Local anesthetics work by blocking sodium channels in nerve cell membranes, preventing the transmission of pain signals. There are two main classes of local anesthetics - aminoesters and aminoamides. Lignocaine is a commonly used local anesthetic with an intermediate duration of action. Bupivacaine is more potent but also more cardiotoxic than lignocaine. Spinal anesthesia involves injecting local anesthetic in the subarachnoid space to block pain signals from the lower body.

2. LOCAL
ANAESTHETICS
•LOCAL
ANAESTHETICS

3. • HISTORY : Ist Local anaesthetic used was
COCAINE by CARRRL KOLLAR in ophthalmic
patient for anaesthetising cornea.
• CLASSIFICATION
• AMINOESTERS AMINOAMIDES
• Procaine Lignocaine
• Chloroprocaine Mepivacaine
• Tetracaine Prilocaine
• Benzocaine Bupivacaine
• Cocaine Ethidocaine

4. Based on duration , action & potency
• Short duration , low potency
• CHLOROPROCAINE
• PROCAINE
• Intermediate duration & intermediate potency
• LIGNOCAINE
• MEPIVACAINE
• PRILOCAINE
• COCAINE
• Long duration , high potency
• BUPIVACAINE
• TETRACAINE
• ETHIDOCAINE
• DIBUCAINE [ Longest duration]
• ROPIVACAINE
•

5. MECHANISM OF ACTION
•
Drug undissociated [ nonionised ] form penetrates axonal
membrane & inside gets dissociated [ ionised]
• Ionised form binds recepter situated in Na channel in
inactivated state from inner side ,blocking channel & prevents
depolarization & hence action potential
• GENERAL CONSIDERATION
• POTENCY depends on lipid solubility
• ONSET OF ACTION depends on PKa closer to body
PH rapid action Addition of Sodabicarb -- rapid action
• TYPE OF NERVE FIBRE
• Myelinated > sensitive than non-myelinated
• B fibre block rapidly than C --- AUTONOMIC [ C &
B] –SENSORY [ C & A ] ---MOTOR

6. IN RECOVERY –MOTOR -- SENSORY --
AUTONOMIC
IN SENSORY --TEMP [COLD > HOT ] –PAIN
--TOUCH –DEEP PRESSURE ---PROPIOCEPTION
• DURATION OF ACTION depends on
− DOSE
− PLASMA PROTIEN BINDING
− METABOLISM
− ADDITION OF VOSOCONSTRICTERS
− ADRENALINE
− SODABICARBONATE
• SYSTEMIC ABSORPTION depends on
− SITE OF INJECTION
− ADDITION OF VASOCONSTRICTERS

7. METABOLISM
• ESTERS are metabolised by
pseudocholinesterase [ except COCAINE]
• AMIDES metabolised by hepatic microsomal
ENZYMES
• Significant amount of prilocaine by lungs

8. SYSTEMIC EFFECTS & TOXICITY
• CVS
− Vasodilaters except COCAINE
− LIGNOCAINE & PROCAINE have stabilizing
effect on cell membrane of cardiac tissue
− Negative inotropic action on myocardium
− Depresses conduction system
− Bradycardia , decraeses myocardial contractility,
hypotention , vetricular arrhythmias causes cardiac
arrest
− Cardiotoxic potential is much higher with
bupivacaine

9. CENTRAL NERVOUS SYSTEM
• Exitation followed by depression of cerebral
tissue leading to
− Circumoral numbness
− Dizziness
−Tongue parasthesia
− Visual and auditory disturbanses
−Muscle twiching , tremors , convulsion,
followed by coma and death.

10. RESPIRATORY SYSTEM
• LIGNOCAINE depresses hypoxic drive . Direct
depression of medullary respiratory center can occur
at high doses
IMMUNOLOGIC
• Allergic reaction are very common with esters but
rare with amides .The reaction with amides is due to
preservative [ Methyl paraben ] Cross sensitivity does
not exist between classes but exist between agents of
same class .

