SPINAL ANAESTHESIA

1. SPINAL ANESTHESIA
Moderator: Dr.Trivikram Shenoy
Presentor: Dr.Shaik Tahoor
Dr.Naveen Kumar Ch

2. • Technique
• Approaches
• Indications and contraindications
• Complications and its prevention and
treatment

3. Technique
• Four P's
• preparation,
• position,
• projection and
• puncture.

4. Preliminary Duties
• Preparation of the equipment and drugs for
subarachnoid injection
• I.V access-wide bore cannula is secured and fluids
bolus is given
• Emergency drugs and equipment for G.A
• Sedation if needed
• Vitals recorded
NIBP/SPO2/ECG
• Verbal contact with patient

5. Spinal needles
Types
Dura cutting: Quincke-babcock &pitkin needle
Dura separating: whitacre & sporte
sizes
16 to 30 g size
Gauge of SN and colour coding
18 G – Pink 25 G – Orange
19 G - Ivory 26 G - Brown
20 G – Yellow
22 G - Black
23 G –Blue

6. • All needles should have a tightly fitting
removable stylet that completely occludes the
lumen to avoid tracking epithelial cells into
the subarachnoid space.
• Check for stiffness,flexibility ,resistance

7. Quincke-Babcock Spinal Needle
• It is considered standard spinal needle
• Consists of a small hub and sharp point with a
medium length cutting bevel.
• There is fitted stylet with a matching bevelled
tip to cannula point and connector
• Different lumen sizes ranging from 18 to 26
• Most are 3.5 to 4 inches in length

8. Whitacre needle
• Sharp pencil point type of bevel
• No cutting edges
• Orfice on one side 2.5mm proximal to tip
• Saperates the fibres
• Cannot easily feel a give or snap
• Exit port smaller than lumen,so great
resistance is noted while giving the drug

9. Sprotte needle
• It is a side-injection needle with a long
opening.
• It has the advantage of more vigorous CSF
flow compared with similar gauge needles.
• However, this can lead to a failed block if the
distal part of the opening is subarachnoid
(with free flow CSF), the proximal part is not
past the dura, and the full dose of medication
is not delivered

10. • PITKIN NEEDLE-it is very sharp point bevel
with cutting bevel
• GREENE NEEDLE-it is rounded ,medium length
non cutting edges to bevel

11. • The use larger needles improves the tactile
sense of needle placement.
• The use of small needles reduces the
incidence of post–spinal puncture headache.
• Multiple punctures increase the incidence of
headaches.
• Conical-tipped needle have lesser incidence of
post spinal headache.
• Poorly matched stylet has the potential to tear
the dura matter,increase leakage

12. Position
LATERAL DECUBITUS -Most common position
The Spinal canal should be on a horizontal plane.
The thighs flexed on their abdomen, and their neck
flexed to allow the forehead to be as close as possible to
the knees

13. • Considerations for differences in body built
b/n males and females for achieving
horizontal level

14. • SITTING POSITION-
• The Spinal canal should be on a vertical plane.
• stool can be provided as a foot rest
and a pillow placed in the lap.
• flexing the patient's neck and arms
over the pillow to open up the lumbar
vertebral space.
• Recommended for
– Obese patients
– Saddle block anaesthesia
– Inability to adequately curl up

15. PRONE JACKKNIFE POSITION-
• This position is appropriate for rectal,
perineal, or lumbar procedures where the
position of surgery is same as that of
anesthesia
• most often paramedian approach is used.
• The anesthesiologist may have to aspirate for
CSF because CSF pressure is minimized when
insertion of the lumbar needle is carried out in
this position.

16. Classification of Technique
• Single injection technique
hyperbaric/isobaric/hypobaric
• Continous injection methods
intermitent-fractional
differential block
continous drip
• Segmental technique

17. Single injection technique
• Hyperbaric technique:
• It is the most commonly used method
• Solutions:
• 0.5% to 0.75% bupivicaine in 8.25% dextrose
• Density-1.0190 , Specific gravity-1.0257
• Each ml contains 5mg of bupivacaine
• 0.5%Tetracaine -5D,5%lignocaine -5D,
5%procaine(50mg)

18. Isobaric technique
• Tetracaine 20mg in 4ml of saline
• 0.5%Bupivicaine in normal saline
• Useful for lower abdominal surgery and
perineal surgery

19. hypobaric technique
• Tetracaine 0.1% in distilled water
• Dibucaine 1:1500 in 0.5% saline
• Useful in prone position surgery

