The Paraneural Sciatic Sheaths in Longitudinal Axis at the Level of Greater Trochanter: An Ultrasound Cadaveric and Clinical Correlation Study.

Background: Paraneural sheath engulfing the sciatic nerve (SN) between the ischial tuberosity and the greater trochanter is well known. Methods: In order to explore the anatomical planes separating the paraneurium from the epineurium in SN, we conducted a cadaveric study (two patients and four specimens), followed by a clinical study in 10 patients. Results: We demonstrated an elevation of 5-7 layers of paraneural tissues after an in-plane injection in the longitudinal axis of the proximal SN, which was possibly the last of the paraneural sheath. In the clinical study, the block provided low pain scores with no rescue analgesia postoperatively and no neurological deficit at the time of discharge. Conclusion: This is probably the first series which has described the elevation of several layers of paraneural tissues after an in-plane injection in the longitudinal axis of the proximal SN.

Analgesic Efficacy and Outcomes of Ultrasound-guided Erector Spinae Plane Block in Patients Undergoing Bariatric and Metabolic Surgeries: A Systematic Review.

Erector spinae plane block (ESPB) has been used as an intervention for providing postoperative analgesia in patients undergoing bariatric and metabolic surgeries. After registering the protocol in PROSPERO, randomized controlled trials and nonrandomized observational studies were searched in various databases till July 2022. The primary outcome was 24-h opioid consumption; the secondary outcomes were intraoperative opioid use, pain scores, time to rescue analgesia, and complications. The risk of bias and Newcastle-Ottawa scale were used to assess the quality of evidence. From the 695 studies identified, 6 studies were selected for analysis. The 24-h opioid consumption was significantly lesser in ESPB group when compared to control (mean difference [MD]: -10.67; 95% confidence interval [CI]: -21.03, -0.31, I² = 99%). The intraoperative opioid consumption was significantly less in the ESPB group (MD: -17.75; 95% CI: -20.36, -15.13, I² = 31%). The time to rescue analgesia was significantly more in the ESPB group (MD: 114.36; CI: 90.42, 138.30, I² = 99%). Although pain scores were significantly less at 6 and 24 h in ESPB group (MD: -2.00, 95% CI: -2.49, -1.51; I² = 0% and MD: -0.48; 95% CI: -0.72, -0.24; I² = 48%), at zero and 12 h, the pain scores were comparable (MD: -1.53, 95% CI: -3.06, -0.00, I² = 97% and MD: -0.80; 95% CI: -1.80, 0.20, I² = 88%). Bilateral ESPB provides opioid-sparing analgesia and better pain scores when compared to control. These results should be interpreted with caution due to high heterogeneity among the included studies.

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Intricacies of Ultrasound-guided Lumbar Plexus Block in Octogenarians: A Retrospective Case Series.

Background: Ultrasound (US)-guided lumbar plexus block (LPB) could be technically challenging in elderly patients. The lumbar paravertebral sonoanatomy is undescribed in the elderly. In an attempt to understand the relevant sonoanatomy, identify the lumbar plexus elements, and understand the difficulties that encountered while performing LPB in elderly patients, we retrospectively analyzed US of 23 elderly patients who were administered US-guided LPBs. Methods: After institutional ethics committee approval, we retrospectively reviewed stored US images of lumbar paravertebral sonoanatomy in 23 elderly patients and analyzed psoas major muscle, lumbar vertebral body, lumbar nerve, and lumbar artery. Results: On US examination, features of psoas major muscle, lumbar vertebral body, lumbar nerve, and lumbar artery were noted and analyzed. Conclusion: US-guided visualization of the components of the lumbar paravertebral area is difficult and inconsistent in the elderly. Therefore, we suggest performing a scout scan, identify the structures, and use neurostimulation all the time for performing LPB in these patients.

Ultrasound-guided single needle tip placement below axillary artery in the infraclavicular area: A cadaveric study.

