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Ultrasound Imaging for Regional Anesthesia in Infants, Children… from Anesthesiology

BlueNeedle — Tue, 06 Apr 2010 12:21:26 +0000

Who in regional anesthesia wouldn’t look forward to an article by Tsui and Suresh? The images in this manuscript are fantastic.

Ultrasound Imaging for Regional Anesthesia in Infants, Child… : Anesthesiology.

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TAP Block Review by NYSORA

admin — Thu, 31 Dec 2009 13:57:17 +0000

A very nice review of the TAP block from NYSORA. Excellent diagrams demonstrating the anatomy. The article is also well researched, especially the portion pertaining to noted complications in the literature.

NYSORA – The New York School of Regional Anesthesia – TAP BLOCK – TRANSVERSUS ABDOMINIS PLANE BLOCK.

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Thoracic Paravertebral Block | Ultrasound for Regional Anesthesia

admin — Thu, 20 Aug 2009 23:47:58 +0000

This is a very nice overview of an ultrasound-guided approach to the thoracic paravertebral block. This approach focuses on a single injection of local anesthetic, although it could easily be customized for catheter placement. These authors use a transverse, in-plane approach. Note their use of the Tuohy needle, an appropriate selection for a para-spinal block.

These photos pretty much summarize the review:

Thoracic Paravertebral Block | Ultrasound for Regional Anesthesia.

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Ultrasound-Guided Obturator Nerve Block

admin — Sat, 28 Mar 2009 19:06:54 +0000

Continuing with our Obturator Nerve Block theme, two more excellent sites describing the anatomy and approach.

ESRA – Learning zone – Techniques – Lower Limb – Ultrasound obturator block.

USRA Obturator Nerve Block Description

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YouTube – Ultrasound-Guided Obturator Nerve Block

admin — Fri, 27 Mar 2009 19:01:54 +0000

A nice video of an ultrasound-guided obturator nerve block. Importantly, they show the anterior and posterior divisions and demonstrate separate blockage of these nerves. As a reminder, always ensure a negative aspiration AND visualize spread of local anesthetic on ultrasound. The obturator artery and vein aren’t that far away….

Click here to view the embedded video.

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Thoracic Paravertebral Catheters in Cadavers

admin — Sat, 14 Mar 2009 01:10:35 +0000

Interesting analysis, if a little disheartening. 11/20 catheters with correct paravertebral spread isn’t reassuring. Still, this may explain the variability inherent to this block’s success.

Ultrasound-guided paravertebral puncture and placement of catheters in human cadavers: an imaging study

British Journal of Anaesthesia – current issue 3/13/09 2:00 AM Luyet, C., Eichenberger, U., Greif, R., Vogt, A., Szucs Farkas, Z., Moriggl, B.

Background

During paravertebral block, the anterolateral limit of the paravertebral space, which consists of the pleura, should preferably not be perforated. Also it is possible that, during the block, the constant superior costotransverse ligament can be missed in the loss-of-resistance technique. We therefore aimed to develop a new technique for an ultrasound-guided puncture of the paravertebral space.

Methods

We performed 20 punctures and catheter placements in 10 human cadavers. A sonographic view showing the pleura and the superior costotransverse ligament was obtained with a slightly oblique scan using a curved array transducer. After inline approach, injection of 10 ml normal saline confirmed the correct position of the needle tip, distended the space, and enabled catheter insertion. The spread of contrast dye injected through the catheters was assessed by CT scans.

Results

The superior costotransverse ligament and the paravertebral space were easy to identify. The needle tip reached the paravertebral space without problems under visualization. In contrast, the introduction of the catheter was difficult. The CT scan revealed a correct paravertebral spread of contrast in 11 cases. Out of the remaining, one catheter was found in the pleural space, in six cases there was an epidural, and in two cases there was a prevertebral spread of contrast dye.

Conclusions

We successfully developed a technique for an accurate ultrasound-guided puncture of the paravertebral space. We also showed that when a catheter is introduced through the needle with the tip lying in the paravertebral space, there is a high probability of catheter misplacement into the epidural, mediastinal, or pleural spaces.

