Epidural Anesthesia

1. Epidural Anaesthesia
Presenter-Dr Tess Jose
Resident Anaesthesia
Moderator –Dr Giles George

2. Anatomy of spine and para axial
region
• The vertebral column consists of
33 vertebrae (7 cervical, 12
thoracic, 5 lumbar, 5 sacral, and 4
coccygeal segments)
• The vertebral column is straight
when viewed dorsally or ventrally.
When viewed from the side, the
cervical and lumbar regions are
concave posteriorly (lordosis), and
the thoracic and sacral regions are
concave anteriorly (kyphosis)

4. Structure of Vertebrae

5. THE SPINAL CORD
• The spinal canal contains the spinal
cord with its coverings (the meninges),
fatty tissue, and a venous plexus
• The meninges are composed of three
layers: the pia mater, the arachnoid
mater, and the dura mater.
• The pia mater is adherent to the spinal
cord, whereas the arachnoid mater is
usually adherent to the thicker and
denser dura mater.
• Cerebrospinal fluid (CSF) is contained
between the pia and arachnoid maters
in the subarachnoid space.
• The spinal subdural space is generally
a poorly demarcated, potential space
that exists between the dura and
arachnoid membranes.
•

6. • The spinal cord normally extends from
the foramen magnum to the level of L1
in adults .In children, the spinal cord
ends at L3 and moves upwith age
• because the spinal cord normally ends at
L1, lower nerve roots course some
distance before exiting the intervertebral
foramina. These lower spinal nerves form
the cauda equina (“horse’s tail”; )
• Therefore, performing a lumbar
(subarachnoid) puncture below L1 in an
adult (L3 in a child) usually avoids
potential needle trauma to the spinal
cord;

7. Surface Anatomy
• Spinous processes are usually palpable and help to define the
midline.
• The spinous processes of the cervical and lumbar spine are
nearly horizontal, whereas those in the thoracic spine slant in
a caudal direction and can overlap significantly .
• Therefore, when performing a lumbar or cervical epidural
block (with maximum spinal flexion), the needle is directed
with only a slight cephalad angle, whereas for a thoracic
block, the needle must be angled significantly more cephalad.
• A line drawn between the highest points of both iliac crests
(Tuffier’s line) usually crosses either the body of L4 or the L4–
L5 interspace.
• In slender persons, the sacrum is easily palpable, and the
sacral hiatus is felt as a depression just above or between the
gluteal clefts and above the coccyx, defining the point of entry
for caudal blocks.

10. History
1885-Corning' first performed peridural anesthesia with cocaine
for relief of pain in an extremity. It was apparently accidental.
1895-Cathelin first used epidural anesthesia in sacral region. This
is now called caudal analgesia.
1910-Läwen investigated the anatomy of the spinal and epidural
areas, he found that injections into the sacral canal did not reach
the subarachnoid space.
1921-F. Pages (Madrid) performed extradural anes thesia in his
surgical practice.
1939-Dogliotti wrote a book on regional anes thesia and
thoroughly discussed epidural anesthesia.
1949-Curbelo first performed continuous peridural anesthesia by
means of a ureteral catheter
1951-Crawford used peridural anesthesia for thoracic surgery.

11. Definition
Epidural anesthesia (peridural or extradural) is anesthesia
obtained by blocking spinal nerves in the epidural space
as the nerves emerge from the dura and then pass into
the intervertebral foramina.
The anesthetic solution is deposited outside the dura and
therefore differs from spinal or subdural anesthesia,
where the solution is deposited in the subarachnoid
space.
A segmental block is produced chiefly of spinal sensory
and sympathetic nerve fibers.
Motor Fibers may be partially blocked.

