|
|
| Línea 1: |
Línea 1: |
| ==Background==
| | #REDIRECT [[Nerve blocks (main)]] |
| Regional nerve block reduces the need for pain control medications, sedation and procedural sedation. When applying to emergency department setting it contributed to decreased length of ED stay, post-procedural observation period and also improve patient's satisfaction. <ref>Wilson JE. et al. Oligoanalgesia in the emergency department. Am J Emerg Med. 1989 Nov;7(6):620-3.</ref><ref>McQuay HJ. et al. Postoperative orthopaedic pain-the effect of opiate premedication and local anaesthetic blocks.Pain. 1988 Jun;33(3):291-5.</ref><ref>Liebmann O. et al.Feasibility of forearm ultrasonography-guided nerve blocks of the radial, ulnar, and median nerves for hand procedures in the emergency department. Ann Emerg Med. 2006 Nov;48(5):558-62.</ref><ref>Stone MB. et al.Ultrasound-guided supraclavicular brachial plexus nerve block vs procedural sedation for the treatment of upper extremity emergencies. Am J Emerg Med. 2008 Jul;26(6):706-10.</ref><ref>Blaivas M et al.Ultrasound-guided interscalene block for shoulder dislocation reduction in the ED.Am J Emerg Med. 2006 May;24(3):293-6.</ref><ref>Beaudoin FL. et al.Ultrasound-guided femoral nerve blocks in elderly patients with hip fractures.Am J Emerg Med. 2010 Jan;28(1):76-81.</ref> Newer ultrasound technology that comes with high-resolution image made ultrasound-guided nerve block, either alone or in combination with other methods to localise the nerve become more favourable due to more success rate comparing to the use of other methods alone. This technique can be utilised for both regional and peripheral nerve block. <ref>Lewis SR. et al. Ultrasound guidance for upper and lower limb blocks.Cochrane Database Syst Rev. 2015 Sep 11;(9)</ref><ref>Walker KJ. et al. Ultrasound guidance for peripheral nerve blockade.Cochrane Database Syst Rev. 2009 Oct 7;(4)</ref><ref>Neal JM. et al. The ASRA evidence-based medicine assessment of ultrasound-guided regional anesthesia and pain medicine: Executive summary.Reg Anesth Pain Med. 2010 Mar-Apr;35(2 Suppl):S1-9</ref>Ultrasound allow dynamic visualisation of target nerves, needed tip and anaesthetic agent while being injected. This minimise the complications that could occurred form nerve blocks.
| |
| | |
| ==Indications==
| |
| *Anaesthesia for procedures commonly performed in the ED
| |
| **Joint dislocation reduction
| |
| **Fracture reduction
| |
| **Wound care, i.e. large laceration repair
| |
| *Analgesia especially for major pain, i.e. multiple ribs fractures, flail chest and femoral fracture.
| |
| | |
| ==Knobology==
| |
| *A linear array probe is required
| |
| *Adjust frequency to the highest setting (optimal frequency is 12-18 MHz). Adjust according to patient habitus, i.e. lower the frequency if the patient is obese.
| |
| *It is easier to identify the nerve in short axis and work in transverse plane.
| |
| *Hold the probe with indicator to your left.
| |
| | |
| ==Preparation==
| |
| *Forearm nerve block superficial cervical plexus block and supraclavicular brachial plexus block are semi-sterile procedures. Femoral nerve block is a sterile procedure.
| |
| *Essential: sterile probe covers, gloves, gel and antiseptic. Needle gauge and length selection depend on the type of block. A longer, 3.5 inches spinal needle may be an option for femoral blocks. Non-Cutting tip needed, for example Whitacre pencil point may reduce nerve injury.
| |
| *Consider attach a short extension tube to the needle for femoral nerve block if you have assistant or extra hands that can help with aspiration and injection while you are handling the needle.
| |
| | |
| ==Identifying the nerves==
| |
| *Shape: round, flat or oval in short axis.
| |
| *Nerve fascicle are hypo echoic but connective tissue around the fascicle is hyper echoic. The characteristic appearance is " honeycomb" appearance.
| |
| *Nerves sometime traverse in oblique fashion. The image will brightest when nerves are image at 90 degree to the beam because nerves are anechoic. Sweeping the probe slightly help lightening up the nerves image.
| |
|
| |
| ==Technique==
| |
| *Anesthetic injection techniques
| |
| **Anesthesize the skin and infiltrate along the anticipated needle path.
| |
| **Identify the nerves in short axis allows easier visualisation of the nerve and adjacent structures.
| |
| **The needle should be advance using in-plane technique.
| |
| **Local anaesthetic should not be injected directly to the nerve bundle. On the other hand it should be injected into the fascial layer surrounding the nerve bundles but not too far from the nerves, i.e. injecting into muscle.
| |
| **Readjusting needle tips to inject aesthetic in different location surrounding the nerves (medial/lateral, anterior/posterior). Always aspirate after readjusting the needle tip position.
| |
| **Injecting initially far field to avoid air artifacts from micro-bubbles in anesthetic. Inject slowly to make sure the fluid is accumulating in the expected position.
| |
| ==Images==
| |
| ===Normal===
| |
| | |
| ===Abnormal===
| |
| | |
| | |
| ==Pearls and Pitfalls==
| |
| | |
| | |
| ==Documentation==
| |
| ===Normal Exam===
| |
| | |
| ===Abnormal Exam===
| |
| | |
| | |
| ==Clips==
| |
| | |
| ==External Links==
| |
| | |
| | |
| ==See Also==
| |
| | |
| | |
| ==References==
| |
| <references/>
| |
| | |
| [[Category:Ultrasound]]
| |
| [[Category:Radiology]]
| |
| | |
| | |
| <references/>
| |
