Spread Of Local Anesthetic Solution Research Articles

A randomized controlled trial to study the effect of hyaluronidase as adjuvant in ultrasound-guided transversus abdominis plane block for postoperative analgesia in total abdominal hysterectomy

Background: Transversus abdominis plane (TAP) block is a regional anesthesia technique for postoperative analgesia. Since multiple nerves are to be blocked in a single prick, mucolytic enzyme hyaluronidase is being used to improve the spread of the local anesthetic. The present study was conducted to evaluate the effect of adding hyaluronidase as an adjuvant to local anesthetic in ultrasound (US)-guided TAP block. Materials and Methods: Eighty patients were randomly divided into two groups, Group B and Group BH. Group B patients received US-guided bilateral TAP block with 38 ml of 0.25% bupivacaine (heavy) and 2 ml of NS. Group BH patients received 38 ml of 0.25% bupivacaine (heavy) with 3000 IU hyaluronidase (2 ml) after completion of surgery under spinal anesthesia. Visual analog score (VAS) and heart rate were noted periodically. Time of demand of the first rescue analgesia and total analgesic consumption in 24 h were noted. Patient satisfaction survey was done at the end of 24 h. Results: Group BH patients had lower mean VAS scores at 6 and 8 h postoperatively as compared to Group B. The mean time of demand for the first rescue analgesia was longer in Group BH (351 ± 16 min) as compared to Group B (307 ± 13 min). The cumulative dose of rescue analgesic needed was more in Group B (370 ± 9 min) as compared to Group BH (343 ± 8 min). Patient satisfaction score was 3.3 ± 0.5 in Group BH and 2.3 ± 0.5 in Group B. All the differences were statistically significant. Conclusion: Addition of hyaluronidase improved quality of postoperative analgesia which can be due to the enzymatic action of hyaluronidase which hydrolyses the hyaluronic acid in the connective tissue and facilitates the spread of local anesthetic solution.

RETRACTED: Spread of local anesthetic solution in the erector spinae plane block

RETRACTED: Spread of local anesthetic solution in the erector spinae plane block

Magnetic Resonance Imaging Analysis of the Spread of Local Anesthetic Solution after Ultrasound-guided Lateral Thoracic Paravertebral Blockade

This study was designed to examine the spread of local anesthetic (LA) via magnetic resonance imaging after a standardized ultrasound-guided thoracic paravertebral blockade. Ten volunteers were enrolled in the study. We performed ultrasound-guided single-shot paravertebral blocks with 20 ml mepivacaine 1% at the thoracic six level at both sides on two consecutive days. After each paravertebral blockade, a magnetic resonance imaging investigation was performed to investigate the three-dimensional spread of the LA. In addition, sensory spread of blockade was evaluated via pinprick testing. The median (interquartile range) cranial and caudal distribution of the LA relative to the thoracic six puncture level was 1.0 (2.5) and 3.0 (0.75) [=4.0 vertebral levels] for the left and 0.5 (1.0) and 3.0 (0.75) [=3.5 vertebral levels] for the right side. Accordingly, the LA distributed more caudally than cranially. The median (interquartile range) number of sensory dermatomes which were affected by the thoracic paravertebral blockade was 9.8 (6.5) for the left and 10.7 (8.8) for the right side. The sensory distribution of thoracic paravertebral blockade was significantly larger compared with the spread of LA. Although the spread of LA was reproducible, the anesthetic effect was unpredictable, even with a standardized ultrasound-guided technique in volunteers. While it can be assumed that approximately 4 vertebral levels are covered by 20 ml LA, the somatic distribution of the thoracic paravertebral blockade remains unpredictable. In a significant percentage, the LA distributes into the epidural space, prevertebral, or to the contralateral side.

