2. Introduction
It is a from of Regional Anaesthesia
Also called as - Spinal block or Subarachnoid
block
First introduced by a German surgeon August
Bier in the year 1898
Involves injection of a local anaesthetic into the
subarachnoid space
3. Anatomic Considerations
Vertebral Column
The bony vertebral column provides
Structural support
Protection of the spinal cord and nerves
Provides mobility
5. Spinal Cord
Extends from foramen magnum to
second lumbar vertebra
Segmented-
Cervical - 8
Thoracic - 12
Lumbar - 5
Sacral - 1
Coccygeal – 1
6. Spinal cord is located in the
vertebral column
Termination of spinal cord :
In adults usually ends at
level of L1
In children it usually extends
to the level of L2 whereas in
infants it ends up at around
L3
7. Meninges –
Dura Mater: outermost and fibrous. Ends
at level of S2 where it forms filum
terminale
Arachnoid: Middle, non-vascular, acts as
anatomic barrier for drugs
Pia Mater: Inner most and vascular
CSF –
Present in the subarachnoid space
Provides mechanical cushioning and
immunological protection to brain
Total volume is 100-160ml in adults
Specific gravity is between
1.003-1.008
8. Surface Anatomy
1. Spinous processes are
palpable over the spine
and help define the
midline
2. In the cervical area
i. the first palpable
spinal process is C2
ii. Most prominent
spinous process is
the C7
9. 3. Spinous process of T7 – inferior
angle of scapula
4. Tuffiers line – Body of L4 or L4-
l5 intervertebral spcae
10. Spinal Anaesthesia
Indications
• Lower limb orthopedic surgery
• Abdominal surgeries including Hernia,
haemorrhoidectomy, hysterectomy, caesarean section
Absolute
Contraindications
• Patient refusal, infection at injection site,
Coagulopathy, Septicimia, Shock, increased ICT,
severe MS/AS, Recent MI are absolute
contraindications
Relative
Contraindiications
• Severe anaemia, Uncooperative patient, preexisting
neurological deficit, severe spinal deformity, severe
hypertension are relative contraindications
11. Steps:-
Patient Evaluation
Indication
Age
Weight
Vitals
Any contraindications
Laboratory testing
Informed consent of the patient
12. Inside the OT :-
Spinal Needle
Available in a variety of sizes (from 16-30 gauge), lengths,
bevel types, and tip designs.
Commonly, a 22 gauge needle is used in patients that are
50 years and older.
A 25-27 gauge needle is used in patients that are less than
50 years of age.
A smaller needle is used in the younger patient to decrease
the incidence of post dural puncture headache.
15. A standard spinal needle consists of three parts-
1. Cannula
2. Hub
3. Stylet
The removable stylet occludes the lumen and avoids tracking tissue into
the subarachnoid space.
16. Types of spinal needles
Sharp / Dura cutting tip
needle
Quincke Needle
Pitket Needle
Blunt tip / Dura splitting
needle
Whitacre Needle
Sprotte Needle
Greene Needle
17. Drug for spinal anaesthesia
• Choosing an appropriate local anesthetic.
• Can be a hypobaric, hyperbaric, or isobaric preparation.
•
• The duration of blockade should match the proposed length of
the surgical procedure
• Hyperbaric bupivacaine is the most commonly used agents for
spinal anesthesia
18. • Baricity:
• Density of a solution in respect to density of CSF
• Hypobaric solutions - raise against gravity
• Hyperbaric solutions - tend to stay at the level injected
• Isobaric solutions - tend to follow gravity
•
19. • Baricity of Local Anesthetic
• Position of Patient
• Concentration of Local
Anesthetic
• Volume Injected
• Level of Injection
• Speed of Injection
• Intra abdominal pressure
Factors
affecting
spread of
local
anaesthetic
*Local anaesthetic from multi-dose vials or those containing preservatives should
never be used
20. Other Checklist :
Sterile towels
Sterile gloves
Sterile spinal needle
Sterile 5 ml syringe for the spinal solution
Sterile 2 ml syringe with a small gauge needle to localize the
skin prior initiation of the spinal anesthetic,
Antiseptics for the skin (such as betadine, chlorhexidine,
methyl alcohol),
Sterile gauze for skin cleansing and to wipe off excess
antiseptic at needle puncture site,
Single use preservative free local anesthetic ampoule.