20. Adjuvants of S.A
• Opioids produce intense visceral analgesia and prolong
only sensory blockade.
• Sites of action : the second and third laminae of the
substantia gelatinosa in the dorsal horn of the spinal
cord.
• Lipophilic agents such as fentanyl and sufentanil have a
much more localized effect ,rapid onset of action and
an effective duration greater than 6 hours.
• Examples
• Fentanyl-10 to 25ug
• Sufentanil-2.5 to 10 ug

21. Adjuvants of S.A
• CLONIDINE-alpha 2 agonist (150ug)
Onset -same; Duration-prolonged
• Epinephrine- vasoconstrictor action (1:10,000)
delays absorption of local anesthetic
• Phenylephrine-1:1,000 concentration
• No changes in systemic circulatory activity

22. Safe Spinal Technique
Scrub hands according to aseptic surgical
technique.
Use sterile gloves.
Avoid contaminating the spinal drug.
Use aseptic technique when opening tray.
Touch only sterile articles once gloved.
Cleanse the skin prior to needle puncture.
Avoid repeated traumatic punctures.

23. Safe Spinal Technique
Do not do spinal puncture if the patients
bleeding parameters are increased.
Never insert a needle through an infected area.
Use Local Anaesthetics in standard
concentrations.
Paint the patients back with antiseptic solution
over the lumbosacral spine and iliac crests and
drape the back.

24. Steps
• Find the widest interspace.
• The palpating fingers should identify the
interspinous area and the midline
• A subcutaneous skin wheal is developed over
this space using LA; usually 2% Lignocaine.
• With spinal needle leaving stylet in place with
its bevel parallel to the longitudnal axis is
advanced steadily and smoothly until the
characteristic change in resistance

25. Steps
• The stylet is then removed and observe for
the free flow of CSF.
• If it does not, the needle should be advanced
a few millimeters and rechecked .
• If CSF still has not appeared and the needle is
at a depth appropriate for the patient, the
needle should be withdrawn and the insertion
steps should be repeated.

26. Injection of drug-Bromage grip
• Stabilise the needle and attach syringe by grasping the
hub with thumb and fore finger and remaing fingers
against pt back to provide support.
• Aspirate small quantity to check
the needle position.
• Given @0.2ml/sec
• Remove syringe and check for the flow
of csf after giving the drug
• Remove the spinal needle and make the pt in prone
position

27. SEQUENCE OF BLOCK
1.Sympathetic nervous system fibers
(B fibers: vasodilation, skin temp ↑)
2.Temperature & pain conduction
(A delta & C fibers)
3.Proprioception & touch (Aγ & Aβ fibers)
4.Motor function (A alpha fibers)

28. Approaches
• Mid line approach
• Paramedian approach
• Taylor’s approach

29. Mid line approach
• Technique of first choice.
• Prerequisites
– Minimize lumbar lardosis
– Access Subarachnoid space between L2-3, L3-4, L4-5.
• Structures pierced are Skin , subcutaneous
tissue, supraspinous ligament , interspinous
ligament , lagementum flavum , dura mater ,
subdural space , arachnoid matter,
subarachnoid space

30. Paramedian approach
• The palpating fingers should identify the caudal
edge of the cephalad spinous process,
• skin wheal is raised 1 cm lateral and 1 cm caudal
to this point.
• The spinal needle is inserted 10 to 15 degrees
off the sagittal plane in a cephalomedial plane .
• Structures piered are Skin , subcutaneous tissue,
interspinous ligament , lagementum flavum , dura
mater , subdural space , arachnoid matter,
subarachnoid space

31. Paramedian approach

32. Taylors approach
• A variation on the para median approach.
• This technique is carried out at the L5-S1
interspace, the largest inter laminar interspace of
the vertebral column.
• A skin wheal raised 1 cm medial and 1 cm
caudad to the lowermost prominence of the
posterior superior iliac spine.
• A 5-inch spinal needle is inserted in a
cephalomedial direction into the subarachnoid
space.

33. Taylors approach

34. Indications and selection of patient
• Location and nature of operation-
Lower limb surgery,Lower abdominal
surgery,Urological & gyneacological procedures
• Attitude-cooperative
• Age-15to70 yrs
• Medical derrangement- HTN tolerate well
lung ,liver, kidney disease better subject
for spinal anesthesia
• Obsteric – can be given for Caesarian section

35. Indications and selection of patient
• Renal failure pts –well tolerated
onset of analgesia is rapid
Due to greater generalised acidity in uremic pts
base form of local drug rapidly converts to cation form
and enhances the interaction with receptor site in sodium
channel
mean spread of sensory block is higher
duration of analgesia is shorter
Due to increased fluid volume&hyperdynamic circulation
in CSF

