Thoracic epidural analgesia via the caudal approach using nerve stimulation in an infant with CATCH22

PURPOSE: To illustrate insertion of an epidural catheter via caudal route in a small infant under electrical stimulation guidance. CLINICAL FEATURES: A six month old boy, weighting 4.25 kg, with a diagnosis of CATCH22 (Cardiac abnormality/abnormal faces, T cell deficit due to thymic hypoplasia, cleft palate, hypocalcemia due to hypoparathyroidism resulting from 22q11 deletion) was scheduled for fundoplication and gastrostomy tube (G-tube) insertion. A combined light general anesthesia and continuous epidural anesthesia technique was selected. Following induction of general anesthesia and tracheal intubation with 1.5 mg midazolam, 10 microg fentanyl and 10 mg succinylcholine, a 16G intravenous catheter was inserted into the caudal space. A 19G epidural catheter (Arrow Flextip Plus) epidural catheter was then inserted up cranially. A low electrical current (1-10mA) was then applied through the catheter. The level of motor movement was advanced from the lower limb muscles to the upper abdominal muscles as the catheter was threaded cranially. After 19 cm of epidural catheter had been inserted, intercostal muscle movement (T9-10 level) was observed at 4.2mA. The tip of the catheter was later confirmed to be at the T9-10 interspace by radiographical imaging. The patient awakened without distress and the trachea was extubated the same evening. The infant was discharged to the ward next morning with good pain relief from a continuous epidural infusion of bupivacane 0.1% with 1 microg x ml(-1) at 1.6 ml(-1). CONCLUSION: Epidural stimulation may help placement of the epidural catheter at the appropriate dermatome for effective anesthesia and analgesia.     

Thoracic caudal epidural catheter localization using ultrasound guidance

Caudal epidural catheters provide exceptional analgesia while avoiding or minimizing opioids. Historically, the catheter tip location (dermatomal level) was estimated or verified via epidurogram. According to the Pediatric Regional Anesthesia Database, the majority of caudal‐to‐thoracic epidural catheters are placed without imaging guidance or verification of the position of the catheter tip. Ponde et al demonstrated that catheter insertion depth was longer when using ultrasound guidance than when estimated by external measurement. We report a simple yet novel ultrasound approach for catheter localization.     

Thoracic epidural catheter placement via the caudal approach in infants by using electrocardiographic guidance

We examined the success of inserting epidural catheters via the caudal route in infants by using electrocardiographic guidance. A case series of 20 patients with thoracic epidural analgesia was studied. After the induction of general anesthesia, an 18-gauge IV catheter was inserted into the caudal space to allow threading of a 20-gauge epidural catheter. The electrocardiogram (ECG) tracings via the epidural catheter, as well as the surface ECG at the target spine level, were recorded simultaneously with a modified two-channel five-lead ECG system. The epidural catheter was advanced from the caudal space until the tip reached the target level as demonstrated by a match in the configuration of the epidural ECG tracing to that of the surface ECG tracing at the target level. The catheter tip location was verified by postoperative radiographs. All catheter tips were located within two vertebrae of the target level, and satisfactory intraoperative epidural anesthesia was achieved in all subjects. IMPLICATIONS: Epidural electrocardiography may be used to guide the positioning of the thoracic epidural catheter tip via the caudal approach to the appropriate dermatome for optimum analgesia.     

Thoracic epidural anesthesia via the caudal approach in children.

We investigated the feasibility of performing thoracic epidural anesthesia via the caudal approach in 20 children (age 62 +/- 38 months and weight 18.5 +/- 7.3 kg; mean +/- standard deviation). Based on external landmarks, a predetermined length of 24-G epidural catheter (Concord Portex 20/24 microcatheter system) with stylet was passed into the epidural space through a 20-G intravenous catheter inserted through the sacrococcygeal ligament, and a radiograph of the abdomen and chest was obtained. The radiographically determined catheter tip position was within two vertebrae of the target position in 17 of 20 subjects. In one subject, it was impossible to advance the catheter more than 10 cm. The other two malpositioned catheters were successfully reinserted. Intraoperative caudal anesthesia and postoperative pain relief were satisfactory in all 20 subjects. We have found it possible to use the caudal approach to thoracic epidural anesthesia in children as old as 10 yr. Ease of removal of the stylet, ease of injection, and negative aspiration and test doses predict successful placement and obviate the need for routine radiographic confirmation of catheter position.     

Thoracic epidural analgesia via the caudal approach in pediatric patients undergoing fundoplication using nerve stimulation guidance.

IMPLICATIONS: Epidural catheter placement using electrical stimulation guidance is an alternative approach for positioning the catheter into the thoracic region via the caudal space. This easily performed clinical assessment provides optimization of catheter tip positioning for achieving effective pain control.     