12. • Deposition of anesthetic solutions may be accom-
plished at the thoracic, lumbar, or caudal area.
• 1. Thoracic epidural block is achieved by
introducing a needle between thoracic spines into
the epidural space and instilling an amount of
solution that will spread sufficiently to block the
desired segments. This is called thoracic segmental
epidural anaesthesia

13. • 2. Lumbar epidural block, often called spinal epi-
dural block, is achieved by introducing a needle
between lumbar spines into the epidural space and
instilling varying volumes of solution de- pending on
the extent of anesthesia desired.
• Thus, for perineal or extremity surgery, 15 mL of 2%
lidocaine are injected; for lower abdominal surgery,
20 mL of solution are used, and for upper abdominal
surgery, 30 mt of solution. Extensive anesthesia thus
depends on diffusion of large volumes of anesthetic
solution.

14. • Caudal epidural block, or caudal anesthesia, is accomplished
by introducing a needle through the sacrococcygeal
ligament into the caudal canal. Varying volumes of
anesthetic solution are instilled depending on extent of
anesthesia de- sired
• The sacrum is a triangular-shaped bone formed by the
fusion of the sacral vertebrae. Nonfusion of the fifth sacral
vertebral arch creates the structure known as the sacral
hiatus, which is covered by the sacrococcygeal ligament (an
extension of the ligamentum flavum) and bordered by bony
prominences known as the sacral cornua. The sacral hiatus
is the point of access into the sacral epidural space. It is
usually identified as a groove above the coccyx

15. • Cervical epidural block :the ligamentum flavum is
discontinuous at midline in the cervical region in a large
percentage of patients, contributing to a false LOR.
Also, it is important to bear in mind that the
ligamentum flavum is thinner at this level (1.5–3 mm)
than at the lumbar and thoracic levels.
• In the cervical region, the C7–T1 interspace is widest
and easiest to access. In addition, the depth from the
skin to the epidural space is larger at this interspace,
and the distance from the epidural space to the dural
sac is greater than at other cervical levels.

17. Indication

18. Physiology
• LA or other solutions injected into epidural space (
steroids or narcotics ) spread anatomically.
• Horizontally spread via intervertebral foramen to
paravertebral space.
• Vertically spread preferentially in cephalad direction.
• Because epidural anaesthesia is DIFFUSION
dependent,relatively LARGE volumes of LA needed to
acheive block that expands several dermatomes.
• The block ONLY goes as high or low deprnding on volume.
• It is a DIFFERENTIAL block.It depends on concentration. A
drug at lower concentration will produce only sensory
block while at higher concentration can produce motor
block.

20. STRUCTURE OF EPIDURAL SPACE
• The epidural space is a potential space between
perioteum lining vertebralcanal and spinal dura
matter.
• Anatomically, the connective tissue is present in
significant amounts ventrally, forming strong con-
nections between the dura mater and the anterior
longitudinal ligaments in the vertebral canal. Of
great interest is the extent of fibrous connections in
the posterior part of the epidural space.

21. Epidural space - boundaries
• Cranially by foramen magnum
• Caudally by sacrococcygeal ligament.
• Anterioly by posterior longitudinal ligament
• Laterally by vertebral pedicles &intervertebral
foramina
• Posterioly by ligamentamum flavum.

22. Epidural space - contents
• It contains
 connective tissue
fat
 aerolar tissue
 spinal nerve roots
lymphatics
 a few blood vessels.

23. Epidural fat
• It is principally present in posterior and lateral space.
• It has effects on pharmacology of drugs injected
• intrathecally.
• There is a linear relationship between opioid's lipid
solubility and its terminal elimination halftime in the
epidural space.
• Increased lipid solubility leads to sequestration of
drugs in fat, thereby reducing bioavailability of drug.

24. Lymphatics
• The lymphatics of the epidural space are
concentrated in the region of the dural roots where
they remove foreign materials including
microorganisms from the subarachnoid and
epidural spaces.

