Anatomy of Anaesthesia and Labour Flashcards
What type of nerves carry pain signals from the ovaries, fallopian tubes and uterus?
Visceral afferents
Where do visceral afferents carrying signals from the superior aspect of the pelvic organs (ie the part touching the peritoneum) enter the spinal cord?
T 11 - L2
Where do visceral afferents carrying signals from the inferior aspect of the pelvic organs (ie the part not touching the peritoneum) enter the spinal cord?
S2, 3 and 4
If a patient has suprapubic pain, between what levels are the visceral afferents entering the spinal cord?
T 11 - L2
If there is inflammation of the uterus or fallopian tubes, where will the patient feel pain?
Suprapubic pain
What nerves do visceral afferents from the superior aspect of the pelvic organs run alongside to get to the spinal cord?
Sympathetic fibres
What nerves do visceral afferents from the inferior aspect of the pelvic organs run alongside to get to the spinal cord?
Parasympathetic fibres
If there is inflammation of the cervix or superior vagina, where will the patient feel pain?
In the S2, 3, 4 dermatome.
If the patient has inflammation in the lower aspect of the vagina where will they feel pain?
Localised pain
At what vertebral level does the spinal cord become the cauda equina?
L2
What level does the subarachnoid space end at?
S2
List the layers that the needle passes through when performing a spinal anaesthetic?
supraspinous ligament interspinous ligament ligamentum flavum epidural space (fat and veins) dura mater arachnoid mater finally reaches subarachnoid space (contains CSF)
Where is a spinal anaesthetic inserted into?
Subarachnoid space
Where is an epidural inserted into?
The epidural space
What does the epidural space mostly contain?
Fat and veins
Lis the layers that the needle has to pass through in an epidural anaesthetic?
supraspinous ligament
interspinous ligament
ligamentum flavum
epidural space (fat and veins)
Why does a spinal anaesthetic cause hypotension?
Spinal nerves and their named nerves all contain sympathetic fibres. Spinal anaesthetic blocks all sympathetic tone to all arterioles in the lower limb causing massive vasodilation and hypotension.
What are the nerve roots of the pudendal nerve?
S2, 3 and 4
When would you use a pudendal nerve block?
Episiotomy
Forceps use
Stitching post delivery
Describe the course of the pudendal nerve
- Exits the pelvis via the greater sciatic foramen
- Passes posterior to the sacrospinous ligament
- Re enters the pelvis via the lesser sciatic foramen
- Travels in the pudendal canacl
- Branches to supply the structures of the perineum
List the contents of the pudendal canal
Internal pudendal artery and vein
Pudendal nerve
Nerve to the obturator internus
What aspect of what ligament does the pudendal nerve cross?
Sacrospinous ligament
What bony landmark is used in pudendal nerve block?
Ischial spine
What vertebral level is at the same level as the most superior point on the iliac crests?
L4
What space is an episiotomy made into?
Ischioanal space
What is the ischioanal spcae filled with?
Fat