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Needles for Neurosurgery: Do preoperative skull blocks improve post-operative pain scores?

admin — Thu, 12 Mar 2009 15:15:08 +0000

Interestingly, not the primary endpoint studied in this article. While the study was adequately powered to detect the hemodynamic endpoint, the same is not true for the post-operative pain scores. The aggregate 1-4h data do suggest a trend towards improvement in post-op pain scores that is statistically significant.

All in all, a nicely written article worth reading. Especially enjoyed the well-written and appropriately researched discussion.

J Neurosurg. 2008 Jul;109(1):44-9
Effect of ropivacaine skull block on perioperative outcomes in patients with supratentorial brain tumors and comparison with remifentanil: a pilot study.
Gazoni FM, Pouratian N, Nemergut EC.

Department of Anesthesiology, University of Virginia Health System, Charlottesville, Virginia 22908-0710, USA.

OBJECT: Skull blockade for craniotomy may result in the reduction of sympathetic stimulation associated with the application of head pins (“pinning”), improvement in intraoperative hemodynamic stability, and a decrease in intraoperative anesthetic requirements. Postoperative benefits may include a decrease in pain, in analgesic requirements, and in the incidence of nausea and vomiting. The authors examined the potential benefits of a skull block in patients in whom a maintenance anesthetic consisting of sevoflurane and a titratable remifentanil infusion was used. In other studies examining the ability of a skull block to improve perioperative outcomes, investigators have not used remifentanil. METHODS: Thirty patients presenting for resection of a supratentorial tumor were prospectively enrolled. Patients were randomized into 2 groups as follows: 14 patients (skull block group) received a skull block with 0.5% ropivacaine at least 15 minutes prior to pinning, whereas the remaining 16 patients (control group) did not. RESULTS: Patients in the skull block group did not have a significant increase in blood pressure or heart rate with placement of head pins, whereas patients in the control group did. Nevertheless, there was no difference in blood pressure variability between the groups. The mean intraoperative concentration of sevoflurane (1.0% in both groups, p = 0.703) and remifentanil (0.163 microg/kg/min compared with 0.205 microg/kg/min, p = 0.186) used was similar in both groups. During the postoperative period, there was no difference in the 1-, 2-, or 4-hour visual analog scale scores; in the need for postoperative narcotic analgesia (0.274 morphine equivalent mg/kg compared with 0.517 morphine equivalent mg/kg, p = 0.162); or in the incidence of nausea or vomiting. CONCLUSIONS:Prospective analysis of perioperative skull blockade failed to demonstrate significant benefit in patients treated with a remifentanil infusion.

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Superficial Cervical Plexus Block

admin — Tue, 10 Mar 2009 16:39:17 +0000

Two nice articles reviewing the superficial cervical plexus block. Abstracts are listed below.

Spread of injectate with superficial cervical plexus block in humans: an anatomical stud
J. J. Pandit*,1, D. Dutta1 and J. F. Morris2

1 Nuffield Department of Anaesthetics, John Radcliffe Hospital, Oxford OX3 9DU, UK. 2 Department of Human Anatomy, Parks Road, Oxford OX1 3PT, UK

Corresponding author. E-mail: jaideep.pandit@physiol.ox.ac.uk

Background. This study was undertaken to investigate why the superficial cervical plexus block for carotid endarterectomy is so effective. Initial consideration would suggest that a superficial injection would be unlikely to block all terminal fibres of relevant nerves. One possibility is that the local anaesthetic crosses the deep cervical fascia and blocks the cervical nerves at their roots.

Methods. Superficial cervical plexus blocks (injections just below the investing fascia) were performed using methylene blue (30 ml) in four cadavers. In one additional control cadaver, a deep cervical plexus injection was performed. In a second control cadaver, a subcutaneous injection (superficial to investing fascia) was performed at the posterior border of the sternomastoid muscle.

Results. Anatomical dissection showed that with superficial block there was spread of the dye to structures beneath the deep cervical fascia. In the first control, dye remained in the deep cervical space. In the second control, dye remained subcutaneous.

