Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2019
Refining a great idea: the consolidation of PECS I, PECS II and serratus blocks into a single thoracic fascial plane block, the SAP block.
The popularity of ultrasound-guided nerve blocks has impacted the practice of regional anesthesia in profound ways, improving some techniques and introducing new ones. Some of these new nerve blocks are based on the concept of fascial plane blocks, in which the local anesthetic is injected into a plane instead of around a specific nerve. Pectoralis muscles (PECS) and serratus blocks, most commonly used for post op analgesia after breast surgery, are good examples. ⋯ After a comprehensive review of the evidence we have concluded that (1) the traditional model of sensory innervation of the chest wall, which derives from the lateral branches of the upper intercostal nerves and does not include branches of the brachial plexus, is correct. (2) PECS/serratus blocks share the same mechanism of action, blocking the lateral branches of the upper intercostal nerves, and so their varied success is tied to their ability to reach them. This common mechanism agrees with the traditional innervation model. (3) A common mechanism of action supports the consolidation of PECS/serratus blocks into a single thoracic fascial plane block with a point of injection closer to the effector site. In a nod to transversus abdominus plane block, the original inspiration for PECS blocks, we propose naming this modified block, the serratus anterior plane block.
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Reg Anesth Pain Med · Sep 2019
Preliminary findings and outcomes associated with the use of a continuous spinal protocol for labor pain relief following accidental dural puncture.
Various interventions have shown promise in reducing complications following accidental dural puncture. However, these have yet to be studied as a single, comprehensive protocol. The aim of this study is to compare outcomes associated with the use of a continuous spinal protocol for labor pain relief versus resiting the epidural catheter following accidental dural puncture. ⋯ Patients managed via this continuous spinal protocol had significantly lower incidence of postdural puncture headache and epidural blood patch with more effective labor analgesia following accidental dural puncture.
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Reg Anesth Pain Med · Sep 2019
AMP-activated protein kinase (AMPK) activator drugs reduce mechanical allodynia in a mouse model of low back pain.
Intervertebral disc herniation is one of the common causes of low back pain. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) activator drugs have been shown to reduce pain in several animal models. The present study examines if early treatment with the drug metformin, an indirect AMPK activator, and/or O304, a new direct AMPK activator, can reduce the mechanical hypersensitivity that develops after lumbar disc puncture in mice. ⋯ Lumbar disc puncture in mice produces consistent mechanical hypersensitivity, and postinjury treatment with AMPK activator drugs (indirect and direct) reduces the mechanical hypersensitivity.
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Although interscalene brachial plexus block (ISB) remains the gold standard for analgesia after shoulder surgery, the inherent risks of ipsilateral phrenic nerve block and hemidiaphragmatic paralysis (HDP) limit its use in patients with preexisting pulmonary compromise. In a previous Daring Discourse (2017), our research team has identified potential diaphragm-sparing alternatives to ISB for patients undergoing shoulder surgery. In recent years, the field has been fertile with research, with the publication of multiple randomized controlled trials investigating supraclavicular blocks, upper trunk blocks, anterior suprascapular nerve blocks, costoclavicular blocks, and combined infraclavicular-suprascapular blocks. ⋯ Anterior suprascapular nerve blocks have been demonstrated to provide surgical anesthesia and similar analgesia to ISB. However, their risk of HDP has not been formally quantified. Of the remaining diaphragm-sparing nerve blocks, supraclavicular blocks (with local anesthetic injection posterolateral to the brachial plexus), upper trunk blocks, and combined infraclavicular-anterior suprascapular blocks merit further investigation, as they have been shown to achieve similar analgesia to ISB, coupled with an HDP incidence <10%.