Arched Needle Technique for Inferior Alveolar Mandibular Nerve Block

Although, needle breakage remains a rare complication during oral local anesthesia (LA) administration, there are ample reports mandating a careful technique and precautionary measures to prevent this complication [1–4]. Chakranarayan and Mukherjee [5] describe a method of inferior alveolar nerve block (IANB) by injecting a local anesthetic solution into the pterygomandibular space by arching the needle and changing the approach angle of the conventional technique. The authors describe arching the needle after the initial insertion and inserting it in a manner that it approaches the medial surface of the ramus at an angle almost perpendicular to it. Although Chakranarayan and Mukherjee highlight in their study that bending the needle was found safe in their study patients, advocating bending an advancing needle within the oral tissues may not be a safe surgical practice. The incidence of needle breakage is such a rare occurrence that studying a small group of patients can not endorse the safety of a technique. Pogrel has estimated the risk of needle breakage amongst Northern California dentists at 1 in 14 million inferior alveolar nerve blocks [2, 8]. If the needle was checked in vitro before using them in patients in their study [5], by theory, this practice further weakens the needle due to undue stress and strains on its material before use. In a review of cases by Malamed et al. [8] intentional bending of the needle by the doctor before injection is reported to be an important factor for needle breakage. The very concept of inferior alveolar nerve block is to deposit the solution in the pterygomandibular space. Depositing the solution near the mandibular foramen may have an advantage of an early onset of LA, but in this case it is at the cost of potential risk of needle breakage. It should be noted that IANB remains the most susceptible technique to have an incidence of a needle breakage. It is not a common occurrence, but when it occurs it may be a detrimental event both for the patient and the treating dental surgeon. The rare incidence of needle breakage will mandate a high radiation imaging study to localize the needle and a surgical exploration under general anesthesia for its retrieval [2]. Okamoto et al. [6, 7] studied the spread of local anesthetic solution in the inferior alveolar nerve block and found that local anesthetic solution spreads and rapidly fills nearly the entire pterygomandibular space by completion of the injection, emphasizing the fact that targeting the mandibular foramen to deposit the solution may not be necessary for the success of IANB.

Weight‐Based Volume of Injection Influences Cranial to Caudal Spread of Local Anesthetic Solution in Ultrasound‐Guided Transversus Abdominis Plane Blocks in Canine Cadavers

To determine if the volume of injected local anesthetic solution affects cranial to caudal spread when performing ultrasound-guided transversus abdominis plane (TAP) blocks in dogs. Prospective experimental study. Adult Beagle cadavers (n = 20) Bilateral TAP blocks using ultrasound guidance was performed in 20 Beagle cadavers (mean ± SD weight, 9.3 ± 1.4 kg) using a 1:1 solution of methylene blue/bupivacaine injected at volumes of 0.25, 0.5, 0.75, and 1.0 mL/kg. Cadavers were dissected to determine injectate spread within the transversus abdominis fascial plane. The transversus abdominis fascial plane was adequately identified by ultrasonography, injected, and dissected in 38 beagle hemi-abdominal walls; injectate was not identified in 2 hemi-abdominal walls. Dermatomal spread (number of ventral nerve roots saturated by injected solution) was volume dependent (P = .026, Kruskal Wallis): 2.9 ± 0.74 nerve roots for 0.25 mL/kg; 3.4 ± 1.1 for 0.5 mL/kg; 4.0 ± 0.67 for 0.75 mL/kg; and 4.2 ± 1.2 for 1 mL/kg. In Beagle cadavers, the volume of injected local anesthetic solution significantly affects cranial to caudal spread within the TAP during ultrasound-guided TAP blocks. The volume of local anesthetic injected could potentially be used to augment the spread of analgesic coverage for a given surgical procedure in dogs.

DGAI-zertifizierte Seminarreihe Anästhesie Fokussierte Sonografie – Modul 3: Neurosonografie

Identification of the right puncture site and the target structures are mandatory in performing nerve blocks. Ultrasound is a new method, that visualizes target structures as well as the injection and spread of local anaesthetic solution. The presented module 3 neurosonography is part of the didactic concept "anaesthesiology focussed sonography" developed by the german society of anaesthesiology and intensive care. It contains all essential nerve blocks of the upper and lower limb. Additionally the structural requirements to provide the course are included.

