Basics of spinal anesthesia

1. Spinal anesthesia
Prepared by
Mohammed Nariman , Rayan Abdulrahman ,Helin jamal

2. Spinal anesthesia
• Spinal anesthesia : also called spinal block, subarachnoid
block, intradural block and intrathecal block, is a form of
neuraxial regional anaesthesia , involving the injection of a local
anaesthetic or opioid into the subarachnoid space.
• It is a safe and effective form of anesthesia usually performed
by anesthesiologists that can be used as an alternative to general
anesthesia commonly in surgeries involving the lower extremities and
surgeries below the umbilicus.

3. Drugs to perform spinal anesthesia
Local anesthetic (LA) is injected into cerebrospinal fluid (CSF) in the
lumbar spine to anesthetize nerves that exit the spinal cord.

4. Indications of spinal anesthesia
• It is especially suited for older patients and those with diseases such
as chronic respiratory/renal/hepatic disease.
• Diabetics also face an advantage from spinal anesthesia.
• 1. Orthopedic trauma surgery(Lower limbes)
• 2.Urological surgery
• 3. Gynecological surgery
• 4. Abdominal surgery (Operations in the lower abdomen)
• 5. Pain relief during and after surgery
• 6. Low-dose spinal anesthesia is also indicated to relieve pain during
childbirth for women who give birth naturally

5. Contraindications
• 1.Presence of neurological disease, or infection of skin around the lumbar
area in the back.
• 2. Anatomical difficulties that might make the administration of
anesthesia difficult.
• 3. Uncooperative patients such as children, mentally challenged
individuals, or patients with psychiatric disorders.
• 4. Patients with severe fluid loss either by bleeding, vomiting, or diarrhea
should be replaced with adequate fluids before being taken up for spinal
anesthesia due to the risk of hypotension.
• 5.Patient's refusal for the administration.

6. Complications
• 1.Direct needle trauma
• 2.Bleeding around spinal column
• 3.Nausea and vomiting
• 4.Hypotension
• 5.Bradycardia
• 6.Allergic reaction
• 7.Post dural puncture headache(PDPH)

7. • The local anesthetic with or without an opioid injected into the
cerebrospinal fluid provides anesthesia, true analgesia, motor,
sensory and autonomic (sympathic) blockade.

8. Sympathetic activation
• Increase heart rate
• Increase blood pressure
• Vasoconstriction
• Dilate pupils
• Bronchodilation
• Lipolysis(gain free fatty acids)
• Glycogenolysis(gain glucose)
• In spinal anesthesia due to sympathetic blockade internal balance of body change
over to parasympathetic system , that’s why we see bradycardia , hypotension …..
• Also for diabetic patients .. Glycogenolysis stop that’s why releasing of glucose to
bloodstream stopover (blood sugar nearly stay normal or reduced).

9. Position and types of needls
• We have three types potions to perform spinal anesthesia :
• 1.Sitting
• 2.Lateral decubitus (right or left)
• 3.Jack-knife position(prone)
• Spinal needls :
• 1.pencil tip(whitcare,sprotte)
• 2.those that cut the dura(quincke,babcock)

11. Sites of needle
• Adult: Between(L3-L4) or (L4-L5)
• Infant: Between(L4-L5)
• Why we choose lumber region(L2,L3,L4) to injection?
• A/spinal cord ends in this region and cauda equina starts , so its safer
to perform in this sites .

12. Baricity of local anesthetics
• Local anesthetics differ in concentration and density compare to
density of CSF:
• Isobaric: stays where you put it , has same density of CSF.
• Hypobaric: Rise from where you put it , lighter than CSF.
• Hyperbaric: Sink to the bottom from where you put it , has a density
greater than CSF.

13. Difference between spinal & epidural
anesthesia
• Spinal anesthesia involves the injection of local anesthetic directly
into subarachnoid space(into CSF). Epidurals anesthesia involve the
injection into the space outside dura matter (epidural space).

14. Difference in the site of needls

15. Sources
• Medicosis perficionalis
• Pubmed
• Clivland clinic
• Master anesthesia
• Open anesthesia