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Introduction Thoracic erector spinae plane block is now performed in many different surgical procedures, including lumbar spinal fusion. We evaluated the analgesic effect of lumbar ESP performed at L4 after lumbar spinal fusion surgery. Methods and case series Eight patients scheduled for lumbar spinal fusion were included in the case series. Erector spinae plane block was performed at L4 preoperatively, administering 20 ml of 0.2% ropivacaine on each side. We recorded patient-reported pain intensity during the first 48 postoperative hours using a visual analogue scale (VAS) and rescue analgesia requirements. Pain at rest was controlled in all patients (VAS 0–3), although pain on movement ranged from mild to severe (VAS 0–8). Rescue analgesia consumption ranged from 1 to 22 mg morphine. Conclusions Lumbar ESP appears to contribute to pain control during the first 48 h after lumbar spinal fusion.

Introduction Thoracic erector spinae plane (ESP) block is now used for postoperative analgesia. However, although reports of lumbar ESP have been published, the anesthetic spread and mechanism of action of this technique remains unclear. We describe the lumbar ESP block technique and evaluate the spread of 20 ml of solution administered at the level of the transverse process of L4 in a cadaver model. Methods Observational study after 12 lumbar ESP blocks at L4 on a fresh cadaver model (6 bilaterally). The spread of 20 ml of injected contrast solution was assessed by computed tomography in all 6 samples. Four of the samples were evaluated by anatomical study, 2 by plane dissection, and 2 others were frozen and cut into 2–2.5 cm axial slices. Results The injected solution spread from L2 to L5 in a cranio-caudal direction in the erector spinae muscle, reaching the facet joints medially and the thoracolumbar fascia laterally. In 33% of cases the solution did not spread anterior to the transverse process; in 51%, spread was minimal and did not affect the corresponding spinal nerves, and in 2 samples (16%), spread was extensive and reached the corresponding spinal nerves. Conclusions Lumbar ESP at L4 always acts on the posterior branches of the spinal nerves, but seldom spreads to the paravertebral space to block the spinal nerve.

Introduction To recognise the relationship between the needle tip and the median nerve during peripheral nerve block is of interest to avoid neural damage. However, signs of intraneural injection are not clearly established. The aim of this study was to define the changes observed in the peripheral nerve after the intraneural or perineural administration of 1 ml of solution. Material and methods Ultrasound guided median nerve blocks were performed in the forearm of 10 fresh cadavers on 60 occasions (3 per forearm). They were randomised into the intraneural (n = 30) or perineural (n = 30) location of the needle tip, after the consensus of location by 7 specialists. After 1 ml of solution was injected an evaluation was made of the changes in the cross-sectional area of the nerve, as well as the displacement along the nerve. Results The cross-sectional area of the median nerve was increased in both groups, however, the increase was significantly higher in the Intraneural group (perineural 0.007 ± 0.013 cm2 vs. intraneural 0.032 ± 0.021 cm2, p Conclusions Based on this experimental study, it is concluded that the injection of a small volume (1 ml) allows to discriminate the disposition of the intraneural vs perineural needle in a high percentage of cases. Therefore, it is suggested that this “dose test” should be considered in the safety algorithms if it is required to reduce the incidence of intraneural injection.

Background Most of the works on ultrasound airway anatomy are limited to a morphological description. A study was conducted in order to provide an objective normal range of measurements. Materials and methods Observational study to describe the ultrasound characteristics of the upper airway in adults without clinical difficult airway criteria, compared to cadaver dissection anatomical models. Results The study included 45 volunteers (27 men and 18 women), and 3 fresh cadavers. The quality of the examination was very good/good in 93% of the cases. Measurements: tracheal diameter (1.3 ± 0.3 cm), vocal cord (1.6 ± 0.5 cm), cricothyroid membrane (0.94 ± 0.32 cm), cricotracheal membrane (0.3 ± 0.09 cm), thickness of the muscles in the floor of the mouth (MFM) (1.5 ± 0.26 cm), sub-mandibular subcutaneous fat plus MFM (2.11 ± 0.34 cm), hyoid-mandible distance (5.35 ± 0.69 cm), palate-floor of the mouth distance (4.92 ± 0.5 cm), palate-anterior border of the mandible (5.51 ± 0.7 cm), and palate-pharynx angle (114 ± 14). Observed differences: Males had a larger tracheal diameter than females (M: 1.4 ± 0.3 vs. F: 1.2 ± 0.2 cm, p = 0.014). Subject height showed a significant correlation with the tracheal diameter (R: 0.501, p Conclusions Ultrasound allows the anatomy of upper airway to be evaluated, as well as to calculate distances between the anatomical structures. The study defines these distances in adult volunteers without clinical difficult airway criteria.