11. LOCAL TOXICITY
• NEUROTOXIC when directly injected into nerve
• MYOTOXIC when directly injected into muscle
• CHLOROPROCAINE can cause neurological defecits
• Cauda equina syndrome seen with repeated doses of 5%
LIGNOCAINE & 0.5% TETRACAINE
• Local anaesthetic with ADRENALINE can cause necrosis
& gangrene if used in ring block
• Methaehaemoglobinemia seen with PRILOCAINE ,
BENZOCAINE & very rarely with LIGNOCAINE
• LIGNOCAINE can cause Malignant hyperthermia in

12. METHODS OF LOCAL ANALGESIA
•
Topical application EMLA [ Euethetic mixure of
PRILOCAINE 5% & LIGNOCAINE 5% ] IN EQUAL
amount.
• XYLOCAINE SPRAY 4% , TETRACAINE &
BENZOCAINE LOZENGES for mucous membrane of mouth
pharynx & larynx
• XYLOCAINE JELLY 2% for catheterization and
proctoscopies
• LIGNOCAINE 4% , DIBUCAINE 1% & BENZOCAINE 5%
for anal fissure and painful piles
• OXETHAZAINE [ mucaine gel ] 0.2% for gastritis

13. • INFILTRATION ANAESTHESIA
• NERVE BLOCKS
• INTRAVENOUS REGIONAL ANAESTHESIA [ BIERS
BLOCK]
• CENTRAL NEURAXIAL BLOCK [ SPINAL ,
EPIDURAL]
• REFRIGERATION ANEASTHESIA [ CO2 snow ,
ice cooling ,ethyl chloride spray ]

14. COCAINE
• Extracted from Erythexylon Coca
• CNS – Euphoria , Agitation , Hyperexcitation ,
Violence convulsion , apnea & death
• CVS—Potent vasoconstricter
• Metabolised in liver. Metabolite ecognine is CNS
stimulant
• USES—Only for surface analgesia 1% solution for
cornea. Never use intravenously .

15. PROCAINE
• Agent of choice in pt of malignant
hyperthermia
CHLOROPROCAINE
• Shortest acting ,most acidic
• Contraindicated in spinal anaesthesia
• Max safe dose of both -- 1,000mg

16. TETRACAINE
• IT can cause ventricular fibrillation
• A lozenges containing tetracaine available
• Duration of action > cocaine & lignocaine
MEPIVACAINE
• Same as lignocaine
PRILOCAINE
• Methaemoglobinemia occurs at higher doses
DIBUCAINE
• Longest acting , most potent ,most toxic

17. LIGNOCAINE
• Ist synthesised in 1943 in Sweden by LOFGREN of
AB astra . Used in clinical practice in 1948
• Solution stable , contains preservative methyl
paraben . PKa--- 7.8 .
• Concentration used
• SURFACE ANAESTHESIA 4 %. 10% 15%
• GARGLING 2% VISCOUS
• NERVE BLOCKS 1 -- 2%
• URETHRAL PROCEDURE 2% Jelly

18. • SPINAL --- 5% Heavy
• EPIDURAL ---1 to 2% WITH
Adrenaline
• CARDIAC ARRYTHMIAS --- 2% XYLOCARD
• IV BIERS BLOCK --- 0.5 %
• INFILTRATION BLOCK --- 1 to 2%

19. PREPARATIONS OF LIGNOCAINE

20. METABOLISM –In liver . Excreted by kidney
half life –6 hrs
• DURATION OF ACTION
• With ADRENALINE --- 2 – 3 hrs
• Without ADRENALINE --- 45 – 60 mins
• Max safe dose ----3mg/ kg plain
---7 mg / kg with ADRENALINE
• EFFECTS -- CNS effects occur at much lesser
dose than CVS .Systemic toxicity is more than
Bupivacaine

21. LIGNOCAINE releases calcium from sarcoplasmic
reticulum so should not be used in pt with malignant
hyperthermia
• Can cause cauda equina syndrome after continuous
spinal
• OTHER USES -- CARDIAC ARRHYTHMIAS
• Blunting response to laryngoscopy & intubation
LIGNOCAINE SENSITIVITY

22. BUPIVACAINE
• 4 times potent than xylocaine 0.5% solution
available ie more stable
• Highly cardiotoxic . It increases in pregnancy ,
hypoxia & acidosis High degree of tissue and protein
binding makes resuscitation prolonged and difficult
• Should not be used in BIERS block
• Metabolised in liver t1/2 – 3.5 hrs

23. PREPARATIONS OF BUPIVACAINE

24. DURATION OF EFFECT without adrenaline --2– 3hrs
with adrenaline -- 3—5 hrs
• Max safe dose –2mg / kg [with /without adrenaline]
• CONCENTRATION USED
• For nerve block -- 0.5%
• Epidural -- 0.5% [ ANAESTHESIA]
-- 0.25% [ ANALGESIA]
-0.125% [ POST OP ANALGSIA]
• SPINAL -- 0.5% [heavy ]
• Labour analgesia – 0.125% to 0.0625 %

