G.J. van Geffen

Ultrasound-guided low-dose interscalene brachial plexus block reduces the incidence of hemidiaphragmatic paresis.

Background and Objectives: Interscalene brachial plexus block is associated with 100% incidence of hemidiaphragmatic paresis as a result of phrenic nerve block. We examined whether an ultrasound (US)-guided interscalene brachial plexus block performed at the level of root C7 versus a nerve stimulation interscalene brachial plexus block, both using 10 mL of ropivacaine 0.75%, resulted in a lower incidence of hemidiaphragmatic paresis. Methods: In a prospective randomized controlled trial, 30 patients scheduled for elective shoulder surgery under combined general anesthesia and interscalene brachial plexus block were included. Interscalene brachial plexus block using the same dose was performed using either US or nerve stimulation guidance of ropivacaine for both groups. General anesthesia was standardized. Ventilatory function was assessed using spirometry, and movement of the hemidiaphragm was assessed by US. Results: Two patients in the US group showed complete paresis of the hemidiaphragm, but in the nerve stimulation group, 12 patients showed complete and 2 patients had partial paresis of the hemidiaphragm (13% versus 93%, respectively; P < 0.0001). Ventilatory function (forced expiratory volume at 1 second, forced vital capacity, and peak expiratory flow) was significantly reduced in the nerve stimulation group compared with the US-guided group (P < 0.05). One block failure occurred in the nerve stimulation group compared with none in the US group. No adverse effects occurred in either group. Conclusions: Ultrasound-guided interscalene brachial plexus block performed at the level of root C7 using 10 mL of ropivacaine 0.75% reduces the incidence of hemidiaphragmatic paresis.

Minimum effective volume of local anesthetic for shoulder analgesia by ultrasound-guided block at root C7 with assessment of pulmonary function.

Background and Objectives: This study was performed to determine the minimum effective volume of ropivacaine 0.75% required to produce effective shoulder analgesia for an ultrasound (US)-guided block at the C7 root level with assessment of pulmonary function. Methods: Using the Dixon and Massey up-and-down method study design, 20 patients scheduled for elective open shoulder surgery under combined general anesthesia and continuous interscalene brachial plexus block were included. Initial volume of ropivacaine 0.75% was 6 mL; block success or failure determined a 1-mL decrease or increase for the subsequent patient, respectively. General anesthesia was standardized. A continuous infusion of ropivacaine 0.2% was started at a rate of 6 mL/hr at 2 hrs after completion of surgery. Ventilatory function was assessed using spirometry, and movement of the hemidiaphragm was assessed by US. Results: The minimum effective volume of local anesthetic in 50% and 95% of the patients was 2.9 mL (95% confidence interval, 2.4-3.5 mL) and 3.6 mL (95% confidence interval, 3.3-6.2 mL), respectively. Ventilatory function and hemidiaphragmatic movement was not reduced up to and including 2 hrs after completion of surgery, but 22 hrs after start of the continuous infusion of ropivacaine 0.2%, ventilatory function and hemidiaphragmatic movement were significantly reduced (P < 0.001). Conclusions: The minimum effective volume of local anesthetic for shoulder analgesia for a US-guided block at the C7 root level in 50% and 95% of the patients was 2.9 and 3.6 mL, respectively. Pulmonary function was unchanged until 2 hrs after completion surgery, but reduced 22 hrs after start of a continuous infusion of ropivacaine 0.2%.

Visualization of the course of the sciatic nerve in adult volunteers by ultrasonography

Background: The sciatic nerve block by the posterior approaches represents one of the more difficult ultrasound‐guided nerve blocks. Our clinical experiences with these blocks indicated a point slightly distal to the subgluteal fold as an advantageous position to allow good ultrasonic visibility. In this study, we systematically scanned the sciatic nerve from the subgluteal fold to the popliteal crease, to determine an optimal point for ultrasonographic visualization.

Soft tissue landmark for ultrasound identification of the sciatic nerve in the infragluteal region: the tendon of the long head of the biceps femoris muscle

Background and objectives: The sciatic nerve block represents one of the more difficult ultrasound‐guided nerve blocks. Easy and reliable internal ultrasound landmarks would be helpful for localization of the sciatic nerve. Earlier, during ultrasound‐guided posterior approaches to the infragluteal sciatic nerve, the authors recognized a hyperechoic structure at the medial border of the long head of biceps femoris muscle (BFL). The present study was performed to determine whether this is a potential internal landmark to identify the infragluteal sciatic nerve.