25. Blood vessels
• Epidural veins -Prominent in lateral portion of
epidural space Drain to azygos vein and connect to
pelvic veins, providing an alternative route from
pelvis to right heart.
• Therefore, they become distended when inferior
vena cava is obstructed
• Also connect to cerebral venous sinuses by way of
basivertebral veins

26. Size of epidural space
• The distance across the semi or half moon circular
epidural space varies.
• In the anterior region it is almost nonexistent while
it canbe measured in posterior region, the average
values are;
• Upper thoracic: 2.5mm-3mm
• Cervical: Imm-1.5mm
• Lower thoracic: 4mm-5mm
• Lumbar: 5mm-6mm

27. How to reach?
• To reach epidural space in midline these structures
have to be penetrated:
• Skin
• subcutaneous tissues
• Supraspinous ligaments
• Interspinous ligaments
• Ligamentum flavum

28. • The first three tissues offer little resistance to the
advancing needle, but when the ligamentum
flavum is reached, the resistance increases. As the
needle passes through this tissue, there is a sudden
disappearance of resistance. In performing
peridural anės- thesia, it is essential that this point
be recognized lest further advancement result in
subarachnoid penetration.

29. Clinical corelation
• Ligamentum flavum has varying degrees of
thickness at different spinal levels .Hence it provide
risk of dural puncture or determine whether
injection was into the epidural space .
• Presence of dorsomedian connection the difficulty
and the effort needed to advance a catheter freely
into the epidural space because of the need to
"stab" through the midline connective tissue.
• The impingement of a catheter in connective tissue
bands may also cause it to coil within the epidural
space.

30. • EPIDURAL SPACE IN CHILDREN
• In children under six years of age, the epidural
space has spongy, gelatinous lobules and distinct
spaces.
• This is in contrast to the densely packed fat
globules and fibrous strands characteristic of the
mature epidural space. Because of this difference,
there is a more rapid longitudinal spread of drugs
within the juvenile epidural space.

31. • POSITION OF PATIENT
• The lateral position is widely
used, especially in the pregnant
patient. In clinical practice,
retaining the lateral position
after injection of the anesthetic
solution can be used to obtain a
more reliable and intense
anesthesia on the dependent
side, if this is appropriate for
surgery on that side.
• To provide a relatively major
block of the dependent side,
the patient should be left in the
lateral position for
approximately 15 minutes

33. • The sitting position is indicated in obese patients for
technical ease of introducing the epidural needle. It is
also desirable when perineal anesthesia is desired,
since blockade of the sacral nerves is morecomplete
and reliable.
• For upper thoracic and cervical region block, the
sitting position also provides greater ease of inser-
tion of the needle into the epidural space,

36. Epidural needles
Typically 17-18 gauge
9cm to hub
Tuohy needle most commonly used
Blunt bevel with a gentle curve of 15-30° at the tip
Pushes away the dura after passing through the
ligamentum flavum instead of penetrating it
Straight needles without a curved tip (Crawford needles)
may have a higher incidence of dural puncture but
facilitate passage of an epidural catheter.
Needle modifications include winged tips and introducer
devices set into the hub designed for guiding catheter
placement.

38. Epidural catheter
• Made of nylon or pvc
• Radioopaque
• Tip is atraumatic, rounded having lateral holes and closed end.
• Connector with Luer-lock cap
• Catheter length: 90–100 cm with markings at 5 cm, 6 cm, 7 cm, 8
cm, 9 cm, 10 cm, 15 cm, 20 cm from the tip
• Catheter size—16 G, 18 G, 19 G, 20 G available. Bigger the gauge
thinner the catheter, it can pass through any size epidural needle.
However a 16 G catheter will not pass through a 18G epidural
needle.
• Catheter diameter: 0.9 mm (18G), 1.1 mm (16 G).
• Color coded: Dark blue (18G), light blue (16 G).
• Filter: 0.22 hydrophilic made of micron mesh

39. • Loss of resistance (LOR) syringe: Made of glass or plastic, has
a low-resistance plunger to identify the epidural space by
the LOR technique. The LOR using saline for catheter
placement is the commonly used technique.
• Catheter distance from tip to the epidural space is 3–4 cm.
• The catheter should be advanced only 3–5 cm into the
epidural space.
• Continuous epidural analgesia is given in chronic pain, acute
postoperative pain, cancer pain with the help of infusion
devices and patient-controlled analgesia (PCA) pumps.16
Epidural catheters are used for labor analgesia

