria. Fifty-four (64%) of the patients (95% CI, 52%-73%) experienced catheter migration of 1 or more vertebral levels (range, 3 levels caudad [outward] to 3 levels cephalad [inward]), and 23 (27%) of the patients (95% CI, 18%-38%) experienced catheter migration to the T4 level or higher. Migration of 2 or more vertebral levels occurred only in children who weighed <6 kg and were under 73 days of age.

CONCLUSIONS

Epidural catheter migration occurs commonly in neonates and infants. Postoperative imaging is crucial to confirm catheter tip location after epidural catheter placement, as failure to assess catheter migration might result in suboptimal analgesia or other undesirable outcomes.

Does ultrasound guidance add accuracy to continuous caudal-epidural catheter placements in neonates and infants?

BACKGROUND

Caudo-lumbar and caudo-thoracic epidural anesthesia is an established technique that carries a low risk of dural puncture or spinal cord trauma in infants. Traditionally catheter advancement is based on external measurements. However, malpositioning of catheters are known to occur. We hypothesized that caudal-epidural catheters inserted under real-time ultrasound guidance may be more accurate than the accuracy of the measurements traditionally used for their placement.

METHODS

We studied 25 patients, aged 2 days to 5 months, posted for abdominal or thoracic surgery, receiving general anesthesia followed by caudo-epidural continuous block. External measurement defined as the distance from the caudal space and the surgically congruent vertebral level was measured in centimeters with the back gently flexed. Subsequently, a caudo-epidural block was performed in the same position. The epidural catheter insertion was followed under real-time ultrasound guidance till the predetermined vertebral level was reached. The actual length placed under real-time ultrasound scan was defined as the actual length. The high-frequency probe was placed longitudinal and paramedian to the spine. The vertebral level was determined by identifying the lumbosacral junction in longitudinal saggital view and counting the vertebrae up from L5. The catheter length at the skin was compared with the length recorded by external measurement.

RESULTS

The actual length placed under real-time ultrasound scan were consistently longer than the external distance between the caudal space and selected vertebral level. The mean values of ultrasound were higher than the mean values of external measurement with a difference of 4.28 cm. Accuracy was not affected by age or affected by the selected vertebral level in the age group we studied.

CONCLUSION

We conclude that catheters placed under ultrasound guidance are more accurate than the traditional method developed before the advent of ultrasound in young infants.

Clinical application of a novel developed pressure bladder indicator in lumbar epidural puncture

STUDY OBJECTIVE

A novel pressure bladder indicator was developed, and this study aimed to evaluate the clinical application of the pressure bladder indicator by measuring the epidural space pressure and bladder working pressure on patients undergoing lumbar epidural puncture.

DESIGN

Randomized, prospective, double-blinded study

PATIENTS

130 patients

SETTING

The Second Hospital of Shandong University

INTERVENTIONS

In this study, 60 patients undergoing surgical procedures under lumbar epidural anesthesia were enrolled to detect epidural pressure, and other 70 patients who were undergoing lumbar epidural anesthesia or combined spinal-epidural anesthesia were enrolled to evaluate the pressure bladder indicator.

MEASUREMENTS

After successful breakthrough of ligamentum flavum by traditional methods, a pressure transducer was connected to an epidural needle tail and a monitor to measure the epidural pressure at L1-L5 in 60 patients. The working pressure of the bladder was also measured by a transducer. Then lumbar epidural puncture was performed with the pressure bladder indicator in other 70 patients.

MAIN RESULTS

The lumbar epidural pressure of the 60 patients was 9.8 ± 4.3 mm Hg, and the bladder working pressure of the pressure bladder indicator was 122 ± 15 mm Hg. All these 70 patients were confirmed with successful bladder indication and lumbar epidural puncture. Thus, the coincidence ratio was 100%.

CONCLUSIONS

The novel developed pressure bladder indicator was a reliable and useful technique to conduct successful lumbar epidural puncture.