Pain relief in amputee patients by ultrasound-guided nerve blocks

EDITOR: A challenge in the management of patients undergoing major limb amputations is to provide adequate pain management in the immediate post-trauma and postoperative period [1]. After amputation, re-operation is common. Performing a peripheral nerve block on an amputated limb may be difficult because conventional end-points (distal muscle contraction upon electrical nerve stimulation or eliciting paraesthesia) may not be possible. Ultrasonography may facilitate the performance of continuous peripheral nerve blocks in amputee patients and broaden the indications for nerve blocks. We present our experience with ultrasound-guided continuous peripheral nerve blocks in a heterogeneous group of amputee patients, in whom other pain relieving techniques failed or were refused. Institutional Research Ethics Board approved this study. Eleven ASA I–IV patients who had undergone a traumatic or an operative amputation and in whom a continuous peripheral nerve block for perioperative pain relief was performed were studied. Before the block procedure, visual analogue pain scores (VAS) were noted. In each case, a 20-G polyamide catheter was placed through an 18-G Contiplex D needle (B. Braun, Melsungen, Germany) using ultrasound guidance with a linear 7–13 MHz ultrasound transducer (Micromaxx, Sonosite Inc., Bothell, WA, USA). In some patients a single injection peripheral nerve block was added. The continuous femoral and sciatic blocks and one brachial plexus block were performed as described by Swenson and colleagues [2]. For the initial bolus injection through the needle 0.3 mL kg ropivacaine 0.75% was used. In order to verify correct catheter placement, an additional injection with 0.1 mL kg ropivacaine 0.75% through the catheter was performed. The patients who underwent a planned (re)amputation of the limb received general anaesthesia. Multimodal pain therapy including continuous infusion of s-ketamine 5 mg h and morphine 0.1 mg kg at the end of surgery was prescribed. In the post-anaesthesia care unit, paracetamol 15 mg kg and diclofenac 1 mg kg were administered intravenously. According to our hospital’s postoperative pain protocol, on all catheters bupivacaine 0.25% was infused at a rate of 0.1 mL kg h with a maximum of 6 mL h. If two catheters were used, the concentration bupivacaine was decreased to 0.125%. The catheters were left in situ for a maximum of 5 days. One hour after the block procedure or awaking from anaesthesia, the pain was evaluated using visual analogue scales. The patients who underwent the block procedure after the amputation were also asked whether heaviness, numbness or paresis of the non-existing limb were experienced before and after the block. Once daily, all patients were visited to record pain scores and whether they were satisfied with the postoperative pain relief (0 5 very unsatisfied, 10 5 absolutely satisfied). In five patients, blocks were performed preoperatively (pre-group) and in six postoperatively (post-group). Patient characteristics were similar between the two groups. The pain and satisfaction scores are described in Table 1. In the pre-group, three patients suffered from mild chronic pain before surgery. One patient suffered from severe chronic pain due to an exacerbation of a chronic infection of the amputation stump. After performance of the block and surgery, the preoperative pain scores decreased in this patient. In the others, pain scores remained unchanged or increased slightly. One of the patients in this group reported altered perceptions in the non-existing extremity after the nerve block. In the post-group, all patients suffered from severe acute Correspondence to: G. J. van Geffen, Radboud University Medical Centre, Institute for Anesthesiology, PO Box 9101, 6500 HB Nijmgen, The Netherlands. E-mail: G.vanGeffen@anes.umcn.nl; Tel: 131 24 3614406; Fax: 131 24 3540462

Patient comfort: A continuum starting from prehospital setting throughout the hospital admission

With great interest we have read the article by Tosounidis et al. [1]: Pain relief management following proximal femoral fractures: Options, issues and controversies recently published in Injury. The focus on adequate pain relief during hip fractures should not start in our hospitals emergency departments. The focus should start in the prehospital setting. In a recent study Dochez et al. [2] showed that the fascia iliaca blockade (FIB) can be performed safely by emergency medical service nurses with great success rates. In one hundred patients, the median NRS pain scores were reduced by more than 50%. We should block them when it hurts, during the prehospital transfers. To address the safety issues; all nurses were well trained. Short acting local anaesthetics (lidocaine 0.3 ml/kg (10 mg/ml) with epinephrine 5 mg/ml were injected and the total dose did not exceed 300 mg, no side effects occurred. Our increasing geriatric population is characterised by polypharmacy and reduced physiological reserves. Polypharmacy is a risk factor for the occurrence of delirium in the elderly emergency patients [3], which is associated with a less favourite outcome after hip fractures [4]. FIB is one of the options to reduce polypharmacy in the acute elderly patient, with good pain relief, especially since our regular analgesic therapy often falls short [5].