25. ROPIVACAINE
• ROPIVACAINE consists of single enantiomer /the S
isomer [ levo isomer ]
• Cardiotoxicity & CNS toxicity is much less than
bupivacaine.so cardiac arrest following ropivacaine
has much better prognosis due
• To Rapid reversal of sodium channel
Rapid clearance from circulation
• Motor & sensory block is similar to bupivacaine
• SAFE DOSE – 3mg/kg

26. INFILTRATION BLOCK
• Managing interacting pain by injecting 0.5%
lignocaine or 0.25% bupivacaine in to painful tissue
• Leads to disappearance of referred pain ,muscle
spasm
• Mostly used in sprains ,strains ,painful undisplaced
fracture , low back pain , burcitis ,tendinitis
,artritis ,myalgia torticolitis
• Painful scars following surgery

28. DIGITAL NERVE BLOCK
• The digital nerves to a fingre or
toe can be blocked by infiltration
of local anaesthetic solution on
either side of base of proximal
phalynx
• .Lignocaine 0.5% shoud be used
but remember without adrenaline.
• Adrenaline causes marked
vasoconstriction of digital vessels
leading to gangrene

29. ANKLE BLOCK
• Deep peroneal ,
superficial peroneal
and sephanous nerve
blocked along with
subcutaneous
infiltration at the
dorsum of foot ,
posterior tibial
posterior to medial
malleolus and sural
laterally between
lateral malleolus and
Achillis tendon

31. PARACERVICAL BLOCK
• Injection of 8-10 ml 1%
Lignocaine into each fornix
blocks afferent supply of
uterus & produces adequete
Ist stage pain relief in 80%
of pt.
• Disadvantage –Foetal
bradycardia [20—30%] due
to decrease in placental
flow resulting from uterine
artery vasoconstriction .

32. PUDENDAL NERVE BLOCK
• Indications
• surgery of lower vagina & perineum
• midcavity forcep delivery & episeotomy
repair
• Not for MRP
• METHODS *Transperineal approach
*Transvaginal approach

33. TRANSPERINEAL PUDENDAL NERVE
BLOCK
• Skin wheal over
ischial tuberocity . 10
cm needle inserted &
guided until point lies
above and behind
ischial spine with free
hand in vagina .10 ml
1% lignocaine
hydrocloride injected
on both side

34. TRANSVAGINAL PUDENDAL NERVE
BLOCK
• Guarded needle , tip
inserted just above
&behind ischial spine
20ml 1% lignocaine
hydrocloride.Needle
first passes through
sacrospinous
ligament .Simpler ,
less painful ,higher
success rate , less
damage to foetus

36. DR. S. DALAL
LECTURER
DEPTT OF ANAESTHESIA
GMC NAGPUR

37. HISTORY

38. ANATOMY OF VERTEBRAL COLUNM
• 33 VERTIBRAS
7 cervical
12 thoracic
5 lumber
5 sacral
4 coccegeal
• 31 PAIRS OF SPINAL
NERVES

39. • 4 curves -- Thoracic
and sacral are
convex posteriorly
[ khyphotic] while
cervical and lumber
spine are convex
anteriorly [ lordotic]

40. ANATOMY OF SPINAL CORD
• Medula oblongeta to
lower border of L1
vertebra .In infants &
neonates, lower border
of L3
• Meninges –inside to
outside piamater ---
arachnoid mater –
duramater
• Duramater extends to
S2 & S4 in infants

41. BLOOD SUPPLY OF SPINAL CORD
• 2 Posterier spinal
arteries from post
inferier cerebellar artery
and 1 anterier spinal
artery formed by branch
of vertebral artery
• Artery of adamkiewisz
[arteria radiculari
magna]

42. SRUCTURES ENCOUNTERED DURING
SPINAL
• SKIN
• SUBCUTANOUS
TISSUE
• SUPRASPINOUS
LIGAMENT
• INTERSPINOUS LIG
• LIGAMENTUM
FLAVEM
• DURA
• ARACHNOID

44. • DERMATOLOGICAL
SEGMENTAL LEVEL
• NIPPLES T4
• XIPHISTERNUM T6
• UMBILICUS T10
• PUBIC SYMPHYSIS
L1
• PERINEUM S1 TO
S4
• SEGMENTAL LEVEL
OF SPINAL REFLEXES
• EPIGASTRIUM T7 , T8
• ABDOMINAL T9 T12
• CREMASTRIC L1,2
• KNEE JERK L2,3,4
• ANKLE JERK S1,2
• ANAL SPHINCTER
S4,5
• PLANTER S1,S2

