External jugular vein pierced by supraclavicular branches in a neonatal cadaver: a case report.

Anatomical variations in the venous structure and drainage patterns in the neck are not uncommon. However, this is the first known report on the external jugular vein being pierced by supraclavicular branches. In the lateral cervical region of a neonatal cadaver, the supraclavicular branches penetrated the external jugular vein superior to the clavicle, resulting in a circular venous channel formed around the nerve trunk. Variations such as these are important to note in order to minimize possible intra-operative complications sustained during surgical interventions such as venous catherization or nerve grafts.

Comparison of Continuous Adductor Canal and Femoral Nerve Blocks for Analgesia and Return of Quadriceps Function After Anterior Cruciate Ligament Reconstruction in Adolescent Patients.

PURPOSE: To compare early pain relief and late quadriceps function after anterior cruciate ligament reconstruction (ACLR) with hamstring autograft in adolescent patients treated with either a continuous femoral nerve block (cFNB) or continuous adductor canal block (cACB). METHODS: We retrospectively reviewed a consecutive series of adolescent patients who underwent ACLR and received either a cACB or cFNB for postoperative pain management. Over a 1-year period, all patients underwent ACLR with cFNBs. Over the subsequent 9 months, all patients underwent their ACLR with cACBs. Patient demographics, postoperative pain scores, opioid consumption, satisfaction and complications, and dates and results of quadriceps function derived at the Return to Sports evaluation were compared. RESULTS: Ninety-one patients (53 cFNB, 38 cACB) were reviewed. There were no differences in the demographics of the 2 groups. There were no statistically significant differences between groups in variations in postoperative pain scores (P = .21), or satisfaction with the blocks (P = .93). Patients in the cFNB group consumed a greater number of opioid doses on postoperative day 3 (2.2 ± 2.1 doses cFNB, 1.1 ± 1.6 doses cACB, P = .03) and a greater number of opioid doses overall for postoperative days 1 to 3 (mean 6.8 ± 5.3 doses cFNB, 3.8 ± 2.1 doses cACB, P = .03). There was no difference in time to return of acceptable quadriceps strength and function when comparing the 2 groups (30.9 ± 7.7 weeks cFNB, 28.9 ± 6.6 weeks cACB, P = .087). CONCLUSIONS: We found few differences in postoperative analgesic requirements when comparing patients who underwent ACLR with hamstring autograft with a cACB to those who underwent a similar procedure with a cFNB. Return of quadriceps strength and function by six months did not appear to vary with regional technique, either cACB or cFNB, employed at surgery. LEVEL OF EVIDENCE: III, Retrospective comparative study.

Early experience with erector spinae plane blocks in children.

BACKGROUND: An erector spinae plane block is a relatively new regional anesthetic technique. Apart from case reports and small series, the literature regarding pediatric use is limited. AIM: Our objective was to determine the efficacy of the erector spinae plane block in children by measuring the heart rate response to incision. Secondary objectives included feasibility, safety, opioid consumption, and pain scores. Furthermore, we reviewed this block in children published since 2016. STUDY DESIGN: Case Series; Level of evidence, IV. METHODS: With Institutional Review Board approval, a retrospective chart review was conducted on all patients who received erector spinae plane block for surgery between October 2017 and May 2019 at a single institution. Blocks were performed under anesthesia, using ultrasound guidance prior to surgical incision. Block details and hemodynamic and analgesic data were collected. In addition, a PubMed literature review was conducted to identify all erector spinae plane block related publications in patients ≤18 years of age. RESULTS: About 164 patients, 2 days-19.4 years, weighing 2.3-94.7 kg, received erector spinae plane blocks. For more than 79% of single injection blocks, placement time was ≤10 minutes. Using a heart rate increase of <10% at skin incision as criterion, 70.1% of patients had a successful block. Only 20% required long-acting opioids intraoperatively. In a subset of infants who underwent gastrostomy surgery using a dose of 0.5 mL/kg, a local anesthetic spread of at least five dermatomes (0.1 mL/kg/dermatome) was achieved. Per the literature review, 33 publications described erector spinae plane block in 128 children. No complications were reported. CONCLUSION: Erector spinae plane blocks are relatively easy to perform in children with no complications reported to date. The efficacy of the block for a broad spectrum of surgeries, involving incisions from T1 to L4, is encouraging.