21. Procedure Preparation
Remove jewellery / watches
Emergency drugs / equipment
Premidication
The patient should be attached to standard
monitors including ECG, blood pressure, and
pulse oximetry. Record an initial set of vital signs
Preload / co-load the patient with crystalloid
intravenous solution
22. Positioning
Three positions used for the administration of
spinal anesthesia
Lateral Flexed
Sitting
Prone (jack-knife) position
23. Lateral Flexed Position
Back parallel to edge of
OT table
Hip and knee flexed,
shoulder and neck flexed
towards knees (fetal
position)
Patient should be
positioned such as to take
advantage of the baricity
of the drug
24. Sitting Position
Patient should sit on the
table with the knees
resting on the edge, legs
hanging over the side and
feet supported by a stool
below
Used for anesthesia of
the lumbar and sacral
levels
(urological, perineal)
25. Preferred in obese patients,
pregnant patients, patients with
abnormal spine curvatures
Identify anatomical landmarks.This
may be a challenge in the obese or
those with abnormal anatomical
curvatures of the spine
26. Prone (Jackknife position)
Patient should be in
prone position with OT
table flexed under his
flanks, jus above the iliac
crest
This position may be
used for anorectal
procedures utilizing an
isobaric or hypobaric
anaesthetic solution.
•
27. The advantage is that the block is done in the same
position as the operative procedure, so that the
patient does not have to be moved following the
block.
The disadvantage is that CSF will not freely flow
through the needle, so that correct subarachnoid
needle tip placement will need to be confirmed by
CSF aspiration.
28. Technique
Hands and lower forearm scrubbed for
a least 3minutes
Sterile gloves should be applied
A large area of L-S spine from lower
border of scapula to iliac crest should be
painted using antiseptic solution
Excess antiseptics should be removed
after waiting for sufficient time for the
antiseptic to act
Identify theTuffier’s line and infiltrate
locally with 2% lignocaine after
negative aspiration for blood
29. Projection and Puncture
Three approach to accessing the
subarachnoid space:
Midline Approach
Paramedian Approach
Taylor Approach
30. Midline Approach
Most common approach, needle introduced in
midline directed cephalad
Advantages:
Anatomic projection is only in 2 planes, making visualization
of the intended trajectory and anatomical structures more
apparent.
The midline provides a relatively avascular plane.
31. Grasp the introducer with one hand and hold the
spinal needle like a dart/pencil.
Placing needle bevel parallel to longitudinal fibers .
Control the needle carefully.
appreciate the “clicks” and “pops” as the needle
traverses the ligamentum flavum and the dura.
As the ligamentum flavum and dura are transversed,
a change in resistance is noted.
32.
33.
34. Once clear CSF appears
in the hub of the spinal
needle, fix the needle in
position with your
nondominant hand and
attach the syringe
containing the
medication.
Aspirate gently, if using a
hyperbaric solution we
can see a birefringence
(Schlieren lines) which
indicate mixing of
solutions of different
baricities
35.
36. After injection aspirate CSF to confirm that the
needle remains in the subarachnoid space
Place the patient in the appropriate position for
the procedure and baricity of the spinal
anesthetic solution
37. LayersTransversed by the spinal needle
(posterior to anterior)
Skin
Subcutaneous tissue
Supraspinous ligament
Interspinous ligament
Ligamentum Flavum
Duramater
Sub dural space
Arachnoidmater
Subarachnoid space
38. Paramedian Approach
Spinal needle is placed
1.5 cm lateral and
slightly caudal to
selected interspinous
space and needle is
directed medially and
cephalad lateral to
supraspinous ligament.
If lamina is contacted,
the needle is redirected
and “walked off” in
medial and cephalad
direction
39. Advantages over midline approach are:
The supra and interspinous ligaments sometimes bony
hard are avoided, so possibly backache.
Little resistance is experienced
Inflicts minimum of trauma
Flexion of back is not so important
Useful in arthritis and deformed spine
40. TaylorTechnique
Injection site is 1 cm medial and
caudal of posterior iliac spine.The
needle is directed 45 degrees caudal
and medial, after contacting the
lamina the needle is walked upward
and medially to enter L5-S1 space.
Useful in spine fusion, arthritic spine,
skin infection in lumbar region
41.
42. Monitoring
Once the anaesthetic agent is administered
monitor the paitient for
Block Progression
Complications
43. Sequence of Block
Sympathetic
paralysis
• Vasomotor block
(dialation of
cutaneous vessels
and increased
cutaneous blood
flow)
Sensory block
• Block of cold
temperature fibre
• Sensation of
warmth felt by the
patient
• Loss of slow pain
• Loss of fast pain
• Loss of tactile
sensation
Motor block
• According to
modified Bromage
scale of onse of
motor block
