45. Neuroaxial anesthesia Flashcards
Distal end of spinal cord in adults and kids
Kids L3
Adults L1
Layers of spinal cord from outside to inside
Dura – Arachnoid – Pia mater
Vascularization of Pia / Arachnoid
Arachnoid. non vascular
Pia. Highly vascularized
Most influence of spinal block level and recovery
CSF volume
Epidural space characteristics
Front post longitudinal lig.
Back. Lig. flavum
Side. pedicles + foramina
Include nerves lymph and vessels (Batson venous plexus)
Exists through intervertebral foramina
Máximum thickness of lig. flavum
Thoracic lumbar. 5-6 mm
Dural sac carachteristics
Ends at S2
Volume 10 - 27
Contain various plexuses
Spinal artery syndrome
Loss of pain, strength, T
Proprioception and vibration Ok
Blood supply to spinal cords
- Ant spinal a. Anterior. from vertebral a. 2/3.
- 2 Post spinal a. from cerebelar a. 1/3
3, Segmental a. from intercostal / lumbar a.
Order of fibers sensitivity to anesthesia
B > C cold > A lambda Prick > A beta touch > A alpha motor
Smaller, no myelin, more sensible
Order of recovery after neuroaxial anesthesia
Motor – pinprick – Cold
Block level for Cesarean and for TURP
Cesarean T4
TURP T10
Is neuraxial safe in MS
Yes
Procaine disadvantages
PONV
High failure rate
Transient neurologic symptoms
Decrease with Chlorprocaine
Increase Lido 4%
Increase if Lithotomy position
Bazold Jarish reflex after spinal
Decrease BP, HR
Time to wait for neuraxial after eliquis
72h
What can cause the use of chlorhexidine
Arachnoiditis
Cauda equina syndrome
After spinal. No control of sphincters
Types of needles
Pencil point : Whitacre / Spotte
Quince (cutting)
Effect of saline in epidural space in Spinal
Increase height of Spinal
Effect of slow injection in neuraxial
Increase the height of block
Side effect of prilocain
Methemoglobinemia
What affects the most the spinal
Baricity and dose (VxC)
Lipophilic drugs in neroaxial
Increase onset, decrease duration
Fentanyl lipophilic vs morphine hydrophilic
when to use neuraxial in systemic infection
Safe after antibiotics and response
Location of cardio accelerator fibers and effect of block
T1-T4
Bradicardia
In epidural, at what level will sympathectomy occurs
At the same level of the motor block
Lumbo sacral CSF pressure
15 cc H2O
Thoracic epidural anesthesia and blood flow
Improves anastomotic mucosal blood flow if MAP is maintained.
Worsen local perfusion if blood flow os decreased
Blood patch
15 - 20 cc
At the level of the Dural puncture or caudal
Factors affecting epidural local anesthetic distribution and block height
Drug. Volume and dose
Patient. Elderly and pregnancy
Procedure. Level
Local anesthetic with antagonist epidural effect of morphine
Chloroprocaine
Action of epidural alpha 2
Increase duration of sensory and motor block
PDPH symptoms
Headache
Blindness
Swallowing difficulty
Convulsions
Epidural space length
Around the DURA is the epidural space which extends from the Foramen Magnum to the Sacral hiatus
Level of block compared to location of block in spinal
Motor
Touch 0
Pinprick +2
Cold + 4
B. Sympathetic
Factors Affecting Local Anesthetic Distribution and Block Height in spinal
Dose
Baricity
Volume
CSF volume
Advanced age
Pregnancy
Patient position
Epidural injection post spinal
