BIMS 201 Lecture Notes - Lecture 14: Conus Medullaris, Arachnoid Granulation, Venous Plexus
7 Jan 2018
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Document Summary
Important since these are the structures your needle will pass through! Contents of spinal space: spinal cord, cerebrospinal fluid, conus medullaris. Contents of epidural space: fat, areolar tissue, lymphatics, blood vessels including the baston venous plexus. Clear fluid that fills the subarachnoid space. Total volume in adults is 100-150 ml. Volume found in the subarachnoid space is 25-35 ml. Continually produced at a rate of 450 ml per 24 hour period replacing itself 3-4 times. Reabsorbed into the blood stream by arachnoid villi and granulations. Specific gravity is between 1. 003-1. 009 (this will play a crucial role in the baracity of local anesthetic that one chooses) Csf plays a role the patient to patient variability in relation to block height and sensory/motor regression (80% of the patient to patient variability) Body wt is the only measurement that coincides with csf volume (this becomes important in the obese and pregnant) Landmark inter iliac crest line l4 or l4-l5 interspace.
