Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Nov 2017
Clinical TrialDetermination of ED50 and ED95 of 0.5% Ropivacaine in Adductor Canal Block to Produce Quadriceps Weakness: A Dose-Finding Study.
Adductor canal block (ACB) is popular for knee analgesia because of its favorable effect on quadriceps strength. The aim of this study was to find the minimum volume of local anesthetic, which can be injected into the ACB that would result in quadriceps weakness. ⋯ This study was registered at ClinicalTrials.gov, identifier NCT02541552.
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Reg Anesth Pain Med · Nov 2017
Electron Microscopy of Dural and Arachnoid Disruptions After Subarachnoid Block.
It has been customary to attribute postdural puncture headache (PDPH) incidence and severity to size and nature of the dural hole produced during major neuraxial blockade or diagnostic dural puncture. Needle orientation in relation to the direction of dural fibers was thought to be of importance because of the propensity for horizontal bevel placement to cause cutting rather than splitting of the dural fibers. ⋯ Accepted theories of the etiology of PDPH need to be revised. This article marks the first time that arachnoid layer damage has been quantified. Dural fibers tend to have sufficient "memory" to close back the hole created by a spinal needle, whereas arachnoid has diminished capacity to do so. The pathogenesis of PDPH and its resolution algorithm are a far more complex process that involves many more "stages" of development than hitherto imagined.