36. Other uses
• Paralytic Ileus(non obstructive )-
contraction of gut occurs and gases expelled
• Hyperthyroidism
enhanced adrenal gland secretions occur
block given upto t5 level is beneficial for thyroid
surgery
• Pulmonary edema-
caused by htn and atheroslerotic heart disease
s.a diminishes venous return and relieves cardiac load
• Megacolon-hirschprungs disease
• Pain evaluation-to know somatic or sympathetic orgin

37. Contraindication
• CNS causes-brain tumours,cns syphilis,meningitis
and infection
• PNS causes-poliomylietis,multiple sclerosis
demylinating diseases
• Circulatory causes-hypovolemia,severe
anemia,shock
• CVS causes-hypotension,coronary diseases,aortic
valvular diseases,cardiac decompensation
• Infections-local infection,systemic sepsis

38. Contraindication
• Anatomical deformity-spinal
anomalies,scoliosis,metastasis to vertebrae,
• Special intra abdominal conditions-raised intra
abdominal pressure, chronic intestinal
obstruction
• Psychological condition-uncooperative pt,
mentally disturbed pts
• Anticoagulant therapy-pts who are on heparin it
is better to check bleeding parameters before
giving spinal anesthesia

39. INTRAOPERATIVE COMPLICATION
• HYPOTENSION: diagnosis is established when a
25% fall in systolic pressure occurs
• Symptoms: related to tissue hypoxia
• First effects are of
stimulation,apprehension,restlessness,diziness,
tinnitus,headache
• Followed by retching, vomting
• Later include depression,
drowsiness,disorientation,coma

40. • Clinical features:
• Higher the level of anesthesia more is the
chance of going to hypotension
• Umbilical level is the critical level,when it goes
beyond this level there is progressive loss of
capacity for reflex compensation

41. mechanism
• Paralysis of sympathetic vasoconstrictor fibres to
arterioles
• Dilation of peripheral veins and venules leading
to pooling of blood
• Paralysis of intercostal muscles leading to
decreased minute volume leading to hypoxia
• Prophylactic dose of mephentaramine or
ephedrine can be administered at the time of
sucessful tap

42. treatment
• Head down position
• i.v fluids
• Administration of o2-mainly to increase the o2
content of circulating blood because if there is
slowing of circulation in tissues and wide av o2
difference
• Recommended for all High spinal anesthestic pts
to given suppliment o2 to minimize
hypoxia,relieve dyspnea, nausea and vomiting
• Key stone to therapy of hypotension is
vasopressor therapy

43. vasopressor therapy
• Ephedrine sulphate-10 to 50 mg c.o increases
• Mephenteramine
• Phenylephrine-0.5 to 1mg arteriolar
constriction
• Epinephrine-increases hr,sbp lowers dbp,pvr
• Norepinephrine-increases both sbp and dbp

44. Choice of vasopressor agent
• We should choose the agent that combines
both alpha and beta cvs effects
• First choice is ephedrine
• Second choice is mephenteramine

45. Spinal hypotension in obsterics
• Aorto caval compression-supine hypotension
combined with inadequate hemostatic circulatory
adjustments for venous return to lower extremeties
• Venous return depends on iliolumbar viens and
vertebral plexus of azygous veins
• Rx:Left uterine displacement,Hydration with
crystalloids, Vasopressors
ephidrine/mephenteramine

46. • Respiratory impairment-occurs when high spinal
level is reached
Rx:Treatment:suppliment o2,airway,ventillatory
support if necessary
• Affective dyspnoea-
When level of block is higher thoracic level pt may
complain of breathlessness ,
It is due to lack of propioception
Rx-encouraging the patient to voluntary take deep
breathes,suppliment o2,inhaling smelling salts
• Nausea and vomiting: usually the result of
hypotension or unopposed vagal stimulation

47. • Traumatic spinal puncture-
repeated attempts to achieve spinal tap may
result in direct trauma to
nerves,periosteum,intervertebral discs
errors-failure to maintain mid line,advancement
too far,blood tap,failure to recognize
penetration of dura

48. High and Total spinal
• Occurs after excessive cephalic spread of the
local anaesthetic
• SYMPTOMS- Unconsciousness, apnea and
hypotension
• Treatment-symptomatic o2 inhalation, iv
fluids ,ventilator may be required

49. Cardiac arrest
• If the block progresses (High Spinal) to the mid thoracic
region involving the heart.
• Usually due to hypoxaemia <85% without obvious
changes in respiration and cyanosis.
• Use of fentanyl,can account for bradycardia and arrest
• Incidence is commoner in young healthy adults
• Preceded by bradycardia
• Treatment-conventional doses of atropine and
ephedrine is given
• Full resuscitation dose of epinephrine is given