Background and Aims: The parasagittal ultrasound-guided infraclavicular block (ICB) aims to cover all the elements of brachial plexus for the surgeries at and below the elbow. Our aim was to demonstrate the spread of 20 ml latex in vicinity of brachial plexus cords after injecting posterior to the axillary artery in Thiel embalmed cadavers. Material and Methods: A blunt insulated needle was inserted posterior to the axillary artery in a traditional parasagittal infraclavicular in 2 Thiel embalmed cadavers, on both the sides (four specimens). A day later cadaver 1 was dissected and cadaver 2 was frozen at ‒20ºC for 2 weeks and sectioned. Both cadavers were photographed. Results: In cadaver 1, dissection revealed a spread of red latex on the lateral cord extending onto the musculocutaneous nerve, the posterior cord engulfing the radial and axillary nerves distally. In cadaver 2, a cross-section revealed latex engulfed all three cords. Conclusion: Single injection of 20 ml latex aimed posterior to the axillary artery in the parasagittal infraclavicular approach engulfed the posterior, medial and lateral cord in Thiel embalmed cadavers. This needs to be investigated in patients who receive ICB clinically and using contrast studies.

Undescribed Vascular Signatures: A Contraindication to Ultrasound-guided Parasagittal Infraclavicular Block! A Retrospective Observational Study.

BACKGROUND: The ultrasound-infraclavicular block (US-ICB) is a popular and efficient block for below-elbow surgeries. However, the vascular anatomy of infraclavicular area close to the brachial plexus has remained unresearched. We aimed to explore the presence of aberrant vasculature in the infraclavicular area that could pose a contraindication to US-ICB. METHODS: In this retrospective observational study, we reviewed the US images of patients undergoing below-elbow surgery under US-ICB. Before performing the block, a scout scan of parasagittal infraclavicular areas was performed and the scan images were saved. The primary objective was to find the prevalence of aberrant vasculature due to which the US-ICB was abandoned. The secondary objective was to understand the pattern and position of the aberrant vessels. RESULTS: Out of 912 patients, 793 patients underwent surgery under US-ICB and in 119 patients (13.05%), the USG-ICB was abandoned due to aberrant vasculature close to the brachial cords and intended position of the needle tip. The anomalous vessels were identified in the lower inner, lower outer, and upper outer quadrants around the axillary artery (AA). Some of these vascular structures also had classical patterns which we described as "satellites," "clamping," or "hugging" of the AA. CONCLUSION: Anomalous vascular structures in the infraclavicular area were seen in 13.05% of patients planned for US-ICB. We, therefore, recommend, that a thorough scout US scan should be mandatorily performed ICB and in the presence of aberrant vascular structures, an alternative approach to brachial plexus block may be adopted.

Management of Malignant Ascites by Indwelling Tunnelled Catheters in Indian Setup: A Case Series.

Malignant Ascites (MA) poses significant symptom burden in patients with peritoneal malignancies at the end of life. Various treatment options are available and Indwelling Tunneled Catheters (ITC) have the advantage of increased patient comfort being soft on abdomen, less painful, easy to tap fluid, and less chances of infection etc. A total of 5 patients underwent insertion of ITC after proper counseling and assessment. Insertion was done in operation theatre under combined ultrasonogram and fluoroscopy guidance. Results: 4 out of 5 patients had favorable outcomes in terms of symptom free days spent at home at end of life. ITC's are a suitable option to manage symptoms in patients with terminal malignant ascites. Careful patient selection and proper education of the caregivers will increase the success rates of procedures.

A retrospective study comparing analgesic efficacy of ultrasound-guided serratus anterior plane block versus intravenous fentanyl infusion in patients with multiple rib fractures.

BACKGROUND AND AIMS: Inadequately managed pain due to multiple rib fractures (MRFs) can lead to atelectasis, pneumonia, prolonged ICU stay thereby leads to significant morbidity, morbidity and cost of treatment. Opioids, non-steroidal anti-inflammatory drugs and regional anaesthesia techniques like thoracic epidural or paravertebral blocks, intercostal nerve blocks are used to manage pain. Serratus anterior plane block (SAPB) is an ultrasound (US) guided interfascial plane block which has been used in managing pain due to MRFs. In this retrospective study, we compared analgesic efficacy and 24 hr fentanyl consumption in patients with MRFs who were managed with continuous SAPB versus patients who were managed with fentanyl infusion alone. MATERIAL AND METHODS: After Institutional Ethics Committee approval, we retrospectively collected data of 72 patients (38 in SAPB group and 34 in fentanyl group). Demographic data, VAS scores and 24 hrs fentanyl consumption was analysed in both groups. RESULTS: There were statistically significant lower pain scores in patients of SAPB group when compared to that of fentanyl group (p=0.001) and in 24 hrs fentanyl consumption in patients who received continuous SAPB versus that in fentanyl group(p=0.001). No complications were observed in patients who received US guided SAPB. CONCLUSION: US guided SAPB is an opioid sparing, effective interfascial plane block which is safe and should be considered early in all patients who sustain MRFs. Continuous SAPB by placing a catheter can provide pain relief for longer duration, facilitate early mobilization, physiotherapy and early ICU discharge.