Studies on the spread of local anaesthetic solution in transversus abdominis plane blocks*

The extent of analgesia provided by transversus abdominis plane blocks depends upon the site of injection and pattern of spread within the plane. There are currently a number of ultrasound-guided approaches in use, including an anterior oblique-subcostal approach, a mid-axillary approach and a more recently proposed posterior approach. We wished to determine whether the site of injection of local anaesthetic into the transversus abdominis plane affects the spread of the local anaesthetic within that plane, by studying the spread of a local anaesthetic and contrast solution in four groups of volunteers. The first group underwent the classical landmark-based transversus abdominis plane block whereby two different volumes of injectate were studied: 0.3 ml.kg(-1) vs 0.6 ml.kg(-1). The second group underwent transversus abdominis plane block using the anterior subcostal approach. The third group underwent transversus abdominis plane block using the mid-axillary approach. The fourth group underwent transversus abdominis plane block using the posterior approach, in which local anaesthetic was deposited close to the antero-lateral border of the quadratus lumborum. All volunteers subsequently underwent magnetic resonance imaging at 1, 2 and 4 h following each block to determine the spread of local anaesthetic over time. The studies demonstrated that the anterior subcostal and mid-axillary ultrasound approaches resulted in a predominantly anterior spread of the contrast solution within the transversus abdominis plane and relatively little posterior spread. There was no spread to the paravertebral space with the anterior subcostal approach. The mid-axillary transversus abdominis plane block gave faint contrast enhancement in the paravertebral space at T12-L2. In contrast, the posterior approaches, using both landmark and ultrasound identifications, resulted in predominantly posterior spread of contrast around the quadratus lumborum to the paravertebral space from T5 to L1 vertebral levels. We concluded that the pattern of spread of local anaesthetic differs depending on the site of injection into the transversus abdominis plane. This may have important implications for the extent of analgesia produced with each approach.

Role of local anesthetic spread pattern and electrical stimulation in ultrasound-guided musculocutaneous nerve block

Study Objective To evaluate local anesthetic spread on the frequency of success of musculocutaneous nerve block, and to determine needle-to-target-nerve distance by ultrasound imaging and electrical stimulation. Design Observational study. Settings Private hospital. Patients 48 ASA physical status I and II adults (16 men and 32 women) scheduled for elective carpal tunnel release or wrist ganglion cyst surgery in an outpatient setting. Interventions The musculocutaneous nerve (MCN) was identified by ultrasound. An insulated needle connected to an electrical stimulator in the “off” position was inserted in the biceps side of the probe in the plane of the ultrasound beam. The needle tip was placed in the vicinity of the MCN. Measurements Local anesthetic spread pattern was determined by ultrasound imaging. The lowest effective current intensity was registered. The average depth of the MCN was measured by ultrasound. Main Results In all patients, the local anesthetic solution spread was uneven. In 32% of patients (15/47), motor response was still elicited with electrical stimulation intensity lower or equal to 0.3 mA. In 26% of patients (12/47), motor response disappeared with electrical stimulation intensity higher or equal to 0.6 mA. In 42% of patients (20/47), motor response disappeared at intensities between 0.3 mA and 0.5 mA. Conclusions A high success rate of MCN anesthesia occurred with non-circumferential spread of local anesthetic solution. Electrical current intensity was not a reliable indicator of needle-to-target-nerve distance.

347: Spread of local anaesthetic solution in epidural space in paediatric single shot caudals under realtime ultrasonography

347: Spread of local anaesthetic solution in epidural space in paediatric single shot caudals under realtime ultrasonography

Spread of local anaesthetic solution in epidural space in paediatric single shot caudals under realtime ultrasonography

Spread of local anaesthetic solution in epidural space in paediatric single shot caudals under realtime ultrasonography

34th Annual Scientific Meeting of the Association of Paediatric Anaesthetists of Great Britain and Ireland, 8?10 March 2007, Manchester. Spread of local anaesthetic solution in epidural space visualisation with ultrasound in single shot caudals