50. Post operative complications
• Urinary retention
• Local anesthetic block of S2-S4 root fibers
decreases urinary bladder tone and inhibits
the voiding reflex
• Foleys cathetor may be required to insert

51. Post-dural Puncture Headache
• First documented by august beir in 1899
• character: in the order of frequency
constriction band arround head which is generally
occipital or at vertex , dull ache,heaviness and
pressure in the head, thrombing sensation,
• Spasm and pain in neck muscles,occular
pain,diziness may accompany the headache
• It is aggravated in erect posture and relieved in
supine posture

52. Differential diagnosis PDPH
• Coincidental headache-headache when
investigated is similar to the previous headache
experienced by the patient.It is not influenced by
posture.
• Spinal headache:it is postural in nature and may
occurs within 48 hours of giving spinal anesthesia
• Caffeine withdrawl headache:patient who
consume caffeine containg beverages are likely to
suffer as abstinence syndrome if intake is
stopped.symptoms develop within 24 hours and
typically headcache,sleeplessness,inactivity and
irritability.

53. PDPH
• Onset:usually appears in second and third
post operative day and usually subside at the
end of
7 to 10 days
• Sex:it more frequent in young females
• Age :the greatest frequency of headache
occurs in the age group 20 to 40 years

54. pathophysiology
• Due to imbalance in the csf dynamics
• Loss is greater than the fluid production
• Loss greater than 30 to 50 ml is critical to
produce headache
• Traction of pain sensitive structures and blood
vessels occur in brain resulting in headache

55. prevention
• Proper hydration
• Use introducer
• Use of smaller size pencil point whitacre
needle
• Bevel parellel to longitudnal axis
• Early ambulation

56. treatment
• Psychological support and reassurance of
recovery
• Large volume of fluids
• Oxygen inhalation
• Analgesics –aspirin
• Caffeine sodium benzoate-causes cerebral
vasoconstriction

57. Severe cases
• When above measures fail
EPIDURAL BLOOD PATCH is done
• Technique:
• Patient is positioned and the lumbar area is
aseptically prepared for epidural puncture
• 8 to 10ml of venous blood withdrawn from
antecubital vein

58. • Epidural puncture is performed at the orginal
site of puncture
• Blood is slowly injected @1ml/sec
• Pt kept in supine for 1 hour
• Afterwards movement and ambulation is
encouraged

59. Mechanism of relief
• Immediate pressure effect which compress
the dura matter which increases sub
arachnoid pressure and restores csf dynamics
• Sealant effect: injected blood forms gelatinous
patch over the puncture site lasting for 3-4
days allowing healing of puncture hole

60. Backache
• usually benign, mild and self-limited,
• can be treated with NSAIDs,
• It may be a clinical sign of a more serious
complication such as epidural hematoma or
abscess

61. Infection
• Cutaneous abscess
• Epidural abscess
• Septic meningitis
Causes result from contamination of
agent,inadequate sterlization,or introduction of
needle through infected tissue
Psuedomonas is the frequent organism
Treatment:antibiotic therapy

62. Cranial nerve disturbances
• Most commonly involve sixth nerve
• Since the function is to rotate the eye ball internal
strabismus occurs leading to visual disturbances
blurring ,diplopia,difficulty in focussing
• Occuring in the 6 to 8 th post operative day is peculiar
to SA
• Men are more frequently involved
• Symptoms are unilateral and generally on right side
• Rx:Symptomatic,supine position,eye patch is helpful

63. Transient neurologic symptoms (TNS)
• Characterized by back pain radiating to the
legs without sensory or motor deficits,
• occurring after the resolution of the block;
• usually resolves spontaneously within several
days; pathogenesis is unclear
• Most common with hyperbaric lidocaine and
after surgery in lithotomy position

64. Meningismus
• Aseptic or chemical meningitis
• Occurs suddenly and usually in 3 or 4th
operative day
• It presents as intense splitting headache,stiff
neck,positive kernig,photophobia,confusion
and vomting
• Usually subside with use of aspirin and
antibiotics

65. Cauda equina syndrome
• Suspected when pt fail to regain motor power
of limbs at usual time after spinal anesthesia
• Symptoms: incontinence of feaces with anal
sphincter paralysis,urinary retention,loss of
proper function of lower extremeties
• Return of function is usually slow and bladder
drianage is recommended as an early form of
therapy

66. Myelitis
• Its an inflammatory reaction of medullary cord
• Causes : bacterial infection or
effect of anesthetic drug on mylein substance
• apparently after the primary effects of spinal
anesthesia wear off,a pronounced paraplegia of
flaccid type develops with loss of sensibility
• If fatality occurs PM examination shows
demyelination of medulla and posterior roots

67. • reference : collins and miller