41. Clinical Factors in Epidural Spread
• 1. Spread increases with age. After 20 years of age, the dose
requirements decrease considerably. This is explained by the fact
that escape from the epidural space is less due to intervertebral
foramina being more fixed and epidural vessels less penetrable.
• 2. Spread is greater in pregnant females. Dosage should be
decreased by one-third the dose in non-pregnant women.
• 3. In arteriosclerosis and occlusive arterial disease, the spread is
also greater than in normals, thus, a smaller dose should be used.
• In early diabetes when widespread angiopathy (arterioles and cap-
illaries) is present, dose-requirement is reduced and more so, later
in the course of the disease as occlusion becomes increasingly
apparent.
• 4. Spread is decreased in dehydration, shock and cachexia,
• 5. Extent of anesthesia is greater with more con- centrated
solutions.
• 6. A greater dose is required in taller individuals.

42. DETECTION OF EPIDURAL SPACE
• NEGATIVE PRESSURE TECHNIQUES
• 1. Hanging Drop Sign.(Gutierrez's sign)
• A small drop of sterile distilled water is placed on
the hub of the needle after it has been introduced
to the level of resis tance indicating the beginning
of the ligamentum flavum. When the needle is
advanced through the yellow fibrous tissue, this
drop will be "sucked into" the epidural space. This
is called the "sign of the drop."

43. • Capillary Tube Method." A Visual Technique). Odom
devised a small capillary tube filled with sterile
saline in which one or two bubbles of air were
placed. These acted as a meniscus. As soon as the
needle entered the epidural space, the saline was
sucked in, and the air bubbles could be seen,An air
bubble can be placed in a syringe filled with saline,
and when the attached needle enters the epidural
space, the bubble will double in size.

44. • 3.Odum's Manometer Technique.
• A small "U-shaped glass tube about 3 to 4 inches
high is used as water manometer.
• After the needle has been in troduced into the
intraspinous ligaments, th sterile glass manometer
is attached to the needle .
• As it is advanced through the ligamentum fla vum
and enters the epidural space, there is a immediate
movement of the liquid, signifying negative
pressure.

45. DISAPPEARANCE OF RESISTANCE TECHNIQUES
• 1.syringe technique
• Sudden loss of resistance on plunger of syringe on
reaching epidural space.

46. • Spring-Loaded Syringe
• Although the syringe is heavy, when the peri- dural
space is entered, the syringe automatically unloads
itself by virtue of the diminished resis tance in the
space.
•

47. • Balloon Technique
• A small light balloon mounted on a glass adapter is
attached to the epidural needle when this needle
has reached the yellow ligament.
• The balloon is just inflated with 2 or 3 mL of air.
When so fully inflated the pressure within the
balloon is approximately 50 mm Hg.
• As the needle is advanced and penetrates into the
epidural space, the balloon will collapse.

48. • Brooks' Device.
• An Odom's indicator or capillary tube can be sealed at
one end and a glass bubble created there.
• This is filled with water or saline, and a few bubbles. of
air placed in the tube part.
• It is attached to the epidural needle when the needle
reaches the ligamentum flavum.
• At this point, the bulb is the barrel. heated to create a
slight positive pressure
• . When the needle penetrates to the epidural space the
positive pressure of the heated water advances, the
meniscal bubble toward the epidural space.

49. • Vertical Tube of Dawkins:
• In this method, a slight positive pressure is created by a
short vertical column of water in a tube less than 10 cm
high connected at right angles to the hub of the
epidural needle.
• A bubble of air also may be placed in the water. The
force of gravity on the column of water produces the
pressure.
• When the epidural space is entered, the level of the
column of water drops indicating a disappearance of
resistance.

50. • Ultrasonography
• Ultrasound technology is being used increasingly to
aid in the identification of the epidural space.
Studies suggest that the use of ultrasonography to
identify the anticipated depth to space, particularly
in obese parturients

51. Clinical Observation (Bonniot's
Phenomenon
• On entering the epidural space with a bare needle
(no stylet or syringe attached), an audible hiss may be
noticed, signifying that air is sucked into the epidural
space. This is not a predictable and dependable sign.
• However, Mostert has reported a reverse
phenomenon. When a syringe filled with a 5- to 10-
mL mixture of equal parts air and saline is injected
rapidly into the epidural space, and the syringe is
quickly reversed, there will occur an outward reflux
of froth.