Background: Ultrasonography is becoming an important adjunct in paediatric neuraxial blockade. Ultrasound guidance helps in visualisation of relevant neuraxial structures, predicting depth of epidural space from skin, reduction in bony contact and faster epidural placement. The visibility of neuraxial structures declines in patients as age increases. To date, there are no studies looking at the extent of spread of local anaesthetic solution in the epidural space and its correlation to the volume used, under ultrasound guidance. We report the results of our audit on spread of local anaesthetic solution in the epidural space in single shot caudal blocks. This abstract is based on the first 17 patients, the presentation will be based on all 50 patients. Methods: This audit was approved by the local audit committee. We aimed to follow the extent of the spread of local anaesthetic within the epidural space with real time ultrasonography. Patients were selected when the planned anaesthetic included a single shot caudal block. The anaesthetists performing the anaesthetic and the caudal block consented to our ultrasound visualisation. All patients were below 5 years of age. No attempt was made to standardise the technique, the dose, or the speed of injection. After the placement of the caudal cannula by the primary anaesthetist involved in patient care, a separate anaesthetist, experienced in using ultrasound, visualised the neuraxial structures and subsequent spread of the local anaesthetic solution with real time ultrasound. The spread was followed during the injection and for 10 s after the completion of the injection. A 5 cm 7.5–12 MHz linear array was used longitudinally with either midline or paramedian approach. Results: We are reporting the preliminary results from 17 patients. Patients were aged between 1 day and 1 year 10 months. They weighed between 3.3 kg and 14.6 kg. Either 22 gauge Jelco or Abbocath were used to perform the procedure; 0.25% or 0.20% L-bupivacaine was used on all occasions. The volume administered per kg ranged between 0.33 and 1.27 ml. The visibility of neuraxial structures was good on all occasions. On calculating the Spearmans correlation coefficient, the extent of spread of local anaesthetic in the epidural space was positively correlated with the volume used by a correlation coefficient of 0.64, with a P value of 0.008. The postoperative pain score in recovery was 0 in 16 out of the 17 cases. The one failure occurred when the observed spread would not have been expected to provide analgesia for the performed operation. Conclusions: Among children below 5 years of age, there seems to be a positive correlation between the volume of local anaesthetic injected into the epidural space and the extent of its spread. This needs to be further investigated by a prospective randomised control trial. The utility of real time ultrasound to allow a reliable achievement of a desired level of sensory block, should be investigated i.e, whether the volume used in achieving a desired level of local anaesthetic spread, as guided by ultrasound, provides superior analgesia and fewer adverse effects compared with the volume calculated using the Armitage regimen. References 1 Rapp HJ, Folger A, Grau T. Ultrasound guided epidural catheter insertion in children. Anesth Analg 2005; 101: 333–339. 2 Willschke H, Marhofer P, Bosenberg A, et al. Epidural catheter placement in children: comparing a novel approach using ultrasound guidance and a standard loss of resistance technique. Br J Anaesth 2006; 97: 200–207. 3 Marhofer P, Bosenberg A, Sitzwohl C et al. Pilot study of neuraxial imaging by ultrasound in infants and children. Pediatr Anesth 2005; 15: 671–676.

Interpleural analgesia in a palliative care setting

We describe four cases in which interpleural analgesia has been used to treat pain arising from malignancy of the lung or pleura. Three out of the four patients had an improvement in pain control as assessed by the EORTC QLQ-C30 quality of life questionnaire. Analgesia appeared to become less effective with disease progression. This may be due to inhibited spread of local anaesthetic solution in the interpleural space since correct catheter placement was reconfirmed using fluoroscopy. Careful selection of patients in earlier stages of the disease process may increase usefulness of the technique.

The effects of arm position on central spread of local anesthetics and on quality of the block with axillary brachial plexus block

Background and Objectives. Spread of local anesthetic solution in axillary brachial plexus block is thought to be influenced by the position of the arm and the use of compression maneuvers. We investigated how these two factors affected central local anesthetic spread and block quality. Methods. Radiographic spread of local anesthetic was studied in 80 adult patients. They received mepivacaine mixed with contrast agent through an indwelling catheter with the arm abducted to either 0 or 90°, and with or without local digital compression. Central and peripheral spread of the contrast agent was evaluated with anteroposterior radiographs of the axilla. Block quality was studied in a separate series of 70 adult patients. They received mepivacaine with the arm abducted 0° or 90°. The degree of sensory and motor block was assessed 20 minutes after the injection. Results. Arm position at 0° abduction promoted central spread of the contrast agent. Although digital compression suppressed peripheral spread effectively, it did not improve the central spread of the solution. Sensory block was comparable in all terminal nerves of the arm in both arm positions, whereas motor block of the radial nerve was promoted with no abduction. Conclusions. The central spread of local anesthetics is facilitated by injection without abduction of the arm but not by the use of compression at the injection site. This, however, did not alter the quality of the block.

