1. SPINAL ANESTHESIA

2. SPINAL ANESTHESIA Local anesthestic deposited at subarachnoid space
Sub Arachnoid Block,
Intrathecal Block
Local anesthestic deposited at subarachnoid space
Acts on spinal nerve roots, dorsal ganglia, not on substance of spinal cord
Redistributed via vascular absorption
Produces sympathetic block, sensory analgesia and motor block

3. Indications Surgery involving lower half of body
Upper abdomen
Lower abdomen
Perineum
Lower Extremity
Obstetrics – vaginal delivery
Caesarian section
Painful diagnostic and therapeutic procedures below diaphragm

4. Contraindications Absolute Relative Bleeding disorders Septicemia
Inc. intracranial pressure
Chronic dermatitis or infection near puncture site
Pre-existing spinal cord disease
Hypotension
Patient refusal
Systemic disease with neurologic sequelae
Relative
Hemorrhage
Back problem due to muscle strain, arthritis
Extremely tense / psychotics
Respiratory disease

5. Drugs Used Factors Determining Level of Anesthesia Tetracaine
Lidocaine
Bupivacaine
Factors Determining Level of Anesthesia
volume of solution
concentration
barbotage
speed of injection
patient position
specific gravity of solution
site of injection
height of patient
increased intra-abdominal pressure

6. Technique Interspaces between L2-L3, L3-:4, L4-L5
A. Position
Lateral decubitus – knees flexed to chest
hin put down on chest (nose-to-knee)
Sitting – when lateral approach is difficult (e.g. obese patients)
B. Puncture Sites
Interspaces between L2-L3, L3-:4, L4-L5
Line joining highest points of iliac crests crosses either body of L4 or interspace between L3-L4

8. Structures Traversed By Spinal Needle
a. Skin
b. Subcutaneous Tissue
c. Supraspinous ligament
d. Interspinuous ligament
e. ligamentum flavum
f. Dura

9. PHYSIOLOGIC EFFECTS (Immediate Complications)
A. Cardiovascular
Sympathectomy  vasodilation   BP,  CR
B. Respiratory
Difficulty of breathing
Apnea (high level)
C. Gastrointestinal
Nausea / vomiting in 20%
DELAYED COMPLICATIONS
Headache – leak of CSF
Backache
Urinary retention
Paraplegia – hematoma

10. Levels of Spinal Anesthesia – Dermatomes Involved
Saddle Block – sensory loss involves lowers lumbar and sacral segments.
Area that “sits on the saddle”.
Low Spinal – level of umbilicus (T10) lower thoracic lumbars and sacrals.
Mid-Spinal – costal margin (T6) lower thoracic lumbars and sacrals
High Spinal – nipple line (T4) thoracic segments (T4 – T12) lumbars and sacrals

12. Epidural anathesia
Spinal anathesia
Site of injection
In the epidural space
Subarachnoid space
Onset and duration
Slow onset and continous duration (use catheter)
Rapid onset and limited duration
advantages
Can be used in analgesia
Not used
Needle dose
Curved,longand blunt (touhy) 10_30ml
Small and sharp 1_4ml
space
Any space usually lumber
lumber
Quality of sensory and motor nerve block
less
More liable
toxicity
Hypotention gradual total spinal +++ systemic toxicity +++
Sudden + +

13. THANK YOU