Flow dynamics of ultrasound-guided lumbar plexus block in adults.

Background and Aims: The outcomes of plexus and peripheral nerve blocks depend on needle-nerve contact and the spread of local anesthetic (LA) around the plexus or nerve. Needle-nerve distance and spread of LA could be visualized during US-guided lumbar plexus block (LPB). Material and Methods: After Institutional Ethics Committee approval and after obtaining informed consent, 24 American Society of Anesthesiologists'-physical status I-III patients who underwent surgical fixation of fractures of proximal femur were enrolled. Spinal anesthesia was a primary anesthetic in all patients. At the end of the surgery, all patients received US and neurostimulation-aided LPB at the third lumbar nerve root (LNr). The primary aim was to determine the spread of LA in the lumbar plexus area with the relation of the needle tip and LNr contact. The secondary aim was to understand block efficacy in terms of pain scores monitored at regular intervals and 100 mg intravenous tramadol was administered as a rescue analgesic if VAS >4. Results: In all 24 patients, we observed an oval and antegrade LA spread after lumbar plexus was identified with neurostimulation at L3. With the needle closer to intervertebral foramina (IVF), a retrograde spread was visualized. Only 2/24 patients received rescue analgesia in the first 24 h. Conclusion: The type of spread after the US-guided LPB could predict block success of block and a possible epidural spread.

Low-volume C5-6 interscalene and supraclavicular nerve blocks for arthroscopic shoulder surgery: A case series.

Interscalene block (ISB) is considered a gold standard regional anesthesia technique for shoulder surgery. Conventionally, 20 ml of local anesthetic is used for ISB. Nevertheless, this high-volume traditional ISB is associated with a high incidence of hemidiaphragmatic paresis due to phrenic nerve block. Recent evidence suggests that low-volume ultrasound-guided (USG)-ISB can provide effective analgesia whilst avoiding complications. Thirty patients of American Society of Anaesthesiologist ASA status I/II undergoing arthroscopic rotator cuff repair surgery under general anesthesia were administered low-volume USG-ISB and supraclavicular nerve block (SCNB). The block provided effective analgesia in 90% (27/30) of the patients as their visual analog score was below 4 at all times in the 24-h postoperative period. Only three patients required a single dose of rescue analgesic (diclofenac 50 mg iv) in the 24-h postoperative period. In postoperative recovery, two patients (6.67%) had desaturation due to hemidiaphragmatic paresis and three patients (10%) had a transient neurological deficit. In conclusion, low-volume USG-ISB with SCNB provides effective analgesia for arthroscopic rotator cuff repair surgery. The advantages of this technique include a low incidence of respiratory and neurological complications.

C5 ventral ramus block for clavicle surgery: How low concerning the volume can we go?

Background and Aims: Clinical case reports mention 3-5 ml of local anesthetic (LA) at the cervical root 5 (C5) for surgical anesthesia essential for clavicle surgeries with reasonable success. A volume of 5 ml LA has been shown to cause hemidiaphragmatic paresis. Material and Methods: We implement the 3-5 ml LA for awake clavicle surgeries along with a supraclavicular nerve (SCN) block with another 2 ml. To understand the spread of injectate, we conducted anatomic macroscopic dissection on Theil based cadavers. Post ultrasound injection of 3 ml of blue latex in one cadaver and green latex in the other, we dissected one cadaver and the other cadaver underwent a cross-section. Results: Dissection confirmed a vertical spread of dye more caudad than cephalad. There was no neuraxial spread visualized in the cross-section. The phrenic nerve (PN) was not stained in both cadavers, but a possibility exists depending on its course. Conclusion: Based on this limited study we recommend a volume of LA of 3 ml at the level of C5 and another 2 ml at the level SCN of LA for clavicle surgeries.