52. • A midline approach is commonly chosen for lumbar and low
thoracic approaches.
• After local anesthetic infiltration of the skin, the nondominant
hand can be rested on the back of the patient, with the thumb
and index finger holding the needle hub or wing.
• The angle of approach should be only slightly cephalad in the
lumbar and low-thoracic regions, whereas in the midthoracic
region, the approach should be more cephalad because of the
significant downward angulation of the spinous processes .
• In a controlled fashion, the needle should be advanced with
the stylet in place through the supraspinous ligament and into
the interspinous ligament, at which point the stylet can be
removed and the syringe attached.
STEPS

54. • Like spinal it can be given in sitting and lateral position.
Usually epidural space is encountered at 4-5 cm from skin
and has negative pressure in 80% individuals.
• Most commonly used method to locate epidural space is by
loss of resistance lechnique.
• Once the needle pierces the ligamemum flavum there is
sudden loss of resistance and the syringe filled with air or
saline will be felt literally sucked in epidural space.
• Once the needle is confirmed in epidural space, a test dose
of 2-3 ml of hyperbaric lignocaine with adrenaline (except for
obstetric patient where epinephrine should not be used) is
given and if in 5 minutes there is no evidence of either spinal
block (inabili ty to move foot) or intravascular injection
(tachycardia by adrenaline), further doses can be given.
• Epidural catheter is passed through the needle 3-4 cm or
catheter should be in epidural space.
• A microfilter is attached to catheter to prevent
contamination.
• Onset of effect takes place in 15-20 Minutes.

55. • Site of Action of Drug
• Anterior and posterior nerve roots (main site of
action).
• Mixed spinal nerves.
• Drug diffuses through dura and arachnoid and
inhibits descending pathways in spinal cord

56. Drugs used for Epidural
Anesthesia Local Anesthetics
• Usually 2-3 mL of local anesthetic is required for blocking
1 segment; therefore normally 15 to 20 mL of drug is
required.
• Lignocaine (with or without adrenaline): 1-2%
concenrration is used.
• Bupivacaine 0.625- 0.5%, Ropivacaine 0.11.0% and
Levobupivacaine 0. 125-0. 75% depending whether used
for sensory or motor b lock. Ropiuacaine because of if
high safety profile is most preferred.
• Other drugs like prilocaine, chloroprocaine or
mepivacaine are seldom used now a day. However, a new
preservative free preparation of chloroprocaine has been
recently launched for central neuraxial blocks

57. •Opioids
• Morphine: 4-6 mg (diluted in 10 mL saline). Onset
within 30 minutes. Effect lasts for 12- 16 hours.
Depodur is an extended-release liposomal form
ulation of morphine which can provide analgesia
for 48 hours.
• Fentanyl: 100 mcg {diluted in IO mL saline). Onset
within 10 minutes. Effect lasts for 2-3 hours.

58. • Fentanyl (2-4 mcg/mL) + bupivacaine (0.125%) or
ropivacaine (0.2%) (ropivacaine preferred) as
continuous infusion given by syringe pump through
epidural catheter is the most commonly used
combination for postoperative analgesia and painless
labor.
• Site of action of opioids after epidural administration:
Opioids after diffusion through meninges reaches the
spinal cord where they bind to opioid receptors
present in substanria gelatinosa of dorsal horn cells.

59. • advantages of epidural opioids over local
anesthetics:
• Only sensory block is produced while with local
anesthetics there are chances of motor blockade if
high concentration is used.
• The effect of single dose (especially morphine) lasts
long (12-16 hrs) obviating the need for frequent
injections. No sympathetic block

60. • Disadvantages:
• Respiratory depression: Respiratory depression is more
profound with less lipid soluble opioids like morphine
than with more lipid soluble (fentanyl, alfentanil,
sufemanil). The less lipid soluble agents because of
prolonged stay in CSF mixes with CSF to reaches brain to
inhibit respiratory medullary centers producing delayed
respiratory depression after 6- 12 hours.
• Urinary retention.
• Pruritus.
• Nausea and vomiting.
• Sedation.