45. CEREBROSPINAL FLUID
• Present between pia & aracnoid mater i.e.
subaracnoid space
• 500ml secreted per 24 hrs
• Volume 135 ml , 75ml in subaracnoid space
• Specific gravity – 1.0003 g/ml
• CSF pressure 70 to 120mm of H2O in lateral
position , 375 to 550 in vertical position

46. INDICATIONS & CONTRAINDICATIONS
• Orthopaedic surgeries
[ lower limb & pelvic ]
• General surgeries [lower
abdominal , pelvic
perineal, bladder,
ureteric & prostetic
surgeries
• Gynaecological &
obstretic surgery
• Bleeding disorders
• Infection at site
• Pt with CNS
abnormality & CVS
problems
• Spine deformity
• Pts refusal

47. POSITION FOR SPINAL
• Either left or right
lateral .
• Flexion – hip & knee so
knee touch to abdomen
• Flexion – neck so chin
touch to sternum
• Sitting –leg should rest
on stool & pillow below
shoulder

48. SPINAL NEEDLES

49. Adv over GA
* Cheaper
* Less pulmonary
aspiration
*Less respiratory
complications
* Less drugs
* Bleeding less
* Decrease
thromboembolism
• DRUGS USED
5% Lignocaine
[ heavy]
• 0.5% Bupivacaine
[ heavy ]
• Opiods ,ketamine
midazolam

50. SYSTEMIC EFFECTS
• CVS : * Venodilatation due to sympathetic block
* Dilatation of post arteriolar capillaries
* Decreases cardiac output
* Decreases venous return
Bradycardia ( Bainbridge reflex )
- Inhibition of cardioaccelator fibers[T1-T4]
- Paralysis of nerve supply to adrenal gland
with decrease
catecholamine supply *Supine
hypotention syndrome

51. CENTRAL NERVOUS SYSTEM
• Sequence of block * Autonomic Sensory
-- Motor and recovery is reverse . Hence autonomic
level is 2 seg higher than sensory level which is 2
seg higher than motor block
-- Ist -- Temp ( cold – hot ) –pinprick –motor ---touch
-- propioception

52. RESPIRATORY SYSTEM
• Tidal volume , minute volume , PaO2 well maintained
• In higher blocks impairment of respiratory function to
paralysis of abdominal & lower intercostal occures
• Apnea only in total spinal due to severe hypotention
causing medullary ischemia.

53. GASTROINTESTINAL SYSTEM
• Contracted gut with relaxed spinctures due to
sympathetic block & parasympathetic overactivity .
Peristalsis increased.
LIVER
• Minimal effect
RENAL
• Impaired only if critical pressure of kidney for
autoregulation falls below 55 mm of hg

54. GENITAL SYSTEM
• Flaacid and enlarged penis is one of the sign of
successful block.
ENDOCRINAL
* Stess response to surgery ( adrenals) inhibited
* Respose to insulin is augmented & there can be
hypoglycemia
* Increase in ADH during surgery suppresed.

55. THERMOREGULATION
• Venodilatation causes heat loss .Compenseted
vasoconstriction & shivering .
SITE OF ACTION ( LOCAL ANAESTHETICS)
* Acts on spinal nerves & dorsal ganglion

56. FACTERS AFFECTING HEIGHT OF BLOCK
• Volume - more --- increase block
• Baricity
Hyperbaric –fixation of drug
Hypobaric – drug cranially
Isobaric - same level
• Intraabdominal pressure
• Spinal curvature
• Age , obesity , height

57. DURATION -- Dose , conc ,addition of
opoids or vasoconstricters
COMPLICATIONS
* Hypotention
* Bradycardia
* Respiratory paralysis
* Nausea & vomiting
* Difficulty in phonation
* Cardiac arrest
* High spinal / total spinal

58. POST OPERATIVE COMPLICATION
• POST-SPINAL HEADACHE mainly occipital
,increases in sitting position ,decrease in lying
down .Ocurrs in 3-30% pts last for 7-10 days
• T/t H– Head low tilt
E- Epidural saline
A- Analgesics
D- Demopressin
A- Abdominal binders
C – Caffine
H – Hydration
E - Epidural blood patch