Which ultrasound transducer type is best for diagnosing pneumothorax

BackgroundAn accurate physical examination is essential in the care of critically ill and injured patients. However, to diagnose or exclude a pneumothorax, chest auscultation is unreliable compared to lung ultrasonography. In the dynamic prehospital environment, it is desirable to have the best possible ultrasound transducer readily available. The objective is to assess the difference between a linear-array, curved-array, and phased-array ultrasound transducer in the assessment for pneumothorax and to determine which is best.MethodsIn this double-blinded, cross-sectional, observational study, 15 observers, experienced in lung ultrasonography, each assessed 66 blinded ultrasound video clips of either normal ventilation or pneumothorax that were recorded with three types of ultrasound transducers. The clips were recorded in 11 adult patients that underwent thoracoscopic lung surgery immediately before and after the surgeon opened the thorax. The diagnostic accuracy of the three transducers, elapsed time until a diagnosis was made, and the perceived image quality was recorded.ResultsIn total, 15 observers assessed 990 ultrasound video clips. The overall sensitivity and specificity were 98.2% and 97.2%, relatively. No significant difference was found in the diagnostic performance between transducers. A diagnosis was made slightly faster in the linear-array transducer clips, compared to the phased-array transducer (p = .031). For the linear-, curved-, and phased-array transducer, the image quality was rated at a median (interquartile range [IQR]) of 4 (IQR 3–4), 3 (IQR 2–4), and 2 (IQR 1–2), relatively. Between the transducers, the difference in image quality was significant (p < .0001).ConclusionsThere was no difference in diagnostic performance of the three transducers. Based on image quality, the linear-array transducer might be preferred for (prehospital) lung ultrasonography for the diagnosis of pneumothorax.

Eligibility criteria in paravertebral block meta-analysis

Heesen et al. reported a meta-analysis of trials reporting the effect of preoperative paravertebral block (PVB) on the risk of developing persistent post-surgical pain (PPP) following breast cancer surgery [1]. We congratulate the authors on their effort to answer an important clinical and research question, and we applaud their use of sequential analysis. However, we have identified some serious methodological concerns about the eligibility criteria, which are likely to have influenced their findings, and which differ from the results of earlier meta-analyses [2, 3]. Firstly, the meta-analysis included only randomised controlled trials comparing the effect of PVB to sham or no block on PPP. However, Ilfeld et al. [4] compared single-shot and continuous PVB, and reported that ‘all patients received a single injection of long-acting local anesthetic (15 ml of ropivacaine 0.5%, with epinephrine 5 lg.ml ) administered through the catheter’ before randomisation to an infusion of local anesthetic or saline. This breaches Heesen et al.’s inclusion criteria. Heesen et al. considered single-shot and continuous PVB as equally important in preventing PPP, combining them into one group when any trial included both interventions. The Ilfled trial does not include a control group and should have been excluded from the analysis. Secondly, the trial by Chui et al. [5], who compared PVB with local infiltration analgesia, also lacked a control group, local infiltration itself being an effective intervention in preventing chronic pain following breast cancer surgery [6–8], and so should have also been excluded from the meta-analysis. These exclusions may affect the validity of Heesen et al.’s findings, particularly as the number of trials pooled for certain outcomes (e.g. PPP at 1 year) would be fewer than three, mitigating any justification for pooling the data. Could we invite the authors to re-analyse and report their results having excluded these ineligible trials?

Fascia iliaca compartment block administered by emergency medical service nurses at home.

Emergency status Emergency RA 41 0 (0.0) 53.5 (25.1–99.9) <0.0001 GA 405 29 (7.2) 121.8 (99.8–141.3) Nonemergency RA 1133 7 (0.6) 67.7 (64.7–69.5) <0.0001 GA 4291 50 (1.2) 71.1 (70.3–72.0) Scheduled surgical duration 30–119 min RA 383 2 (0.5) 70.2 (52.6–73.8) <0.0001 GA 1043 16 (1.5) 89.9 (77.7–95.5) 120–149 min RA 241 1 (0.4) 67.2 (49.3–70.5) 0.0003 GA 950 28 (3.0) 74.2 (70.9–80.8) 150–179 min RA 108 0 (0.0) 68.9 (54.0–72.1) 0.8725 GA 503 13 (2.6) 67.4 (65.1–69.5) 180+ min RA 442 4 (0.9) 66.9 (61.5–69.1) <0.0001 GA 2200 22 (1.0) 70.7 (69.9–71.7)

Reply to Dr. Cornish.

To the Editor: W e write with reference to an article by Fredrickson et al, which claims an advantage for continuous peripheral nerve catheter management of pain relief versus single-shot blocks after a range of more Bminor[ shoulder surgeries. We, too, have had a large experience in this area and wish to query certain aspects of their study. We are puzzled that no pain scores have been included for the period within the first 24 hours after surgery. Presumably, both groups had no pain initially. It would be interesting to know when the single-shot blocks wore off and what strategies were used to counter its effect? There seems to have been more difficulty siting the single-shot blocks, and how this may or may not have affected the duration of the block is uncertain. From the data presented, it is difficult to judge the extent of the separation between the 2 groups. There was some mixing of surgical groups, which has the potential to confound results. For example, our experience has been that lateral clavicular surgeries do not warrant continuous catheter management. Elastomeric pumps require a large volume (400 mL) to fill. Given that there is no advantage to running a catheter longer than a day and a half according to their data, a large volume of local anesthetic (È200 mL) is likely to be wasted with this approach. The authors have rightly commented on other costsVsurely, this is another one to consider. We do agree, however, with the authors’ comment that the first 36 hours after surgery seems to be the time of greatest advantage for running peripheral nerve catheters in these situations.