Anatomy of the greater occipital nerve block in infants.

BACKGROUND: Pain relief for posterior fossa craniotomies as well as occipital neuralgia, are indications for the use of the greater occipital nerve block in children. The greater occipital nerve originates from the C2 spinal nerve and is accompanied by the occipital artery as it supplies the posterior scalp. AIMS: The aim of this study was to develop a unique, yet simple technique for blocking the greater occipital nerve in children through the evaluation of the anatomy of this nerve and the accompanying occipital artery in the occipital region. METHODS: The greater occipital nerve and occipital artery were dissected and exposed in six formalin-fixed cadavers (five infants [average age of 51.4 days] and one 2-year-old) from the Department of Anatomy, University of Pretoria. Measurements between the nerve and selected bony landmarks were obtained. The relationship between the greater occipital nerve and the occipital artery at the trapezius muscle hiatus was also evaluated. RESULTS: The greater occipital nerve is on average 22.6 ± 5.6 mm from the external occipital protuberance in infants. The average width of the medial three fingers measured at the proximal interphalangeal joint, for each respective cadaver is 20.4 ± 4.0 mm, with a strong correlation coefficient of 0.97 between the aforementioned distances. In 83.3% of the specimens, the occipital artery lies lateral to the greater occipital nerve at the trapezius muscle hiatus. CONCLUSION: In infants, the greater occipital nerve can be blocked approximately 23 mm from the external occipital protuberance, medial to the occipital artery. This distance is equal to the width of the medial three fingers at the proximal interphalangeal joint of the patient.

Determining the extent of the dural sac for the performance of caudal epidural blocks in newborns.

BACKGROUND: Information regarding the position and relationship of vital structures within the caudal canal is important for anesthesiologists who perform a caudal block. This information can be acquired by anatomical dissection, with ultrasound technology, or radiological studies. AIMS: The aim of this study was to determine the position of the dural sac in neonates by measuring the distance of the termination of the dural sac from the apex of the sacral hiatus in neonatal cadavers. METHODS: After careful dissection, the distance from the apex of the sacral hiatus to the dural sac was measured in a sample of neonatal cadavers. RESULTS: In 39 neonatal cadavers, the mean distance from the apex of the sacral hiatus to the dural sac was 10.45 mm. The range of this distance was between 4.94 and 26.28 mm. The mean distance for females was 9.64 mm (range from 6.66 to 15.09); that for males was 10.90 mm (range between 4.94 and 26.28). Linear regression with the log of this distance as the outcome variable gave an estimated 3.3% increase in the distance for each 1 cm increase in the length of the neonate (95% CI for this proportion was 1.91-4.71). CONCLUSION: Anesthesiologists should be aware of the short distance between the sacral hiatus and the dural sac when performing caudal blocks, the shortest distance was 4.94 mm. Armed with this knowledge, caudal techniques should be modified to improve the safety and reduce the risk of complications, such as dural puncture.

