Search Results (10)

Mandibular dental disease is common in pet rabbits and often requires invasive procedures associated with significant nociceptive input. Mandibular alveolar nerve blocks have been described in this species using blind techniques; however, their accuracy has not been objectively evaluated, and ultrasound-guided approaches have not been reported. This cadaveric study aimed to describe an ultrasound-guided mandibular alveolar nerve block in rabbits and to compare in-plane and out-of-plane approaches. Twelve adult New Zealand White rabbit cadavers (24 mandibular alveolar nerves) were included. For each rabbit, one nerve was assigned to an in-plane ultrasound-guided approach, while the contralateral nerve was assigned to an out-of-plane approach. Following ultrasound-guided needle placement, 0.1 mL/kg of a mixture of 2% lidocaine and 1% methylene blue was injected. Ultrasound image quality and perineural staining were assessed and scored, and longitudinal dye spread was measured after anatomical dissection. Both approaches allowed consistent identification of the target region and resulted in comparable ultrasound image quality scores, staining scores, and longitudinal dye spread, with no statistically significant differences between techniques. These results demonstrate the anatomical feasibility of ultrasound-guided mandibular alveolar nerve blocks in rabbits using either approach. Further in vivo studies are required to assess clinical efficacy and safety. Full article

The ultrasound-guided erector spinae plane (ESP) block is a locoregional anaesthesia technique primarily used to provide analgesia to anatomical structures innervated by the dorsal branches (DB) of the spinal nerves. However, several clinical studies in humans have demonstrated its analgesic efficacy in areas innervated by the ventral branches (VB) of the spinal nerves, such as thoracic and abdominal surgeries. In veterinary medicine, the ESP block has been extensively studied in dogs at the thoracic, thoracolumbar, and lumbar regions. In contrast, only one cadaveric study, focused on the lumbar area, has been published in cats. The objective of this research was to evaluate the feasibility of an ultrasound-guided longitudinal approach to the thoracic ESP block in feline cadavers. A total of 15 feline cadavers were used for this purpose: 3 for the anatomical study, and 12 for the ultrasound-guided approach (24 sides). The needle tip was ultrasound-guided to the transverse process of the seventh thoracic vertebra (T7), and a mixture of methylene blue (0.5%), lidocaine, and iopromide (0.4 mL kg⁻¹) was administered. A computed tomography (CT) scan was subsequently performed to assess the distribution of the contrast medium, followed by anatomical dissection to evaluate the distribution of dye. Contrast medium was observed within the erector spinae musculature, between T1 and T13 (24 out of 24 sides), with a distribution spanning 8 (4–11) vertebral bodies. Anatomical dissection showed staining of two (0–9) DB, mainly T6, T7, and T8, and 0.5 (0–1) VB, with T7 the only one stained. Additionally, staining of the sympathetic trunk was observed in 7 out of 24 sides. Based on these findings, this technique may be indicated in surgeries involving the epaxial region. However, further studies are needed to confirm its effectiveness in providing analgesia to structures associated with the VB of the spinal nerves and the sympathetic trunk. Full article

Background: Hand surgery is increasingly transitioning from hospital operating theatres to outpatient settings, requiring anaesthetic methods that are efficient, cost-effective, and patient-centred. Traditional anaesthesia, such as general anaesthesia, poses challenges including prolonged recovery and physiological stress. Novel strategies, such as Wide-Awake Local Anaesthesia No Tourniquet (WALANT), ultrasound-guided distal nerve blocks, and adjunctive approaches (vapocoolant spray, patient-controlled regional analgesia, cryoanalgesia, jet injectors), have emerged to address these limitations. This narrative review consolidates current evidence regarding the efficacy, applicability, and economic implications of these evolving anaesthesia techniques. Methods: A literature search was conducted across MEDLINE, Embase, CENTRAL, and Scopus databases up to 1 June 2025. Inclusion criteria were English-language original studies on WALANT, vapocoolant sprays, ultrasound-guided distal nerve blocks, or emerging adjunctive anaesthesia methods applicable to hand and upper limb surgery. Exclusion criteria included non-English publications and those without original clinical data. Two independent reviewers screened and selected studies, ensuring relevance and methodological quality. Results: WALANT can provide high patient satisfaction, cost savings of 70–85%, and allow for real-time functional testing during surgery. Ultrasound-guided nerve blocks provided targeted analgesia, preserved elbow function, reduced the need for sedation, and improved perioperative efficiency. Adjuncts such as vapocoolant sprays significantly decreased needle-injection discomfort, offering quick and economical analgesia for superficial procedures. Other emerging adjuncts, including patient-controlled regional anaesthesia (PCRA), cryoanalgesia, and jet injectors, offered additional patient-tailored pain management options, although with higher resource demands. Conclusions: The review highlights the transformative potential of WALANT and adjunctive techniques to enhance efficiency, patient experience, and cost-effectiveness in hand surgery. Despite clear benefits, optimal application requires tailored patient selection, clinician familiarity, and consideration of procedure-specific demands. Full article

