Pediatric Lumbar Epidural Catheter Placement via the Landmark Technique.

This video demonstrates the surface landmark technique for epidural catheter placement for postoperative pain control in a pediatric patient undergoing left hip osteotomy.  Following induction of general anesthesia, an epidural catheter (20 Gauge closed-tip) was placed at the L4-L5 vertebral level through a Tuohy needle (18 Gauge 5-cm long). Negative catheter aspiration of blood or CSF was confirmed followed by a negative test dose.  A bolus of local anesthetic followed by an infusion was administered via the epidural catheter for intra- and post-operative pain control. After completion of the surgery, the child was extubated and exhibited adequate postoperative pain control with the continuous epidural analgesia and multimodal pain management. In complex surgical procedures associated with significant postoperative pain, epidural analgesia is a useful technique to manage intraoperative and postoperative pain. Epidural catheter placement can be performed either using surface landmark or ultrasound-guided techniques. For patient safety, it is imperative to understand relevant differences between adults and children when determining and performing neuraxial blocks. Parental consent was obtained for the publication of this video.

Epidural analgesia is a technique used as part of multimodal pain management for invasive and painful surgical procedures. In addition to pain relief, epidural analgesia has been associated with decreased volatile anesthetic requirements, decreased catecholamine release, improved ventilation, earlier return of gut function, and decreased hospital and ICU length of stay¹. Neuraxial blocks have been traditionally performed using the surface landmark technique. In recent times, ultrasound guidance is also being used to guide epidural catheter placement. In the pediatric population, the performance of this procedure after induction of general anesthesia has been shown to be safe¹. Children’s cognitive immaturity often precludes compliance with immobility for the procedure, and also they are less capable of reporting paresthesia during placement. The benefits of epidural analgesia with catheter placement under general anesthesia outweigh the risks associated with needle placement in uncooperative patients¹.

A preoperative anesthesia evaluation including relevant medical history and focused physical exam should be performed. This patient had a history of sacral dimple which is sometimes associated with neurologic spinal canal abnormalities. A spinal ultrasound showed that the termination of the conus medullaris was at L3 without other anatomical abnormalities. The neurologic exam was grossly normal. A discussion between the anesthesia and surgical teams pertaining epidural catheter placement as a part of the multimodal pain control was conducted. Consent was obtained from the parents after discussing the risks, benefits and alternatives of the epidural procedure and their questions answered. Available equipment and procedure set up included chlorhexidine for skin preparation, sterile drape, plastic and glass syringes, epidural needle, epidural catheter and Luer-lock connectors. A prepackaged epidural tray often includes the most commonly used items. Proper needle introducer and epidural catheter sizes for the patient are addressed later under the Discussion section. Resuscitation equipment and medications including 20% lipid emulsion was within reach. After proper patient identification verification, induction of general anesthesia, and confirmation of a functioning peripheral intravenous catheter, the epidural procedure time out was conducted and the patient was positioned on left lateral decubitus. The patient was continuously monitored with standard American Society of Anesthesiologists monitors. Surface landmarks like Tuffier’s line, or the intercristal line corresponding to L4-L5 level, were identified and marked on the patient. The site was cleaned with chlorhexidine and draped in a sterile fashion. A midline approach was used at the L4-L5 vertebral space. A 5-cm 18 Gauge Tuohy epidural needle introducer was slowly advanced into the vertebral space. The epidural space was identified with a loss of resistance technique using a glass syringe filled with saline. The loss of resistance was noted to occur at approximately the 1.5 cm mark on the Tuohy needle. At this point, the needle advancing stopped and 2-3 mL saline was injected in the epidural space with little resistance. A closed-tip polyamide epidural catheter was threaded through the needle introducer into the epidural space. Minimal resistance should have been encountered. The Tuohy needle was then withdrawn from the epidural space, during which simultaneous mild countertraction is held on the catheter to prevent dislodgement. The catheter was then retracted to the desired level. A catheter length of 3 to 4 cm into the space predicts catheter tip placement 2 segments higher than the needle entry point¹. In this child, since the distance from skin to epidural space was 1.5 cm on the Tuohy needle, leaving 3 cm into the space results in a total of 4.5 cm of catheter length at the skin level (1.5 cm +3 cm). The clamp was attached to the end of the catheter. The catheter was aspirated to confirm absence of CSF flow or blood flow and a test dose of lidocaine 1.5% with epinephrine 1: 200,000 was used to rule out intravascular placement. A test dose was calculated at 0.5 mcg/kg epinephrine or 0.1ml/kg of lidocaine 1.5% with epinephrine 1:200,000 up to 15 mcg of Epinephrine or 3 cc of 1:200,000 epinephrine solution. Confirmation of no changes on the EKG tracing like increase or decrease in T wave amplitude ≥ 25%, increase HR ≥ 10 bpm or increase SBP ≥ 15 mmHg on the monitors¹. Sterile dressing was placed after securing the catheter.

We did not encounter any complications before, during, or after the epidural catheter placement. Subsequently, the catheter was removed uneventfully after transitioning to oral pain medications on postoperative day 2 after surgery.