Introduction Ultrasound-guided infraclavicular block in the costoclavicular space located between the clavicle and the first rib, reaches the secondary trunks when they are clustered together and lateral to the axillary artery. This block is most often performed through a lateral approach, the difficulty being finding the coracoid process an obstacle and guiding the needle towards the vessels and pleura. A medial approach, meaning from inside to outside, will avoid these structures. Traditionally the assessment of a successful block is through motor or sensitive responses but a sympathetic fibre block can also be evaluated measuring the changes in humeral artery blood flow, skin temperature and/or perfusion index. Objective To describe the medial approach of the ultrasound-guided costoclavicular block evaluating its development by motor and sensitive response and measurement of sympathetic changes. Materials and methods Description of the technique and administration of 20 ml of contrast in a fresh cadaver model, evaluating the distribution with CT-scan and sagittal sections of the anatomic piece. Subsequently in a clinical phase, including 11 patients, we evaluated the establishment of motor, sensitive and sympathetic blocks. We evaluated the sympathetic changes reflected by humeral artery blood flow, skin temperature and distal perfusion index. Results In the anatomical model the block was conducted without difficulties, showing an adequate periclavicular distribution of the contrast in the CT-scan and in sagittal sections, reaching the interscalenic space as far as the secondary trunks. Successful blocks were observed in 91% of patients after 25 min. All the parameters reflecting sympathetic block increased significantly. The humeral artery blood flow showed an increase from 108 ± 86 to 188 ± 141 ml/min ( p = 0.05), skin temperature from 32.1 ± 2 to 32.8 ± 9 °C ( p = 0.03) and perfusion index from 4 ± 3 to 9 ± 5 ( p = 0.003). Conclusions The medial approach of the ultrasound-guided costoclavicular block is anatomically feasible, with high clinical effectiveness using 20 ml of 1.5% mepivacaine. The sympathetic block can be evaluated with all three parameters studied.

Introduction Regional anaesthesia is commonly preferred for arteriovenous fistula (AVF) creation. Previous studies suggest a shorter block duration in patients with chronic renal failure, maybe because of the changes in regional blood flow. The aim of our study was to evaluate the duration of the axillary block with 1.5% mepivacaine in patients with chronic renal failure scheduled for AVF compared with healthy controls.

Local anaesthetic injection between the tibial and commmon peroneal nerves within connective tissue sheath results in a predictable diffusion and allows for a reduction in the volume needed to achieve a consistent sciatic popliteal block. Using 3D ultrasound volumetric acquisition, we quantified the visible volume in contact with the nerve along a 5 cm segment. Methods We included 20 consecutive patients scheduled for bunion surgery. Ultrasound guided popliteal block was performed using a posterior, out of plane approach at the level of division of the sciatic nerve. Thirty mL of mepivacaine 1.5% and levobupivacaine 0.5% were slowly injected while assessing the injection pressure and the diffusion of the local anaesthetic. Volumetric acquisition was performed before and after the block to quantify the volume of the sciatic nerve and the volume of the surrounding hypoechoic halo contained inside the connective tissue in a 5 cm segment. Results All blocks were successful within 20 min after the injection. The total estimated volume contained inside the common connective tissue sheath was 6.8 ± 2.6 cm 3 . Of this, the volume of the halo surrounding the nerve was 4.4 ± 1.7 cm 3 and the volume inside the sciatic nerve was 2.4 ± 1.7 cm 3 . Conclusions The volume of local anaesthetic in close contact with the sciatic nerve can be estimated by volumetric acquisition. Our results suggest that the effective volume of local anaesthetic needed for a successful sciatic popliteal block could be reduced to less than 7 mL.

Background In 2003 a simple test to detect difficult intubation (DI) in patients underwent laryngeal microsurgery was described. The present study was conducted to validate the test. Methods Patients with laryngeal disease scheduled for laryngeal microsurgery were included. The variables evaluated were eleven parameters: Mallampati Score ≥ III, thyromental distance iii – iv and/or if auxiliary equipment was required to achieve orotracheal intubation. A comparison of ROC curves was conducted to estimate the best predicting cut-off, as well as differences between the index described in 2003 and the rapid assessment by an expert anaesthesiologist. Results One hundred and five patients were included in the study. The incidence of DI according to the predefined criteria was 45% (47 patients). The score at the cut-off of 5 provides a sensitivity of 89% and a specificity of 55%. The fast-evaluation by an expert anaesthesiologist obtained similar sensitivity (89%) and better specificity (81%). Area under curve (AUC) was 0.87, similar to a fast evaluation (AUC: 0.85; P = .71). Conclusion The index was validated at a cut-off of ≥5, being a useful and reliable test to predict DI in patients with laryngeal diseases and it is a useful tool for anaesthesiologists with conventional training.

Objectives Total knee arthroplasty (TKA) has a high transfusion rate. In our protocol, the use of postoperative cell salvage is indicated in patients with contraindications to tranexamic acid (TA). An analysis was performed on the effect of post-operative cell salvage (POCS) regarding transfusion rate and costs in patients undergoing TKA. Material and methods A prospective analysis was conducted on 518 patients, of whom 434 received TA, and 84 were contraindicated. The red cell mass, blood volume, and the percentage of lost blood volume were calculated. Incidents associated with the use of post-operative re-perfusion of drained blood and the rate of transfusion were recorded. An analysis was performed on the costs associated with allogeneic transfusion prevention methods. Results A POCS drain was not inserted in 10 out of the 84 patients not candidates for TA. In the 74 in which it was placed, 158 ± 72 ml of red cell mass was reinfused. The allogeneic transfusion rate was 36%, and was 52% in those with no drain inserted. Relative risk of transfusion using POCS was 0.69 (0.41 to 1.16) with an absolute risk reduction of 16% (−8 to 40%). The number needed to treat to avoid allogeneic transfusion was 7. The direct costs to avoid allogeneic transfusion were €1610. No complications associated with blood re-infusion were observed. Conclusions The use of POCS would be required in 7 patients after TKA to avoid one allogeneic transfusion with a cost over 10 times that of a transfusion of red cell concentrates.