Background: The pericapsular nerve group (PENG) block is a novel ultrasound-guided regional technique that may provide analgesia to patients undergoing hip surgery. It has been extensively studied in recent years, but the evidence of superiority over other regional anaesthetic techniques is inconclusive. This review aimed to compare outcomes of the PENG block in patients undergoing hip surgery with standard techniques under general anaesthesia. Methods: PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed throughout the preparation of this review. Randomised trials from electronic databases were included. We investigated postoperative pain scores, required analgesia, and adverse events associated with the block. Results: Ten studies satisfied the criteria to be included in the meta-analysis. Data from 646 patients were analysed, in which 321 patients received PENG block and 325 were included in the comparative groups. Pain scores at rest, at 24 h (p = 0.04) and 48 h (p = 0.02) were lower in patients who had received the PENG block. This group also required a smaller amount of opioids at 24 h after the procedure, but this difference was not statistically significant (p = 0.53); while a similar non-significant reduction in opioid consumption was also observed at 48 h. Although PENG seems to delay the time to the first analgesic request, we failed to prove a statistically significant difference (p = 0.83). Patient satisfaction also seems to be better in the PENG group, but not in a statistically significant way. No important side effects related to the block were described. Conclusions: PENG block for major hip surgery offers better postoperative analgesia, with possibly less opioid consumption. It seems to prolong the time to the first analgesic but does not significantly affect common side effects of anaesthesia/analgesia such as PONV or duration of hospital stay. Full article

The rectus sheath block is an ultrasound-guided anaesthetic technique which aims to provide analgesia to the abdominal midline. This study aimed to assess the distribution of 0.4 mL kg⁻¹ of a mixture of methylene blue and iopromide injected into each hemiabdomen in the internal rectus sheath in cat cadavers. We hypothesise that this technique would be feasible and would cover the rami ventrales of the last thoracic and the first lumbar spinal nerves. The study was divided into two phases. Phase 1 aimed to study the anatomical structures of the ventral abdominal wall (four cats were dissected). Phase 2 (ten cadavers) consisted of an ultrasound-guided injection of the mixture mentioned above and the assessment of its distribution by computed tomography and anatomical dissection. The results showed the staining of the cranioventral abdominal wall with a craniocaudal spread of four (three to eight) vertebral bodies. Methylene blue stained three (one to four) rami ventrales, affecting T10 (60%), T11 (100%), T12 (90%), T13 (50%) and L1 (5%). Based on these results, it could be stated that this technique could supply anaesthesia to the midline of the abdominal midline cranial to the umbilicus in clinical patients, but it may not be able to provide anaesthesia to the middle and caudal midline abdominal region. Full article

Ultrasound-guided regional anaesthesia with real-time visualization of anatomical structures and needle trajectory has become the standard method for accurately achieving nerve block procedures. Nevertheless, ultrasound is particularly limited in accurately detecting the needle tip in tissues with complex echogenicity. Fat-filled circumneural fascial tissue provides a barrier to local anaesthetic diffusion. Injection during gentle needle nerve contact is more likely to spread under the circumneurium (halo sign). On the other hand, excessive force may cause hematoma or activate the piezo ion channels and intraneural calcium release. Therefore, it is vital to understand the mechanics of needle–tissue interaction for optimizing the procedural outcomes and patients’ safety. We hypothesised that continuous fluid infusion would reduce the needle force applied on the nerve compared to that of bolus injection. Thus, the primary objective of this study was to compare the forces associated with the bolus injection and continuous infusion techniques on the sciatic nerves of fresh lamb legs ex vivo. A needle combining pressure and force was inserted into six legs of lambs ex vivo using a motor stage at a constant velocity and imaged with a linear transducer. Saline injections were block randomised to bolus injection or infusion in the muscle upon gently touching and indenting of the epineurium at nine sites on six sciatic nerves at three angles (30°, 45° and 60°) in each location. The bolus was delivered over 6 s and infused for over 60 s. The result showed less force was generated during the infusion technique when gently touching the epineurium than that of the bolus technique, with p = 0.004, with significant differences observed at a 60° angle (0.49 N, p = 0.001). The injection pressure was also lower when light epineurium touches were applied (9.6 kPa, p = 0.02) and at 60° (8.9 kPa). The time to peak pressure varied across the insertion angles (p < 0.001), with the shortest time at 60° (6.53 s). This study explores future applications by emphasizing the significance of understanding needle–tissue interaction mechanics. This understanding is crucial for optimizing the procedural outcomes and enhancing patients’ safety in ultrasound-guided regional anaesthesia administration. Specifically, continuous infusion demonstrated a notable reduction in needle force compared to that of the bolus injection, especially during gentle epineurium contact. Full article