Recent developments in paediatric neuraxial blocks

Paediatric anaesthesia and paediatric regional anaesthesia are intertwined. Almost all surgeries unless contradicted could be and should be supplemented with a regional block. The main objective of this review is to elaborate on the recent advances of the central neuraxial blocks, such as application of ultrasound guidance and electrical stimulation in the pursuit of safety and an objective end point. This review also takes account of the traditional technique and understand the benefits as well the risk of each as compared with the recent technique. The recent trends in choosing the most appropriate peripheral block for a given surgery thereby sparing the central neuroaxis is considered. A penile block for circumcision or a sciatic block for unilateral foot surgery, rather than caudal epidural would have a better risk benefit equation. Readers will find a special mention on the recent thoughts on continuous epidural analgesia in paediatrics, especially its rise and fall, yet its unique importance. Lastly, the issue of block placements under sedation or general anaesthesia with its implication in this special population is dealt with. We conducted searches in MEDLINE (PubMed) and assessed the relevance of the abstracts of citations identified from literature searches. The search was carried out in English, for last 10 years, with the following key words: Recent advances in paediatric regional anaesthesia; ultrasound guidance for central neuraxial blocks in children; role of electrical stimulation in neuraxial blocks in children; complications in neuraxial block. Full-text articles of potentially relevant abstracts were retrieved for further review.

Caudal blocks

Caudal anesthesia is the single most important pediatric regional anesthetic technique. The technique is relatively easy to learn (1), has a remarkable safety record (2), and can be used for a large variety of procedures. The technique has been reviewed in the English (3) and French (4) literature, as well as in German guidelines (5) and in pediatric anesthesia textbooks (6).

[Therapy of perioperative pain in pediatric urology]

Difficulties in estimating the kind and intensity of pain as well as uncertainty in drug selection and dosing are often responsible for a suboptimal treatment of pain therapy in the various age groups in childhood. The following article will help to minimize these deficits by contributing full details of safe and effective concepts for perioperative pain therapy in childhood.

[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.

Anesthetic management of gastrochisis--a review of our practice over the past 5 years

BACKGROUND

Surgical closure of gastrochisis has traditionally been performed under general anesthesia followed by admission to intensive care and postoperative ventilation. We reviewed the management of these neonates in our hospital over the past 5 years to identify changes in practice and possible factors which affect the perioperative course.

METHODS

We retrospectively identified cases of gastrochisis undergoing repair from June 2002 to May 2007. Details of the demographic data, preoperative factors, intraoperative anesthetic and surgical management and postoperative care were collected from the anesthetic chart, operative record and patient notes.

RESULTS

Forty-eight self-ventilating neonates underwent operative repair in theatre. A neuraxial local anesthetic block was performed as part of the anesthetic technique in 22 patients. There was a significant difference in the need for postoperative ventilation in this group (23%) when compared with a traditional opioid-based method of providing analgesia (88%, P < 0.05). This difference was seen in both term and preterm babies.

CONCLUSION

Conclusions are difficult when analyzing retrospective data in patients with a variety of factors. The results suggest that anesthesia which includes a regional technique is a valid method in these cases. Traditional opioid analgesia when compared to regional techniques may be associated with increased need for postoperative ventilation.

Anaesthetic management of gastroschisis - a review of our practice over the past 5 years

BACKGROUND

Surgical closure of gastrochisis has traditionally been performed under general anesthesia followed by admission to intensive care and postoperative ventilation. We reviewed the management of these neonates in our hospital over the past 5 years to identify the changes in practice and possible factors which affect the peri-operative course.

METHODS

We retrospectively identified cases of gastrochisis undergoing repair from June 2002 to May 2007. Details of the demographic data, preoperative factors, intra-operative anesthetic and surgical management, and postoperative care were collected from the anesthetic chart, operative record, and patient notes.