Inadvertent cervical epidural catheter placement via the caudal route using electrical stimulation

Inadvertent placement of an epidural catheter in the cervical region via the caudal route is described in an infant who underwent revision of a fundoplication. We attempted electrical stimulation (the Tsui test) via the epidural catheter to confirm correct placement and positioning of the catheter tip. In this case, the epidural catheter was inadvertently advanced to the cervical region, resulting in stimulation of the phrenic nerve. These diaphragmatic twitches were misinterpreted as chest wall twitches, and it was incorrectly assumed that the catheter was in the thoracic region. To avoid misinterpretation of the stimulation level, the catheter should be continuously stimulated while it is advanced. We also recommend that the catheter length be estimated before insertion (although doing so did not help in this case) and that the catheter position be radiographically confirmed after surgery.     

Ultrasound-guided epidural catheter insertion in children

Epidural catheters (EC) are often used in pediatric patients for intraoperative and postoperative pain relief. The small anatomical structures and catheter insertion under general anesthesia make it more difficult to perform EC and to prevent damage. In this study we investigated the use of ultrasound (US) in detecting neuraxial structures during insertion and placement of EC in children. ASA I-II children scheduled for elective surgery under combined general and epidural anesthesia were studied. Patients received balanced anesthesia using sevoflurane, opioids and rocuronium. Before EC insertion US examination in a lateral position was done to visualize and identify neuraxial structures. Quality of visualization and site and depth of structures were recorded. Using a sterile kit to hold the US probe in position and enable the visualization of the neuraxial structures, an epidural cannula was inserted, using the loss of resistance technique, as the EC passed under US control to the desired level. Of 25 children, 23 were evaluated. Epidural space, ligamentum flavum, and dural structures were clearly identified and the depth to skin level estimated in all patients. Loss of resistance was visualized in all patients with a lumbar epidural approach. Correlation of US measured depth and depth of loss of resistance was 0.88. In eight of 23 patients EC could be visualized during insertion and in 11 others it could be visualized with additional US planes. US is an excellent tool to identify neuraxial structures in both infants and children. The size and the incomplete ossification of the vertebra allow exact visualization and localization of the depth of the epidural space, the loss of resistance, and all relevant neuraxial structures. IMPLICATIONS: Epidural catheters in children are mostly inserted under sedation or general anesthesia. This study showed that the use of ultrasound could help visualize all relevant neuraxial structures and their site and depth from the skin.     

Thoracic and lumbar epidural analgesia via the caudal approach using electrical stimulation guidance in pediatric patients: a review of 289 patients

BACKGROUND: Nerve stimulation guidance (Tsui test) has been reported to be an effective alternative to radiographic imaging for proper catheter placement. The purpose of this study was to examine the success rate and complications of continuous caudal epidural analgesia since the implementation of routine use of the Tsui test at the authors' institution. METHODS: The authors examined prospectively collected data in their pediatric pain service database from 289 children who had attempted caudal placement of a lumbar or thoracic catheter between 1999 and 2002. RESULTS: In five patients (aged 5 months-1.6 yr), the catheter did not thread to the desired level and was abandoned in the operating room (technical success rate, 98.2%). Of the remaining 284 patients, the overall analgesic success rate of all caudal route epidural analgesia procedures was 84.9%. There was no significant difference in adequate pain control (success) in infants (aged 1 day-1 yr) versus older children (aged younger than 1 yr). The most common adverse effects were pruritus (26.1%) and nausea and vomiting (16.9%). Of the patients in our study, 57.7% had urinary catheters in situ; of those who did not have a catheter placed, 20.8% experienced urinary retention. The incidence of respiratory depression was 4.2%, but the administration of naloxone for severe respiratory depression was never necessary. Three percent of catheters were removed because of suspected contamination, but no epidural abscesses or systemic infection were noted. CONCLUSIONS: The results of this study suggest that epidural catheter placement via the caudal approach using the Tsui test is an effective and reasonable alternative to direct lumbar and thoracic epidural analgesia in pediatric patients.     

Thoracic epidural analgesia via the lumbar approach using nerve stimulation in a pediatric patient with Down syndrome

This case illustrates the threading of an epidural catheter with electrical stimulation guidance from the lumbar epidural space to the thoracic space in a pediatric patient. A 17-year-old boy with Down syndrome, weighing 48 kg, was scheduled to undergo a laparotomy for duodenal obstruction and gastrostomy tube insertion. Combined general and continuous epidural anesthesia was selected for his anesthetic. Following the induction of general anesthesia and tracheal intubation, a 17G Tuohy needle (Arrow International, Inc., Reading, PA) was inserted into the lumbar space (L3-4) using loss of resistance with air. A 20G styletted epidural catheter was then inserted and threaded cranially. As the catheter was advanced, a low electrical current (1-10mA) was applied to the catheter. Motor response was observed from the lower limb muscles to the upper abdominal muscles as the catheter advanced cranially. After 22 cm of the epidural catheter had been inserted, intercostal muscle movement (T9 - 10) was observed at 3.0 mA. Radiographical imaging later confirmed the catheter tip at T10. The patient awoke without distress and was discharged to the ward with subsequent good pain control from a continuous epidural infusion of bupivacaine 0.1% with 1 microg ml(-1) fentanyl at 4-6 ml(-1).     