59. • Urinary retention
• Paraplegia
• Paralysis of 6 th cranial nerve
• Aracnoiditis
• spinal cord ischemia
• Anterior artery syndrome
• Backache
• Meningeal irritation
• Cauda equina syndrome

60. DR.S.DALAL
LECTURER

61. HISTORY 1st
epidural was given by CORNING
in 1885
• What is epidural space?
• Lies within body cavity of
spinal canal & outside
dural sac
• Ant-body of vertebra &
post longitudinal ligament
• Post-ligamentum flavem

62. Epidural space contains-fat & venous plexes
• Negative pressure in space due to
* negative pressure is transmitted from pleural cavity
via thoracic paravertebral space
* negative pressure created by flexion of
spine
* created by identing the dura with needle
point
• TWO TYPES Single shot epidural
continous with catheter

63. WHY EPIDURAL ?
• Early ambulation of patient possible
• Better wound healing
• Less respiratory discomfort
• Less abdominal discomfort
• Psycological stability
• Economic , less hospital stay
• Mothers & baby outcome well in labour analgesia

64. INDICATIONS
• LUMBAR EPIDURAL – all lower abdominal
surgeries
• THORACIC EPIDURAL – upper abdominal ,
thoracic surgeries
• CERVICAL EPIDURAL –neck surgeries by
CONTINOUS EPIDURAL CATHETER –
postoperative pain relief
• LABOUR ANALGESIA –mother is delivering
baby with a smile on her face

65. • CHRONIC PAIN RELIEF --CANCER PTS
• ACUTE OCCLUSIVE VASCULAR CONDITIONS
• BLOOD PATCH – for postspinal headache
• BETTER in ASA grade 3 & 4 pts
CONTRAINDICATIONS
• SAME as spinal
• Coagulation disorders, septicemia ,infection at site,
pts refusal ,aortic stenosis , critical mitral stenosis

66. EPIDURAL TRAY
• Touhy epidural
needle with stelyet
• 10 cc syringe for air
or saline
• Epidural catheter
with introducer &
adapter
• 2 cc / 5 cc syringe for
local
• Stickings

67. POSITION FOR EPIDURAL

68. METHODS OF IDENTIFYING EPIDURAL
SPACE
• Loss of resistance technique [ piercing ligamentum
flavem ]
• Hanging drop technique [ drop of saline sucked]
• Air injection / saline injection technique
• Machtosh extradural space indicater
• Odoms indicater
• Saline drip technique

69. Test dose – 3cc lignocaine with adrenaline
• Effect – WITHIN 15 -- 20 MINS motor effect less
as compare to spinal
SITE OF ACTION
• Anterior & posterior nerve roots
• Mixed spinal nerves
• Drug diffuses through dura & aracnoid & inhibits
descending pathways in spinal cord.

70. DRUGS -- Volume is more imp than concentration
• LIGNOCAINE [ with or without adrenaline ]2%
• BUPIVACAINE
Anaesthesia -- 0.5%
Analgesia -- 0.25%
post op analgesia– 0.125% along with opoids
[ opiods act by binding the opoid receptor in
substansia gelatinosa of dorsal horn cell]
• DISADVANTAGES Respiratory depression ,urinary
retention ,vomiting, itching

71. OPIODS USED IN EPIDURAL
• MORPHINE ----12—16 hrs
• TRAMADOL --- 8 hrs – 100 mg 8 hrly
• BUPREGESIC– 12 hrs – 100-150 ug 12 hrly
• BUTRUM ------- 3 hrs – 1-2 mg
• MIDAZOLAM --- 4 hrs – 2mg 4 hrly

72. COMPLICATIONS
• Patchy effect
• Surgical relaxation not good
• Hypotention less as in spinal
• Apnea occurs with higher blocks
• Chances of total spinal is more
• Dural puncture
• Subdural block
• Intravascular injection
• Horners syndrome

73. – Epidural abscess
– Backache
– Broken catheter
– Meningitis
– Epidural haematoma

75. HISTORY – Ist given by SORIESI in 1937
ADVANTAGES : Both spinal & epidural
* Early & reliable onset
* Fast tracking of pt saving ot time
* Good surgical relaxation
* Facility for extended anaesthesia
* Provision for postop analgesia
* Less dose requirement of local anaesthetics
* Less post-spinal headache

76. CAUDAL BLOCK
• Type of epidural block
INDICATIONS
• IN children for anaes or
postop anaelgesia like
perianal , genital urethral
surgeries
• Lat or prone position
• DOSE -0.5 to 1ml/kg