Complications in Pediatric Regional Anesthesia: An Analysis of More than 100,000 Blocks from the Pediatric Regional Anesthesia Network.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Complications in pediatric regional anesthesia are rare, so a large sample size is necessary to quantify risk. The Pediatric Regional Anesthesia Network contains data on more than 100,000 blocks administered at more than 20 children's hospitals. This study analyzed the risk of major complications associated with regional anesthesia in children. METHODS: This is a prospective, observational study of routine clinical practice. Data were collected on every regional block placed by an anesthesiologist at participating institutions and were uploaded to a secure database. The data were audited at multiple points for accuracy. RESULTS: There were no permanent neurologic deficits reported (95% CI, 0 to 0.4:10,000). The risk of transient neurologic deficit was 2.4:10,000 (95% CI, 1.6 to 3.6:10,000) and was not different between peripheral and neuraxial blocks. The risk of severe local anesthetic systemic toxicity was 0.76:10,000 (95% CI, 0.3 to 1.6:10,000); the majority of cases occurred in infants. There was one epidural abscess reported (0.76:10,000, 95% CI, 0 to 4.8:10,000). The incidence of cutaneous infections was 0.5% (53:10,000, 95% CI, 43 to 64:10,000). There were no hematomas associated with neuraxial catheters (95% CI, 0 to 3.5:10,000), but one epidural hematoma occurred with a paravertebral catheter. No additional risk was observed with placing blocks under general anesthesia. The most common adverse events were benign catheter-related failures (4%). CONCLUSIONS: The data from this study demonstrate a level of safety in pediatric regional anesthesia that is comparable to adult practice and confirms the safety of placing blocks under general anesthesia in children.

Anatomical description of the sciatic nerve block at the subgluteal region in a neonatal cadaver population.

INTRODUCTION: Sciatic nerve blocks provide intraoperative and prolonged postoperative pain management after lower limb surgery (posterior knee, foot, skin graft surgery). Accurate needle placement requires sound anatomical knowledge. Anatomical studies on children are uncommon; most have been performed on adult cadavers. We studied the location of the sciatic nerve at the gluteal level in neonatal cadavers to establish useful anatomical landmarks. METHODS: We identified the sciatic nerve in the gluteal and thigh region of 20 neonatal cadavers. The skin covering the gluteal and thigh region was reflected laterally, and the underlying structures and muscles were identified. We located the sciatic nerve and measured the distance from the nerve to the greater trochanter of the femur and to the tip of the coccyx with a mechanical dial caliper. The total distance between the two landmarks was then recorded. RESULTS: We combined measurements from both sides to form a sample size n = 40. The sciatic nerve was 14.9 ± 2.4 mm lateral to the tip of the coccyx. The total distance between the greater trochanter and the tip of the coccyx was 27.3 ± 4.0 mm. CONCLUSION: Our results provide anatomical evidence that the optimal needle insertion point is approximately halfway between the greater trochanter and the tip of the coccyx-a landmark readily palpable in neonates and infants.

Descriptive study of the differences in the level of the conus medullaris in four different age groups.

In performing neuraxial procedures, knowledge of the location of the conus medullaris in patients of all ages is important. The aim of this study was to determine the location of conus medullaris in a sample of newborn/infant cadavers and sagittal MRIs of children, adolescents, and young adults. The subjects of both the samples were subdivided into four developmental stages. No statistical difference was seen between the three older age groups (P > 0.05). A significant difference was evident when the newborn/infant stage was compared with the other, older stages (P < 0.001 for all comparisons). In the newborn/infant group the spinal cord terminated most frequently at the level of L2/L3 (16%). In the childhood stage, the spinal cord terminated at the levels of T12/L1 and the lower third of L1 (21%). In the adolescent population, it was most often found at the level of the middle third of L1 and L1/L2 (19%). Finally, in the young adult group, the spinal cord terminated at the level of L1/L2 (25%). This study confirmed the different level of spinal cord termination between newborns/infants less than one-year-old and subjects older than one year. In this sample the conus medullaris was not found caudal to the L3 vertebral body, which is more cranial than the prescribed level of needle insertion recommended for lumbar neuraxial procedures. It is recommended that the exact level of spinal cord termination should be determined prior to attempting lumbar neuraxial procedures in newborns or infants.

Interscalene brachial plexus blocks under general anesthesia in children: is this safe practice?: A report from the Pediatric Regional Anesthesia Network (PRAN).