The most common indications for epidural anesthesia in the pediatric population include procedures involving the lower limbs, pelvis, perineum, abdomen and thorax. Contraindications to neuraxial blockade include patient or guardian refusal, infection at the insertion site, spina bifida, increased intracranial pressure, local anesthetic allergy, and coagulopathy². In patients with sepsis, degenerative neurologic conditions, spine abnormalities or spine hardware, and hypovolemia, the increased risk for complications should be carefully weighed against the benefits. There are some anatomical differences in infants and children vs. adults: 1) the pediatric conus medullaris is located lower in the spinal column, L3 level compared with L1-2 in adults, 2) the pediatric ligamentum flavum is thinner and less dense leading to a diminished loss of resistance sensation when entering the epidural space with the potential for unintended dural puncture, and 3) the pediatric sacrum is flatter and narrower². A correct size of introducer needle and epidural catheter should be selected based on age for pediatric patients: A 5-cm 20 Gauge Tuohy needle with a 24 Gauge epidural catheter is appropriate for patients younger than 2 years. A 5- or 10-cm 18 Gauge Tuohy needle and a 20 Gauge epidural catheter are typically used in older children¹. Prescription and dosing of test solution and medication also varies by age and size (see below). Pharmacologic differences between pediatric and adult patients can significantly impact epidural management necessitating dosing adjustments for volume, concentration and toxic limits for efficacy and patient safety. These differences include: surface area to body mass ratio, immaturity of liver and kidney function, concentration of plasma-binding proteins, and underdeveloped blood-brain barrier¹. The two most common local anesthetics used for epidurals are bupivacaine and ropivacaine. Lidocaine is used for the test dose only. Bupivacaine or levobupivacaine 0.25% and ropivacaine 0.2% are typically used at 0.5 mL/kg for lumbar epidural initial loading (0.3 mL/kg thoracic epidural initial loading) and 0.25 mL/kg for subsequent “top-up” in order to obtain intraoperative analgesia. Continuous epidural anesthesia with either bupivacaine or levobupivacaine, or ropivacaine can be safely infused at rates of 0.2 mg/kg/h for children younger than 3 months, 0.3 mg/kg/h for children between 3 months and 1 year, and 0.4 mg/kg/h for children older than 1 year³. Some authors use more volume of diluted ropivacaine (0.1%), or bupivacaine or levobupivacaine (0.125%) on the continuous infusion to achieve the desired level while keeping the dosage under toxic limits. In this case, we used ropivacaine for bolus and infusion at the age appropriate doses mentioned before. For testing of catheter location, epinephrine is the only adjunct added by drug manufacturers to their marketed local anesthetic preparations. Typically, it has been used in a concentration of 5 mcg/mL (1 : 200,000), with the intent of identifying inadvertent intravascular injection (test dose). The test dose of epinephrine is typically limited to 0.5 mcg/kg (0.1 mL/kg of a 1 : 200,000 solution) to a maximum dose of 15 mcg (3mL). A positive test dose after intravenous injection of 0.5 mcg/kg of epinephrine is defined as an increase in HR of 10 to 20 bpm, a 25% change in T-wave amplitude, new ST segment changes on ECG, or an increase of 15 mmHg or 10% in systolic blood pressure¹. Epidural complications and side effects can be associated with the procedure itself or to the drug administered. Potential complications associated with the administration of the drug include local anesthetic systemic toxicity (LAST), allergy to local anesthetic, direct local anesthetic-induced nervous tissue injury, and errors from drug or mode of delivery. Transient complications include back pain, pneumocephalus, and postdural puncture headache. Life-threatening complications include subdural injection of local anesthetic, total or high spinal, infectious or aseptic meningitis, cardiac arrest, spinal epidural abscess, epidural hematoma formation, and permanent neurologic injuries⁴. Consistent protocols help prevent complications: ensuring correct dosing of medication, performing the epinephrine test dose, proper calculation of the desired depth of the catheter, location and availability of lipid emulsion (20%) solution for rescue in the event of suspected LAST. Daily patient evaluations should be done for assessment of the block and possible catheter-related complications.

There are no conflicts to disclose on this case.

There are no acknowledgements.

1. Peter J. Davis, MD, FAAP, Franklyn P. Cladis, MD. SMITH'S ANESTHESIA FOR INFANTS AND CHILDREN, NINTH EDITION. ELSEVIER. St. Louis, Missouri: Elsevier, [2017] Chapter 22. ISBN: 978-0-323-34125-7. 2. De Jose Maria B, Tielens L, Roberts S. Pediatric epidural and spinal anesthesia and Analgesia. NYSORA. https://www.nysora.com/topics/sub-specialties/pediatric-anesthesia/pediatric-epidural-spinal- anesthesia-analgesia/. Published April 18, 2022. Accessed July 18, 2022. 3. Santhanam Suresh, Claude Ecoffey et al. The European Society of Regional Anesthesia and Pain Therapy/American Society of Regional Anesthesia and Pain Medicine Recommendations on Local Anesthetics and Adjuvants Dosage in Pediatric Regional Anesthesia. Regional Anesthesia and Pain Medicine • Volume 43, Number 2, February 2018 4. Roulhac D. Toledano and Marc Van de Velde Epidural Anesthesia and Analgesia. NYSORA. https://www.nysora.com/topics/regional-anesthesia-for-specific-surgical- procedures/abdomen/epidural-anesthesia-analgesia/. Accessed September 27, 2022.