61. • Factors Affecting the Spread (Level) of
Block
• Volume of the drug: It is the most important factor.
• Age: Old requiring less dose because volume of epidural
space is less.
• Gravity (Patient's position): Does not affect level too
much as in case of spinal.
• Intra-abdominal tumors, pregnancy: Less dose is
required.
• Level of injection.
• Length of vertebral column: Taller individuals require
higher dose.
• Concentration of local anesthetic: High the
concentration, higher is the spread

62. Factor Effecting Onset and Duration of Block
• Dose and concentration: Higher dose or higher concentration
facilitates onset
• pKa: It is the pH at which a local anesthetic is 50% ionized and 50%
nonionized. Since local anesthetics are weak bases, agents with
pKa closer to physiologic pH vvill have more drugs in nonionized
form which can diffuse through axonal membrane enhancing the
onset. That is why lignocaine with lower pKa of 7.8 has fast onset
as compared to bupivacaine with higher pKa of8.l.
• Addition of sodabicarbona/e: As local anesthetics are bases,
adding soda bicarbonate will prevent ionization making more drug
to be available in nonionized form to cross the axonal membrane.
On the other hand in ischemic tissue (like abscess) acidic pHwilll
ionize the drug, delaying the onset of action
• Type of nerve fiber: A fibers are blocked earlier than B which are
blocked earlier than C
• Frequency of nerve stimulation: Since activated channels are
blocked more easily, a stimulated nerve will be blocked earlier as
compared to nonstimulated nerve. This kind of block by local
anesLherics is called as use-dependent block.

63. • Addition of vasoconstrictors: Vasoconstrictors by
decreas ing the systemic absorption increases the
duration of action. The most commonly used
vasoconstrictor is adrenaline in a concentration of 1
in 2,00,000 (l in 2 lakhs).
• Adrenaline when added to Lignocaine increases the
duration of both sensory and motor blockade while
with bupivacaine only sensory block is prolonged.
• Other vasoconstrictors which can be used are
phenylephrine (I in 20,000), noradrenaline and
felypressin.

64. Advantages of Epidural over Spinal
1. Less hypotension: As the onset of action of
epidural is slow body gets sufficient time to
compensate for hypotension making epidural a
better choice than spinal for cardiac
compromised patients.
2. No postspinal headache however headache can
occur if dura is punctured accidentally.
3. By giving top up doses through catheter can
change level of block and duration of anesthesia.

65. Disadvantages Over Spinal
1. Inadequate (patchy) block/block failure rate is high:
Epidural space has fibrous bands and other tissues
leading to unequal distribution of drug producing
patchy block/failed block. y.
2. higher chances of total spinal: Total spinal is one of the
mos t feared complication of epidural. It occurs, if
accidently dura is punctured during drug injection and
whole volume (10-20 mL) of drug is injected in
subarachnoid space. As plain bupivacaine and
lignocaine are slightly hypobaric th is volume will reach
cranium producing total spinal manifested as marked
hypotension,

66. 3. bradycardia, apnea, dilated pupils and
unconsciousness.
• Prevention –
1. Always confirm the position of needle or catheter by
giving a test dose with lignocaine with adrenaline
2. Never inject as a bolus, always give drug in
increments of 3-5 mL
3. confirm negative aspiration of CSF before injecting
next increment of the drug.
• Treatment Intubate and IPPV with 100% oxygen.
Vasopressors

67. 4.Accidental dural puncture:
If dura is punctured with epidural needle, there are
two alternatives:
1. - Give hyperbaric local anesthetic through this
needle, i.e., convert it to spinal.
2. - Remove the needle and give epidural in higher
space.

68. • 5. More chances of epidural hematoma
and intravascular injection:
As the needle or catheter is near to
epidural venous plexus chances of
bleeding, hematoma formation and
intravascular injection are more.
 The possibility of hematoma formation
can be 10 fold higher than spinal.
As the veins are denser laterally the
epidura l should be given in midline.
 To prevent intravascular injection inject
the drug only after confirming negative
aspiration of blood.