BACKGROUND AND OBJECTIVES: A practice advisory on regional anesthesia in children in 2008, published in this journal, supported the placement of regional blocks in children under general anesthesia (GA). Interscalene brachial plexus (IS) blocks were specifically excluded, based on case reports (level 3 evidence) of injury, which occurred predominantly in heavily sedated or anesthetized adult patients. Apart from case reports, there is a paucity of data that explore the safety of IS blocks placed in patients under GA, and the level of evidence available on which to base recommendations is limited. METHODS: Querying the database of the Pediatric Regional Anesthesia Network (PRAN), we report on the incidence of postoperative neurological symptoms, local anesthetic systemic toxicity, and other reported adverse events in children receiving IS blocks under GA or sedated. RESULTS: A total of 518 interscalene blocks were performed, 390 under GA and 123 with the patient sedated or awake (5 cases had missing status); 472 of these were single injection, and 46 involved the placement of infusion catheters. Eighty-eight percent of blocks were placed with ultrasound guidance, 7.7% with no location device, and 2.5% with a nerve stimulator. No local anesthetic systemic toxicity, postoperative neurological symptoms, cardiovascular complications, or dural puncture was reported in this cohort. There were 1 vascular puncture and 1 postoperative infection. These negative results are compatible with 0 to 7.7/1000 events for each of these complications for IS blocks placed under GA. There was no paralysis, motor block, or sensory deficit beyond the expected block duration time. CONCLUSIONS: Analyzing interscalene blocks in children placed under GA, we identified no serious adverse events. The upper limit of the confidence interval for these events is similar to that in awake or sedated adults receiving IS blocks. Based on these prospectively collected data, placement of IS blocks under GA in children is no less safe than placement in awake adults, calling into question the American Society of Regional Anesthesia and Pain Medicine advisory proscribing GA during IS block in pediatric patients.

Clinical anatomy of the maxillary nerve block in pediatric patients.

BACKGROUND: Anatomical landmarks in children are mostly extrapolated from studies in adults. Despite this, complex regional anesthetic procedures are frequently performed on pediatric patients. Sophisticated imaging techniques are available but the exact position, course and/or relationships of the structures are best understood with appropriate anatomical dissections. Maxillary nerve blocks are being used for peri-operative analgesia after cleft palate repair in infants. However, the best approach for blocking the maxillary nerve in pediatric patients has yet to be established. OBJECTIVE: To determine the best approach for blocking the maxillary nerve within the pterygopalatine fossa. METHODS: In an attempt to define an optimal approach for maxillary nerve block in this age group three approaches were simulated and compared on 10 dried pediatric skulls as well as 30 dissected pediatric cadavers. The needle course, including depth and angles, to block the maxillary nerve, as it exits the skull at the foramen rotundum within the pterygopalatine fossa, was measured and compared. Two groups were studied: Group 1 consisted of skulls and cadavers of neonates (0-28 days after birth) and Group 2 consisted of skulls and cadavers from 28 days to 1 year after birth. RESULTS: No statistically significant difference (P > 0.05) was found between the left and right side of each skull or cadaver. Only technique B, the suprazygomatic approach from the frontozygomatic angle towards the pterygopalatine fossa, exhibited no statistical significance (P > 0.05) when other measurements made on the skulls and cadavers were compared. Technique A, a suprazygomatic approach from the midpoint on the lateral border of the orbit, as well as technique C, an infrazygomatic approach with an entry at a point on a vertical line extending along the lateral orbit wall, showed statistical significant differences when measurements of the skulls and cadavers were compared. CONCLUSIONS: On the basis of these findings technique B produces the most consistent data for age groups 1 and 2 and supports the clinical findings recently reported.

Asleep versus awake: does it matter?: Pediatric regional block complications by patient state: a report from the Pediatric Regional Anesthesia Network.