RESULTS

Forty-eight self-ventilating neonates underwent operative repair in theatre. A neuraxial local anesthetic block was performed as part of the anesthetic technique in 22 patients. There was a significant difference in the need for postoperative ventilation in this group (23%) when compared with a traditional opioid-based method of providing analgesia (88%, P < 0.05). This difference was seen in both term and preterm babies.

CONCLUSION

Conclusions are difficult to make when analyzing retrospective data in patients with a heterogeneous variety of factors. The results suggest that anesthesia which includes a regional technique is a valid method in these cases. Traditional opioid analgesia when compared with regional techniques may be associated with increased need for postoperative ventilation.

Combined spinal-epidural anesthesia in major abdominal surgery in high-risk neonates and infants

BACKGROUND

Combined spinal-epidural anesthesia (CSE-A) is reportedly safe and effective for the pediatric population in infraumbilical surgery. Our main purpose was to describe our experience of this technique in neonates and infants undergoing elective major upper abdominal surgery.

METHODS

Spinal anesthesia was performed in 28 neonates and infants with isobaric bupivacaine 0.5%, 1 mg.kg(-1) followed by placement of a caudal epidural catheter to thoracic spinal segments. The catheter tip position was confirmed radiographically. Respiratory and hemodynamic data were collected before and after the CSE-A and throughout the operation, as a measure of anesthetic effectiveness. Complications related to the anesthesia technique were collected as a measure of the anesthetic technique safety.

RESULTS

Satisfactory surgical anesthesia was achieved in 24 neonates and infants, four patients were converted to general anesthesia. Respiratory and hemodynamic variables did not change significantly during surgery, compared with baseline values: oxygen saturation (P = 0.07), systolic and diastolic blood pressures (P = 0.143, P = 0.198 respectively), heart rate (P = 0.080) and respiratory rate (P = 0.127). However, twenty infants were fussy during the surgical procedures and were calmed with intravenous midazolam; our patients required oxygen supplementation and transient manual ventilation intraoperatively.

CONCLUSIONS

Combined spinal-epidural anesthesia could be considered as an effective anesthetic technique for elective major upper abdominal surgery in awake or sedated neonates and infants, and could be used cautiously by a pediatric anesthesiologist as an alternate to general anesthesia in high-risk neonates and infants undergoing upper gastrointestinal surgery.

Pediatric regional anesthesia - update

PURPOSE OF REVIEW

New topics in pediatric regional anesthesia are discussed.

RECENT FINDINGS

Continuous peripheral nerve blocks, new local anesthetics and the performance of regional blocks with ultrasonography guidance are summarized.

SUMMARY

Prolonged analgesia with continuous peripheral nerve blocks in the treatment of pediatric postoperative limb pain, sometimes with patient-controlled regional analgesia, should be preferred instead of continuous epidural analgesia. Levobupivacaine and ropivacaine display the same pharmacokinetic profile as racemic bupivacaine with less cardiac toxicity. Conversely, continuous infusion of these new local anesthetics offers the safest therapeutic index, especially in infants. Many adjuvants have been used, but clonidine offers clear advantages. Ultrasonography guidance blocks will probably become the reference technique for local anesthetics injection and regional anesthesia catheter placement; new training in this field should be available.

Innovative approaches to neuraxial blockade in children: the introduction of epidural nerve root stimulation and ultrasound guidance for epidural catheter placement

Continuous epidural blockade remains the cornerstone of pediatric regional anesthesia. However, the risk of catastrophic trauma to the spinal cord when inserting direct thoracic and high lumbar epidural needles in anesthetized or heavily sedated pediatric patients is a concern. To reduce this risk, research has focused on low lumbar or caudal blocks (ie, avoiding the spinal cord) and threading catheters from distal puncture sites in a cephalad direction. However, with conventional epidural techniques, including loss-of-resistance for localization of the needle, optimal catheter tip placement is difficult to assess because considerable distances are required during threading. Novel approaches include electrical epidural stimulation for physiological confirmation and segmental localization of epidural catheters, and ultrasound guidance for assessing related neuroanatomy and real-time observation of the needle puncture and, potentially, catheter advancement. The present article provides a brief and focused review of these two advances, and outlines recent clinical experiences relevant to pediatric epidural anesthesia.