69. 6. .Higher chances of infectious complications: the
maximum safe time for which an epidural
catheter can be kept however majority of the
clinicians recommended a maximum period of 4
days.
7. Higher incidence of neuropathies: Studies have
shown higher incidence of radiculopathies with
epidural as compared to spinal.

70. 8. Higher incidence of local anesthetic toxicity:
Higher volumes used in epidural increases the
chances of local anesthetic toxicity.
9. Catheter related complications like broken
catheter. If the catheter gets broken in epidural
space and is not infected, it can be left in situ (a
retained catheter is no more reactive than a
suture) and reassure the patient however if it
gets broken in subcutaneous tissue then it should
be removed.

71. 10. lntraocular hemorrhage: Rapid injection of drug
can raise intraocular pressure causing subhyaloid
bleeding.
11. Compare to spinal epidural sets are more
expensive.
12. Technically epidural is more difficult as compared
to spinal.

72. Contraindications for Central Neuraxial
Blocks
• Absolute
Raised intracranial tension: Medullary coning can cause
death if spinal is given to patients with raised ICT.
Patient refusal.
Severe hypovolemia and hypotension.
Patients on anticoagulants : Patients on anticoagulants
can bleed significantly cause epidural hematoma and
paraplegia.

75. Patients on new anticoagulants
CNB should be delayed for 48 hours after fondaparinux, 72
hours after rivaroxaban (Xarelto} and 5 days after dabigatran
(Pradaxa).
 They can be given safely 6 hours after CNB or epidural
catheter removal.
Patients on antiplalelels:
Patients on aspirin and NSAIDs can be safely given central
neuraxial blocks while for other antiplatelets CNB should be
delayed for 7 days after clopidogrel, dipyridamol, and
prasugrel, 14 days after eticlopidine, 2 days after abciximab
and 8 hours after ep tifibatide.
 Antiplatelets can be restarted 6 hours after CNB or epidural
catheter removal.

76. Bleeding disorders/coagulopathy.
 Infection at local site.
Severe fixed cardiac output lesions (aortic and
mitral stenosis, constrictive pericarditis, coarctation
of aorta): These patients can not compensate for
decrease in cardiac output and cannot tolerate fluid
overload, therefore should not receive CNB.

77. • Relative
Mild to moderate fixed cardiac output lesions: Mild to
moderate cases can be given central Neuraxial block if
necessary.
Mild to moderate hypotension and hypovolemia.
Uncontrolled hypertension(may develop sudden
hypotension after spinal.)
Severe ischemic heart disease especially history of recent
MI.
Thrombocytopenia: Patients with platelet count more than
80,000/ cubic mm can be safely given central neuraxial
blocks. Platelet count between 50,000- 80,000/cubic mm is
a relative contraindication while count less than 50000
becomes an absolute contraindication.
 Heart blocks and patient on Bblockers: Severe bradycardia
can occur.
 Spinal deformity and previous spinal surgery

78. Psychiatric and uncooperative patients
History of headache: (are more vulnerable PDPH)
GIT perforation:Theoretically parasympathetic over
activity increases the peristalsis and can open the
seal.
 Myelopathy and peripheral neuropathies:
exaggerates an existing neuropathy Nerve blocks
should be avoided in these patients for medicolegal
reasons.

79. • CNS disorders: -
① Multiple sclerosis: Due to increased sensitivity of local
anesthetics patients of multiple sclerosis exhibit a
prolonged block however, the evidence proving the
exacerbation of multiple sclerosis symptoms by central
neuraxial blocks is lacking.
② - Spinal stenosis: These patients may be at increased
risk of neurologic complications after neuraxial blocks.
③ Resistant surgeon
④ Chronic backache
• Septicemia and bacteremia

80. Thank you.

81. Reference
• Oxford regional anaesthesia a pocket guide.
• Collins
• Millers anaesthesia 9th edition.
• nysora