Conclusions. The superficial cervical space communicates with the deep cervical space and this may explain the efficacy of the superficial block. The method of communication remains unknown. Our findings also indicate that the suitable site of injection for the superficial cervical plexus block is below the investing fascia of the neck, and not just subcutaneous.

Br J Anaesth 2003; 91: 733–5

The Superficial Cervical Plexus Block for Postoperative Pain Therapy in Carotid Artery Surgery. A Prospective Randomised Controlled Trial

M. Messner, S. Albrecht, W. Lang, R. Sittl and M. Dinkel

Eur J Vasc Endovasc Surg 2006;33:49-53..
Available online 8 January 2007.

Objectives Rapid and reliable neurological evaluation soon after carotid artery surgery is feasible with modern methods of general anesthesia, but postoperative pain therapy remains a challenge. Use of opioids can mask neurological deficits. We investigated whether superficial cervical plexus block reduced postoperative opioid consumption after carotid endarterectomy.

Design Prospective, randomised, double-blinded, placebo controlled trial.

Methods 46 patients undergoing unilateral carotid endarterectomy under general anesthesia were randomized to either superficial cervical block with ropivacaine (n = 23) or placebo (n = 23). A patient controlled analgesia device (PCA) delivering morphine was provided for all patients. Subjective pain levels (visual analog scale, VAS) were recorded. The primary outcome was total morphine consumption on discharge from the recovery room. Secondary outcomes included arterial pCO2 (as an indicator of central nervous effects of morphine) and patient satisfaction.

Results No adverse effects of the superficial cervical plexus block were reported. Four patients in the placebo group were excluded because of other drug use post-operatively. Per protocol analysis compared 23 patients in ropivacaine group and 19 patients in the placebo group. The ropivacaine group had a significant reduction in morphine consumption (3.8 ± 2.0 versus 12.9 ± 4.0, p < 0.001), lower maximal pain scores (2.6 ± 2.0 versus 5.8 ± 1.6, p < 0.001), and paCO2 levels (39.0 ± 2.6 versus 41.9 ± 3.4, p = 0.008) at discharge from the recovery room. Patient satisfaction (1 = very good to 6 = insufficient) was substantially higher in the ropivacaine group (1.7 ± 0.7 versus 3.1 ± 1.2, p < 00.01).

Conclusion The significant and clinically relevant lower morphine consumption and pain score, as well as the substantially higher patient satisfaction demonstrate that superficial cervical plexus block provides effective pain relief for patients undergoing carotid endarterectomy.

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Youtube: Ultrasound Guided Tap Block

admin — Tue, 10 Mar 2009 02:04:21 +0000
Some Youtube clips of ultrasound-guided TAP blocks. httpv://www.youtube.com/watch?v=N0DcDPrXGUg Notice how the above clip demonstrates a TAP block likely performed via the triangle of Petit, while the below clip demonstrates similar anatomy in the subcostal region. httpv://www.youtube.com/watch?v=8g1UxIugnkY No related posts. Related posts brought to you by Yet Another Related Posts Plugin. No related posts. Related posts brought to you by Yet Another Related Posts Plugin.

The Role of a Preprocedure Systematic Sonographic Survey in Ultrasound-Guided Regional Anesthesia

admin — Thu, 01 Jan 2009 00:00:00 +0000

Background and Objectives: The presence of neurovascular abnormalities may increase the risk of complications following regional anesthesia techniques. Use of conventional nerve localization methods may fail to detect such abnormalities and potentially result in block failure and/or unintentional neurovascular injury.Methods: We use 2 examples to illustrate this, and the concept that systematic use of a preprocedure ultrasound (US) scan may serve as an aid both for diagnosis of abnormal anatomy, and in planning the appropriate anesthetic technique.Results: Use of a preprocedure US scan helped to diagnose abnormal anatomy and assisted in planning a more appropriate anesthetic technique.Conclusions: We believe that a systematic sonographic survey prior to regional anesthesia can be a valuable bedside screening tool to assess the suitability and challenges involved in performing US-guided peripheral nerve block.

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