Spinal anaesthesia Flashcards
Why did Freud love cocaine?
Mitigated pain from physical injury and from the effects of morphine withdrawal
Carl Koller use of cocaine
a few grains of cocaine dissolved in water
droplets placed in frog’s eyes
a few seconds later, the reflex of the cornea was tested using a needle
frog permitted his cornea be touched and even injured without a trace of reflex action
Position for spinal injection
sat with back curved forward- anterior flexion
Why is the position important?
Spinous processes of vertebrae move apart, providing a space for the needle
Passage of needle
supraspinous ligament, interspinous ligament, ligamentum flavus, posterior longitudinal ligament, epidural space, dura
What drug used for spinal anaesthesia ?
Bupivacaine 0.5% with 6% glucose
What is the purpose of the glucose?
makes it heavier than the cerebrospinal fluid thus causing it to move downhill- don’t want paralysis of the lungs and heart
Site of administration
between L2-L5 where the caudal equina is bathed in lumbar cerebrospinal fluid
How is drug spread to thoracic region?
spine curvature allows the movement from lumbar to thoracic thanks to gravity, when lying down
Use of spinal anaesthesia
pain relief and muscle paralysis during surgery
adverse effects of spinal anaesthesia + explained
hypotension- sympathetic constrictor nerves to blood vessels are blocked
bradycardia- slowing of the heart if anaesthetic reaches T1-T4
nerve damage, meningitis and deafness
Epidural anaesthesia use
block all nerves in a band around the body at the levels reached by the injection- T10-S1
- use in labour for childbirth
- top up of drug
What is epidural anaesthesia?
Injection of anaesthetic (usually bupivacaine) in the epidural space around the spinal cord
Volume of drug
Large, 20 ml as epidural space is large
What is the epidural space?
space between the layers of dura (inner meningeal layer and outer periosteal layer)