BACKGROUND AND OBJECTIVES: The impact of the patient state at time of placement of regional blocks on the risk of complications is unknown. Current opinion is based almost entirely on case reports, despite considerable interest in the question. Analyzing more than 50,000 pediatric regional anesthesia blocks from an observational prospective database, we determined the rate of adverse events in relation to the patient's state at the time of block placement. Primary outcomes considered were postoperative neurologic symptoms (PONSs) and local anesthetic systemic toxicity (LAST). Secondary outcome was extended hospital stay due to a block complication. METHODS: The Pediatric Regional Anesthesia Network is a multi-institutional research consortium that was created with an emphasis on rigorous, prospective, and complete data collection including a data validation and audit process. For the purpose of the analysis, blocks were divided in major groups by single injection versus continuous and by block location. Rates were determined in aggregate for these groups and classified further based on the patient's state (general anesthesia [GA] without neuromuscular blockade [NMB], GA with NMB, sedated, and awake) at the time of block placement. RESULTS: Postoperative neurological symptoms occurred at a rate of 0.93/1000 (confidence interval [CI], 0.7-1.2) under GA and 6.82/1000 (CI, 4.2-10.5) in sedated and awake patients. The only occurrence of PONSs lasting longer than 6 months (PONSs-L) was a small sensory deficit in a sedated patient (0.019/1000 [CI, 0-0.1] for all, 0.48/1000 [CI, 0.1-2.7] for sedated patients). There were no cases of paralysis. There were 5 cases of LAST or 0.09/1000 (CI, 0.03-0.21). The incidence of LAST in patients under GA (both with and without NMB) was 0.08/1000 (CI, 0.02-0.2) and 0.34/1000 (CI, 0-1.9) in awake/sedated patients. Extended hospital stays were described 18 times (0.33/1000 [CI, 0.2-0.53]). The rate for patients under GA without NMB was 0.29/1000 (CI, 0.13-0.48); GA with NMB, 0.29/1000 (CI, 0.06-0.84); sedated, 1.47/1000 (CI, 0.3-4.3); and awake, 1.15/1000 (CI, 0.02-6.4). CONCLUSIONS: The placement of regional anesthetic blocks in pediatric patients under GA is as safe as placement in sedated and awake children. Our results provide the first prospective evidence for the pediatric anesthesia community that the practice of placing blocks in anesthetized patients should be considered safe and should remain the prevailing standard of care. Prohibitive recommendations based on anecdote and case reports cannot be supported.

Ultrasound-guided rectus sheath block or wound infiltration in children: a randomized blinded study of analgesia and bupivacaine absorption.

BACKGROUND: Rectus sheath block can provide analgesia following umbilical hernia repair. However, conflicting reports on its analgesic effectiveness exist. No study has investigated plasma local anesthetic concentration following ultrasound-guided rectus sheath block (USGRSB) in children. OBJECTIVES: Compare the effectiveness and bupivacaine absorption following USGRSB or wound infiltration (WI) for umbilical hernia repair in children. METHODS: A randomized blinded study comparing WI with USGRSB in 40 children undergoing umbilical hernia repair was performed. Group WI (n = 20) received wound infiltration 1 mg·kg(-1) 0.25% bupivacaine. Group RS (n = 20) received USGRSB 0.5 mg·kg(-1) 0.25% bupivacaine per side in the posterior rectus sheath compartment. Pain scores and rescue analgesia were recorded. Blood samples were drawn at 0, 10, 20, 30, 45, and 60 min. RESULTS: Patients in the WI group had a twofold increased risk of requiring morphine (hazard ratio 2.06, 95% CI 1.01, 4.20, P = 0.05). When required, median time to first morphine dose was longer in the USGRSB group (65.5 min vs. 47.5 min, P = 0.049). Peak plasma bupivacaine concentration was higher following USGRSB than WI (median: 631.9 ng·ml(-1) IQR: 553.9-784.1 vs. 389.7 ng·ml(-1) IQR: 250.5-502.7, P = 0.002). Tmax was longer in the USGRSB group (median 45 min IQR: 30-60 vs. 20 min IQR: 20-45, P = 0.006). CONCLUSIONS: USGRSB provides more effective analgesia than WI for umbilical hernia repair. USGRSB with 1 mg·kg(-1) 0.25% bupivacaine is associated with safe plasma bupivacaine concentration that peaks higher and later than WI. Caution against using larger volumes of higher concentration local anesthetic for USGRSB is advised.