Lumbar epidural catheter insertion: the midline vs. the paramedian approach

BACKGROUND AND OBJECTIVE: The purpose of this study was to compare the characteristics of epidural catheter insertion via the midline or the paramedian approach with regard to ease of catheter insertion, incidence of paraesthesias and efficacy of epidural block. In addition to the type of approach, the prognostic value of Patients characteristics variables with regard to the incidence of paraesthesias was assessed. METHODS: Thirty patients scheduled for surgery under epidural anaesthesia were randomly assigned to one of two groups of 15 patients each. Epidural anaesthesia was performed via a midline or paramedian approach using loss of resistance to saline. Variables measured were: time needed to identify the epidural space, time needed for and ease of epidural catheter insertion and the incidence of paraesthesias. After completion of these observations, epidural anaesthesia was established with 150 mg ropivacaine 1%. Efficacy of the epidural block was assessed by the need for intraoperative analgesics and by the patient on a three-point scale (good/fair/poor). RESULTS: Quality of sensory blockade was adequate in both groups. Catheter insertion was significantly faster using the paramedian approach. The difference between the two approaches with regard to the incidence of paraesthesias was not significant, however, there was a trend towards more paraesthesias in the midline group. In the multivariate analysis, type of approach was an independent significant predictor of paraesthesias and we found a trend towards a higher incidence of paraesthesias in female patients. CONCLUSIONS: Catheter insertion was faster in the paramedian group and we found a trend towards a higher incidence of paraesthesias with the midline approach.     

Determining epidural catheter location using nerve stimulation with radiological confirmation

BACKGROUND AND OBJECTIVES: The use of epidural stimulation to confirm epidural catheter placement has been shown. This case report describes the benefits and problems of using the epidural stimulation test to confirm epidural catheter placement and provides supporting evidence for these observations using radiological imaging. CASE REPORT: METHODS: A nerve stimulator was connected to the proximal end of an epidural catheter via an adapter. The cathode lead was connected to the adapter. The anode lead was connected to an electrode placed on the upper extremity as a grounding site. Using 1 to 10 mA current, a segmental motor response indicated that the catheter was in the epidural space. The absence of a motor response indicated that it was not. CASES: In the first patient, the new test predicted subcutaneous epidural catheter placement, which was subsequently confirmed radiologically. In the second patient, the catheter tip was found to be lying near a nerve root, which was again confirmed radiologically. In the third case, a negative test was initially observed with only local muscle movement over the biceps area (T2). After relocation of the grounding electrode to the lower extremity, segmental intercostal muscle movement (T4-5 level) was observed. The catheter placement was radiologically shown to be in the T4-5 region. CONCLUSION: This report illustrates some of the potential benefits and problems of using the nerve stimulation test to confirm epidural catheter placement, with radiological verification.     

Lumbar plexus posterior approach: a catheter placement description using electrical nerve stimulation

IMPLICATIONS: The authors describe a modified technique of posterior approach to the lumbar plexus in the psoas compartment which allows nerve stimulation for the location of the plexus and catheter placement for extended-duration surgery and postoperative patient-controlled regional analgesia. A frequent incidence of total lumbar plexus block was observed.     

Syncope after administration of epidural analgesia in an obstetric patient with a vagus nerve stimulator

Vagus nerve stimulation (VNS) is an adjunctive therapy for medically refractory epilepsy and depression. Vagus nerve stimulation is generally well-tolerated, but cardiac arrhythmias or asystole are rare complications that have been reported. This case report describes an obstetric patient who received epidural analgesia and subsequently experienced two episodes of syncope synchronous with stimulation from her VNS device. These resolved after deactivating the device. This is the first report of a suspected arrhythmia during VNS in the setting of epidural analgesia.     

Haemodynamic effects of the position chosen for the insertion of an epidural catheter

An epidural catheter may be inserted with the patient either in the flexed left lateral or the sitting position. We have studied, non-invasively, the haemodynamic changes associated with these positions, using the thoracic bio-impedance method (BOMED NCCOM3 Monitor). Maternal arterial pressure and fetal heart rate were monitored simultaneously. Twenty healthy pregnant patients at term and 20 non-pregnant healthy controls, matched for age and height, were studied. The pregnant patients were scheduled for elective caesarean section and had singleton healthy fetuses. A significant reduction in stroke index (SI) occurred when the pregnant patients were repositioned from supine 15degrees wedged position to either flexed left lateral (P < 0.01) or sitting positions (P < 0.05). Similar reductions in SI with positioning were observed in the non-pregnant patients: flexed left lateral (P < 0.01); and sitting (P < 0.01). These changes in SI produced significant reductions in cardiac index (CI) in both groups. In the pregnant patients the CI was significantly lower in the flexed left lateral than in the sitting position (P < 0.01). Consequently maternal systolic blood pressure was lower in the flexed left lateral position (P < 0.01).