In neonatal equines, pathologies involving umbilical structures are an important cause of morbidity, and surgical removal of urachal remnants is a common procedure in clinical practice. Surgery involving the ventral abdominal wall can cause substantial pain, leading to complications and prolonged recovery. The objectives of this study were to describe a two-point bilateral ultrasound-guided rectus sheath block at the level of the umbilicus and to evaluate the extent of dye distribution in foal cadavers. Ten foal cadavers were included in the study, in which a bilateral two-point ultrasound-guided rectus sheath block was performed—one injection 5 cm cranially and a second one 5 cm caudally to the umbilicus. The injectate consisted of a mixture of iodinated contrast medium and blue dye at a volume of 0.25 mL kg⁻¹ per injection point (total 1 mL kg⁻¹). After the injection, computer tomography and subsequent dissection of the ventral abdominal wall were performed. The extension of the contrast medium, the number of stained nerves, and contamination of the abdominal cavity were evaluated. The cranio-caudal extension of the contrast ranged from 0.8 to 1.4 cm per milliliter of injectate. The most commonly stained ventral branches of spinal nerves were thoracic (Th) nerves 16, 17, and 18 (95%, 85%, and 80% of the nerves, respectively). Abdominal contamination was found in four animals. The results suggest that the block could provide periumbilical analgesia. Further studies with different volumes of injectate and living animals are warranted. Full article

Ultrasound guided parasternal block is a regional anaesthesia technique targeting the anterior branches of intercostal nerves, which supply the anterior thoracic wall. The aim of this prospective study is to assess the efficacy of parasternal block to manage postoperative analgesia and reduce opioid consumption in patients undergoing cardiac surgery throughout sternotomy. A total of 126 consecutive patients were allocated to two different groups, receiving (Parasternal group) or not (Control group) preoperative ultrasound guided bilateral parasternal block with 20 mL of 0.5% ropivacaine per side. The following data were recorded: postoperative pain expressed by a 0–10 numeric rating scale (NRS), intraoperative fentanyl consumption, postoperative morphine consumption, time to extubation and perioperative pulmonary performance at incentive spirometry. Postoperative NRS was not significantly different between Parasternal and Control groups with a median (IQR) of 2 (0–4.5) vs. 3 (0–6) upon awakening (p = 0.07); 0 (0–3) vs. 2 (0–4) at 6 h (p = 0.46); 0 (0–2) vs. 0 (0–2) at 12 h (p = 0.57). Postoperative morphine consumption was similar among groups. However, intraoperative fentanyl consumption was significantly lower in the Parasternal group [406.3 ± 81.6 mcg vs. 864.3 ± 154.4, (p < 0.001)]. Parasternal group showed shorter times to extubation [(191 ± 58 min vs. 305 ± 72 min, (p)] and better performance at incentive spirometer with a median (IQR) of 2 raised balls (1–2) vs. 1 (1–2) after awakening (p = 0.04). Ultrasound guided parasternal block provided an optimal perioperative analgesia with a significant reduction in intraoperative opioid consumption, time to extubation and a better postoperative performance at spirometry when compared to the Control group. Full article

An ultrasonic needle-actuating device for tissue biopsy and regional anaesthesia offers enhanced needle visibility with color Doppler imaging. However, its specific performance is not yet fully determined. This work investigated the influence on needle visibility of the insertion angle and drive voltage, as well as determined the accuracy and agreement of needle tip localization by comparing color Doppler measurements with paired photographic and B-mode ultrasound measurements. Needle tip accuracy measurements in a gelatin phantom gave a regression trend, where the slope of trend is 0.8808; coefficient of determination (R²) is 0.8877; bias is −0.50 mm; and the 95% limits of agreement are from −1.31 to 0.31 mm when comparing color Doppler with photographic measurements. When comparing the color Doppler with B-mode ultrasound measurements, the slope of the regression trend is 1.0179; R² is 0.9651; bias is −0.16 mm; and the 95% limits of agreement are from −1.935 to 1.605 mm. The results demonstrate the accuracy of this technique and its potential for application to biopsy and ultrasound guided regional anaesthesia. Full article

Introduction: The aim of the study was to assess the diagnostic yield of transoesophageal endoscopic ultrasound-guided needle aspiration (EUS-NA) in lung cancer (LC). Material and methods: Real time EUS-NA was performed under local anaesthesia and sedation in consecutive LC patients. All negative EUS-NA results in NSCLC patients were verified by transcervical extended bilateral mediastinal lymphadenectomy (TEMLA). Results: In 146 patients there were 206 biopsies performed in lymph node stations: subcarinal (7):124, left lower paratracheal (4L):70, paraoesophageal (8):9 and pulmonary ligament (9):3. A mean short axis of punctured node was 10 ± 6.3 (95% CI) mm. Lymph node biopsy was technically successful in 95.6% and was diagnostic in 40.1% of LC patients. In NSCLC staging, the sensitivity of EUS-NA calculated on the per-patient basis was 85.5%, specificity 100%, accuracy 93.6% and negative predictive value (NPV) 89.7% in stations accessible for EUS-NA, but in all mediastinal stations it was 70.7%, 100%, 84.3% and 74.7, respectively (p = 0.009). The sensitivity of EUS-NA in NSCLC staging patients, calculated on the per-biopsy basis was 88.6%, specificity 100%, accuracy 95.4% and NPV 91.4%. A diagnostic yield of EUS-NA on the per-biopsy basis was higher for station 4L than 7, but the difference was not significant (χ² p = 0.4). Conclusions: The diagnostic value of EUS-NA in LC is high. In NSCLC staging EUS-NA is insufficient and should be complemented by other invasive techniques, especially those that give access to the right paratracheal region. Full article