Neonatal anesthesia with limited resources.

Neonates are the most vulnerable age group in terms of anesthetic risk and perioperative mortality, especially in the developing world. Prematurity, malnutrition, delays in presentation, and sepsis contribute to this risk. Lack of healthcare workers, poorly maintained equipment, limited drug supplies, absence of postoperative intensive care, unreliable water supplies, or electricity are further contributory factors. Trained anesthesiologists with the skills required for pediatric and neonatal anesthesia as well as basic monitoring equipment such as pulse oximetry will go a long way to improve the unacceptably high anesthetic mortality.

High-frequency micro-ultrasound for vascular access in young children--a feasibility study by the High-frequency UltraSound in Kids studY (HUSKY) group.

BACKGROUND: Cannulation of small arteries and veins in young children can be challenging. Although anesthesiologists frequently use ultrasound for placement of central venous lines and nerve blocks, its use for cannulation of small, peripheral vessels is less helpful. Ultrasound systems (7-15 MHz) currently used in clinical practice focus poorly at the sub-10-mm space and thus lack the resolution to allow accurate ultrasound-guided cannulation of small vessels. High-frequency micro-ultrasound (HFMU) is a new technology that allows higher resolution (15-50 MHz) compared with conventional ultrasound. Limited human studies have been performed thus far with HFMU, and none have been performed in young children or for vascular access. METHODS: This study was conducted to determine the feasibility of using HFMU to visualize and cannulate peripheral arteries and central veins in children under the age of 6 years old. The diameter of radial and ulnar arteries was also measured. RESULTS: The anesthesiologists involved in this study found the 50 MHz HFMU probe useful for cannulation of peripheral arteries, especially in the youngest children. The higher-frequency probes were less helpful for internal jugular vein cannulation because it was not always possible to view the carotid artery while cannulating the vein. CONCLUSIONS: The experience gained in this feasibility study suggests that HFMU could be a valuable addition to our armamentarium for difficult vascular access in the future.

Revisiting the anatomy of the ilio-inguinal/iliohypogastric nerve block.

BACKGROUND: The ilio-inguinal/iliohypogastric nerve block (INB) is one of the most common peripheral nerve block techniques in pediatric anesthesia, which is largely due to the introduction of ultrasound (US) guidance. Despite the benefits of US guidance, the absence of an US machine should not deter the provider from performing INB, considering that many institutions, especially in developing countries, cannot afford to provide ultrasound machines in their anesthesiology departments. The aim of this study was to revisit the anatomical position of the ilio-inguinal and iliohypogastric nerves in relation to the anterior superior iliac spine (ASIS), in a large sample of neonatal cadavers, and compare the results with a similar group in a previously published US-guided study. METHODS: With Ethics Committee approval, the ilio-inguinal and iliohypogastric nerves were carefully dissected in 54 neonatal cadavers. RESULTS: In the total sample, the ilio-inguinal nerve was found to be 2.2 ± 1.2 mm from the ASIS, on a line connecting the ASIS to the umbilicus. The iliohypogastric nerve was on average 3.8 ± 1.3 mm from the ASIS. For the entire sample, the optimal needle insertion site was 3.00 mm from the ASIS. Although there is a strong correlation between the needle insertion point and the weight of the neonate, this will only 'fit' for 60% of the population. CONCLUSION: The linear regression formula; needle insertion distance (mm) = 0.6 × weight + 1.8 can be used as a guideline for the position of the ilio-inguinal and iliohypogastric nerves.