Ultrasonographic guidance in pediatric regional anesthesia. Part 2: techniques

The benefits of regional anesthesia are well documented. The downsides of such techniques have been a significant failure rate and a potential for serious complications. Nearly, all regional blocks were first described as essentially 'blind' techniques. The development of high-resolution portable ultrasound (US) has made the use of US for regional anesthesia possible. Improved understanding of sonographic anatomy should lessen both the failure rate and the possibility of incurring serious complications. Natural caution has dictated that only a selection of blocks used in adults has been commonly used in pediatric practice, but with the aid of US, the repertoire of blocks for infants and children may be widened. The second part of this review will concentrate on the practice of both peripheral and central blocks.

Ultrasonographic guidance in pediatric regional anesthesia Part 1: Theoretical background

Recent findings support the use of ultrasonographic guidance in pediatric regional anesthesia. This review article illustrates basic knowledge in physics of ultrasound and ultrasonographic appearance of neuronal structures, which are prerequisites for the safe application of this technique in daily clinical practice. A critical view on education and ethics in science should emphasize future developments in ultrasonography for pediatric regional anesthesia.

Ultrasonography-guided rectus sheath block in paediatric anaesthesia—a new approach to an old technique †

BACKGROUND

The purpose of this study was an anatomical and clinical evaluation of ultrasonography-guided rectus sheath blocks in children.

METHOD

A total of 30 children were included in the sono-anatomical part of the study. The depth of the anterior and posterior rectus sheath was evaluated with a portable SonSite 180 plus ultrasound machine and a 5-10 MHz linear probe. In total, 20 consecutive children undergoing umbilical hernia repair were included in the clinical part of this study. After induction of general anaesthesia children received a rectus sheath block under real-time ultrasonographic guidance by placing 0.1 ml kg(-1) bilaterally in the space between the posterior aspect of the sheath and the rectus abdominis muscle.

RESULTS

Ultrasonographic visualization of the posterior rectus sheath was possible in all children. The correlation between the depth of the posterior rectus sheath and weight (adjusted r(2)=0.175), height (adjusted r(2)=0.314) and body surface area (adjusted r(2)=0.241) was poor. The ultrasound-guided rectus sheath blockade provided sufficient analgesia in all children with no need for additional analgesia in the perioperative period.

CONCLUSION

The bilateral placement of levobupivacaine 0.25% 0.1 ml kg(-1) in the space between the posterior aspect of the rectus sheath and the rectus abdominis muscle under real-time ultrasonographic guidance provides sufficient analgesia for umbilical hernia repair. The unpredictable depth of the posterior rectus sheath in children is a good argument for the use of ultrasonography in this regional anaesthetic technique in children.

Paediatric caudal extradural catheterisation: an evaluation of a purpose designed equipment set

Using a purpose designed set of equipment, the Caudal Extradural Catheter Tray, Oxford Set (B Braun Medical Ltd, Sheffield, UK) we have evaluated the ease of cannulation of the caudal space, and the subsequent success in threading extradural catheters and obtaining satisfactory analgesia via the caudal route. The set was evaluated in 91 children (age range: 1 day to 10 years). Cannulation of the caudal space was achieved in all patients, and catheterisation of the extradural space was successful in 96.7% of patients. Postoperative analgesia was satisfactory in 95% of children who had continuous extradural analgesia. There were no major complications or neurological sequelae associated with using the set. We found the Caudal Extradural Catheter Tray provides the necessary equipment to perform extradural anaesthesia and analgesia safely and successfully in children of a wide age range.