Correspondence

Correspondence

Periodontal ligament injection in the dog primary dentition: spread of local anaesthetic solution.

The spread of local anaesthetic solution administered with a pressure syringe has not been studied as extensively in young animals having primary or mixed dentitions as in adult animals. The purpose of this investigation was to study the distribution of local anaesthetic solution injected into the periodontal ligament of young dogs. India ink was added to carpules containing 2% lidocaine and 1:100,000 epinephrine, and the spread of solution was examined macroscopically and microscopically. Injections were made with a pressure syringe (Ligmaject) at 58 sites mesial and distal to primary teeth in five dogs aged 3-9 months. Three dogs were killed within 12 hours, the other two after 5 days. Spread of the ink was studied in non-decalcified slabs, in three-dimensional cleared specimens, and in histological sections. The solution usually reached the alveolar bone crest, seeped under the periosteum and alongside vascular channels into bone marrow, reaching natural cavities such as the crypts of tooth buds and the mandibular canal. The ink did not penetrate into the enamel organ or contact the permanent tooth buds. The solution appeared to spread along the path of least resistance, governed by the intricacies of anatomical structures and fascial planes. Therefore the risk of mechanical damage to permanent tooth germs appears to be minimal.

Extensive Spread of Local Anesthetic Solution Following Subdural Insertion of an Epidural Catheter During Labour

Obstetric Anesthesia Digest provides timely summaries of the world literature in obstetric anesthesia. Each quarterly issue features dozens of clear, concise summaries of the most significant recent articles, frequently accompanied by insightful commentary by one of the Digest's renowned editorial consultants. The comprehensive coverage includes editorials and reviews, special articles, case reports, and "Short Takes"—abbreviated abstracts of secondary papers

Extensive Spread of Local Anesthetic Solution Following Subdural Insertion of an Epidural Catheter During Labour

Extensive Spread of Local Anesthetic Solution Following Subdural Insertion of an Epidural Catheter During Labour

Uterine Contractions and the Spread of Local Anesthetics in the Epidural Space

Local anesthetics injected into the epidural space during a uterine contraction are commonly believed to produce a higher than usual level of anesthesia. This was evaluated in 34 parturients undergoing continuous lumbar epidural labor analgesia. The patients were divided into two equal groups. In group A, the inducing dose (2% chloroprocaine, 8 ml) was injected during an active uterine contraction and the top-up dose was injected between contractions. In group B, the injection sequence was reversed. Irrespective of the time of injection, in relation to uterine contractions, approximately 16 dermatomal segments were blocked in both groups. It is concluded that uterine contractions do not affect spread of local anesthetic solution in the epidural space.

Uterine Contractions and the Spread of Local Anesthetics in the Epidural Space

Local anesthetics injected into the epidural space during a uterine contraction are commonly believed to produce a higher than usual level of anesthesia. This was evaluated in 34 parturients undergoing continuous lumbar epidural labor analgesia. The patients were divided into two equal groups. In group A, the inducing dose (2% chloroprocaine, 8 ml) was injected during an active uterine contraction and the top-up dose was injected between contractions. In group B, the injection sequence was reversed. Irrespective of the time of injection, in relation to uterine contractions, approximately 16 dermatomal segments were blocked in both groups. It is concluded that uterine contractions do not affect spread of local anesthetic solution in the epidural space.

EFFECT OF THE TRENDELENBERG POSITION ON SPINAL ANAESTHESIA WITH HYPERBARIC BUPIVACAINE

In a double-blind study, the effect of the Trendelenberg position was compared with the supine, in 20 patients following intrathecal injection of 3 ml of 0.5% bupivacaine in 8% glucose. All patients had blocks suitable for abdominal surgery. Although the mean spread was greater in those patients titled head-down, this was not statistically significant. The variation of the spread around the mean was greater in the head-down group, and blocks extended into the cervical region in two patients. There were no differences in motor block, duration or cardiovascular changes between the groups. It is concluded that the trendelenberg position is not necessary to ensure spread of local anaesthetic solution into the mid thoracic region for abdominal surgery.