Regional anesthesia Flashcards
What is RA?
Reversible abolition of pain and sensation in a part of the body without loss of consciousness
What are the categories of RA?
1.Neuraxial anesthesia (Spinal anesthesia and Epidural)
2.Peripheral nerve blockades
What is the MOA of LA?
LA produce anesthesia by inhibiting excitation of nerve endings or by blocking conduction in peripheral nerves.
Anesthetics reversibly bind to and inactivate sodium channels.
What happens when autonomic fibers are blocked?
Vasodilation and hypotension occurs
What are the advantages of spinal anesthesia?
1.Avoids hazards of GA
2.Rapid action
3.consciousness is preserved
4.Alternative to GA for certain poor risk patients
5.Lesser post op confusion
6.Safe and cheaper alternative
prolonged post op analgesia
Where does the spinal cord end in adults and Children?
Adults -L1
Children-L3
Describe the anatomical landmark of the spine?
-1st palpable spinous process-C2
-Most prominent spinous process-C7
-Inferior angle of the scapula-T7
-Illac crest -L4/5
-Posterior Superior Iliac Spine-S2
What is the importance of the palpable spinous processes?
Help define midline
What is the name of the line joining the top of the illiac crests at L4/5?
Tuffiers line
Describe the skin anatomy from posterior to anterior?
Skin
Subcutaneous fat
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural Space
Dura matter
Subdural space
Arachnoid matter
Subarachnoid space
What do dermatomes help with?
To know level of spinal anesthesia.
Sympathetic block higher than sensory which is higher than motor block.
Describe the dermatomal levels?
T10-Umbilicus
T6-Xiphoid
T4-nipples
T12,L1-Inguinal ligament,Crest of ilium
S2-S4-perineum
What are the cardiac accelerator fibers and what is their effect when blocked?
Cardiac accelerator fibre: T1-T4(Bradycardia & ↓ contractility)
What are the vasomotor fibres and what are their effects when block?
Vasomotor fibre : T5-L1( Determine vasomotor tone)(vasodilation on blockade)
What are the indications for Spinal anesthesia?
1.Operations below lower half of body -include surgery on the lower limb, pelvis, genitals, and perineum, and most urological procedures, obstetric procedures e.g ceasarean section
2.Patients with systemic disease